Initial commit

src/util/CMakeLists.txt

@@ -0,0 +1,19 @@
+set(UTIL_SRCS
+	${CMAKE_CURRENT_SOURCE_DIR}/areastore.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/auth.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/base64.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/directiontables.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/enriched_string.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/ieee_float.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/metricsbackend.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/numeric.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/pointedthing.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/quicktune.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/serialize.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/sha1.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/sha256.c
+	${CMAKE_CURRENT_SOURCE_DIR}/string.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/srp.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/timetaker.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/png.cpp
+	PARENT_SCOPE)

src/util/Optional.h

@@ -0,0 +1,105 @@
+/*
+Minetest
+Copyright (C) 2021  rubenwardy
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#pragma once
+
+#include <utility>
+#include "debug.h"
+
+struct nullopt_t
+{
+};
+constexpr nullopt_t nullopt{};
+
+/**
+ * An implementation of optional for C++11, which aims to be
+ * compatible with a subset of std::optional features.
+ *
+ * Unfortunately, Minetest doesn't use C++17 yet.
+ *
+ * @tparam T The type to be stored
+ */
+template <typename T>
+class Optional
+{
+	bool m_has_value = false;
+	T m_value;
+
+public:
+	Optional() noexcept {}
+	Optional(nullopt_t) noexcept {}
+
+	Optional(const T &value) noexcept : m_has_value(true), m_value(value) {}
+	Optional(T &&value) noexcept : m_has_value(true), m_value(std::move(value)) {}
+
+	Optional(const Optional<T> &other) noexcept :
+			m_has_value(other.m_has_value), m_value(other.m_value)
+	{}
+	Optional(Optional<T> &&other) noexcept :
+			m_has_value(other.m_has_value), m_value(std::move(other.m_value))
+	{
+		other.m_has_value = false;
+	}
+
+	Optional<T> &operator=(nullopt_t) noexcept { m_has_value = false; return *this; }
+
+	Optional<T> &operator=(const Optional<T> &other) noexcept
+	{
+		if (&other == this)
+			return *this;
+		m_has_value = other.m_has_value;
+		m_value = other.m_value;
+		return *this;
+	}
+
+	Optional<T> &operator=(Optional<T> &&other) noexcept
+	{
+		if (&other == this)
+			return *this;
+		m_has_value = other.m_has_value;
+		m_value = std::move(other.m_value);
+		other.m_has_value = false;
+		return *this;
+	}
+
+	T &value()
+	{
+		FATAL_ERROR_IF(!m_has_value, "optional doesn't have value");
+		return m_value;
+	}
+
+	const T &value() const
+	{
+		FATAL_ERROR_IF(!m_has_value, "optional doesn't have value");
+		return m_value;
+	}
+
+	const T &value_or(const T &def) const { return m_has_value ? m_value : def; }
+
+	// Unchecked access consistent with std::optional
+	T* operator->() { return &m_value; }
+	const T* operator->() const { return &m_value; }
+
+	T& operator*() { return m_value; }
+	const T& operator*() const { return m_value; }
+
+	bool has_value() const noexcept { return m_has_value; }
+
+	explicit operator bool() const { return m_has_value; }
+};

src/util/areastore.cpp

@@ -0,0 +1,329 @@
+/*
+Minetest
+Copyright (C) 2015 est31 <mtest31@outlook.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "util/areastore.h"
+#include "util/serialize.h"
+#include "util/container.h"
+
+#if USE_SPATIAL
+	#include <spatialindex/SpatialIndex.h>
+	#include <spatialindex/RTree.h>
+	#include <spatialindex/Point.h>
+#endif
+
+#define AST_SMALLER_EQ_AS(p, q) (((p).X <= (q).X) && ((p).Y <= (q).Y) && ((p).Z <= (q).Z))
+
+#define AST_OVERLAPS_IN_DIMENSION(amine, amaxe, b, d) \
+	(!(((amine).d > (b)->maxedge.d) || ((amaxe).d < (b)->minedge.d)))
+
+#define AST_CONTAINS_PT(a, p) (AST_SMALLER_EQ_AS((a)->minedge, (p)) && \
+	AST_SMALLER_EQ_AS((p), (a)->maxedge))
+
+#define AST_CONTAINS_AREA(amine, amaxe, b)         \
+	(AST_SMALLER_EQ_AS((amine), (b)->minedge) \
+	&& AST_SMALLER_EQ_AS((b)->maxedge, (amaxe)))
+
+#define AST_AREAS_OVERLAP(amine, amaxe, b)                \
+	(AST_OVERLAPS_IN_DIMENSION((amine), (amaxe), (b), X) && \
+	AST_OVERLAPS_IN_DIMENSION((amine), (amaxe), (b), Y) &&  \
+	AST_OVERLAPS_IN_DIMENSION((amine), (amaxe), (b), Z))
+
+
+AreaStore *AreaStore::getOptimalImplementation()
+{
+#if USE_SPATIAL
+	return new SpatialAreaStore();
+#else
+	return new VectorAreaStore();
+#endif
+}
+
+const Area *AreaStore::getArea(u32 id) const
+{
+	AreaMap::const_iterator it = areas_map.find(id);
+	if (it == areas_map.end())
+		return nullptr;
+	return &it->second;
+}
+
+void AreaStore::serialize(std::ostream &os) const
+{
+	// WARNING:
+	// Before 5.1.0-dev: version != 0 throws SerializationError
+	// After 5.1.0-dev:  version >= 5 throws SerializationError
+	// Forwards-compatibility is assumed before version 5.
+
+	writeU8(os, 0); // Serialisation version
+
+	// TODO: Compression?
+	writeU16(os, areas_map.size());
+	for (const auto &it : areas_map) {
+		const Area &a = it.second;
+		writeV3S16(os, a.minedge);
+		writeV3S16(os, a.maxedge);
+		writeU16(os, a.data.size());
+		os.write(a.data.data(), a.data.size());
+	}
+
+	// Serialize IDs
+	for (const auto &it : areas_map)
+		writeU32(os, it.second.id);
+}
+
+void AreaStore::deserialize(std::istream &is)
+{
+	u8 ver = readU8(is);
+	// Assume forwards-compatibility before version 5
+	if (ver >= 5)
+		throw SerializationError("Unknown AreaStore "
+				"serialization version!");
+
+	u16 num_areas = readU16(is);
+	std::vector<Area> areas;
+	areas.reserve(num_areas);
+	for (u32 i = 0; i < num_areas; ++i) {
+		Area a(U32_MAX);
+		a.minedge = readV3S16(is);
+		a.maxedge = readV3S16(is);
+		u16 data_len = readU16(is);
+		a.data = std::string(data_len, '\0');
+		is.read(&a.data[0], data_len);
+		areas.emplace_back(std::move(a));
+	}
+
+	bool read_ids = is.good(); // EOF for old formats
+
+	for (auto &area : areas) {
+		if (read_ids)
+			area.id = readU32(is);
+		insertArea(&area);
+	}
+}
+
+void AreaStore::invalidateCache()
+{
+	if (m_cache_enabled) {
+		m_res_cache.invalidate();
+	}
+}
+
+u32 AreaStore::getNextId() const
+{
+	u32 free_id = 0;
+	for (const auto &area : areas_map) {
+		if (area.first > free_id)
+			return free_id; // Found gap
+
+		free_id = area.first + 1;
+	}
+	// End of map
+	return free_id;
+}
+
+void AreaStore::setCacheParams(bool enabled, u8 block_radius, size_t limit)
+{
+	m_cache_enabled = enabled;
+	m_cacheblock_radius = MYMAX(block_radius, 16);
+	m_res_cache.setLimit(MYMAX(limit, 20));
+	invalidateCache();
+}
+
+void AreaStore::cacheMiss(void *data, const v3s16 &mpos, std::vector<Area *> *dest)
+{
+	AreaStore *as = (AreaStore *)data;
+	u8 r = as->m_cacheblock_radius;
+
+	// get the points at the edges of the mapblock
+	v3s16 minedge(mpos.X * r, mpos.Y * r, mpos.Z * r);
+	v3s16 maxedge(
+		minedge.X + r - 1,
+		minedge.Y + r - 1,
+		minedge.Z + r - 1);
+
+	as->getAreasInArea(dest, minedge, maxedge, true);
+
+	/* infostream << "Cache miss with " << dest->size() << " areas, between ("
+			<< minedge.X << ", " << minedge.Y << ", " << minedge.Z
+			<< ") and ("
+			<< maxedge.X << ", " << maxedge.Y << ", " << maxedge.Z
+			<< ")" << std::endl; // */
+}
+
+void AreaStore::getAreasForPos(std::vector<Area *> *result, v3s16 pos)
+{
+	if (m_cache_enabled) {
+		v3s16 mblock = getContainerPos(pos, m_cacheblock_radius);
+		const std::vector<Area *> *pre_list = m_res_cache.lookupCache(mblock);
+
+		size_t s_p_l = pre_list->size();
+		for (size_t i = 0; i < s_p_l; i++) {
+			Area *b = (*pre_list)[i];
+			if (AST_CONTAINS_PT(b, pos)) {
+				result->push_back(b);
+			}
+		}
+	} else {
+		return getAreasForPosImpl(result, pos);
+	}
+}
+
+
+////
+// VectorAreaStore
+////
+
+
+bool VectorAreaStore::insertArea(Area *a)
+{
+	if (a->id == U32_MAX)
+		a->id = getNextId();
+	std::pair<AreaMap::iterator, bool> res =
+			areas_map.insert(std::make_pair(a->id, *a));
+	if (!res.second)
+		// ID is not unique
+		return false;
+	m_areas.push_back(&res.first->second);
+	invalidateCache();
+	return true;
+}
+
+bool VectorAreaStore::removeArea(u32 id)
+{
+	AreaMap::iterator it = areas_map.find(id);
+	if (it == areas_map.end())
+		return false;
+	Area *a = &it->second;
+	for (std::vector<Area *>::iterator v_it = m_areas.begin();
+			v_it != m_areas.end(); ++v_it) {
+		if (*v_it == a) {
+			m_areas.erase(v_it);
+			break;
+		}
+	}
+	areas_map.erase(it);
+	invalidateCache();
+	return true;
+}
+
+void VectorAreaStore::getAreasForPosImpl(std::vector<Area *> *result, v3s16 pos)
+{
+	for (Area *area : m_areas) {
+		if (AST_CONTAINS_PT(area, pos)) {
+			result->push_back(area);
+		}
+	}
+}
+
+void VectorAreaStore::getAreasInArea(std::vector<Area *> *result,
+		v3s16 minedge, v3s16 maxedge, bool accept_overlap)
+{
+	for (Area *area : m_areas) {
+		if (accept_overlap ? AST_AREAS_OVERLAP(minedge, maxedge, area) :
+				AST_CONTAINS_AREA(minedge, maxedge, area)) {
+			result->push_back(area);
+		}
+	}
+}
+
+#if USE_SPATIAL
+
+static inline SpatialIndex::Region get_spatial_region(const v3s16 minedge,
+		const v3s16 maxedge)
+{
+	const double p_low[] = {(double)minedge.X,
+		(double)minedge.Y, (double)minedge.Z};
+	const double p_high[] = {(double)maxedge.X, (double)maxedge.Y,
+		(double)maxedge.Z};
+	return SpatialIndex::Region(p_low, p_high, 3);
+}
+
+static inline SpatialIndex::Point get_spatial_point(const v3s16 pos)
+{
+	const double p[] = {(double)pos.X, (double)pos.Y, (double)pos.Z};
+	return SpatialIndex::Point(p, 3);
+}
+
+
+bool SpatialAreaStore::insertArea(Area *a)
+{
+	if (a->id == U32_MAX)
+		a->id = getNextId();
+	if (!areas_map.insert(std::make_pair(a->id, *a)).second)
+		// ID is not unique
+		return false;
+	m_tree->insertData(0, nullptr, get_spatial_region(a->minedge, a->maxedge), a->id);
+	invalidateCache();
+	return true;
+}
+
+bool SpatialAreaStore::removeArea(u32 id)
+{
+	std::map<u32, Area>::iterator itr = areas_map.find(id);
+	if (itr != areas_map.end()) {
+		Area *a = &itr->second;
+		bool result = m_tree->deleteData(get_spatial_region(a->minedge,
+			a->maxedge), id);
+		areas_map.erase(itr);
+		invalidateCache();
+		return result;
+	} else {
+		return false;
+	}
+}
+
+void SpatialAreaStore::getAreasForPosImpl(std::vector<Area *> *result, v3s16 pos)
+{
+	VectorResultVisitor visitor(result, this);
+	m_tree->pointLocationQuery(get_spatial_point(pos), visitor);
+}
+
+void SpatialAreaStore::getAreasInArea(std::vector<Area *> *result,
+		v3s16 minedge, v3s16 maxedge, bool accept_overlap)
+{
+	VectorResultVisitor visitor(result, this);
+	if (accept_overlap) {
+		m_tree->intersectsWithQuery(get_spatial_region(minedge, maxedge),
+			visitor);
+	} else {
+		m_tree->containsWhatQuery(get_spatial_region(minedge, maxedge), visitor);
+	}
+}
+
+SpatialAreaStore::~SpatialAreaStore()
+{
+	delete m_tree;
+	delete m_storagemanager;
+}
+
+SpatialAreaStore::SpatialAreaStore()
+{
+	m_storagemanager =
+		SpatialIndex::StorageManager::createNewMemoryStorageManager();
+	SpatialIndex::id_type id;
+	m_tree = SpatialIndex::RTree::createNewRTree(
+		*m_storagemanager,
+		.7, // Fill factor
+		100, // Index capacity
+		100, // Leaf capacity
+		3, // dimension :)
+		SpatialIndex::RTree::RV_RSTAR,
+		id);
+}
+
+#endif

src/util/areastore.h

@@ -0,0 +1,197 @@
+/*
+Minetest
+Copyright (C) 2015 est31 <mtest31@outlook.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#pragma once
+
+#include "irr_v3d.h"
+#include "noise.h" // for PcgRandom
+#include <map>
+#include <list>
+#include <vector>
+#include <istream>
+#include "util/container.h"
+#include "util/numeric.h"
+#ifndef ANDROID
+	#include "cmake_config.h"
+#endif
+#if USE_SPATIAL
+	#include <spatialindex/SpatialIndex.h>
+	#include "util/serialize.h"
+#endif
+
+
+struct Area {
+	Area(u32 area_id) : id(area_id) {}
+
+	Area(const v3s16 &mine, const v3s16 &maxe, u32 area_id = U32_MAX) :
+		id(area_id), minedge(mine), maxedge(maxe)
+	{
+		sortBoxVerticies(minedge, maxedge);
+	}
+
+	u32 id;
+	v3s16 minedge, maxedge;
+	std::string data;
+};
+
+
+class AreaStore {
+public:
+	AreaStore() :
+		m_res_cache(1000, &cacheMiss, this)
+	{}
+
+	virtual ~AreaStore() = default;
+
+	static AreaStore *getOptimalImplementation();
+
+	virtual void reserve(size_t count) {};
+	size_t size() const { return areas_map.size(); }
+
+	/// Add an area to the store.
+	/// Updates the area's ID if it hasn't already been set.
+	/// @return Whether the area insertion was successful.
+	virtual bool insertArea(Area *a) = 0;
+
+	/// Removes an area from the store by ID.
+	/// @return Whether the area was in the store and removed.
+	virtual bool removeArea(u32 id) = 0;
+
+	/// Finds areas that the passed position is contained in.
+	/// Stores output in passed vector.
+	void getAreasForPos(std::vector<Area *> *result, v3s16 pos);
+
+	/// Finds areas that are completely contained inside the area defined
+	/// by the passed edges.  If @p accept_overlap is true this finds any
+	/// areas that intersect with the passed area at any point.
+	virtual void getAreasInArea(std::vector<Area *> *result,
+		v3s16 minedge, v3s16 maxedge, bool accept_overlap) = 0;
+
+	/// Sets cache parameters.
+	void setCacheParams(bool enabled, u8 block_radius, size_t limit);
+
+	/// Returns a pointer to the area coresponding to the passed ID,
+	/// or NULL if it doesn't exist.
+	const Area *getArea(u32 id) const;
+
+	/// Serializes the store's areas to a binary ostream.
+	void serialize(std::ostream &is) const;
+
+	/// Deserializes the Areas from a binary istream.
+	/// This does not currently clear the AreaStore before adding the
+	/// areas, making it possible to deserialize multiple serialized
+	/// AreaStores.
+	void deserialize(std::istream &is);
+
+protected:
+	/// Invalidates the getAreasForPos cache.
+	/// Call after adding or removing an area.
+	void invalidateCache();
+
+	/// Implementation of getAreasForPos.
+	/// getAreasForPos calls this if the cache is disabled.
+	virtual void getAreasForPosImpl(std::vector<Area *> *result, v3s16 pos) = 0;
+
+	/// Returns the next area ID and increments it.
+	u32 getNextId() const;
+
+	// Note: This can't be an unordered_map, since all
+	// references would be invalidated on rehash.
+	typedef std::map<u32, Area> AreaMap;
+	AreaMap areas_map;
+
+private:
+	/// Called by the cache when a value isn't found in the cache.
+	static void cacheMiss(void *data, const v3s16 &mpos, std::vector<Area *> *dest);
+
+	bool m_cache_enabled = true;
+	/// Range, in nodes, of the getAreasForPos cache.
+	/// If you modify this, call invalidateCache()
+	u8 m_cacheblock_radius = 64;
+	LRUCache<v3s16, std::vector<Area *> > m_res_cache;
+};
+
+
+class VectorAreaStore : public AreaStore {
+public:
+	virtual void reserve(size_t count) { m_areas.reserve(count); }
+	virtual bool insertArea(Area *a);
+	virtual bool removeArea(u32 id);
+	virtual void getAreasInArea(std::vector<Area *> *result,
+		v3s16 minedge, v3s16 maxedge, bool accept_overlap);
+
+protected:
+	virtual void getAreasForPosImpl(std::vector<Area *> *result, v3s16 pos);
+
+private:
+	std::vector<Area *> m_areas;
+};
+
+
+#if USE_SPATIAL
+
+class SpatialAreaStore : public AreaStore {
+public:
+	SpatialAreaStore();
+	virtual ~SpatialAreaStore();
+
+	virtual bool insertArea(Area *a);
+	virtual bool removeArea(u32 id);
+	virtual void getAreasInArea(std::vector<Area *> *result,
+		v3s16 minedge, v3s16 maxedge, bool accept_overlap);
+
+protected:
+	virtual void getAreasForPosImpl(std::vector<Area *> *result, v3s16 pos);
+
+private:
+	SpatialIndex::ISpatialIndex *m_tree = nullptr;
+	SpatialIndex::IStorageManager *m_storagemanager = nullptr;
+
+	class VectorResultVisitor : public SpatialIndex::IVisitor {
+	public:
+		VectorResultVisitor(std::vector<Area *> *result, SpatialAreaStore *store) :
+			m_store(store),
+			m_result(result)
+		{}
+		~VectorResultVisitor() {}
+
+		virtual void visitNode(const SpatialIndex::INode &in) {}
+
+		virtual void visitData(const SpatialIndex::IData &in)
+		{
+			u32 id = in.getIdentifier();
+
+			std::map<u32, Area>::iterator itr = m_store->areas_map.find(id);
+			assert(itr != m_store->areas_map.end());
+			m_result->push_back(&itr->second);
+		}
+
+		virtual void visitData(std::vector<const SpatialIndex::IData *> &v)
+		{
+			for (size_t i = 0; i < v.size(); i++)
+				visitData(*(v[i]));
+		}
+
+	private:
+		SpatialAreaStore *m_store = nullptr;
+		std::vector<Area *> *m_result = nullptr;
+	};
+};
+
+#endif // USE_SPATIAL

src/util/auth.cpp

@@ -0,0 +1,137 @@
+/*
+Minetest
+Copyright (C) 2015, 2016 est31 <MTest31@outlook.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include <algorithm>
+#include <string>
+#include "auth.h"
+#include "base64.h"
+#include "sha1.h"
+#include "srp.h"
+#include "util/string.h"
+#include "debug.h"
+
+// Get an sha-1 hash of the player's name combined with
+// the password entered. That's what the server uses as
+// their password. (Exception : if the password field is
+// blank, we send a blank password - this is for backwards
+// compatibility with password-less players).
+std::string translate_password(const std::string &name,
+	const std::string &password)
+{
+	if (password.length() == 0)
+		return "";
+
+	std::string slt = name + password;
+	SHA1 sha1;
+	sha1.addBytes(slt.c_str(), slt.length());
+	unsigned char *digest = sha1.getDigest();
+	std::string pwd = base64_encode(digest, 20);
+	free(digest);
+	return pwd;
+}
+
+// Call lower level SRP code to generate a verifier with the
+// given pointers. Contains the preparations, call parameters
+// and error checking common to all srp verifier generation code.
+// See docs of srp_create_salted_verification_key for more info.
+static inline void gen_srp_v(const std::string &name,
+	const std::string &password, char **salt, size_t *salt_len,
+	char **bytes_v, size_t *len_v)
+{
+	std::string n_name = lowercase(name);
+	SRP_Result res = srp_create_salted_verification_key(SRP_SHA256, SRP_NG_2048,
+		n_name.c_str(), (const unsigned char *)password.c_str(),
+		password.size(), (unsigned char **)salt, salt_len,
+		(unsigned char **)bytes_v, len_v, NULL, NULL);
+	FATAL_ERROR_IF(res != SRP_OK, "Couldn't create salted SRP verifier");
+}
+
+/// Creates a verification key with given salt and password.
+std::string generate_srp_verifier(const std::string &name,
+	const std::string &password, const std::string &salt)
+{
+	size_t salt_len = salt.size();
+	// The API promises us that the salt doesn't
+	// get modified if &salt_ptr isn't NULL.
+	char *salt_ptr = (char *)salt.c_str();
+
+	char *bytes_v = nullptr;
+	size_t verifier_len = 0;
+	gen_srp_v(name, password, &salt_ptr, &salt_len, &bytes_v, &verifier_len);
+	std::string verifier = std::string(bytes_v, verifier_len);
+	free(bytes_v);
+	return verifier;
+}
+
+/// Creates a verification key and salt with given password.
+void generate_srp_verifier_and_salt(const std::string &name,
+	const std::string &password, std::string *verifier,
+	std::string *salt)
+{
+	char *bytes_v = nullptr;
+	size_t verifier_len;
+	char *salt_ptr = nullptr;
+	size_t salt_len;
+	gen_srp_v(name, password, &salt_ptr, &salt_len, &bytes_v, &verifier_len);
+	*verifier = std::string(bytes_v, verifier_len);
+	*salt = std::string(salt_ptr, salt_len);
+	free(bytes_v);
+	free(salt_ptr);
+}
+
+/// Gets an SRP verifier, generating a salt,
+/// and encodes it as DB-ready string.
+std::string get_encoded_srp_verifier(const std::string &name,
+	const std::string &password)
+{
+	std::string verifier;
+	std::string salt;
+	generate_srp_verifier_and_salt(name, password, &verifier, &salt);
+	return encode_srp_verifier(verifier, salt);
+}
+
+/// Converts the passed SRP verifier into a DB-ready format.
+std::string encode_srp_verifier(const std::string &verifier,
+	const std::string &salt)
+{
+	std::ostringstream ret_str;
+	ret_str << "#1#"
+		<< base64_encode((unsigned char *)salt.c_str(), salt.size()) << "#"
+		<< base64_encode((unsigned char *)verifier.c_str(), verifier.size());
+	return ret_str.str();
+}
+
+/// Reads the DB-formatted SRP verifier and gets the verifier
+/// and salt components.
+bool decode_srp_verifier_and_salt(const std::string &encoded,
+	std::string *verifier, std::string *salt)
+{
+	std::vector<std::string> components = str_split(encoded, '#');
+
+	if ((components.size() != 4)
+			|| (components[1] != "1") // 1 means srp
+			|| !base64_is_valid(components[2])
+			|| !base64_is_valid(components[3]))
+		return false;
+
+	*salt = base64_decode(components[2]);
+	*verifier = base64_decode(components[3]);
+	return true;
+
+}

src/util/auth.h

@@ -0,0 +1,47 @@
+/*
+Minetest
+Copyright (C) 2015, 2016 est31 <MTest31@outlook.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#pragma once
+
+/// Gets the base64 encoded legacy password db entry.
+std::string translate_password(const std::string &name,
+	const std::string &password);
+
+/// Creates a verification key with given salt and password.
+std::string generate_srp_verifier(const std::string &name,
+	const std::string &password, const std::string &salt);
+
+/// Creates a verification key and salt with given password.
+void generate_srp_verifier_and_salt(const std::string &name,
+	const std::string &password, std::string *verifier,
+	std::string *salt);
+
+/// Gets an SRP verifier, generating a salt,
+/// and encodes it as DB-ready string.
+std::string get_encoded_srp_verifier(const std::string &name,
+	const std::string &password);
+
+/// Converts the passed SRP verifier into a DB-ready format.
+std::string encode_srp_verifier(const std::string &verifier,
+	const std::string &salt);
+
+/// Reads the DB-formatted SRP verifier and gets the verifier
+/// and salt components.
+bool decode_srp_verifier_and_salt(const std::string &encoded,
+	std::string *verifier, std::string *salt);

src/util/base64.cpp

@@ -0,0 +1,154 @@
+/*
+base64.cpp and base64.h
+
+Copyright (C) 2004-2008 René Nyffenegger
+
+This source code is provided 'as-is', without any express or implied
+warranty. In no event will the author be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+
+1. The origin of this source code must not be misrepresented; you must not
+   claim that you wrote the original source code. If you use this source code
+   in a product, an acknowledgment in the product documentation would be
+   appreciated but is not required.
+
+2. Altered source versions must be plainly marked as such, and must not be
+   misrepresented as being the original source code.
+
+3. This notice may not be removed or altered from any source distribution.
+
+René Nyffenegger rene.nyffenegger@adp-gmbh.ch
+
+*/
+
+#include "base64.h"
+#include <iostream>
+
+static const std::string base64_chars =
+		"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+		"abcdefghijklmnopqrstuvwxyz"
+		"0123456789+/";
+
+static const std::string base64_chars_padding_1 = "AEIMQUYcgkosw048";
+static const std::string base64_chars_padding_2 = "AQgw";
+
+static inline bool is_base64(unsigned char c)
+{
+	return (c >= '0' && c <= '9')
+			|| (c >= 'A' && c <= 'Z')
+			|| (c >= 'a' && c <= 'z')
+			|| c == '+' || c == '/';
+}
+
+bool base64_is_valid(std::string const& s)
+{
+	size_t i = 0;
+	for (; i < s.size(); ++i)
+		if (!is_base64(s[i]))
+			break;
+	unsigned char padding = 3 - ((i + 3) % 4);
+	if ((padding == 1 && base64_chars_padding_1.find(s[i - 1]) == std::string::npos)
+			|| (padding == 2 && base64_chars_padding_2.find(s[i - 1]) == std::string::npos)
+			|| padding == 3)
+		return false;
+	int actual_padding = s.size() - i;
+	// omission of padding characters is allowed
+	if (actual_padding == 0)
+		return true;
+
+	// remaining characters (max. 2) may only be padding
+	for (; i < s.size(); ++i)
+		if (s[i] != '=')
+			return false;
+	// number of padding characters needs to match
+	return padding == actual_padding;
+}
+
+std::string base64_encode(unsigned char const* bytes_to_encode, unsigned int in_len) {
+	std::string ret;
+	int i = 0;
+	int j = 0;
+	unsigned char char_array_3[3];
+	unsigned char char_array_4[4];
+
+	while (in_len--) {
+		char_array_3[i++] = *(bytes_to_encode++);
+		if (i == 3) {
+			char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
+			char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
+			char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
+			char_array_4[3] = char_array_3[2] & 0x3f;
+
+			for(i = 0; (i <4) ; i++)
+				ret += base64_chars[char_array_4[i]];
+			i = 0;
+		}
+	}
+
+	if (i)
+	{
+		for(j = i; j < 3; j++)
+			char_array_3[j] = '\0';
+
+		char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
+		char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
+		char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
+		char_array_4[3] = char_array_3[2] & 0x3f;
+
+		for (j = 0; (j < i + 1); j++)
+			ret += base64_chars[char_array_4[j]];
+
+	// Don't pad it with =
+		/*while((i++ < 3))
+			ret += '=';*/
+
+	}
+
+	return ret;
+
+}
+
+std::string base64_decode(std::string const& encoded_string) {
+	int in_len = encoded_string.size();
+	int i = 0;
+	int j = 0;
+	int in_ = 0;
+	unsigned char char_array_4[4], char_array_3[3];
+	std::string ret;
+
+	while (in_len-- && ( encoded_string[in_] != '=') && is_base64(encoded_string[in_])) {
+		char_array_4[i++] = encoded_string[in_]; in_++;
+		if (i ==4) {
+			for (i = 0; i <4; i++)
+				char_array_4[i] = base64_chars.find(char_array_4[i]);
+
+			char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
+			char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
+			char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];
+
+			for (i = 0; (i < 3); i++)
+				ret += char_array_3[i];
+			i = 0;
+		}
+	}
+
+	if (i) {
+		for (j = i; j <4; j++)
+			char_array_4[j] = 0;
+
+		for (j = 0; j <4; j++)
+			char_array_4[j] = base64_chars.find(char_array_4[j]);
+
+		char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
+		char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
+		char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];
+
+		for (j = 0; (j < i - 1); j++) ret += char_array_3[j];
+	}
+
+	return ret;
+}

src/util/base64.h

@@ -0,0 +1,26 @@
+/*
+Minetest
+Copyright (C) 2013-2017 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#pragma once
+
+#include <string>
+
+bool base64_is_valid(std::string const& s);
+std::string base64_encode(unsigned char const* , unsigned int len);
+std::string base64_decode(std::string const& s);

src/util/basic_macros.h

@@ -0,0 +1,64 @@
+/*
+Minetest
+Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#pragma once
+
+#define ARRLEN(x) (sizeof(x) / sizeof((x)[0]))
+
+#define MYMIN(a, b) ((a) < (b) ? (a) : (b))
+
+#define MYMAX(a, b) ((a) > (b) ? (a) : (b))
+
+// Requires <algorithm>
+#define CONTAINS(c, v) (std::find((c).begin(), (c).end(), (v)) != (c).end())
+
+// To disable copy constructors and assignment operations for some class
+// 'Foobar', add the macro DISABLE_CLASS_COPY(Foobar) in the class definition.
+// Note this also disables copying for any classes derived from 'Foobar' as well
+// as classes having a 'Foobar' member.
+#define DISABLE_CLASS_COPY(C)        \
+	C(const C &) = delete;           \
+	C &operator=(const C &) = delete;
+
+// If you have used DISABLE_CLASS_COPY with a class but still want to permit moving
+// use this macro to add the default move constructors back.
+#define ALLOW_CLASS_MOVE(C)      \
+	C(C &&other) = default;      \
+	C &operator=(C &&) = default;
+
+#ifndef _MSC_VER
+	#define UNUSED_ATTRIBUTE __attribute__ ((unused))
+#else
+	#define UNUSED_ATTRIBUTE
+#endif
+
+// Fail compilation if condition expr is not met.
+// Note that 'msg' must follow the format of a valid identifier, e.g.
+// STATIC_ASSERT(sizeof(foobar_t) == 40), foobar_t_is_wrong_size);
+#define STATIC_ASSERT(expr, msg) \
+	UNUSED_ATTRIBUTE typedef char msg[!!(expr) * 2 - 1]
+
+// Macros to facilitate writing position vectors to a stream
+// Usage:
+//	v3s16 pos(1,2,3);
+//	mystream << "message " << PP(pos) << std::endl;
+
+#define PP(x) "("<<(x).X<<","<<(x).Y<<","<<(x).Z<<")"
+
+#define PP2(x) "("<<(x).X<<","<<(x).Y<<")"

src/util/container.h

@@ -0,0 +1,307 @@
+/*
+Minetest
+Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#pragma once
+
+#include "irrlichttypes.h"
+#include "exceptions.h"
+#include "threading/mutex_auto_lock.h"
+#include "threading/semaphore.h"
+#include <list>
+#include <vector>
+#include <map>
+#include <set>
+#include <queue>
+
+/*
+Queue with unique values with fast checking of value existence
+*/
+
+template<typename Value>
+class UniqueQueue
+{
+public:
+
+	/*
+	Does nothing if value is already queued.
+	Return value:
+	true: value added
+	false: value already exists
+	*/
+	bool push_back(const Value& value)
+	{
+		if (m_set.insert(value).second)
+		{
+			m_queue.push(value);
+			return true;
+		}
+		return false;
+	}
+
+	void pop_front()
+	{
+		m_set.erase(m_queue.front());
+		m_queue.pop();
+	}
+
+	const Value& front() const
+	{
+		return m_queue.front();
+	}
+
+	u32 size() const
+	{
+		return m_queue.size();
+	}
+
+private:
+	std::set<Value> m_set;
+	std::queue<Value> m_queue;
+};
+
+template<typename Key, typename Value>
+class MutexedMap
+{
+public:
+	MutexedMap() = default;
+
+	void set(const Key &name, const Value &value)
+	{
+		MutexAutoLock lock(m_mutex);
+		m_values[name] = value;
+	}
+
+	bool get(const Key &name, Value *result) const
+	{
+		MutexAutoLock lock(m_mutex);
+		auto n = m_values.find(name);
+		if (n == m_values.end())
+			return false;
+		if (result)
+			*result = n->second;
+		return true;
+	}
+
+	std::vector<Value> getValues() const
+	{
+		MutexAutoLock lock(m_mutex);
+		std::vector<Value> result;
+		result.reserve(m_values.size());
+		for (auto it = m_values.begin(); it != m_values.end(); ++it)
+			result.push_back(it->second);
+		return result;
+	}
+
+	void clear() { m_values.clear(); }
+
+private:
+	std::map<Key, Value> m_values;
+	mutable std::mutex m_mutex;
+};
+
+
+// Thread-safe Double-ended queue
+
+template<typename T>
+class MutexedQueue
+{
+public:
+	template<typename Key, typename U, typename Caller, typename CallerData>
+	friend class RequestQueue;
+
+	MutexedQueue() = default;
+
+	bool empty() const
+	{
+		MutexAutoLock lock(m_mutex);
+		return m_queue.empty();
+	}
+
+	void push_back(const T &t)
+	{
+		MutexAutoLock lock(m_mutex);
+		m_queue.push_back(t);
+		m_signal.post();
+	}
+
+	void push_back(T &&t)
+	{
+		MutexAutoLock lock(m_mutex);
+		m_queue.push_back(std::move(t));
+		m_signal.post();
+	}
+
+	/* this version of pop_front returns a empty element of T on timeout.
+	* Make sure default constructor of T creates a recognizable "empty" element
+	*/
+	T pop_frontNoEx(u32 wait_time_max_ms)
+	{
+		if (m_signal.wait(wait_time_max_ms)) {
+			MutexAutoLock lock(m_mutex);
+
+			T t = std::move(m_queue.front());
+			m_queue.pop_front();
+			return t;
+		}
+
+		return T();
+	}
+
+	T pop_front(u32 wait_time_max_ms)
+	{
+		if (m_signal.wait(wait_time_max_ms)) {
+			MutexAutoLock lock(m_mutex);
+
+			T t = std::move(m_queue.front());
+			m_queue.pop_front();
+			return t;
+		}
+
+		throw ItemNotFoundException("MutexedQueue: queue is empty");
+	}
+
+	T pop_frontNoEx()
+	{
+		m_signal.wait();
+
+		MutexAutoLock lock(m_mutex);
+
+		T t = std::move(m_queue.front());
+		m_queue.pop_front();
+		return t;
+	}
+
+	T pop_back(u32 wait_time_max_ms=0)
+	{
+		if (m_signal.wait(wait_time_max_ms)) {
+			MutexAutoLock lock(m_mutex);
+
+			T t = std::move(m_queue.back());
+			m_queue.pop_back();
+			return t;
+		}
+
+		throw ItemNotFoundException("MutexedQueue: queue is empty");
+	}
+
+	/* this version of pop_back returns a empty element of T on timeout.
+	* Make sure default constructor of T creates a recognizable "empty" element
+	*/
+	T pop_backNoEx(u32 wait_time_max_ms)
+	{
+		if (m_signal.wait(wait_time_max_ms)) {
+			MutexAutoLock lock(m_mutex);
+
+			T t = std::move(m_queue.back());
+			m_queue.pop_back();
+			return t;
+		}
+
+		return T();
+	}
+
+	T pop_backNoEx()
+	{
+		m_signal.wait();
+
+		MutexAutoLock lock(m_mutex);
+
+		T t = std::move(m_queue.back());
+		m_queue.pop_back();
+		return t;
+	}
+
+protected:
+	std::mutex &getMutex() { return m_mutex; }
+
+	std::deque<T> &getQueue() { return m_queue; }
+
+	std::deque<T> m_queue;
+	mutable std::mutex m_mutex;
+	Semaphore m_signal;
+};
+
+template<typename K, typename V>
+class LRUCache
+{
+public:
+	LRUCache(size_t limit, void (*cache_miss)(void *data, const K &key, V *dest),
+			void *data)
+	{
+		m_limit = limit;
+		m_cache_miss = cache_miss;
+		m_cache_miss_data = data;
+	}
+
+	void setLimit(size_t limit)
+	{
+		m_limit = limit;
+		invalidate();
+	}
+
+	void invalidate()
+	{
+		m_map.clear();
+		m_queue.clear();
+	}
+
+	const V *lookupCache(K key)
+	{
+		typename cache_type::iterator it = m_map.find(key);
+		V *ret;
+		if (it != m_map.end()) {
+			// found!
+
+			cache_entry_t &entry = it->second;
+
+			ret = &entry.second;
+
+			// update the usage information
+			m_queue.erase(entry.first);
+			m_queue.push_front(key);
+			entry.first = m_queue.begin();
+		} else {
+			// cache miss -- enter into cache
+			cache_entry_t &entry =
+				m_map[key];
+			ret = &entry.second;
+			m_cache_miss(m_cache_miss_data, key, &entry.second);
+
+			// delete old entries
+			if (m_queue.size() == m_limit) {
+				const K &id = m_queue.back();
+				m_map.erase(id);
+				m_queue.pop_back();
+			}
+
+			m_queue.push_front(key);
+			entry.first = m_queue.begin();
+		}
+		return ret;
+	}
+private:
+	void (*m_cache_miss)(void *data, const K &key, V *dest);
+	void *m_cache_miss_data;
+	size_t m_limit;
+	typedef typename std::template pair<typename std::template list<K>::iterator, V> cache_entry_t;
+	typedef std::template map<K, cache_entry_t> cache_type;
+	cache_type m_map;
+	// we can't use std::deque here, because its iterators get invalidated
+	std::list<K> m_queue;
+};

src/util/directiontables.cpp

@@ -0,0 +1,120 @@
+/*
+Minetest
+Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "directiontables.h"
+
+const v3s16 g_6dirs[6] =
+{
+	// +right, +top, +back
+	v3s16( 0, 0, 1), // back
+	v3s16( 0, 1, 0), // top
+	v3s16( 1, 0, 0), // right
+	v3s16( 0, 0,-1), // front
+	v3s16( 0,-1, 0), // bottom
+	v3s16(-1, 0, 0) // left
+};
+
+const v3s16 g_7dirs[7] =
+{
+	v3s16(0,0,1), // back
+	v3s16(0,1,0), // top
+	v3s16(1,0,0), // right
+	v3s16(0,0,-1), // front
+	v3s16(0,-1,0), // bottom
+	v3s16(-1,0,0), // left
+	v3s16(0,0,0), // self
+};
+
+const v3s16 g_26dirs[26] =
+{
+	// +right, +top, +back
+	v3s16( 0, 0, 1), // back
+	v3s16( 0, 1, 0), // top
+	v3s16( 1, 0, 0), // right
+	v3s16( 0, 0,-1), // front
+	v3s16( 0,-1, 0), // bottom
+	v3s16(-1, 0, 0), // left
+	// 6
+	v3s16(-1, 1, 0), // top left
+	v3s16( 1, 1, 0), // top right
+	v3s16( 0, 1, 1), // top back
+	v3s16( 0, 1,-1), // top front
+	v3s16(-1, 0, 1), // back left
+	v3s16( 1, 0, 1), // back right
+	v3s16(-1, 0,-1), // front left
+	v3s16( 1, 0,-1), // front right
+	v3s16(-1,-1, 0), // bottom left
+	v3s16( 1,-1, 0), // bottom right
+	v3s16( 0,-1, 1), // bottom back
+	v3s16( 0,-1,-1), // bottom front
+	// 18
+	v3s16(-1, 1, 1), // top back-left
+	v3s16( 1, 1, 1), // top back-right
+	v3s16(-1, 1,-1), // top front-left
+	v3s16( 1, 1,-1), // top front-right
+	v3s16(-1,-1, 1), // bottom back-left
+	v3s16( 1,-1, 1), // bottom back-right
+	v3s16(-1,-1,-1), // bottom front-left
+	v3s16( 1,-1,-1), // bottom front-right
+	// 26
+};
+
+const v3s16 g_27dirs[27] =
+{
+	// +right, +top, +back
+	v3s16( 0, 0, 1), // back
+	v3s16( 0, 1, 0), // top
+	v3s16( 1, 0, 0), // right
+	v3s16( 0, 0,-1), // front
+	v3s16( 0,-1, 0), // bottom
+	v3s16(-1, 0, 0), // left
+	// 6
+	v3s16(-1, 1, 0), // top left
+	v3s16( 1, 1, 0), // top right
+	v3s16( 0, 1, 1), // top back
+	v3s16( 0, 1,-1), // top front
+	v3s16(-1, 0, 1), // back left
+	v3s16( 1, 0, 1), // back right
+	v3s16(-1, 0,-1), // front left
+	v3s16( 1, 0,-1), // front right
+	v3s16(-1,-1, 0), // bottom left
+	v3s16( 1,-1, 0), // bottom right
+	v3s16( 0,-1, 1), // bottom back
+	v3s16( 0,-1,-1), // bottom front
+	// 18
+	v3s16(-1, 1, 1), // top back-left
+	v3s16( 1, 1, 1), // top back-right
+	v3s16(-1, 1,-1), // top front-left
+	v3s16( 1, 1,-1), // top front-right
+	v3s16(-1,-1, 1), // bottom back-left
+	v3s16( 1,-1, 1), // bottom back-right
+	v3s16(-1,-1,-1), // bottom front-left
+	v3s16( 1,-1,-1), // bottom front-right
+	// 26
+	v3s16(0,0,0),
+};
+
+const u8 wallmounted_to_facedir[6] = {
+	20,
+	0,
+	16 + 1,
+	12 + 3,
+	8,
+	4 + 2
+};

src/util/directiontables.h

@@ -0,0 +1,89 @@
+/*
+Minetest
+Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#pragma once
+
+#include "irrlichttypes.h"
+#include "irr_v3d.h"
+
+extern const v3s16 g_6dirs[6];
+
+extern const v3s16 g_7dirs[7];
+
+extern const v3s16 g_26dirs[26];
+
+// 26th is (0,0,0)
+extern const v3s16 g_27dirs[27];
+
+extern const u8 wallmounted_to_facedir[6];
+
+/// Direction in the 6D format. g_27dirs contains corresponding vectors.
+/// Here P means Positive, N stands for Negative.
+enum Direction6D {
+// 0
+	D6D_ZP,
+	D6D_YP,
+	D6D_XP,
+	D6D_ZN,
+	D6D_YN,
+	D6D_XN,
+// 6
+	D6D_XN_YP,
+	D6D_XP_YP,
+	D6D_YP_ZP,
+	D6D_YP_ZN,
+	D6D_XN_ZP,
+	D6D_XP_ZP,
+	D6D_XN_ZN,
+	D6D_XP_ZN,
+	D6D_XN_YN,
+	D6D_XP_YN,
+	D6D_YN_ZP,
+	D6D_YN_ZN,
+// 18
+	D6D_XN_YP_ZP,
+	D6D_XP_YP_ZP,
+	D6D_XN_YP_ZN,
+	D6D_XP_YP_ZN,
+	D6D_XN_YN_ZP,
+	D6D_XP_YN_ZP,
+	D6D_XN_YN_ZN,
+	D6D_XP_YN_ZN,
+// 26
+	D6D,
+
+// aliases
+	D6D_BACK   = D6D_ZP,
+	D6D_TOP    = D6D_YP,
+	D6D_RIGHT  = D6D_XP,
+	D6D_FRONT  = D6D_ZN,
+	D6D_BOTTOM = D6D_YN,
+	D6D_LEFT   = D6D_XN,
+};
+
+/// Direction in the wallmounted format.
+/// P is Positive, N is Negative.
+enum DirectionWallmounted {
+	DWM_YP,
+	DWM_YN,
+	DWM_XP,
+	DWM_XN,
+	DWM_ZP,
+	DWM_ZN,
+};

src/util/enriched_string.cpp

@@ -0,0 +1,211 @@
+/*
+Copyright (C) 2013 xyz, Ilya Zhuravlev <whatever@xyz.is>
+Copyright (C) 2016 Nore, Nathanaëlle Courant <nore@mesecons.net>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "enriched_string.h"
+#include "util/string.h"
+#include "debug.h"
+#include "log.h"
+
+using namespace irr::video;
+
+EnrichedString::EnrichedString()
+{
+	clear();
+}
+
+EnrichedString::EnrichedString(const std::wstring &string,
+		const std::vector<SColor> &colors)
+{
+	clear();
+	m_string = string;
+	m_colors = colors;
+}
+
+EnrichedString::EnrichedString(const std::wstring &s, const SColor &color)
+{
+	clear();
+	addAtEnd(translate_string(s), color);
+}
+
+EnrichedString::EnrichedString(const wchar_t *str, const SColor &color)
+{
+	clear();
+	addAtEnd(translate_string(std::wstring(str)), color);
+}
+
+void EnrichedString::clear()
+{
+	m_string.clear();
+	m_colors.clear();
+	m_has_background = false;
+	m_default_length = 0;
+	m_default_color = irr::video::SColor(255, 255, 255, 255);
+	m_background = irr::video::SColor(0, 0, 0, 0);
+}
+
+void EnrichedString::operator=(const wchar_t *str)
+{
+	clear();
+	addAtEnd(translate_string(std::wstring(str)), m_default_color);
+}
+
+void EnrichedString::addAtEnd(const std::wstring &s, SColor initial_color)
+{
+	SColor color(initial_color);
+	bool use_default = (m_default_length == m_string.size() &&
+		color == m_default_color);
+
+	m_colors.reserve(m_colors.size() + s.size());
+
+	size_t i = 0;
+	while (i < s.length()) {
+		if (s[i] != L'\x1b') {
+			m_string += s[i];
+			m_colors.push_back(color);
+			++i;
+			continue;
+		}
+		++i;
+		size_t start_index = i;
+		size_t length;
+		if (i == s.length()) {
+			break;
+		}
+		if (s[i] == L'(') {
+			++i;
+			++start_index;
+			while (i < s.length() && s[i] != L')') {
+				if (s[i] == L'\\') {
+					++i;
+				}
+				++i;
+			}
+			length = i - start_index;
+			++i;
+		} else {
+			++i;
+			length = 1;
+		}
+		std::wstring escape_sequence(s, start_index, length);
+		std::vector<std::wstring> parts = split(escape_sequence, L'@');
+		if (parts[0] == L"c") {
+			if (parts.size() < 2) {
+				continue;
+			}
+			parseColorString(wide_to_utf8(parts[1]), color, true);
+
+			// No longer use default color after first escape
+			if (use_default) {
+				m_default_length = m_string.size();
+				use_default = false;
+			}
+		} else if (parts[0] == L"b") {
+			if (parts.size() < 2) {
+				continue;
+			}
+			parseColorString(wide_to_utf8(parts[1]), m_background, true);
+			m_has_background = true;
+		}
+	}
+
+	// Update if no escape character was found
+	if (use_default)
+		m_default_length = m_string.size();
+}
+
+void EnrichedString::addChar(const EnrichedString &source, size_t i)
+{
+	m_string += source.m_string[i];
+	m_colors.push_back(source.m_colors[i]);
+}
+
+void EnrichedString::addCharNoColor(wchar_t c)
+{
+	m_string += c;
+	if (m_colors.empty()) {
+		m_colors.emplace_back(m_default_color);
+	} else {
+		m_colors.push_back(m_colors[m_colors.size() - 1]);
+	}
+}
+
+EnrichedString EnrichedString::operator+(const EnrichedString &other) const
+{
+	EnrichedString result = *this;
+	result += other;
+	return result;
+}
+
+void EnrichedString::operator+=(const EnrichedString &other)
+{
+	bool update_default_color = m_default_length == m_string.size();
+
+	m_string += other.m_string;
+	m_colors.insert(m_colors.end(), other.m_colors.begin(), other.m_colors.end());
+
+	if (update_default_color) {
+		m_default_length += other.m_default_length;
+		updateDefaultColor();
+	}
+}
+
+EnrichedString EnrichedString::substr(size_t pos, size_t len) const
+{
+	if (pos >= m_string.length())
+		return EnrichedString();
+
+	if (len == std::string::npos || pos + len > m_string.length())
+		len = m_string.length() - pos;
+
+	EnrichedString str(
+		m_string.substr(pos, len),
+		std::vector<SColor>(m_colors.begin() + pos, m_colors.begin() + pos + len)
+	);
+
+	str.m_has_background = m_has_background;
+	str.m_background = m_background;
+
+	if (pos < m_default_length)
+		str.m_default_length = std::min(m_default_length - pos, str.size());
+	str.setDefaultColor(m_default_color);
+	return str;
+}
+
+const wchar_t *EnrichedString::c_str() const
+{
+	return m_string.c_str();
+}
+
+const std::vector<SColor> &EnrichedString::getColors() const
+{
+	return m_colors;
+}
+
+const std::wstring &EnrichedString::getString() const
+{
+	return m_string;
+}
+
+void EnrichedString::updateDefaultColor()
+{
+	sanity_check(m_default_length <= m_colors.size());
+
+	for (size_t i = 0; i < m_default_length; ++i)
+		m_colors[i] = m_default_color;
+}

src/util/enriched_string.h

@@ -0,0 +1,110 @@
+/*
+Copyright (C) 2013 xyz, Ilya Zhuravlev <whatever@xyz.is>
+Copyright (C) 2016 Nore, Nathanaëlle Courant <nore@mesecons.net>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#pragma once
+
+#include <string>
+#include <vector>
+#include <SColor.h>
+
+using namespace irr;
+
+class EnrichedString {
+public:
+	EnrichedString();
+	EnrichedString(const std::wstring &s,
+		const video::SColor &color = video::SColor(255, 255, 255, 255));
+	EnrichedString(const wchar_t *str,
+		const video::SColor &color = video::SColor(255, 255, 255, 255));
+	EnrichedString(const std::wstring &string,
+		const std::vector<video::SColor> &colors);
+	void operator=(const wchar_t *str);
+
+	void clear();
+
+	void addAtEnd(const std::wstring &s, video::SColor color);
+
+	// Adds the character source[i] at the end.
+	// An EnrichedString should always be able to be copied
+	// to the end of an existing EnrichedString that way.
+	void addChar(const EnrichedString &source, size_t i);
+
+	// Adds a single character at the end, without specifying its
+	// color. The color used will be the one from the last character.
+	void addCharNoColor(wchar_t c);
+
+	EnrichedString substr(size_t pos = 0, size_t len = std::string::npos) const;
+	EnrichedString operator+(const EnrichedString &other) const;
+	void operator+=(const EnrichedString &other);
+	const wchar_t *c_str() const;
+	const std::vector<video::SColor> &getColors() const;
+	const std::wstring &getString() const;
+
+	inline void setDefaultColor(video::SColor color)
+	{
+		m_default_color = color;
+		updateDefaultColor();
+	}
+	void updateDefaultColor();
+	inline const video::SColor &getDefaultColor() const
+	{
+		return m_default_color;
+	}
+
+	inline bool operator==(const EnrichedString &other) const
+	{
+		return (m_string == other.m_string && m_colors == other.m_colors);
+	}
+	inline bool operator!=(const EnrichedString &other) const
+	{
+		return !(*this == other);
+	}
+	inline bool empty() const
+	{
+		return m_string.empty();
+	}
+	inline size_t size() const
+	{
+		return m_string.size();
+	}
+
+	inline bool hasBackground() const
+	{
+		return m_has_background;
+	}
+	inline video::SColor getBackground() const
+	{
+		return m_background;
+	}
+	inline void setBackground(video::SColor color)
+	{
+		m_background = color;
+		m_has_background = true;
+	}
+
+private:
+	std::wstring m_string;
+	std::vector<video::SColor> m_colors;
+	bool m_has_background;
+	video::SColor m_default_color;
+	video::SColor m_background;
+	// This variable defines the length of the default-colored text.
+	// Change this to a std::vector if an "end coloring" tag is wanted.
+	size_t m_default_length = 0;
+};

src/util/hex.h

@@ -0,0 +1,60 @@
+/*
+Minetest
+Copyright (C) 2013 Jonathan Neuschäfer <j.neuschaefer@gmx.net>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#pragma once
+
+#include <string>
+
+static const char hex_chars[] = "0123456789abcdef";
+
+static inline std::string hex_encode(const char *data, unsigned int data_size)
+{
+	std::string ret;
+	ret.reserve(data_size * 2);
+
+	char buf2[3];
+	buf2[2] = '\0';
+
+	for (unsigned int i = 0; i < data_size; i++) {
+		unsigned char c = (unsigned char)data[i];
+		buf2[0] = hex_chars[(c & 0xf0) >> 4];
+		buf2[1] = hex_chars[c & 0x0f];
+		ret.append(buf2);
+	}
+
+	return ret;
+}
+
+static inline std::string hex_encode(const std::string &data)
+{
+	return hex_encode(data.c_str(), data.size());
+}
+
+static inline bool hex_digit_decode(char hexdigit, unsigned char &value)
+{
+	if (hexdigit >= '0' && hexdigit <= '9')
+		value = hexdigit - '0';
+	else if (hexdigit >= 'A' && hexdigit <= 'F')
+		value = hexdigit - 'A' + 10;
+	else if (hexdigit >= 'a' && hexdigit <= 'f')
+		value = hexdigit - 'a' + 10;
+	else
+		return false;
+	return true;
+}

src/util/ieee_float.cpp

@@ -0,0 +1,136 @@
+/*
+ * Conversion of f32 to IEEE-754 and vice versa.
+ *
+ * © Copyright 2018 Pedro Gimeno Fortea.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include "ieee_float.h"
+#include "log.h"
+#include "porting.h"
+#include <limits>
+#include <cmath>
+
+// Given an unsigned 32-bit integer representing an IEEE-754 single-precision
+// float, return the float.
+f32 u32Tof32Slow(u32 i)
+{
+	// clang-format off
+	int exp = (i >> 23) & 0xFF;
+	u32 sign = i & 0x80000000UL;
+	u32 imant = i & 0x7FFFFFUL;
+	if (exp == 0xFF) {
+		// Inf/NaN
+		if (imant == 0) {
+			if (std::numeric_limits<f32>::has_infinity)
+				return sign ? -std::numeric_limits<f32>::infinity() :
+					std::numeric_limits<f32>::infinity();
+			return sign ? std::numeric_limits<f32>::max() :
+				std::numeric_limits<f32>::lowest();
+		}
+		return std::numeric_limits<f32>::has_quiet_NaN ?
+			std::numeric_limits<f32>::quiet_NaN() : -0.f;
+	}
+
+	if (!exp) {
+		// Denormal or zero
+		return sign ? -ldexpf((f32)imant, -149) : ldexpf((f32)imant, -149);
+	}
+
+	return sign ? -ldexpf((f32)(imant | 0x800000UL), exp - 150) :
+		ldexpf((f32)(imant | 0x800000UL), exp - 150);
+	// clang-format on
+}
+
+// Given a float, return an unsigned 32-bit integer representing the f32
+// in IEEE-754 single-precision format.
+u32 f32Tou32Slow(f32 f)
+{
+	u32 signbit = std::copysign(1.0f, f) == 1.0f ? 0 : 0x80000000UL;
+	if (f == 0.f)
+		return signbit;
+	if (std::isnan(f))
+		return signbit | 0x7FC00000UL;
+	if (std::isinf(f))
+		return signbit | 0x7F800000UL;
+	int exp = 0; // silence warning
+	f32 mant = frexpf(f, &exp);
+	u32 imant = (u32)std::floor((signbit ? -16777216.f : 16777216.f) * mant);
+	exp += 126;
+	if (exp <= 0) {
+		// Denormal
+		return signbit | (exp <= -31 ? 0 : imant >> (1 - exp));
+	}
+
+	if (exp >= 255) {
+		// Overflow due to the platform having exponents bigger than IEEE ones.
+		// Return signed infinity.
+		return signbit | 0x7F800000UL;
+	}
+
+	// Regular number
+	return signbit | (exp << 23) | (imant & 0x7FFFFFUL);
+}
+
+// This test needs the following requisites in order to work:
+// - The float type must be a 32 bits IEEE-754 single-precision float.
+// - The endianness of f32s and integers must match.
+FloatType getFloatSerializationType()
+{
+	// clang-format off
+	const f32 cf = -22220490.f;
+	const u32 cu = 0xCBA98765UL;
+	if (std::numeric_limits<f32>::is_iec559 && sizeof(cf) == 4 &&
+			sizeof(cu) == 4 && !memcmp(&cf, &cu, 4)) {
+		// u32Tof32Slow and f32Tou32Slow are not needed, use memcpy
+		return FLOATTYPE_SYSTEM;
+	}
+
+	// Run quick tests to ensure the custom functions provide acceptable results
+	warningstream << "floatSerialization: f32 and u32 endianness are "
+		"not equal or machine is not IEEE-754 compliant" << std::endl;
+	u32 i;
+	char buf[128];
+
+	// NaN checks aren't included in the main loop
+	if (!std::isnan(u32Tof32Slow(0x7FC00000UL))) {
+		porting::mt_snprintf(buf, sizeof(buf),
+			"u32Tof32Slow(0x7FC00000) failed to produce a NaN, actual: %.9g",
+			u32Tof32Slow(0x7FC00000UL));
+		infostream << buf << std::endl;
+	}
+	if (!std::isnan(u32Tof32Slow(0xFFC00000UL))) {
+		porting::mt_snprintf(buf, sizeof(buf),
+			"u32Tof32Slow(0xFFC00000) failed to produce a NaN, actual: %.9g",
+			u32Tof32Slow(0xFFC00000UL));
+		infostream << buf << std::endl;
+	}
+
+	i = f32Tou32Slow(std::numeric_limits<f32>::quiet_NaN());
+	// check that it corresponds to a NaN encoding
+	if ((i & 0x7F800000UL) != 0x7F800000UL || (i & 0x7FFFFFUL) == 0) {
+		porting::mt_snprintf(buf, sizeof(buf),
+			"f32Tou32Slow(NaN) failed to encode NaN, actual: 0x%X", i);
+		infostream << buf << std::endl;
+	}
+
+	return FLOATTYPE_SLOW;
+	// clang-format on
+}

src/util/ieee_float.h

@@ -0,0 +1,34 @@
+/*
+Minetest
+Copyright (C) 2018 SmallJoker <mk939@ymail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#pragma once
+
+#include "irrlichttypes.h"
+
+enum FloatType
+{
+	FLOATTYPE_UNKNOWN,
+	FLOATTYPE_SLOW,
+	FLOATTYPE_SYSTEM
+};
+
+f32 u32Tof32Slow(u32 i);
+u32 f32Tou32Slow(f32 f);
+
+FloatType getFloatSerializationType();

src/util/md32_common.h

@@ -0,0 +1,430 @@
+/* md32_common.h file used by sha256 implementation */
+/* ====================================================================
+ * Copyright (c) 1999-2007 The OpenSSL Project.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. All advertising materials mentioning features or use of this
+ *    software must display the following acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission. For written permission, please contact
+ *    licensing@OpenSSL.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ *    nor may "OpenSSL" appear in their names without prior written
+ *    permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ *    acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ * ====================================================================
+ *
+ */
+
+/*-
+ * This is a generic 32 bit "collector" for message digest algorithms.
+ * Whenever needed it collects input character stream into chunks of
+ * 32 bit values and invokes a block function that performs actual hash
+ * calculations.
+ *
+ * Porting guide.
+ *
+ * Obligatory macros:
+ *
+ * DATA_ORDER_IS_BIG_ENDIAN or DATA_ORDER_IS_LITTLE_ENDIAN
+ *      this macro defines byte order of input stream.
+ * HASH_CBLOCK
+ *      size of a unit chunk HASH_BLOCK operates on.
+ * HASH_LONG
+ *      has to be at lest 32 bit wide, if it's wider, then
+ *      HASH_LONG_LOG2 *has to* be defined along
+ * HASH_CTX
+ *      context structure that at least contains following
+ *      members:
+ *              typedef struct {
+ *                      ...
+ *                      HASH_LONG       Nl,Nh;
+ *                      either {
+ *                      HASH_LONG       data[HASH_LBLOCK];
+ *                      unsigned char   data[HASH_CBLOCK];
+ *                      };
+ *                      unsigned int    num;
+ *                      ...
+ *                      } HASH_CTX;
+ *      data[] vector is expected to be zeroed upon first call to
+ *      HASH_UPDATE.
+ * HASH_UPDATE
+ *      name of "Update" function, implemented here.
+ * HASH_TRANSFORM
+ *      name of "Transform" function, implemented here.
+ * HASH_FINAL
+ *      name of "Final" function, implemented here.
+ * HASH_BLOCK_DATA_ORDER
+ *      name of "block" function capable of treating *unaligned* input
+ *      message in original (data) byte order, implemented externally.
+ * HASH_MAKE_STRING
+ *      macro convering context variables to an ASCII hash string.
+ *
+ * MD5 example:
+ *
+ *      #define DATA_ORDER_IS_LITTLE_ENDIAN
+ *
+ *      #define HASH_LONG               MD5_LONG
+ *      #define HASH_LONG_LOG2          MD5_LONG_LOG2
+ *      #define HASH_CTX                MD5_CTX
+ *      #define HASH_CBLOCK             MD5_CBLOCK
+ *      #define HASH_UPDATE             MD5_Update
+ *      #define HASH_TRANSFORM          MD5_Transform
+ *      #define HASH_FINAL              MD5_Final
+ *      #define HASH_BLOCK_DATA_ORDER   md5_block_data_order
+ *
+ *                                      <appro@fy.chalmers.se>
+ */
+
+#pragma once
+
+#if !defined(DATA_ORDER_IS_BIG_ENDIAN) && !defined(DATA_ORDER_IS_LITTLE_ENDIAN)
+# error "DATA_ORDER must be defined!"
+#endif
+
+#ifndef HASH_CBLOCK
+# error "HASH_CBLOCK must be defined!"
+#endif
+#ifndef HASH_LONG
+# error "HASH_LONG must be defined!"
+#endif
+#ifndef HASH_CTX
+# error "HASH_CTX must be defined!"
+#endif
+
+#ifndef HASH_UPDATE
+# error "HASH_UPDATE must be defined!"
+#endif
+#ifndef HASH_TRANSFORM
+# error "HASH_TRANSFORM must be defined!"
+#endif
+#ifndef HASH_FINAL
+# error "HASH_FINAL must be defined!"
+#endif
+
+#ifndef HASH_BLOCK_DATA_ORDER
+# error "HASH_BLOCK_DATA_ORDER must be defined!"
+#endif
+
+/*
+ * Engage compiler specific rotate intrinsic function if available.
+ */
+#undef ROTATE
+#ifndef PEDANTIC
+# if defined(_MSC_VER)
+#  define ROTATE(a,n)   _lrotl(a,n)
+# elif defined(__ICC)
+#  define ROTATE(a,n)   _rotl(a,n)
+# elif defined(__MWERKS__)
+#  if defined(__POWERPC__)
+#   define ROTATE(a,n)  __rlwinm(a,n,0,31)
+#  elif defined(__MC68K__)
+    /* Motorola specific tweak. <appro@fy.chalmers.se> */
+#   define ROTATE(a,n)  ( n<24 ? __rol(a,n) : __ror(a,32-n) )
+#  else
+#   define ROTATE(a,n)  __rol(a,n)
+#  endif
+# elif defined(__GNUC__) && __GNUC__>=2 && !defined(OPENSSL_NO_ASM) && !defined(OPENSSL_NO_INLINE_ASM)
+  /*
+   * Some GNU C inline assembler templates. Note that these are
+   * rotates by *constant* number of bits! But that's exactly
+   * what we need here...
+   *                                    <appro@fy.chalmers.se>
+   */
+#  if defined(__i386) || defined(__i386__) || defined(__x86_64) || defined(__x86_64__)
+#   define ROTATE(a,n)  ({ register unsigned int ret;   \
+                                asm (                   \
+                                "roll %1,%0"            \
+                                : "=r"(ret)             \
+                                : "I"(n), "0"((unsigned int)(a))        \
+                                : "cc");                \
+                           ret;                         \
+                        })
+#  elif defined(_ARCH_PPC) || defined(_ARCH_PPC64) || \
+        defined(__powerpc) || defined(__ppc__) || defined(__powerpc64__)
+#   define ROTATE(a,n)  ({ register unsigned int ret;   \
+                                asm (                   \
+                                "rlwinm %0,%1,%2,0,31"  \
+                                : "=r"(ret)             \
+                                : "r"(a), "I"(n));      \
+                           ret;                         \
+                        })
+#  elif defined(__s390x__)
+#   define ROTATE(a,n) ({ register unsigned int ret;    \
+                                asm ("rll %0,%1,%2"     \
+                                : "=r"(ret)             \
+                                : "r"(a), "I"(n));      \
+                          ret;                          \
+                        })
+#  endif
+# endif
+#endif                          /* PEDANTIC */
+
+#ifndef ROTATE
+# define ROTATE(a,n)     (((a)<<(n))|(((a)&0xffffffff)>>(32-(n))))
+#endif
+
+#if defined(DATA_ORDER_IS_BIG_ENDIAN)
+
+# ifndef PEDANTIC
+#  if defined(__GNUC__) && __GNUC__>=2 && !defined(OPENSSL_NO_ASM) && !defined(OPENSSL_NO_INLINE_ASM)
+#   if ((defined(__i386) || defined(__i386__)) && !defined(I386_ONLY)) || \
+      (defined(__x86_64) || defined(__x86_64__))
+#    if !defined(B_ENDIAN)
+    /*
+     * This gives ~30-40% performance improvement in SHA-256 compiled
+     * with gcc [on P4]. Well, first macro to be frank. We can pull
+     * this trick on x86* platforms only, because these CPUs can fetch
+     * unaligned data without raising an exception.
+     */
+#     define HOST_c2l(c,l)        ({ unsigned int r=*((const unsigned int *)(c)); \
+                                   asm ("bswapl %0":"=r"(r):"0"(r));    \
+                                   (c)+=4; (l)=r;                       })
+#     define HOST_l2c(l,c)        ({ unsigned int r=(l);                  \
+                                   asm ("bswapl %0":"=r"(r):"0"(r));    \
+                                   *((unsigned int *)(c))=r; (c)+=4; r; })
+#    endif
+#   elif defined(__aarch64__)
+#    if defined(__BYTE_ORDER__)
+#     if defined(__ORDER_LITTLE_ENDIAN__) && __BYTE_ORDER__==__ORDER_LITTLE_ENDIAN__
+#      define HOST_c2l(c,l)      ({ unsigned int r;              \
+                                   asm ("rev    %w0,%w1"        \
+                                        :"=r"(r)                \
+                                        :"r"(*((const unsigned int *)(c))));\
+                                   (c)+=4; (l)=r;               })
+#      define HOST_l2c(l,c)      ({ unsigned int r;              \
+                                   asm ("rev    %w0,%w1"        \
+                                        :"=r"(r)                \
+                                        :"r"((unsigned int)(l)));\
+                                   *((unsigned int *)(c))=r; (c)+=4; r; })
+#     elif defined(__ORDER_BIG_ENDIAN__) && __BYTE_ORDER__==__ORDER_BIG_ENDIAN__
+#      define HOST_c2l(c,l)      ((l)=*((const unsigned int *)(c)), (c)+=4, (l))
+#      define HOST_l2c(l,c)      (*((unsigned int *)(c))=(l), (c)+=4, (l))
+#     endif
+#    endif
+#   endif
+#  endif
+#  if defined(__s390__) || defined(__s390x__)
+#   define HOST_c2l(c,l) ((l)=*((const unsigned int *)(c)), (c)+=4, (l))
+#   define HOST_l2c(l,c) (*((unsigned int *)(c))=(l), (c)+=4, (l))
+#  endif
+# endif
+
+# ifndef HOST_c2l
+#  define HOST_c2l(c,l)   (l =(((unsigned long)(*((c)++)))<<24),          \
+                         l|=(((unsigned long)(*((c)++)))<<16),          \
+                         l|=(((unsigned long)(*((c)++)))<< 8),          \
+                         l|=(((unsigned long)(*((c)++)))    )           )
+# endif
+# ifndef HOST_l2c
+#  define HOST_l2c(l,c)   (*((c)++)=(unsigned char)(((l)>>24)&0xff),      \
+                         *((c)++)=(unsigned char)(((l)>>16)&0xff),      \
+                         *((c)++)=(unsigned char)(((l)>> 8)&0xff),      \
+                         *((c)++)=(unsigned char)(((l)    )&0xff),      \
+                         l)
+# endif
+
+#elif defined(DATA_ORDER_IS_LITTLE_ENDIAN)
+
+# ifndef PEDANTIC
+#  if defined(__GNUC__) && __GNUC__>=2 && !defined(OPENSSL_NO_ASM) && !defined(OPENSSL_NO_INLINE_ASM)
+#   if defined(__s390x__)
+#    define HOST_c2l(c,l)        ({ asm ("lrv    %0,%1"                  \
+                                   :"=d"(l) :"m"(*(const unsigned int *)(c)));\
+                                   (c)+=4; (l);                         })
+#    define HOST_l2c(l,c)        ({ asm ("strv   %1,%0"                  \
+                                   :"=m"(*(unsigned int *)(c)) :"d"(l));\
+                                   (c)+=4; (l);                         })
+#   endif
+#  endif
+#  if defined(__i386) || defined(__i386__) || defined(__x86_64) || defined(__x86_64__)
+#   ifndef B_ENDIAN
+    /* See comment in DATA_ORDER_IS_BIG_ENDIAN section. */
+#    define HOST_c2l(c,l)        ((l)=*((const unsigned int *)(c)), (c)+=4, l)
+#    define HOST_l2c(l,c)        (*((unsigned int *)(c))=(l), (c)+=4, l)
+#   endif
+#  endif
+# endif
+
+# ifndef HOST_c2l
+#  define HOST_c2l(c,l)   (l =(((unsigned long)(*((c)++)))    ),          \
+                         l|=(((unsigned long)(*((c)++)))<< 8),          \
+                         l|=(((unsigned long)(*((c)++)))<<16),          \
+                         l|=(((unsigned long)(*((c)++)))<<24)           )
+# endif
+# ifndef HOST_l2c
+#  define HOST_l2c(l,c)   (*((c)++)=(unsigned char)(((l)    )&0xff),      \
+                         *((c)++)=(unsigned char)(((l)>> 8)&0xff),      \
+                         *((c)++)=(unsigned char)(((l)>>16)&0xff),      \
+                         *((c)++)=(unsigned char)(((l)>>24)&0xff),      \
+                         l)
+# endif
+
+#endif
+
+/*
+ * Time for some action:-)
+ */
+
+int HASH_UPDATE(HASH_CTX *c, const void *data_, size_t len)
+{
+    const unsigned char *data = (const unsigned char *)data_;
+    unsigned char *p;
+    HASH_LONG l;
+    size_t n;
+
+    if (len == 0)
+        return 1;
+
+    l = (c->Nl + (((HASH_LONG) len) << 3)) & 0xffffffffUL;
+    /*
+     * 95-05-24 eay Fixed a bug with the overflow handling, thanks to Wei Dai
+     * <weidai@eskimo.com> for pointing it out.
+     */
+    if (l < c->Nl)              /* overflow */
+        c->Nh++;
+    c->Nh += (HASH_LONG) (len >> 29); /* might cause compiler warning on
+                                       * 16-bit */
+    c->Nl = l;
+
+    n = c->num;
+    if (n != 0) {
+        p = (unsigned char *)c->data;
+
+        if (len >= HASH_CBLOCK || len + n >= HASH_CBLOCK) {
+            memcpy(p + n, data, HASH_CBLOCK - n);
+            HASH_BLOCK_DATA_ORDER(c, p, 1);
+            n = HASH_CBLOCK - n;
+            data += n;
+            len -= n;
+            c->num = 0;
+            memset(p, 0, HASH_CBLOCK); /* keep it zeroed */
+        } else {
+            memcpy(p + n, data, len);
+            c->num += (unsigned int)len;
+            return 1;
+        }
+    }
+
+    n = len / HASH_CBLOCK;
+    if (n > 0) {
+        HASH_BLOCK_DATA_ORDER(c, data, n);
+        n *= HASH_CBLOCK;
+        data += n;
+        len -= n;
+    }
+
+    if (len != 0) {
+        p = (unsigned char *)c->data;
+        c->num = (unsigned int)len;
+        memcpy(p, data, len);
+    }
+    return 1;
+}
+
+void HASH_TRANSFORM(HASH_CTX *c, const unsigned char *data)
+{
+    HASH_BLOCK_DATA_ORDER(c, data, 1);
+}
+
+int HASH_FINAL(unsigned char *md, HASH_CTX *c)
+{
+    unsigned char *p = (unsigned char *)c->data;
+    size_t n = c->num;
+
+    p[n] = 0x80;                /* there is always room for one */
+    n++;
+
+    if (n > (HASH_CBLOCK - 8)) {
+        memset(p + n, 0, HASH_CBLOCK - n);
+        n = 0;
+        HASH_BLOCK_DATA_ORDER(c, p, 1);
+    }
+    memset(p + n, 0, HASH_CBLOCK - 8 - n);
+
+    p += HASH_CBLOCK - 8;
+#if   defined(DATA_ORDER_IS_BIG_ENDIAN)
+    (void)HOST_l2c(c->Nh, p);
+    (void)HOST_l2c(c->Nl, p);
+#elif defined(DATA_ORDER_IS_LITTLE_ENDIAN)
+    (void)HOST_l2c(c->Nl, p);
+    (void)HOST_l2c(c->Nh, p);
+#endif
+    p -= HASH_CBLOCK;
+    HASH_BLOCK_DATA_ORDER(c, p, 1);
+    c->num = 0;
+    memset(p, 0, HASH_CBLOCK);
+
+#ifndef HASH_MAKE_STRING
+# error "HASH_MAKE_STRING must be defined!"
+#else
+    HASH_MAKE_STRING(c, md);
+#endif
+
+    return 1;
+}
+
+#ifndef MD32_REG_T
+# if defined(__alpha) || defined(__sparcv9) || defined(__mips)
+#  define MD32_REG_T long
+/*
+ * This comment was originaly written for MD5, which is why it
+ * discusses A-D. But it basically applies to all 32-bit digests,
+ * which is why it was moved to common header file.
+ *
+ * In case you wonder why A-D are declared as long and not
+ * as MD5_LONG. Doing so results in slight performance
+ * boost on LP64 architectures. The catch is we don't
+ * really care if 32 MSBs of a 64-bit register get polluted
+ * with eventual overflows as we *save* only 32 LSBs in
+ * *either* case. Now declaring 'em long excuses the compiler
+ * from keeping 32 MSBs zeroed resulting in 13% performance
+ * improvement under SPARC Solaris7/64 and 5% under AlphaLinux.
+ * Well, to be honest it should say that this *prevents*
+ * performance degradation.
+ *                              <appro@fy.chalmers.se>
+ */
+# else
+/*
+ * Above is not absolute and there are LP64 compilers that
+ * generate better code if MD32_REG_T is defined int. The above
+ * pre-processor condition reflects the circumstances under which
+ * the conclusion was made and is subject to further extension.
+ *                              <appro@fy.chalmers.se>
+ */
+#  define MD32_REG_T int
+# endif
+#endif

src/util/metricsbackend.cpp

@@ -0,0 +1,204 @@
+/*
+Minetest
+Copyright (C) 2013-2020 Minetest core developers team
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "metricsbackend.h"
+#include "util/thread.h"
+#if USE_PROMETHEUS
+#include <prometheus/exposer.h>
+#include <prometheus/registry.h>
+#include <prometheus/counter.h>
+#include <prometheus/gauge.h>
+#include "log.h"
+#include "settings.h"
+#endif
+
+/* Plain implementation */
+
+class SimpleMetricCounter : public MetricCounter
+{
+public:
+	SimpleMetricCounter() : MetricCounter(), m_counter(0.0) {}
+
+	virtual ~SimpleMetricCounter() {}
+
+	void increment(double number) override
+	{
+		MutexAutoLock lock(m_mutex);
+		m_counter += number;
+	}
+	double get() const override
+	{
+		MutexAutoLock lock(m_mutex);
+		return m_counter;
+	}
+
+private:
+	mutable std::mutex m_mutex;
+	double m_counter;
+};
+
+class SimpleMetricGauge : public MetricGauge
+{
+public:
+	SimpleMetricGauge() : MetricGauge(), m_gauge(0.0) {}
+
+	virtual ~SimpleMetricGauge() {}
+
+	void increment(double number) override
+	{
+		MutexAutoLock lock(m_mutex);
+		m_gauge += number;
+	}
+	void decrement(double number) override
+	{
+		MutexAutoLock lock(m_mutex);
+		m_gauge -= number;
+	}
+	void set(double number) override
+	{
+		MutexAutoLock lock(m_mutex);
+		m_gauge = number;
+	}
+	double get() const override
+	{
+		MutexAutoLock lock(m_mutex);
+		return m_gauge;
+	}
+
+private:
+	mutable std::mutex m_mutex;
+	double m_gauge;
+};
+
+MetricCounterPtr MetricsBackend::addCounter(
+		const std::string &name, const std::string &help_str, Labels labels)
+{
+	return std::make_shared<SimpleMetricCounter>();
+}
+
+MetricGaugePtr MetricsBackend::addGauge(
+		const std::string &name, const std::string &help_str, Labels labels)
+{
+	return std::make_shared<SimpleMetricGauge>();
+}
+
+/* Prometheus backend */
+
+#if USE_PROMETHEUS
+
+class PrometheusMetricCounter : public MetricCounter
+{
+public:
+	PrometheusMetricCounter() = delete;
+
+	PrometheusMetricCounter(const std::string &name, const std::string &help_str,
+			MetricsBackend::Labels labels,
+			std::shared_ptr<prometheus::Registry> registry) :
+			MetricCounter(),
+			m_family(prometheus::BuildCounter()
+							.Name(name)
+							.Help(help_str)
+							.Register(*registry)),
+			m_counter(m_family.Add(labels))
+	{
+	}
+
+	virtual ~PrometheusMetricCounter() {}
+
+	virtual void increment(double number) { m_counter.Increment(number); }
+	virtual double get() const { return m_counter.Value(); }
+
+private:
+	prometheus::Family<prometheus::Counter> &m_family;
+	prometheus::Counter &m_counter;
+};
+
+class PrometheusMetricGauge : public MetricGauge
+{
+public:
+	PrometheusMetricGauge() = delete;
+
+	PrometheusMetricGauge(const std::string &name, const std::string &help_str,
+			MetricsBackend::Labels labels,
+			std::shared_ptr<prometheus::Registry> registry) :
+			MetricGauge(),
+			m_family(prometheus::BuildGauge()
+							.Name(name)
+							.Help(help_str)
+							.Register(*registry)),
+			m_gauge(m_family.Add(labels))
+	{
+	}
+
+	virtual ~PrometheusMetricGauge() {}
+
+	virtual void increment(double number) { m_gauge.Increment(number); }
+	virtual void decrement(double number) { m_gauge.Decrement(number); }
+	virtual void set(double number) { m_gauge.Set(number); }
+	virtual double get() const { return m_gauge.Value(); }
+
+private:
+	prometheus::Family<prometheus::Gauge> &m_family;
+	prometheus::Gauge &m_gauge;
+};
+
+class PrometheusMetricsBackend : public MetricsBackend
+{
+public:
+	PrometheusMetricsBackend(const std::string &addr) :
+			MetricsBackend(), m_exposer(std::make_unique<prometheus::Exposer>(addr)),
+			m_registry(std::make_shared<prometheus::Registry>())
+	{
+		m_exposer->RegisterCollectable(m_registry);
+	}
+
+	virtual ~PrometheusMetricsBackend() {}
+
+	MetricCounterPtr addCounter(
+			const std::string &name, const std::string &help_str,
+			Labels labels = {}) override;
+	MetricGaugePtr addGauge(
+			const std::string &name, const std::string &help_str,
+			Labels labels = {}) override;
+
+private:
+	std::unique_ptr<prometheus::Exposer> m_exposer;
+	std::shared_ptr<prometheus::Registry> m_registry;
+};
+
+MetricCounterPtr PrometheusMetricsBackend::addCounter(
+		const std::string &name, const std::string &help_str, Labels labels)
+{
+	return std::make_shared<PrometheusMetricCounter>(name, help_str, labels, m_registry);
+}
+
+MetricGaugePtr PrometheusMetricsBackend::addGauge(
+		const std::string &name, const std::string &help_str, Labels labels)
+{
+	return std::make_shared<PrometheusMetricGauge>(name, help_str, labels, m_registry);
+}
+
+MetricsBackend *createPrometheusMetricsBackend()
+{
+	std::string addr;
+	g_settings->getNoEx("prometheus_listener_address", addr);
+	return new PrometheusMetricsBackend(addr);
+}
+
+#endif

src/util/metricsbackend.h

@@ -0,0 +1,72 @@
+/*
+Minetest
+Copyright (C) 2013-2020 Minetest core developers team
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#pragma once
+#include <memory>
+#include <string>
+#include <utility>
+#include "config.h"
+
+class MetricCounter
+{
+public:
+	MetricCounter() = default;
+
+	virtual ~MetricCounter() {}
+
+	virtual void increment(double number = 1.0) = 0;
+	virtual double get() const = 0;
+};
+
+typedef std::shared_ptr<MetricCounter> MetricCounterPtr;
+
+class MetricGauge
+{
+public:
+	MetricGauge() = default;
+	virtual ~MetricGauge() {}
+
+	virtual void increment(double number = 1.0) = 0;
+	virtual void decrement(double number = 1.0) = 0;
+	virtual void set(double number) = 0;
+	virtual double get() const = 0;
+};
+
+typedef std::shared_ptr<MetricGauge> MetricGaugePtr;
+
+class MetricsBackend
+{
+public:
+	MetricsBackend() = default;
+
+	virtual ~MetricsBackend() {}
+
+	typedef std::initializer_list<std::pair<const std::string, std::string>> Labels;
+
+	virtual MetricCounterPtr addCounter(
+			const std::string &name, const std::string &help_str,
+			Labels labels = {});
+	virtual MetricGaugePtr addGauge(
+			const std::string &name, const std::string &help_str,
+			Labels labels = {});
+};
+
+#if USE_PROMETHEUS
+MetricsBackend *createPrometheusMetricsBackend();
+#endif

src/util/numeric.cpp

@@ -0,0 +1,223 @@
+/*
+Minetest
+Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "numeric.h"
+
+#include "log.h"
+#include "constants.h" // BS, MAP_BLOCKSIZE
+#include "noise.h" // PseudoRandom, PcgRandom
+#include "threading/mutex_auto_lock.h"
+#include <cstring>
+#include <cmath>
+
+
+// myrand
+
+PcgRandom g_pcgrand;
+
+u32 myrand()
+{
+	return g_pcgrand.next();
+}
+
+void mysrand(unsigned int seed)
+{
+	g_pcgrand.seed(seed);
+}
+
+void myrand_bytes(void *out, size_t len)
+{
+	g_pcgrand.bytes(out, len);
+}
+
+float myrand_float()
+{
+	u32 uv = g_pcgrand.next();
+	return (float)uv / (float)U32_MAX;
+}
+
+int myrand_range(int min, int max)
+{
+	return g_pcgrand.range(min, max);
+}
+
+float myrand_range(float min, float max)
+{
+	return (max-min) * myrand_float() + min;
+}
+
+
+/*
+	64-bit unaligned version of MurmurHash
+*/
+u64 murmur_hash_64_ua(const void *key, int len, unsigned int seed)
+{
+	const u64 m = 0xc6a4a7935bd1e995ULL;
+	const int r = 47;
+	u64 h = seed ^ (len * m);
+
+	const u8 *data = (const u8 *)key;
+	const u8 *end = data + (len / 8) * 8;
+
+	while (data != end) {
+		u64 k;
+		memcpy(&k, data, sizeof(u64));
+		data += sizeof(u64);
+
+		k *= m;
+		k ^= k >> r;
+		k *= m;
+
+		h ^= k;
+		h *= m;
+	}
+
+	const unsigned char *data2 = (const unsigned char *)data;
+	switch (len & 7) {
+		case 7: h ^= (u64)data2[6] << 48;
+		case 6: h ^= (u64)data2[5] << 40;
+		case 5: h ^= (u64)data2[4] << 32;
+		case 4: h ^= (u64)data2[3] << 24;
+		case 3: h ^= (u64)data2[2] << 16;
+		case 2: h ^= (u64)data2[1] << 8;
+		case 1: h ^= (u64)data2[0];
+				h *= m;
+	}
+
+	h ^= h >> r;
+	h *= m;
+	h ^= h >> r;
+
+	return h;
+}
+
+/*
+	blockpos_b: position of block in block coordinates
+	camera_pos: position of camera in nodes
+	camera_dir: an unit vector pointing to camera direction
+	range: viewing range
+	distance_ptr: return location for distance from the camera
+*/
+bool isBlockInSight(v3s16 blockpos_b, v3f camera_pos, v3f camera_dir,
+		f32 camera_fov, f32 range, f32 *distance_ptr)
+{
+	v3s16 blockpos_nodes = blockpos_b * MAP_BLOCKSIZE;
+
+	// Block center position
+	v3f blockpos(
+			((float)blockpos_nodes.X + MAP_BLOCKSIZE/2) * BS,
+			((float)blockpos_nodes.Y + MAP_BLOCKSIZE/2) * BS,
+			((float)blockpos_nodes.Z + MAP_BLOCKSIZE/2) * BS
+	);
+
+	// Block position relative to camera
+	v3f blockpos_relative = blockpos - camera_pos;
+
+	// Total distance
+	f32 d = MYMAX(0, blockpos_relative.getLength() - BLOCK_MAX_RADIUS);
+
+	if (distance_ptr)
+		*distance_ptr = d;
+
+	// If block is far away, it's not in sight
+	if (d > range)
+		return false;
+
+	// If block is (nearly) touching the camera, don't
+	// bother validating further (that is, render it anyway)
+	if (d == 0)
+		return true;
+
+	// Adjust camera position, for purposes of computing the angle,
+	// such that a block that has any portion visible with the
+	// current camera position will have the center visible at the
+	// adjusted postion
+	f32 adjdist = BLOCK_MAX_RADIUS / cos((M_PI - camera_fov) / 2);
+
+	// Block position relative to adjusted camera
+	v3f blockpos_adj = blockpos - (camera_pos - camera_dir * adjdist);
+
+	// Distance in camera direction (+=front, -=back)
+	f32 dforward = blockpos_adj.dotProduct(camera_dir);
+
+	// Cosine of the angle between the camera direction
+	// and the block direction (camera_dir is an unit vector)
+	f32 cosangle = dforward / blockpos_adj.getLength();
+
+	// If block is not in the field of view, skip it
+	// HOTFIX: use sligthly increased angle (+10%) to fix too agressive
+	// culling. Somebody have to find out whats wrong with the math here.
+	// Previous value: camera_fov / 2
+	if (cosangle < std::cos(camera_fov * 0.55f))
+		return false;
+
+	return true;
+}
+
+inline float adjustDist(float dist, float zoom_fov)
+{
+	// 1.775 ~= 72 * PI / 180 * 1.4, the default FOV on the client.
+	// The heuristic threshold for zooming is half of that.
+	static constexpr const float threshold_fov = 1.775f / 2.0f;
+	if (zoom_fov < 0.001f || zoom_fov > threshold_fov)
+		return dist;
+
+	return dist * std::cbrt((1.0f - std::cos(threshold_fov)) /
+		(1.0f - std::cos(zoom_fov / 2.0f)));
+}
+
+s16 adjustDist(s16 dist, float zoom_fov)
+{
+	return std::round(adjustDist((float)dist, zoom_fov));
+}
+
+void setPitchYawRollRad(core::matrix4 &m, const v3f &rot)
+{
+	f64 a1 = rot.Z, a2 = rot.X, a3 = rot.Y;
+	f64 c1 = cos(a1), s1 = sin(a1);
+	f64 c2 = cos(a2), s2 = sin(a2);
+	f64 c3 = cos(a3), s3 = sin(a3);
+	f32 *M = m.pointer();
+
+	M[0] = s1 * s2 * s3 + c1 * c3;
+	M[1] = s1 * c2;
+	M[2] = s1 * s2 * c3 - c1 * s3;
+
+	M[4] = c1 * s2 * s3 - s1 * c3;
+	M[5] = c1 * c2;
+	M[6] = c1 * s2 * c3 + s1 * s3;
+
+	M[8] = c2 * s3;
+	M[9] = -s2;
+	M[10] = c2 * c3;
+}
+
+v3f getPitchYawRollRad(const core::matrix4 &m)
+{
+	const f32 *M = m.pointer();
+
+	f64 a1 = atan2(M[1], M[5]);
+	f32 c2 = std::sqrt((f64)M[10]*M[10] + (f64)M[8]*M[8]);
+	f32 a2 = atan2f(-M[9], c2);
+	f64 c1 = cos(a1);
+	f64 s1 = sin(a1);
+	f32 a3 = atan2f(s1*M[6] - c1*M[2], c1*M[0] - s1*M[4]);
+
+	return v3f(a2, a3, a1);
+}

src/util/numeric.h

@@ -0,0 +1,471 @@
+/*
+Minetest
+Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#pragma once
+
+#include "basic_macros.h"
+#include "constants.h"
+#include "irrlichttypes.h"
+#include "irr_v2d.h"
+#include "irr_v3d.h"
+#include "irr_aabb3d.h"
+#include "SColor.h"
+#include <matrix4.h>
+
+#define rangelim(d, min, max) ((d) < (min) ? (min) : ((d) > (max) ? (max) : (d)))
+#define myfloor(x) ((x) < 0.0 ? (int)(x) - 1 : (int)(x))
+// The naive swap performs better than the xor version
+#define SWAP(t, x, y) do { \
+	t temp = x; \
+	x = y; \
+	y = temp; \
+} while (0)
+
+// Maximum radius of a block.  The magic number is
+// sqrt(3.0) / 2.0 in literal form.
+static constexpr const f32 BLOCK_MAX_RADIUS = 0.866025403784f * MAP_BLOCKSIZE * BS;
+
+inline s16 getContainerPos(s16 p, s16 d)
+{
+	return (p >= 0 ? p : p - d + 1) / d;
+}
+
+inline v2s16 getContainerPos(v2s16 p, s16 d)
+{
+	return v2s16(
+		getContainerPos(p.X, d),
+		getContainerPos(p.Y, d)
+	);
+}
+
+inline v3s16 getContainerPos(v3s16 p, s16 d)
+{
+	return v3s16(
+		getContainerPos(p.X, d),
+		getContainerPos(p.Y, d),
+		getContainerPos(p.Z, d)
+	);
+}
+
+inline v2s16 getContainerPos(v2s16 p, v2s16 d)
+{
+	return v2s16(
+		getContainerPos(p.X, d.X),
+		getContainerPos(p.Y, d.Y)
+	);
+}
+
+inline v3s16 getContainerPos(v3s16 p, v3s16 d)
+{
+	return v3s16(
+		getContainerPos(p.X, d.X),
+		getContainerPos(p.Y, d.Y),
+		getContainerPos(p.Z, d.Z)
+	);
+}
+
+inline void getContainerPosWithOffset(s16 p, s16 d, s16 &container, s16 &offset)
+{
+	container = (p >= 0 ? p : p - d + 1) / d;
+	offset = p & (d - 1);
+}
+
+inline void getContainerPosWithOffset(const v2s16 &p, s16 d, v2s16 &container, v2s16 &offset)
+{
+	getContainerPosWithOffset(p.X, d, container.X, offset.X);
+	getContainerPosWithOffset(p.Y, d, container.Y, offset.Y);
+}
+
+inline void getContainerPosWithOffset(const v3s16 &p, s16 d, v3s16 &container, v3s16 &offset)
+{
+	getContainerPosWithOffset(p.X, d, container.X, offset.X);
+	getContainerPosWithOffset(p.Y, d, container.Y, offset.Y);
+	getContainerPosWithOffset(p.Z, d, container.Z, offset.Z);
+}
+
+
+inline bool isInArea(v3s16 p, s16 d)
+{
+	return (
+		p.X >= 0 && p.X < d &&
+		p.Y >= 0 && p.Y < d &&
+		p.Z >= 0 && p.Z < d
+	);
+}
+
+inline bool isInArea(v2s16 p, s16 d)
+{
+	return (
+		p.X >= 0 && p.X < d &&
+		p.Y >= 0 && p.Y < d
+	);
+}
+
+inline bool isInArea(v3s16 p, v3s16 d)
+{
+	return (
+		p.X >= 0 && p.X < d.X &&
+		p.Y >= 0 && p.Y < d.Y &&
+		p.Z >= 0 && p.Z < d.Z
+	);
+}
+
+inline void sortBoxVerticies(v3s16 &p1, v3s16 &p2) {
+	if (p1.X > p2.X)
+		SWAP(s16, p1.X, p2.X);
+	if (p1.Y > p2.Y)
+		SWAP(s16, p1.Y, p2.Y);
+	if (p1.Z > p2.Z)
+		SWAP(s16, p1.Z, p2.Z);
+}
+
+inline v3s16 componentwise_min(const v3s16 &a, const v3s16 &b)
+{
+	return v3s16(MYMIN(a.X, b.X), MYMIN(a.Y, b.Y), MYMIN(a.Z, b.Z));
+}
+
+inline v3s16 componentwise_max(const v3s16 &a, const v3s16 &b)
+{
+	return v3s16(MYMAX(a.X, b.X), MYMAX(a.Y, b.Y), MYMAX(a.Z, b.Z));
+}
+
+
+/** Returns \p f wrapped to the range [-360, 360]
+ *
+ *  See test.cpp for example cases.
+ *
+ *  \note This is also used in cases where degrees wrapped to the range [0, 360]
+ *  is innapropriate (e.g. pitch needs negative values)
+ *
+ *  \internal functionally equivalent -- although precision may vary slightly --
+ *  to fmodf((f), 360.0f) however empirical tests indicate that this approach is
+ *  faster.
+ */
+inline float modulo360f(float f)
+{
+	int sign;
+	int whole;
+	float fraction;
+
+	if (f < 0) {
+		f = -f;
+		sign = -1;
+	} else {
+		sign = 1;
+	}
+
+	whole = f;
+
+	fraction = f - whole;
+	whole %= 360;
+
+	return sign * (whole + fraction);
+}
+
+
+/** Returns \p f wrapped to the range [0, 360]
+  */
+inline float wrapDegrees_0_360(float f)
+{
+	float value = modulo360f(f);
+	return value < 0 ? value + 360 : value;
+}
+
+
+/** Returns \p v3f wrapped to the range [0, 360]
+  */
+inline v3f wrapDegrees_0_360_v3f(v3f v)
+{
+	v3f value_v3f;
+	value_v3f.X = modulo360f(v.X);
+	value_v3f.Y = modulo360f(v.Y);
+	value_v3f.Z = modulo360f(v.Z);
+
+	// Now that values are wrapped, use to get values for certain ranges
+	value_v3f.X = value_v3f.X < 0 ? value_v3f.X + 360 : value_v3f.X;
+	value_v3f.Y = value_v3f.Y < 0 ? value_v3f.Y + 360 : value_v3f.Y;
+	value_v3f.Z = value_v3f.Z < 0 ? value_v3f.Z + 360 : value_v3f.Z;
+	return value_v3f;
+}
+
+
+/** Returns \p f wrapped to the range [-180, 180]
+  */
+inline float wrapDegrees_180(float f)
+{
+	float value = modulo360f(f + 180);
+	if (value < 0)
+		value += 360;
+	return value - 180;
+}
+
+/*
+	Pseudo-random (VC++ rand() sucks)
+*/
+#define MYRAND_RANGE 0xffffffff
+u32 myrand();
+void mysrand(unsigned int seed);
+void myrand_bytes(void *out, size_t len);
+int myrand_range(int min, int max);
+float myrand_range(float min, float max);
+float myrand_float();
+
+/*
+	Miscellaneous functions
+*/
+
+inline u32 get_bits(u32 x, u32 pos, u32 len)
+{
+	u32 mask = (1 << len) - 1;
+	return (x >> pos) & mask;
+}
+
+inline void set_bits(u32 *x, u32 pos, u32 len, u32 val)
+{
+	u32 mask = (1 << len) - 1;
+	*x &= ~(mask << pos);
+	*x |= (val & mask) << pos;
+}
+
+inline u32 calc_parity(u32 v)
+{
+	v ^= v >> 16;
+	v ^= v >> 8;
+	v ^= v >> 4;
+	v &= 0xf;
+	return (0x6996 >> v) & 1;
+}
+
+u64 murmur_hash_64_ua(const void *key, int len, unsigned int seed);
+
+bool isBlockInSight(v3s16 blockpos_b, v3f camera_pos, v3f camera_dir,
+		f32 camera_fov, f32 range, f32 *distance_ptr=NULL);
+
+s16 adjustDist(s16 dist, float zoom_fov);
+
+/*
+	Returns nearest 32-bit integer for given floating point number.
+	<cmath> and <math.h> in VC++ don't provide round().
+*/
+inline s32 myround(f32 f)
+{
+	return (s32)(f < 0.f ? (f - 0.5f) : (f + 0.5f));
+}
+
+inline constexpr f32 sqr(f32 f)
+{
+	return f * f;
+}
+
+/*
+	Returns integer position of node in given floating point position
+*/
+inline v3s16 floatToInt(v3f p, f32 d)
+{
+	return v3s16(
+		(p.X + (p.X > 0 ? d / 2 : -d / 2)) / d,
+		(p.Y + (p.Y > 0 ? d / 2 : -d / 2)) / d,
+		(p.Z + (p.Z > 0 ? d / 2 : -d / 2)) / d);
+}
+
+/*
+	Returns integer position of node in given double precision position
+ */
+inline v3s16 doubleToInt(v3d p, double d)
+{
+	return v3s16(
+		(p.X + (p.X > 0 ? d / 2 : -d / 2)) / d,
+		(p.Y + (p.Y > 0 ? d / 2 : -d / 2)) / d,
+		(p.Z + (p.Z > 0 ? d / 2 : -d / 2)) / d);
+}
+
+/*
+	Returns floating point position of node in given integer position
+*/
+inline v3f intToFloat(v3s16 p, f32 d)
+{
+	return v3f(
+		(f32)p.X * d,
+		(f32)p.Y * d,
+		(f32)p.Z * d
+	);
+}
+
+// Random helper. Usually d=BS
+inline aabb3f getNodeBox(v3s16 p, float d)
+{
+	return aabb3f(
+		(float)p.X * d - 0.5f * d,
+		(float)p.Y * d - 0.5f * d,
+		(float)p.Z * d - 0.5f * d,
+		(float)p.X * d + 0.5f * d,
+		(float)p.Y * d + 0.5f * d,
+		(float)p.Z * d + 0.5f * d
+	);
+}
+
+
+class IntervalLimiter
+{
+public:
+	IntervalLimiter() = default;
+
+	/*
+		dtime: time from last call to this method
+		wanted_interval: interval wanted
+		return value:
+			true: action should be skipped
+			false: action should be done
+	*/
+	bool step(float dtime, float wanted_interval)
+	{
+		m_accumulator += dtime;
+		if (m_accumulator < wanted_interval)
+			return false;
+		m_accumulator -= wanted_interval;
+		return true;
+	}
+
+private:
+	float m_accumulator = 0.0f;
+};
+
+
+/*
+	Splits a list into "pages". For example, the list [1,2,3,4,5] split
+	into two pages would be [1,2,3],[4,5]. This function computes the
+	minimum and maximum indices of a single page.
+
+	length: Length of the list that should be split
+	page: Page number, 1 <= page <= pagecount
+	pagecount: The number of pages, >= 1
+	minindex: Receives the minimum index (inclusive).
+	maxindex: Receives the maximum index (exclusive).
+
+	Ensures 0 <= minindex <= maxindex <= length.
+*/
+inline void paging(u32 length, u32 page, u32 pagecount, u32 &minindex, u32 &maxindex)
+{
+	if (length < 1 || pagecount < 1 || page < 1 || page > pagecount) {
+		// Special cases or invalid parameters
+		minindex = maxindex = 0;
+	} else if(pagecount <= length) {
+		// Less pages than entries in the list:
+		// Each page contains at least one entry
+		minindex = (length * (page-1) + (pagecount-1)) / pagecount;
+		maxindex = (length * page + (pagecount-1)) / pagecount;
+	} else {
+		// More pages than entries in the list:
+		// Make sure the empty pages are at the end
+		if (page < length) {
+			minindex = page-1;
+			maxindex = page;
+		} else {
+			minindex = 0;
+			maxindex = 0;
+		}
+	}
+}
+
+inline float cycle_shift(float value, float by = 0, float max = 1)
+{
+    if (value + by < 0)   return value + by + max;
+    if (value + by > max) return value + by - max;
+    return value + by;
+}
+
+inline bool is_power_of_two(u32 n)
+{
+	return n != 0 && (n & (n - 1)) == 0;
+}
+
+// Compute next-higher power of 2 efficiently, e.g. for power-of-2 texture sizes.
+// Public Domain: https://graphics.stanford.edu/~seander/bithacks.html#RoundUpPowerOf2
+inline u32 npot2(u32 orig) {
+	orig--;
+	orig |= orig >> 1;
+	orig |= orig >> 2;
+	orig |= orig >> 4;
+	orig |= orig >> 8;
+	orig |= orig >> 16;
+	return orig + 1;
+}
+
+// Gradual steps towards the target value in a wrapped (circular) system
+// using the shorter of both ways
+template<typename T>
+inline void wrappedApproachShortest(T &current, const T target, const T stepsize,
+	const T maximum)
+{
+	T delta = target - current;
+	if (delta < 0)
+		delta += maximum;
+
+	if (delta > stepsize && maximum - delta > stepsize) {
+		current += (delta < maximum / 2) ? stepsize : -stepsize;
+		if (current >= maximum)
+			current -= maximum;
+	} else {
+		current = target;
+	}
+}
+
+void setPitchYawRollRad(core::matrix4 &m, const v3f &rot);
+
+inline void setPitchYawRoll(core::matrix4 &m, const v3f &rot)
+{
+	setPitchYawRollRad(m, rot * core::DEGTORAD64);
+}
+
+v3f getPitchYawRollRad(const core::matrix4 &m);
+
+inline v3f getPitchYawRoll(const core::matrix4 &m)
+{
+	return getPitchYawRollRad(m) * core::RADTODEG64;
+}
+
+// Muliply the RGB value of a color linearly, and clamp to black/white
+inline irr::video::SColor multiplyColorValue(const irr::video::SColor &color, float mod)
+{
+	return irr::video::SColor(color.getAlpha(),
+			core::clamp<u32>(color.getRed() * mod, 0, 255),
+			core::clamp<u32>(color.getGreen() * mod, 0, 255),
+			core::clamp<u32>(color.getBlue() * mod, 0, 255));
+}
+
+template <typename T> inline T numericAbsolute(T v) { return v < 0 ? T(-v) : v;                }
+template <typename T> inline T numericSign(T v)     { return T(v < 0 ? -1 : (v == 0 ? 0 : 1)); }
+
+inline v3f vecAbsolute(v3f v)
+{
+	return v3f(
+		numericAbsolute(v.X),
+		numericAbsolute(v.Y),
+		numericAbsolute(v.Z)
+	);
+}
+
+inline v3f vecSign(v3f v)
+{
+	return v3f(
+		numericSign(v.X),
+		numericSign(v.Y),
+		numericSign(v.Z)
+	);
+}

src/util/png.cpp

@@ -0,0 +1,68 @@
+/*
+Minetest
+Copyright (C) 2021 hecks
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "png.h"
+#include <string>
+#include <sstream>
+#include <zlib.h>
+#include <cassert>
+#include "util/serialize.h"
+#include "serialization.h"
+#include "irrlichttypes.h"
+
+static void writeChunk(std::ostringstream &target, const std::string &chunk_str)
+{
+	assert(chunk_str.size() >= 4);
+	assert(chunk_str.size() - 4 < U32_MAX);
+	writeU32(target, chunk_str.size() - 4); // Write length minus the identifier
+	target << chunk_str;
+	writeU32(target, crc32(0,(const u8*)chunk_str.data(), chunk_str.size()));
+}
+
+std::string encodePNG(const u8 *data, u32 width, u32 height, s32 compression)
+{
+	std::ostringstream file(std::ios::binary);
+	file << "\x89PNG\r\n\x1a\n";
+
+	{
+		std::ostringstream IHDR(std::ios::binary);
+		IHDR << "IHDR";
+		writeU32(IHDR, width);
+		writeU32(IHDR, height);
+		// 8 bpp, color type 6 (RGBA)
+		IHDR.write("\x08\x06\x00\x00\x00", 5);
+		writeChunk(file, IHDR.str());
+	}
+
+	{
+		std::ostringstream IDAT(std::ios::binary);
+		IDAT << "IDAT";
+		std::ostringstream scanlines(std::ios::binary);
+		for(u32 i = 0; i < height; i++) {
+			scanlines.write("\x00", 1); // Null predictor
+			scanlines.write((const char*) data + width * 4 * i, width * 4);
+		}
+		compressZlib(scanlines.str(), IDAT, compression);
+		writeChunk(file, IDAT.str());
+	}
+
+	file.write("\x00\x00\x00\x00IEND\xae\x42\x60\x82", 12);
+
+	return file.str();
+}

src/util/png.h

@@ -0,0 +1,27 @@
+/*
+Minetest
+Copyright (C) 2021 hecks
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#pragma once
+
+#include <string>
+#include "irrlichttypes.h"
+
+/*	Simple PNG encoder. Encodes an RGBA image with no predictors.
+	Returns a binary string. */
+std::string encodePNG(const u8 *data, u32 width, u32 height, s32 compression);

src/util/pointedthing.cpp

@@ -0,0 +1,134 @@
+/*
+Minetest
+Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "pointedthing.h"
+
+#include "serialize.h"
+#include "exceptions.h"
+#include <sstream>
+
+PointedThing::PointedThing(const v3s16 &under, const v3s16 &above,
+	const v3s16 &real_under, const v3f &point, const v3s16 &normal,
+	u16 box_id, f32 distSq):
+	type(POINTEDTHING_NODE),
+	node_undersurface(under),
+	node_abovesurface(above),
+	node_real_undersurface(real_under),
+	intersection_point(point),
+	intersection_normal(normal),
+	box_id(box_id),
+	distanceSq(distSq)
+{}
+
+PointedThing::PointedThing(s16 id, const v3f &point, const v3s16 &normal,
+	f32 distSq) :
+	type(POINTEDTHING_OBJECT),
+	object_id(id),
+	intersection_point(point),
+	intersection_normal(normal),
+	distanceSq(distSq)
+{}
+
+std::string PointedThing::dump() const
+{
+	std::ostringstream os(std::ios::binary);
+	switch (type) {
+	case POINTEDTHING_NOTHING:
+		os << "[nothing]";
+		break;
+	case POINTEDTHING_NODE:
+	{
+		const v3s16 &u = node_undersurface;
+		const v3s16 &a = node_abovesurface;
+		os << "[node under=" << u.X << "," << u.Y << "," << u.Z << " above="
+			<< a.X << "," << a.Y << "," << a.Z << "]";
+	}
+		break;
+	case POINTEDTHING_OBJECT:
+		os << "[object " << object_id << "]";
+		break;
+	default:
+		os << "[unknown PointedThing]";
+	}
+	return os.str();
+}
+
+void PointedThing::serialize(std::ostream &os) const
+{
+	writeU8(os, 0); // version
+	writeU8(os, (u8)type);
+	switch (type) {
+	case POINTEDTHING_NOTHING:
+		break;
+	case POINTEDTHING_NODE:
+		writeV3S16(os, node_undersurface);
+		writeV3S16(os, node_abovesurface);
+		break;
+	case POINTEDTHING_OBJECT:
+		writeS16(os, object_id);
+		break;
+	}
+}
+
+void PointedThing::deSerialize(std::istream &is)
+{
+	int version = readU8(is);
+	if (version != 0) throw SerializationError(
+			"unsupported PointedThing version");
+	type = (PointedThingType) readU8(is);
+	switch (type) {
+	case POINTEDTHING_NOTHING:
+		break;
+	case POINTEDTHING_NODE:
+		node_undersurface = readV3S16(is);
+		node_abovesurface = readV3S16(is);
+		break;
+	case POINTEDTHING_OBJECT:
+		object_id = readS16(is);
+		break;
+	default:
+		throw SerializationError("unsupported PointedThingType");
+	}
+}
+
+bool PointedThing::operator==(const PointedThing &pt2) const
+{
+	if (type != pt2.type)
+	{
+		return false;
+	}
+	if (type == POINTEDTHING_NODE)
+	{
+		if ((node_undersurface != pt2.node_undersurface)
+				|| (node_abovesurface != pt2.node_abovesurface)
+				|| (node_real_undersurface != pt2.node_real_undersurface))
+			return false;
+	}
+	else if (type == POINTEDTHING_OBJECT)
+	{
+		if (object_id != pt2.object_id)
+			return false;
+	}
+	return true;
+}
+
+bool PointedThing::operator!=(const PointedThing &pt2) const
+{
+	return !(*this == pt2);
+}

src/util/pointedthing.h

@@ -0,0 +1,105 @@
+/*
+Minetest
+Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#pragma once
+
+#include "irrlichttypes.h"
+#include "irr_v3d.h"
+#include <iostream>
+#include <string>
+
+enum PointedThingType
+{
+	POINTEDTHING_NOTHING,
+	POINTEDTHING_NODE,
+	POINTEDTHING_OBJECT
+};
+
+//! An active object or node which is selected by a ray on the map.
+struct PointedThing
+{
+	//! The type of the pointed object.
+	PointedThingType type = POINTEDTHING_NOTHING;
+	/*!
+	 * Only valid if type is POINTEDTHING_NODE.
+	 * The coordinates of the node which owns the
+	 * nodebox that the ray hits first.
+	 * This may differ from node_real_undersurface if
+	 * a nodebox exceeds the limits of its node.
+	 */
+	v3s16 node_undersurface;
+	/*!
+	 * Only valid if type is POINTEDTHING_NODE.
+	 * The coordinates of the last node the ray intersects
+	 * before node_undersurface. Same as node_undersurface
+	 * if the ray starts in a nodebox.
+	 */
+	v3s16 node_abovesurface;
+	/*!
+	 * Only valid if type is POINTEDTHING_NODE.
+	 * The coordinates of the node which contains the
+	 * point of the collision and the nodebox of the node.
+	 */
+	v3s16 node_real_undersurface;
+	/*!
+	 * Only valid if type is POINTEDTHING_OBJECT.
+	 * The ID of the object the ray hit.
+	 */
+	s16 object_id = -1;
+	/*!
+	 * Only valid if type isn't POINTEDTHING_NONE.
+	 * First intersection point of the ray and the nodebox in irrlicht
+	 * coordinates.
+	 */
+	v3f intersection_point;
+	/*!
+	 * Only valid if type isn't POINTEDTHING_NONE.
+	 * Normal vector of the intersection.
+	 * This is perpendicular to the face the ray hits,
+	 * points outside of the box and it's length is 1.
+	 */
+	v3s16 intersection_normal;
+	/*!
+	 * Only valid if type isn't POINTEDTHING_NONE.
+	 * Indicates which selection box is selected, if there are more of them.
+	 */
+	u16 box_id = 0;
+	/*!
+	 * Square of the distance between the pointing
+	 * ray's start point and the intersection point in irrlicht coordinates.
+	 */
+	f32 distanceSq = 0;
+
+	//! Constructor for POINTEDTHING_NOTHING
+	PointedThing() = default;
+	//! Constructor for POINTEDTHING_NODE
+	PointedThing(const v3s16 &under, const v3s16 &above,
+		const v3s16 &real_under, const v3f &point, const v3s16 &normal,
+		u16 box_id, f32 distSq);
+	//! Constructor for POINTEDTHING_OBJECT
+	PointedThing(s16 id, const v3f &point, const v3s16 &normal, f32 distSq);
+	std::string dump() const;
+	void serialize(std::ostream &os) const;
+	void deSerialize(std::istream &is);
+	/*!
+	 * This function ignores the intersection point and normal.
+	 */
+	bool operator==(const PointedThing &pt2) const;
+	bool operator!=(const PointedThing &pt2) const;
+};

src/util/pointer.h

@@ -0,0 +1,273 @@
+/*
+Minetest
+Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#pragma once
+
+#include "irrlichttypes.h"
+#include "debug.h" // For assert()
+#include <cstring>
+#include <memory> // std::shared_ptr
+
+
+template<typename T> class ConstSharedPtr {
+public:
+	ConstSharedPtr(T *ptr) : ptr(ptr) {}
+	ConstSharedPtr(const std::shared_ptr<T> &ptr) : ptr(ptr) {}
+
+	const T* get() const noexcept { return ptr.get(); }
+	const T& operator*() const noexcept { return *ptr.get(); }
+	const T* operator->() const noexcept { return ptr.get(); }
+
+private:
+	std::shared_ptr<T> ptr;
+};
+
+template <typename T>
+class Buffer
+{
+public:
+	Buffer()
+	{
+		m_size = 0;
+		data = nullptr;
+	}
+	Buffer(unsigned int size)
+	{
+		m_size = size;
+		if(size != 0)
+			data = new T[size];
+		else
+			data = nullptr;
+	}
+
+	// Disable class copy
+	Buffer(const Buffer &) = delete;
+	Buffer &operator=(const Buffer &) = delete;
+
+	Buffer(Buffer &&buffer)
+	{
+		m_size = buffer.m_size;
+		if(m_size != 0)
+		{
+			data = buffer.data;
+			buffer.data = nullptr;
+			buffer.m_size = 0;
+		}
+		else
+			data = nullptr;
+	}
+	// Copies whole buffer
+	Buffer(const T *t, unsigned int size)
+	{
+		m_size = size;
+		if(size != 0)
+		{
+			data = new T[size];
+			memcpy(data, t, size);
+		}
+		else
+			data = nullptr;
+	}
+
+	~Buffer()
+	{
+		drop();
+	}
+
+	Buffer& operator=(Buffer &&buffer)
+	{
+		if(this == &buffer)
+			return *this;
+		drop();
+		m_size = buffer.m_size;
+		if(m_size != 0)
+		{
+			data = buffer.data;
+			buffer.data = nullptr;
+			buffer.m_size = 0;
+		}
+		else
+			data = nullptr;
+		return *this;
+	}
+
+	void copyTo(Buffer &buffer) const
+	{
+		buffer.drop();
+		buffer.m_size = m_size;
+		if (m_size != 0) {
+			buffer.data = new T[m_size];
+			memcpy(buffer.data, data, m_size);
+		} else {
+			buffer.data = nullptr;
+		}
+	}
+
+	T & operator[](unsigned int i) const
+	{
+		return data[i];
+	}
+	T * operator*() const
+	{
+		return data;
+	}
+
+	unsigned int getSize() const
+	{
+		return m_size;
+	}
+
+private:
+	void drop()
+	{
+		delete[] data;
+	}
+	T *data;
+	unsigned int m_size;
+};
+
+/************************************************
+ *           !!!  W A R N I N G  !!!            *
+ *                                              *
+ * This smart pointer class is NOT thread safe. *
+ * ONLY use in a single-threaded context!       *
+ *                                              *
+ ************************************************/
+template <typename T>
+class SharedBuffer
+{
+public:
+	SharedBuffer()
+	{
+		m_size = 0;
+		data = NULL;
+		refcount = new unsigned int;
+		(*refcount) = 1;
+	}
+	SharedBuffer(unsigned int size)
+	{
+		m_size = size;
+		if(m_size != 0)
+			data = new T[m_size];
+		else
+			data = nullptr;
+		refcount = new unsigned int;
+		memset(data,0,sizeof(T)*m_size);
+		(*refcount) = 1;
+	}
+	SharedBuffer(const SharedBuffer &buffer)
+	{
+		m_size = buffer.m_size;
+		data = buffer.data;
+		refcount = buffer.refcount;
+		(*refcount)++;
+	}
+	SharedBuffer & operator=(const SharedBuffer & buffer)
+	{
+		if(this == &buffer)
+			return *this;
+		drop();
+		m_size = buffer.m_size;
+		data = buffer.data;
+		refcount = buffer.refcount;
+		(*refcount)++;
+		return *this;
+	}
+	/*
+		Copies whole buffer
+	*/
+	SharedBuffer(const T *t, unsigned int size)
+	{
+		m_size = size;
+		if(m_size != 0)
+		{
+			data = new T[m_size];
+			memcpy(data, t, m_size);
+		}
+		else
+			data = nullptr;
+		refcount = new unsigned int;
+		(*refcount) = 1;
+	}
+	/*
+		Copies whole buffer
+	*/
+	SharedBuffer(const Buffer<T> &buffer)
+	{
+		m_size = buffer.getSize();
+		if (m_size != 0) {
+				data = new T[m_size];
+				memcpy(data, *buffer, buffer.getSize());
+		}
+		else
+			data = nullptr;
+		refcount = new unsigned int;
+		(*refcount) = 1;
+	}
+	~SharedBuffer()
+	{
+		drop();
+	}
+	T & operator[](unsigned int i) const
+	{
+		assert(i < m_size);
+		return data[i];
+	}
+	T * operator*() const
+	{
+		return data;
+	}
+	unsigned int getSize() const
+	{
+		return m_size;
+	}
+	operator Buffer<T>() const
+	{
+		return Buffer<T>(data, m_size);
+	}
+private:
+	void drop()
+	{
+		assert((*refcount) > 0);
+		(*refcount)--;
+		if(*refcount == 0)
+		{
+			delete[] data;
+			delete refcount;
+		}
+	}
+	T *data;
+	unsigned int m_size;
+	unsigned int *refcount;
+};
+
+// This class is not thread-safe!
+class IntrusiveReferenceCounted {
+public:
+	IntrusiveReferenceCounted() = default;
+	virtual ~IntrusiveReferenceCounted() = default;
+	void grab() noexcept { ++m_refcount; }
+	void drop() noexcept { if (--m_refcount == 0) delete this; }
+
+	// Preserve own reference count.
+	IntrusiveReferenceCounted(const IntrusiveReferenceCounted &) {}
+	IntrusiveReferenceCounted &operator=(const IntrusiveReferenceCounted &) { return *this; }
+private:
+	u32 m_refcount = 1;
+};

src/util/quicktune.cpp

@@ -0,0 +1,104 @@
+/*
+Minetest
+Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "quicktune.h"
+#include "threading/mutex_auto_lock.h"
+#include "util/string.h"
+
+std::string QuicktuneValue::getString()
+{
+	switch(type){
+	case QVT_NONE:
+		return "(none)";
+	case QVT_FLOAT:
+		return ftos(value_QVT_FLOAT.current);
+	}
+	return "<invalid type>";
+}
+void QuicktuneValue::relativeAdd(float amount)
+{
+	switch(type){
+	case QVT_NONE:
+		break;
+	case QVT_FLOAT:
+		value_QVT_FLOAT.current += amount * (value_QVT_FLOAT.max - value_QVT_FLOAT.min);
+		if(value_QVT_FLOAT.current > value_QVT_FLOAT.max)
+			value_QVT_FLOAT.current = value_QVT_FLOAT.max;
+		if(value_QVT_FLOAT.current < value_QVT_FLOAT.min)
+			value_QVT_FLOAT.current = value_QVT_FLOAT.min;
+		break;
+	}
+}
+
+static std::map<std::string, QuicktuneValue> g_values;
+static std::vector<std::string> g_names;
+std::mutex *g_mutex = NULL;
+
+static void makeMutex()
+{
+	if(!g_mutex){
+		g_mutex = new std::mutex();
+	}
+}
+
+std::vector<std::string> getQuicktuneNames()
+{
+	return g_names;
+}
+
+QuicktuneValue getQuicktuneValue(const std::string &name)
+{
+	makeMutex();
+	MutexAutoLock lock(*g_mutex);
+	std::map<std::string, QuicktuneValue>::iterator i = g_values.find(name);
+	if(i == g_values.end()){
+		QuicktuneValue val;
+		val.type = QVT_NONE;
+		return val;
+	}
+	return i->second;
+}
+
+void setQuicktuneValue(const std::string &name, const QuicktuneValue &val)
+{
+	makeMutex();
+	MutexAutoLock lock(*g_mutex);
+	g_values[name] = val;
+	g_values[name].modified = true;
+}
+
+void updateQuicktuneValue(const std::string &name, QuicktuneValue &val)
+{
+	makeMutex();
+	MutexAutoLock lock(*g_mutex);
+	std::map<std::string, QuicktuneValue>::iterator i = g_values.find(name);
+	if(i == g_values.end()){
+		g_values[name] = val;
+		g_names.push_back(name);
+		return;
+	}
+	QuicktuneValue &ref = i->second;
+	if(ref.modified)
+		val = ref;
+	else{
+		ref = val;
+		ref.modified = false;
+	}
+}
+

src/util/quicktune.h

@@ -0,0 +1,98 @@
+/*
+Minetest
+Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+/*
+	Used for tuning constants when developing.
+
+	Eg. if you have this constant somewhere that you just can't get right
+	by changing it and recompiling all over again:
+		v3f wield_position = v3f(55, -35, 65);
+
+	Make it look like this:
+		v3f wield_position = v3f(55, -35, 65);
+		QUICKTUNE_AUTONAME(QVT_FLOAT, wield_position.X, 0, 100);
+		QUICKTUNE_AUTONAME(QVT_FLOAT, wield_position.Y, -80, 20);
+		QUICKTUNE_AUTONAME(QVT_FLOAT, wield_position.Z, 0, 100);
+
+	Then you can modify the values at runtime, using the keys
+		keymap_quicktune_prev
+		keymap_quicktune_next
+		keymap_quicktune_dec
+		keymap_quicktune_inc
+
+	Once you have modified the values at runtime and then quit, the game
+	will print out all the modified values at the end:
+		Modified quicktune values:
+		wield_position.X = 60
+		wield_position.Y = -30
+		wield_position.Z = 65
+
+	The QUICKTUNE macros shouldn't generally be left in committed code.
+*/
+
+#pragma once
+
+#include <string>
+#include <map>
+#include <vector>
+
+enum QuicktuneValueType{
+	QVT_NONE,
+	QVT_FLOAT
+};
+struct QuicktuneValue
+{
+	QuicktuneValueType type = QVT_NONE;
+	union{
+		struct{
+			float current;
+			float min;
+			float max;
+		} value_QVT_FLOAT;
+	};
+	bool modified = false;
+
+	QuicktuneValue() = default;
+
+	std::string getString();
+	void relativeAdd(float amount);
+};
+
+std::vector<std::string> getQuicktuneNames();
+QuicktuneValue getQuicktuneValue(const std::string &name);
+void setQuicktuneValue(const std::string &name, const QuicktuneValue &val);
+
+void updateQuicktuneValue(const std::string &name, QuicktuneValue &val);
+
+#ifndef NDEBUG
+	#define QUICKTUNE(type_, var, min_, max_, name){\
+		QuicktuneValue qv;\
+		qv.type = type_;\
+		qv.value_##type_.current = var;\
+		qv.value_##type_.min = min_;\
+		qv.value_##type_.max = max_;\
+		updateQuicktuneValue(name, qv);\
+		var = qv.value_##type_.current;\
+	}
+#else // NDEBUG
+	#define QUICKTUNE(type, var, min_, max_, name){}
+#endif
+
+#define QUICKTUNE_AUTONAME(type_, var, min_, max_)\
+	QUICKTUNE(type_, var, min_, max_, #var)

src/util/quicktune_shortcutter.h

@@ -0,0 +1,84 @@
+/*
+Minetest
+Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#pragma once
+
+#include "quicktune.h"
+
+class QuicktuneShortcutter
+{
+private:
+	std::vector<std::string> m_names;
+	u32 m_selected_i;
+	std::string m_message;
+public:
+	bool hasMessage() const
+	{
+		return !m_message.empty();
+	}
+
+	std::string getMessage()
+	{
+		std::string s = m_message;
+		m_message = "";
+		if (!s.empty())
+			return std::string("[quicktune] ") + s;
+		return "";
+	}
+	std::string getSelectedName()
+	{
+		if(m_selected_i < m_names.size())
+			return m_names[m_selected_i];
+		return "(nothing)";
+	}
+	void next()
+	{
+		m_names = getQuicktuneNames();
+		if(m_selected_i < m_names.size()-1)
+			m_selected_i++;
+		else
+			m_selected_i = 0;
+		m_message = std::string("Selected \"")+getSelectedName()+"\"";
+	}
+	void prev()
+	{
+		m_names = getQuicktuneNames();
+		if(m_selected_i > 0)
+			m_selected_i--;
+		else
+			m_selected_i = m_names.size()-1;
+		m_message = std::string("Selected \"")+getSelectedName()+"\"";
+	}
+	void inc()
+	{
+		QuicktuneValue val = getQuicktuneValue(getSelectedName());
+		val.relativeAdd(0.05);
+		m_message = std::string("\"")+getSelectedName()
+				+"\" = "+val.getString();
+		setQuicktuneValue(getSelectedName(), val);
+	}
+	void dec()
+	{
+		QuicktuneValue val = getQuicktuneValue(getSelectedName());
+		val.relativeAdd(-0.05);
+		m_message = std::string("\"")+getSelectedName()
+				+"\" = "+val.getString();
+		setQuicktuneValue(getSelectedName(), val);
+	}
+};

src/util/serialize.cpp

@@ -0,0 +1,294 @@
+/*
+Minetest
+Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "serialize.h"
+#include "porting.h"
+#include "util/string.h"
+#include "util/hex.h"
+#include "exceptions.h"
+#include "irrlichttypes.h"
+
+#include <iostream>
+#include <cassert>
+
+FloatType g_serialize_f32_type = FLOATTYPE_UNKNOWN;
+
+
+////
+//// String
+////
+
+std::string serializeString16(const std::string &plain)
+{
+	std::string s;
+	char buf[2];
+
+	if (plain.size() > STRING_MAX_LEN)
+		throw SerializationError("String too long for serializeString16");
+	s.reserve(2 + plain.size());
+
+	writeU16((u8 *)&buf[0], plain.size());
+	s.append(buf, 2);
+
+	s.append(plain);
+	return s;
+}
+
+std::string deSerializeString16(std::istream &is)
+{
+	std::string s;
+	char buf[2];
+
+	is.read(buf, 2);
+	if (is.gcount() != 2)
+		throw SerializationError("deSerializeString16: size not read");
+
+	u16 s_size = readU16((u8 *)buf);
+	if (s_size == 0)
+		return s;
+
+	s.resize(s_size);
+	is.read(&s[0], s_size);
+	if (is.gcount() != s_size)
+		throw SerializationError("deSerializeString16: couldn't read all chars");
+
+	return s;
+}
+
+
+////
+//// Long String
+////
+
+std::string serializeString32(const std::string &plain)
+{
+	std::string s;
+	char buf[4];
+
+	if (plain.size() > LONG_STRING_MAX_LEN)
+		throw SerializationError("String too long for serializeLongString");
+	s.reserve(4 + plain.size());
+
+	writeU32((u8*)&buf[0], plain.size());
+	s.append(buf, 4);
+	s.append(plain);
+	return s;
+}
+
+std::string deSerializeString32(std::istream &is)
+{
+	std::string s;
+	char buf[4];
+
+	is.read(buf, 4);
+	if (is.gcount() != 4)
+		throw SerializationError("deSerializeLongString: size not read");
+
+	u32 s_size = readU32((u8 *)buf);
+	if (s_size == 0)
+		return s;
+
+	// We don't really want a remote attacker to force us to allocate 4GB...
+	if (s_size > LONG_STRING_MAX_LEN) {
+		throw SerializationError("deSerializeLongString: "
+			"string too long: " + itos(s_size) + " bytes");
+	}
+
+	s.resize(s_size);
+	is.read(&s[0], s_size);
+	if ((u32)is.gcount() != s_size)
+		throw SerializationError("deSerializeLongString: couldn't read all chars");
+
+	return s;
+}
+
+////
+//// JSON-like strings
+////
+
+std::string serializeJsonString(const std::string &plain)
+{
+	std::string tmp;
+
+	tmp.reserve(plain.size() + 2);
+	tmp.push_back('"');
+
+	for (char c : plain) {
+		switch (c) {
+			case '"':
+				tmp.append("\\\"");
+				break;
+			case '\\':
+				tmp.append("\\\\");
+				break;
+			case '\b':
+				tmp.append("\\b");
+				break;
+			case '\f':
+				tmp.append("\\f");
+				break;
+			case '\n':
+				tmp.append("\\n");
+				break;
+			case '\r':
+				tmp.append("\\r");
+				break;
+			case '\t':
+				tmp.append("\\t");
+				break;
+			default: {
+				if (c >= 32 && c <= 126) {
+					tmp.push_back(c);
+				} else {
+					// We pretend that Unicode codepoints map to bytes (they don't)
+					u8 cnum = static_cast<u8>(c);
+					tmp.append("\\u00");
+					tmp.push_back(hex_chars[cnum >> 4]);
+					tmp.push_back(hex_chars[cnum & 0xf]);
+				}
+				break;
+			}
+		}
+	}
+
+	tmp.push_back('"');
+	return tmp;
+}
+
+static void deSerializeJsonString(std::string &s)
+{
+	assert(s.size() >= 2);
+	assert(s.front() == '"' && s.back() == '"');
+
+	size_t w = 0; // write index
+	size_t i = 1; // read index
+	const size_t len = s.size() - 1; // string length with trailing quote removed
+
+	while (i < len) {
+		char c = s[i++];
+		assert(c != '"');
+
+		if (c != '\\') {
+			s[w++] = c;
+			continue;
+		}
+
+		if (i >= len)
+			throw SerializationError("JSON string ended prematurely");
+		char c2 = s[i++];
+		switch (c2) {
+			case 'b':
+				s[w++] = '\b';
+				break;
+			case 'f':
+				s[w++] = '\f';
+				break;
+			case 'n':
+				s[w++] = '\n';
+				break;
+			case 'r':
+				s[w++] = '\r';
+				break;
+			case 't':
+				s[w++] = '\t';
+				break;
+			case 'u': {
+				if (i + 3 >= len)
+					throw SerializationError("JSON string ended prematurely");
+				unsigned char v[4] = {};
+				for (int j = 0; j < 4; j++)
+					hex_digit_decode(s[i+j], v[j]);
+				i += 4;
+				u32 hexnumber = (v[0] << 12) | (v[1] << 8) | (v[2] << 4) | v[3];
+				// Note that this does not work for anything other than ASCII
+				// but these functions do not actually interact with real JSON input.
+				s[w++] = (int) hexnumber;
+				break;
+			}
+			default:
+				s[w++] = c2;
+				break;
+		}
+	}
+
+	assert(w <= i && i <= len);
+	// Truncate string to current write index
+	s.resize(w);
+}
+
+std::string deSerializeJsonString(std::istream &is)
+{
+	std::string tmp;
+	char c;
+	bool was_backslash = false;
+
+	// Parse initial doublequote
+	c = is.get();
+	if (c != '"')
+		throw SerializationError("JSON string must start with doublequote");
+	tmp.push_back(c);
+
+	// Grab the entire json string
+	for (;;) {
+		c = is.get();
+		if (is.eof())
+			throw SerializationError("JSON string ended prematurely");
+
+		tmp.push_back(c);
+		if (was_backslash)
+			was_backslash = false;
+		else if (c == '\\')
+			was_backslash = true;
+		else if (c == '"')
+			break; // found end of string
+	}
+
+	deSerializeJsonString(tmp);
+	return tmp;
+}
+
+std::string serializeJsonStringIfNeeded(const std::string &s)
+{
+	for (size_t i = 0; i < s.size(); ++i) {
+		if (s[i] <= 0x1f || s[i] >= 0x7f || s[i] == ' ' || s[i] == '\"')
+			return serializeJsonString(s);
+	}
+	return s;
+}
+
+std::string deSerializeJsonStringIfNeeded(std::istream &is)
+{
+	// Check for initial quote
+	char c = is.peek();
+	if (is.eof())
+		return "";
+
+	if (c == '"') {
+		// json string: defer to the right implementation
+		return deSerializeJsonString(is);
+	}
+
+	// not a json string:
+	std::string tmp;
+	std::getline(is, tmp, ' ');
+	if (!is.eof())
+		is.unget(); // we hit a space, put it back
+	return tmp;
+}
+

src/util/serialize.h

@@ -0,0 +1,475 @@
+/*
+Minetest
+Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#pragma once
+
+#include "irrlichttypes_bloated.h"
+#include "exceptions.h" // for SerializationError
+#include "debug.h" // for assert
+#include "ieee_float.h"
+
+#include "config.h"
+#if HAVE_ENDIAN_H
+	#ifdef _WIN32
+		#define __BYTE_ORDER 0
+		#define __LITTLE_ENDIAN 0
+		#define __BIG_ENDIAN 1
+	#elif defined(__MACH__) && defined(__APPLE__)
+		#include <machine/endian.h>
+	#elif defined(__FreeBSD__) || defined(__DragonFly__)
+		#include <sys/endian.h>
+	#else
+		#include <endian.h>
+	#endif
+#endif
+#include <cstring> // for memcpy
+#include <iostream>
+#include <string>
+#include <vector>
+
+#define FIXEDPOINT_FACTOR 1000.0f
+
+// 0x7FFFFFFF / 1000.0f is not serializable.
+// The limited float precision at this magnitude may cause the result to round
+// to a greater value than can be represented by a 32 bit integer when increased
+// by a factor of FIXEDPOINT_FACTOR.  As a result, [F1000_MIN..F1000_MAX] does
+// not represent the full range, but rather the largest safe range, of values on
+// all supported architectures.  Note: This definition makes assumptions on
+// platform float-to-int conversion behavior.
+#define F1000_MIN ((float)(s32)((float)(-0x7FFFFFFF - 1) / FIXEDPOINT_FACTOR))
+#define F1000_MAX ((float)(s32)((float)(0x7FFFFFFF) / FIXEDPOINT_FACTOR))
+
+#define STRING_MAX_LEN 0xFFFF
+#define WIDE_STRING_MAX_LEN 0xFFFF
+// 64 MB ought to be enough for anybody - Billy G.
+#define LONG_STRING_MAX_LEN (64 * 1024 * 1024)
+
+
+extern FloatType g_serialize_f32_type;
+
+#if HAVE_ENDIAN_H
+// use machine native byte swapping routines
+// Note: memcpy below is optimized out by modern compilers
+
+inline u16 readU16(const u8 *data)
+{
+	u16 val;
+	memcpy(&val, data, 2);
+	return be16toh(val);
+}
+
+inline u32 readU32(const u8 *data)
+{
+	u32 val;
+	memcpy(&val, data, 4);
+	return be32toh(val);
+}
+
+inline u64 readU64(const u8 *data)
+{
+	u64 val;
+	memcpy(&val, data, 8);
+	return be64toh(val);
+}
+
+inline void writeU16(u8 *data, u16 i)
+{
+	u16 val = htobe16(i);
+	memcpy(data, &val, 2);
+}
+
+inline void writeU32(u8 *data, u32 i)
+{
+	u32 val = htobe32(i);
+	memcpy(data, &val, 4);
+}
+
+inline void writeU64(u8 *data, u64 i)
+{
+	u64 val = htobe64(i);
+	memcpy(data, &val, 8);
+}
+
+#else
+// generic byte-swapping implementation
+
+inline u16 readU16(const u8 *data)
+{
+	return
+		((u16)data[0] << 8) | ((u16)data[1] << 0);
+}
+
+inline u32 readU32(const u8 *data)
+{
+	return
+		((u32)data[0] << 24) | ((u32)data[1] << 16) |
+		((u32)data[2] <<  8) | ((u32)data[3] <<  0);
+}
+
+inline u64 readU64(const u8 *data)
+{
+	return
+		((u64)data[0] << 56) | ((u64)data[1] << 48) |
+		((u64)data[2] << 40) | ((u64)data[3] << 32) |
+		((u64)data[4] << 24) | ((u64)data[5] << 16) |
+		((u64)data[6] <<  8) | ((u64)data[7] << 0);
+}
+
+inline void writeU16(u8 *data, u16 i)
+{
+	data[0] = (i >> 8) & 0xFF;
+	data[1] = (i >> 0) & 0xFF;
+}
+
+inline void writeU32(u8 *data, u32 i)
+{
+	data[0] = (i >> 24) & 0xFF;
+	data[1] = (i >> 16) & 0xFF;
+	data[2] = (i >>  8) & 0xFF;
+	data[3] = (i >>  0) & 0xFF;
+}
+
+inline void writeU64(u8 *data, u64 i)
+{
+	data[0] = (i >> 56) & 0xFF;
+	data[1] = (i >> 48) & 0xFF;
+	data[2] = (i >> 40) & 0xFF;
+	data[3] = (i >> 32) & 0xFF;
+	data[4] = (i >> 24) & 0xFF;
+	data[5] = (i >> 16) & 0xFF;
+	data[6] = (i >>  8) & 0xFF;
+	data[7] = (i >>  0) & 0xFF;
+}
+
+#endif // HAVE_ENDIAN_H
+
+//////////////// read routines ////////////////
+
+inline u8 readU8(const u8 *data)
+{
+	return ((u8)data[0] << 0);
+}
+
+inline s8 readS8(const u8 *data)
+{
+	return (s8)readU8(data);
+}
+
+inline s16 readS16(const u8 *data)
+{
+	return (s16)readU16(data);
+}
+
+inline s32 readS32(const u8 *data)
+{
+	return (s32)readU32(data);
+}
+
+inline s64 readS64(const u8 *data)
+{
+	return (s64)readU64(data);
+}
+
+inline f32 readF1000(const u8 *data)
+{
+	return (f32)readS32(data) / FIXEDPOINT_FACTOR;
+}
+
+inline f32 readF32(const u8 *data)
+{
+	u32 u = readU32(data);
+
+	switch (g_serialize_f32_type) {
+	case FLOATTYPE_SYSTEM: {
+			f32 f;
+			memcpy(&f, &u, 4);
+			return f;
+		}
+	case FLOATTYPE_SLOW:
+		return u32Tof32Slow(u);
+	case FLOATTYPE_UNKNOWN: // First initialization
+		g_serialize_f32_type = getFloatSerializationType();
+		return readF32(data);
+	}
+	throw SerializationError("readF32: Unreachable code");
+}
+
+inline video::SColor readARGB8(const u8 *data)
+{
+	video::SColor p(readU32(data));
+	return p;
+}
+
+inline v2s16 readV2S16(const u8 *data)
+{
+	v2s16 p;
+	p.X = readS16(&data[0]);
+	p.Y = readS16(&data[2]);
+	return p;
+}
+
+inline v3s16 readV3S16(const u8 *data)
+{
+	v3s16 p;
+	p.X = readS16(&data[0]);
+	p.Y = readS16(&data[2]);
+	p.Z = readS16(&data[4]);
+	return p;
+}
+
+inline v2s32 readV2S32(const u8 *data)
+{
+	v2s32 p;
+	p.X = readS32(&data[0]);
+	p.Y = readS32(&data[4]);
+	return p;
+}
+
+inline v3s32 readV3S32(const u8 *data)
+{
+	v3s32 p;
+	p.X = readS32(&data[0]);
+	p.Y = readS32(&data[4]);
+	p.Z = readS32(&data[8]);
+	return p;
+}
+
+inline v3f readV3F1000(const u8 *data)
+{
+	v3f p;
+	p.X = readF1000(&data[0]);
+	p.Y = readF1000(&data[4]);
+	p.Z = readF1000(&data[8]);
+	return p;
+}
+
+inline v2f readV2F32(const u8 *data)
+{
+	v2f p;
+	p.X = readF32(&data[0]);
+	p.Y = readF32(&data[4]);
+	return p;
+}
+
+inline v3f readV3F32(const u8 *data)
+{
+	v3f p;
+	p.X = readF32(&data[0]);
+	p.Y = readF32(&data[4]);
+	p.Z = readF32(&data[8]);
+	return p;
+}
+
+/////////////// write routines ////////////////
+
+inline void writeU8(u8 *data, u8 i)
+{
+	data[0] = (i >> 0) & 0xFF;
+}
+
+inline void writeS8(u8 *data, s8 i)
+{
+	writeU8(data, (u8)i);
+}
+
+inline void writeS16(u8 *data, s16 i)
+{
+	writeU16(data, (u16)i);
+}
+
+inline void writeS32(u8 *data, s32 i)
+{
+	writeU32(data, (u32)i);
+}
+
+inline void writeS64(u8 *data, s64 i)
+{
+	writeU64(data, (u64)i);
+}
+
+inline void writeF1000(u8 *data, f32 i)
+{
+	assert(i >= F1000_MIN && i <= F1000_MAX);
+	writeS32(data, i * FIXEDPOINT_FACTOR);
+}
+
+inline void writeF32(u8 *data, f32 i)
+{
+	switch (g_serialize_f32_type) {
+	case FLOATTYPE_SYSTEM: {
+			u32 u;
+			memcpy(&u, &i, 4);
+			return writeU32(data, u);
+		}
+	case FLOATTYPE_SLOW:
+		return writeU32(data, f32Tou32Slow(i));
+	case FLOATTYPE_UNKNOWN: // First initialization
+		g_serialize_f32_type = getFloatSerializationType();
+		return writeF32(data, i);
+	}
+	throw SerializationError("writeF32: Unreachable code");
+}
+
+inline void writeARGB8(u8 *data, video::SColor p)
+{
+	writeU32(data, p.color);
+}
+
+inline void writeV2S16(u8 *data, v2s16 p)
+{
+	writeS16(&data[0], p.X);
+	writeS16(&data[2], p.Y);
+}
+
+inline void writeV3S16(u8 *data, v3s16 p)
+{
+	writeS16(&data[0], p.X);
+	writeS16(&data[2], p.Y);
+	writeS16(&data[4], p.Z);
+}
+
+inline void writeV2S32(u8 *data, v2s32 p)
+{
+	writeS32(&data[0], p.X);
+	writeS32(&data[4], p.Y);
+}
+
+inline void writeV3S32(u8 *data, v3s32 p)
+{
+	writeS32(&data[0], p.X);
+	writeS32(&data[4], p.Y);
+	writeS32(&data[8], p.Z);
+}
+
+inline void writeV3F1000(u8 *data, v3f p)
+{
+	writeF1000(&data[0], p.X);
+	writeF1000(&data[4], p.Y);
+	writeF1000(&data[8], p.Z);
+}
+
+inline void writeV2F32(u8 *data, v2f p)
+{
+	writeF32(&data[0], p.X);
+	writeF32(&data[4], p.Y);
+}
+
+inline void writeV3F32(u8 *data, v3f p)
+{
+	writeF32(&data[0], p.X);
+	writeF32(&data[4], p.Y);
+	writeF32(&data[8], p.Z);
+}
+
+////
+//// Iostream wrapper for data read/write
+////
+
+#define MAKE_STREAM_READ_FXN(T, N, S)    \
+	inline T read ## N(std::istream &is) \
+	{                                    \
+		char buf[S] = {0};               \
+		is.read(buf, sizeof(buf));       \
+		return read ## N((u8 *)buf);     \
+	}
+
+#define MAKE_STREAM_WRITE_FXN(T, N, S)              \
+	inline void write ## N(std::ostream &os, T val) \
+	{                                               \
+		char buf[S];                                \
+		write ## N((u8 *)buf, val);                 \
+		os.write(buf, sizeof(buf));                 \
+	}
+
+MAKE_STREAM_READ_FXN(u8,    U8,       1);
+MAKE_STREAM_READ_FXN(u16,   U16,      2);
+MAKE_STREAM_READ_FXN(u32,   U32,      4);
+MAKE_STREAM_READ_FXN(u64,   U64,      8);
+MAKE_STREAM_READ_FXN(s8,    S8,       1);
+MAKE_STREAM_READ_FXN(s16,   S16,      2);
+MAKE_STREAM_READ_FXN(s32,   S32,      4);
+MAKE_STREAM_READ_FXN(s64,   S64,      8);
+MAKE_STREAM_READ_FXN(f32,   F1000,    4);
+MAKE_STREAM_READ_FXN(f32,   F32,      4);
+MAKE_STREAM_READ_FXN(v2s16, V2S16,    4);
+MAKE_STREAM_READ_FXN(v3s16, V3S16,    6);
+MAKE_STREAM_READ_FXN(v2s32, V2S32,    8);
+MAKE_STREAM_READ_FXN(v3s32, V3S32,   12);
+MAKE_STREAM_READ_FXN(v3f,   V3F1000, 12);
+MAKE_STREAM_READ_FXN(v2f,   V2F32,    8);
+MAKE_STREAM_READ_FXN(v3f,   V3F32,   12);
+MAKE_STREAM_READ_FXN(video::SColor, ARGB8, 4);
+
+MAKE_STREAM_WRITE_FXN(u8,    U8,       1);
+MAKE_STREAM_WRITE_FXN(u16,   U16,      2);
+MAKE_STREAM_WRITE_FXN(u32,   U32,      4);
+MAKE_STREAM_WRITE_FXN(u64,   U64,      8);
+MAKE_STREAM_WRITE_FXN(s8,    S8,       1);
+MAKE_STREAM_WRITE_FXN(s16,   S16,      2);
+MAKE_STREAM_WRITE_FXN(s32,   S32,      4);
+MAKE_STREAM_WRITE_FXN(s64,   S64,      8);
+MAKE_STREAM_WRITE_FXN(f32,   F1000,    4);
+MAKE_STREAM_WRITE_FXN(f32,   F32,      4);
+MAKE_STREAM_WRITE_FXN(v2s16, V2S16,    4);
+MAKE_STREAM_WRITE_FXN(v3s16, V3S16,    6);
+MAKE_STREAM_WRITE_FXN(v2s32, V2S32,    8);
+MAKE_STREAM_WRITE_FXN(v3s32, V3S32,   12);
+MAKE_STREAM_WRITE_FXN(v3f,   V3F1000, 12);
+MAKE_STREAM_WRITE_FXN(v2f,   V2F32,    8);
+MAKE_STREAM_WRITE_FXN(v3f,   V3F32,   12);
+MAKE_STREAM_WRITE_FXN(video::SColor, ARGB8, 4);
+
+////
+//// More serialization stuff
+////
+
+inline float clampToF1000(float v)
+{
+	return core::clamp(v, F1000_MIN, F1000_MAX);
+}
+
+inline v3f clampToF1000(v3f v)
+{
+	return {clampToF1000(v.X), clampToF1000(v.Y), clampToF1000(v.Z)};
+}
+
+// Creates a string with the length as the first two bytes
+std::string serializeString16(const std::string &plain);
+
+// Reads a string with the length as the first two bytes
+std::string deSerializeString16(std::istream &is);
+
+// Creates a string with the length as the first four bytes
+std::string serializeString32(const std::string &plain);
+
+// Reads a string with the length as the first four bytes
+std::string deSerializeString32(std::istream &is);
+
+// Creates a string encoded in JSON format (almost equivalent to a C string literal)
+std::string serializeJsonString(const std::string &plain);
+
+// Reads a string encoded in JSON format
+std::string deSerializeJsonString(std::istream &is);
+
+// If the string contains spaces, quotes or control characters, encodes as JSON.
+// Else returns the string unmodified.
+std::string serializeJsonStringIfNeeded(const std::string &s);
+
+// Parses a string serialized by serializeJsonStringIfNeeded.
+std::string deSerializeJsonStringIfNeeded(std::istream &is);

src/util/sha1.cpp

@@ -0,0 +1,198 @@
+/* sha1.cpp
+
+Copyright (c) 2005 Michael D. Leonhard
+
+http://tamale.net/
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
+*/
+
+#include <cstdio>
+#include <cstring>
+#include <cstdlib>
+#include <cassert>
+
+#include "sha1.h"
+
+// print out memory in hexadecimal
+void SHA1::hexPrinter( unsigned char* c, int l )
+{
+	assert( c );
+	assert( l > 0 );
+	while( l > 0 )
+	{
+		printf( " %02x", *c );
+		l--;
+		c++;
+	}
+}
+
+// circular left bit rotation.  MSB wraps around to LSB
+Uint32 SHA1::lrot( Uint32 x, int bits )
+{
+	return (x<<bits) | (x>>(32 - bits));
+};
+
+// Save a 32-bit unsigned integer to memory, in big-endian order
+void SHA1::storeBigEndianUint32( unsigned char* byte, Uint32 num )
+{
+	assert( byte );
+	byte[0] = (unsigned char)(num>>24);
+	byte[1] = (unsigned char)(num>>16);
+	byte[2] = (unsigned char)(num>>8);
+	byte[3] = (unsigned char)num;
+}
+
+
+// Constructor *******************************************************
+SHA1::SHA1()
+{
+	// make sure that the data type is the right size
+	assert( sizeof( Uint32 ) * 5 == 20 );
+}
+
+// Destructor ********************************************************
+SHA1::~SHA1()
+{
+	// erase data
+	H0 = H1 = H2 = H3 = H4 = 0;
+	for( int c = 0; c < 64; c++ ) bytes[c] = 0;
+	unprocessedBytes = size = 0;
+}
+
+// process ***********************************************************
+void SHA1::process()
+{
+	assert( unprocessedBytes == 64 );
+	//printf( "process: " ); hexPrinter( bytes, 64 ); printf( "\n" );
+	int t;
+	Uint32 a, b, c, d, e, K, f, W[80];
+	// starting values
+	a = H0;
+	b = H1;
+	c = H2;
+	d = H3;
+	e = H4;
+	// copy and expand the message block
+	for( t = 0; t < 16; t++ ) W[t] = (bytes[t*4] << 24)
+									+(bytes[t*4 + 1] << 16)
+									+(bytes[t*4 + 2] << 8)
+									+ bytes[t*4 + 3];
+	for(; t< 80; t++ ) W[t] = lrot( W[t-3]^W[t-8]^W[t-14]^W[t-16], 1 );
+
+	/* main loop */
+	Uint32 temp;
+	for( t = 0; t < 80; t++ )
+	{
+		if( t < 20 ) {
+			K = 0x5a827999;
+			f = (b & c) | ((b ^ 0xFFFFFFFF) & d);//TODO: try using ~
+		} else if( t < 40 ) {
+			K = 0x6ed9eba1;
+			f = b ^ c ^ d;
+		} else if( t < 60 ) {
+			K = 0x8f1bbcdc;
+			f = (b & c) | (b & d) | (c & d);
+		} else {
+			K = 0xca62c1d6;
+			f = b ^ c ^ d;
+		}
+		temp = lrot(a,5) + f + e + W[t] + K;
+		e = d;
+		d = c;
+		c = lrot(b,30);
+		b = a;
+		a = temp;
+		//printf( "t=%d %08x %08x %08x %08x %08x\n",t,a,b,c,d,e );
+	}
+	/* add variables */
+	H0 += a;
+	H1 += b;
+	H2 += c;
+	H3 += d;
+	H4 += e;
+	//printf( "Current: %08x %08x %08x %08x %08x\n",H0,H1,H2,H3,H4 );
+	/* all bytes have been processed */
+	unprocessedBytes = 0;
+}
+
+// addBytes **********************************************************
+void SHA1::addBytes( const char* data, int num )
+{
+	assert( data );
+	assert( num >= 0 );
+	// add these bytes to the running total
+	size += num;
+	// repeat until all data is processed
+	while( num > 0 )
+	{
+		// number of bytes required to complete block
+		int needed = 64 - unprocessedBytes;
+		assert( needed > 0 );
+		// number of bytes to copy (use smaller of two)
+		int toCopy = (num < needed) ? num : needed;
+		// Copy the bytes
+		memcpy( bytes + unprocessedBytes, data, toCopy );
+		// Bytes have been copied
+		num -= toCopy;
+		data += toCopy;
+		unprocessedBytes += toCopy;
+
+		// there is a full block
+		if( unprocessedBytes == 64 ) process();
+	}
+}
+
+// digest ************************************************************
+unsigned char* SHA1::getDigest()
+{
+	// save the message size
+	Uint32 totalBitsL = size << 3;
+	Uint32 totalBitsH = size >> 29;
+	// add 0x80 to the message
+	addBytes( "\x80", 1 );
+
+	unsigned char footer[64] = {
+		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
+	// block has no room for 8-byte filesize, so finish it
+	if( unprocessedBytes > 56 )
+		addBytes( (char*)footer, 64 - unprocessedBytes);
+	assert( unprocessedBytes <= 56 );
+	// how many zeros do we need
+	int neededZeros = 56 - unprocessedBytes;
+	// store file size (in bits) in big-endian format
+	storeBigEndianUint32( footer + neededZeros    , totalBitsH );
+	storeBigEndianUint32( footer + neededZeros + 4, totalBitsL );
+	// finish the final block
+	addBytes( (char*)footer, neededZeros + 8 );
+	// allocate memory for the digest bytes
+	unsigned char* digest = (unsigned char*)malloc( 20 );
+	// copy the digest bytes
+	storeBigEndianUint32( digest, H0 );
+	storeBigEndianUint32( digest + 4, H1 );
+	storeBigEndianUint32( digest + 8, H2 );
+	storeBigEndianUint32( digest + 12, H3 );
+	storeBigEndianUint32( digest + 16, H4 );
+	// return the digest
+	return digest;
+}

src/util/sha1.h

@@ -0,0 +1,54 @@
+/* sha1.h
+
+Copyright (c) 2005 Michael D. Leonhard
+
+http://tamale.net/
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
+*/
+
+#pragma once
+
+typedef unsigned int Uint32;
+
+class SHA1
+{
+private:
+	// fields
+	Uint32 H0 = 0x67452301;
+	Uint32 H1 = 0xefcdab89;
+	Uint32 H2 = 0x98badcfe;
+	Uint32 H3 = 0x10325476;
+	Uint32 H4 = 0xc3d2e1f0;
+	unsigned char bytes[64];
+	int unprocessedBytes = 0;
+	Uint32 size = 0;
+	void process();
+
+public:
+	SHA1();
+	~SHA1();
+	void addBytes(const char *data, int num);
+	unsigned char *getDigest();
+	// utility methods
+	static Uint32 lrot(Uint32 x, int bits);
+	static void storeBigEndianUint32(unsigned char *byte, Uint32 num);
+	static void hexPrinter(unsigned char *c, int l);
+};

src/util/sha2.h

@@ -0,0 +1,154 @@
+/* crypto/sha/sha.h */
+/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
+ * All rights reserved.
+ *
+ * This package is an SSL implementation written
+ * by Eric Young (eay@cryptsoft.com).
+ * The implementation was written so as to conform with Netscapes SSL.
+ *
+ * This library is free for commercial and non-commercial use as long as
+ * the following conditions are aheared to.  The following conditions
+ * apply to all code found in this distribution, be it the RC4, RSA,
+ * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
+ * included with this distribution is covered by the same copyright terms
+ * except that the holder is Tim Hudson (tjh@cryptsoft.com).
+ *
+ * Copyright remains Eric Young's, and as such any Copyright notices in
+ * the code are not to be removed.
+ * If this package is used in a product, Eric Young should be given attribution
+ * as the author of the parts of the library used.
+ * This can be in the form of a textual message at program startup or
+ * in documentation (online or textual) provided with the package.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *    "This product includes cryptographic software written by
+ *     Eric Young (eay@cryptsoft.com)"
+ *    The word 'cryptographic' can be left out if the rouines from the library
+ *    being used are not cryptographic related :-).
+ * 4. If you include any Windows specific code (or a derivative thereof) from
+ *    the apps directory (application code) you must include an acknowledgement:
+ *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * The licence and distribution terms for any publically available version or
+ * derivative of this code cannot be changed.  i.e. this code cannot simply be
+ * copied and put under another distribution licence
+ * [including the GNU Public Licence.]
+ */
+
+#pragma once
+
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#if defined(OPENSSL_NO_SHA) || (defined(OPENSSL_NO_SHA0) && defined(OPENSSL_NO_SHA1))
+#error SHA is disabled.
+#endif
+
+#if defined(OPENSSL_FIPS)
+#define FIPS_SHA_SIZE_T size_t
+#endif
+
+/*
+	Compat stuff from OpenSSL land
+ */
+
+/* crypto.h */
+
+#define fips_md_init(alg) fips_md_init_ctx(alg, alg)
+
+#define fips_md_init_ctx(alg, cx) int alg##_Init(cx##_CTX *c)
+#define fips_cipher_abort(alg) while (0)
+
+/*-
+ * !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+ * ! SHA_LONG has to be at least 32 bits wide. If it's wider, then !
+ * ! SHA_LONG_LOG2 has to be defined along.                        !
+ * !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+ */
+
+#if defined(__LP32__)
+#define SHA_LONG unsigned long
+#elif defined(__ILP64__)
+#define SHA_LONG unsigned long
+#define SHA_LONG_LOG2 3
+#else
+#define SHA_LONG unsigned int
+#endif
+
+#define SHA_LBLOCK 16
+#define SHA_CBLOCK                                                                       \
+	(SHA_LBLOCK * 4) /* SHA treats input data as a                                   \
+			  * contiguous array of 32 bit wide                              \
+			  * big-endian values. */
+#define SHA_LAST_BLOCK (SHA_CBLOCK - 8)
+#define SHA_DIGEST_LENGTH 20
+
+typedef struct SHAstate_st
+{
+	SHA_LONG h0, h1, h2, h3, h4;
+	SHA_LONG Nl, Nh;
+	SHA_LONG data[SHA_LBLOCK];
+	unsigned int num;
+} SHA_CTX;
+
+#define SHA256_CBLOCK                                                                    \
+	(SHA_LBLOCK * 4) /* SHA-256 treats input data as a                               \
+			  * contiguous array of 32 bit wide                              \
+			  * big-endian values. */
+#define SHA224_DIGEST_LENGTH 28
+#define SHA256_DIGEST_LENGTH 32
+
+typedef struct SHA256state_st
+{
+	SHA_LONG h[8];
+	SHA_LONG Nl, Nh;
+	SHA_LONG data[SHA_LBLOCK];
+	unsigned int num, md_len;
+} SHA256_CTX;
+
+#ifndef OPENSSL_NO_SHA256
+#ifdef OPENSSL_FIPS
+int private_SHA224_Init(SHA256_CTX *c);
+int private_SHA256_Init(SHA256_CTX *c);
+#endif
+int SHA224_Init(SHA256_CTX *c);
+int SHA224_Update(SHA256_CTX *c, const void *data, size_t len);
+int SHA224_Final(unsigned char *md, SHA256_CTX *c);
+unsigned char *SHA224(const unsigned char *d, size_t n, unsigned char *md);
+int SHA256_Init(SHA256_CTX *c);
+int SHA256_Update(SHA256_CTX *c, const void *data, size_t len);
+int SHA256_Final(unsigned char *md, SHA256_CTX *c);
+unsigned char *SHA256(const unsigned char *d, size_t n, unsigned char *md);
+void SHA256_Transform(SHA256_CTX *c, const unsigned char *data);
+#endif
+
+#define SHA384_DIGEST_LENGTH 48
+#define SHA512_DIGEST_LENGTH 64
+
+#ifdef __cplusplus
+}
+#endif

src/util/sha256.c

@@ -0,0 +1,399 @@
+/* crypto/sha/sha256.c */
+/* ====================================================================
+ * Copyright (c) 2004 The OpenSSL Project.  All rights reserved
+ * according to the OpenSSL license [found in ../../LICENSE].
+ * ====================================================================
+ */
+# include <stdlib.h>
+# include <string.h>
+
+# include <util/sha2.h>
+
+#  define OPENSSL_VERSION_TEXT    "OpenSSL 1.0.2a 19 Mar 2015"
+# define OPENSSL_VERSION_PTEXT   " part of " OPENSSL_VERSION_TEXT
+
+const char SHA256_version[] = "SHA-256" OPENSSL_VERSION_PTEXT;
+
+/* mem_clr.c */
+unsigned static char cleanse_ctr = 0;
+static void OPENSSL_cleanse(void *ptr, size_t len)
+{
+    unsigned char *p = (unsigned char *)ptr;
+    size_t loop = len, ctr = cleanse_ctr;
+    while (loop--) {
+        *(p++) = (unsigned char)ctr;
+        ctr += (17 + ((size_t)p & 0xF));
+    }
+    p = (unsigned char *)memchr(ptr, (unsigned char)ctr, len);
+    if (p)
+        ctr += (63 + (size_t)p);
+    cleanse_ctr = (unsigned char)ctr;
+}
+
+fips_md_init_ctx(SHA224, SHA256)
+{
+    memset(c, 0, sizeof(*c));
+    c->h[0] = 0xc1059ed8UL;
+    c->h[1] = 0x367cd507UL;
+    c->h[2] = 0x3070dd17UL;
+    c->h[3] = 0xf70e5939UL;
+    c->h[4] = 0xffc00b31UL;
+    c->h[5] = 0x68581511UL;
+    c->h[6] = 0x64f98fa7UL;
+    c->h[7] = 0xbefa4fa4UL;
+    c->md_len = SHA224_DIGEST_LENGTH;
+    return 1;
+}
+
+fips_md_init(SHA256)
+{
+    memset(c, 0, sizeof(*c));
+    c->h[0] = 0x6a09e667UL;
+    c->h[1] = 0xbb67ae85UL;
+    c->h[2] = 0x3c6ef372UL;
+    c->h[3] = 0xa54ff53aUL;
+    c->h[4] = 0x510e527fUL;
+    c->h[5] = 0x9b05688cUL;
+    c->h[6] = 0x1f83d9abUL;
+    c->h[7] = 0x5be0cd19UL;
+    c->md_len = SHA256_DIGEST_LENGTH;
+    return 1;
+}
+
+unsigned char *SHA224(const unsigned char *d, size_t n, unsigned char *md)
+{
+    SHA256_CTX c;
+    static unsigned char m[SHA224_DIGEST_LENGTH];
+
+    if (md == NULL)
+        md = m;
+    SHA224_Init(&c);
+    SHA256_Update(&c, d, n);
+    SHA256_Final(md, &c);
+    OPENSSL_cleanse(&c, sizeof(c));
+    return (md);
+}
+
+unsigned char *SHA256(const unsigned char *d, size_t n, unsigned char *md)
+{
+    SHA256_CTX c;
+    static unsigned char m[SHA256_DIGEST_LENGTH];
+
+    if (md == NULL)
+        md = m;
+    SHA256_Init(&c);
+    SHA256_Update(&c, d, n);
+    SHA256_Final(md, &c);
+    OPENSSL_cleanse(&c, sizeof(c));
+    return (md);
+}
+
+int SHA224_Update(SHA256_CTX *c, const void *data, size_t len)
+{
+    return SHA256_Update(c, data, len);
+}
+
+int SHA224_Final(unsigned char *md, SHA256_CTX *c)
+{
+    return SHA256_Final(md, c);
+}
+
+# define DATA_ORDER_IS_BIG_ENDIAN
+
+# define HASH_LONG               SHA_LONG
+# define HASH_CTX                SHA256_CTX
+# define HASH_CBLOCK             SHA_CBLOCK
+/*
+ * Note that FIPS180-2 discusses "Truncation of the Hash Function Output."
+ * default: case below covers for it. It's not clear however if it's
+ * permitted to truncate to amount of bytes not divisible by 4. I bet not,
+ * but if it is, then default: case shall be extended. For reference.
+ * Idea behind separate cases for pre-defined lenghts is to let the
+ * compiler decide if it's appropriate to unroll small loops.
+ */
+# define HASH_MAKE_STRING(c,s)   do {    \
+        unsigned long ll;               \
+        unsigned int  nn;               \
+        switch ((c)->md_len)            \
+        {   case SHA224_DIGEST_LENGTH:  \
+                for (nn=0;nn<SHA224_DIGEST_LENGTH/4;nn++)       \
+                {   ll=(c)->h[nn]; (void)HOST_l2c(ll,(s));   }  \
+                break;                  \
+            case SHA256_DIGEST_LENGTH:  \
+                for (nn=0;nn<SHA256_DIGEST_LENGTH/4;nn++)       \
+                {   ll=(c)->h[nn]; (void)HOST_l2c(ll,(s));   }  \
+                break;                  \
+            default:                    \
+                if ((c)->md_len > SHA256_DIGEST_LENGTH) \
+                    return 0;                           \
+                for (nn=0;nn<(c)->md_len/4;nn++)                \
+                {   ll=(c)->h[nn]; (void)HOST_l2c(ll,(s));   }  \
+                break;                  \
+        }                               \
+        } while (0)
+
+# define HASH_UPDATE             SHA256_Update
+# define HASH_TRANSFORM          SHA256_Transform
+# define HASH_FINAL              SHA256_Final
+# define HASH_BLOCK_DATA_ORDER   sha256_block_data_order
+# ifndef SHA256_ASM
+static
+# endif
+void sha256_block_data_order(SHA256_CTX *ctx, const void *in, size_t num);
+
+# include "md32_common.h"
+
+# ifndef SHA256_ASM
+static const SHA_LONG K256[64] = {
+    0x428a2f98UL, 0x71374491UL, 0xb5c0fbcfUL, 0xe9b5dba5UL,
+    0x3956c25bUL, 0x59f111f1UL, 0x923f82a4UL, 0xab1c5ed5UL,
+    0xd807aa98UL, 0x12835b01UL, 0x243185beUL, 0x550c7dc3UL,
+    0x72be5d74UL, 0x80deb1feUL, 0x9bdc06a7UL, 0xc19bf174UL,
+    0xe49b69c1UL, 0xefbe4786UL, 0x0fc19dc6UL, 0x240ca1ccUL,
+    0x2de92c6fUL, 0x4a7484aaUL, 0x5cb0a9dcUL, 0x76f988daUL,
+    0x983e5152UL, 0xa831c66dUL, 0xb00327c8UL, 0xbf597fc7UL,
+    0xc6e00bf3UL, 0xd5a79147UL, 0x06ca6351UL, 0x14292967UL,
+    0x27b70a85UL, 0x2e1b2138UL, 0x4d2c6dfcUL, 0x53380d13UL,
+    0x650a7354UL, 0x766a0abbUL, 0x81c2c92eUL, 0x92722c85UL,
+    0xa2bfe8a1UL, 0xa81a664bUL, 0xc24b8b70UL, 0xc76c51a3UL,
+    0xd192e819UL, 0xd6990624UL, 0xf40e3585UL, 0x106aa070UL,
+    0x19a4c116UL, 0x1e376c08UL, 0x2748774cUL, 0x34b0bcb5UL,
+    0x391c0cb3UL, 0x4ed8aa4aUL, 0x5b9cca4fUL, 0x682e6ff3UL,
+    0x748f82eeUL, 0x78a5636fUL, 0x84c87814UL, 0x8cc70208UL,
+    0x90befffaUL, 0xa4506cebUL, 0xbef9a3f7UL, 0xc67178f2UL
+};
+
+/*
+ * FIPS specification refers to right rotations, while our ROTATE macro
+ * is left one. This is why you might notice that rotation coefficients
+ * differ from those observed in FIPS document by 32-N...
+ */
+#  define Sigma0(x)       (ROTATE((x),30) ^ ROTATE((x),19) ^ ROTATE((x),10))
+#  define Sigma1(x)       (ROTATE((x),26) ^ ROTATE((x),21) ^ ROTATE((x),7))
+#  define sigma0(x)       (ROTATE((x),25) ^ ROTATE((x),14) ^ ((x)>>3))
+#  define sigma1(x)       (ROTATE((x),15) ^ ROTATE((x),13) ^ ((x)>>10))
+
+#  define Ch(x,y,z)       (((x) & (y)) ^ ((~(x)) & (z)))
+#  define Maj(x,y,z)      (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)))
+
+#  ifdef OPENSSL_SMALL_FOOTPRINT
+
+static void sha256_block_data_order(SHA256_CTX *ctx, const void *in,
+                                    size_t num)
+{
+    unsigned MD32_REG_T a, b, c, d, e, f, g, h, s0, s1, T1, T2;
+    SHA_LONG X[16], l;
+    int i;
+    const unsigned char *data = in;
+
+    while (num--) {
+
+        a = ctx->h[0];
+        b = ctx->h[1];
+        c = ctx->h[2];
+        d = ctx->h[3];
+        e = ctx->h[4];
+        f = ctx->h[5];
+        g = ctx->h[6];
+        h = ctx->h[7];
+
+        for (i = 0; i < 16; i++) {
+            HOST_c2l(data, l);
+            T1 = X[i] = l;
+            T1 += h + Sigma1(e) + Ch(e, f, g) + K256[i];
+            T2 = Sigma0(a) + Maj(a, b, c);
+            h = g;
+            g = f;
+            f = e;
+            e = d + T1;
+            d = c;
+            c = b;
+            b = a;
+            a = T1 + T2;
+        }
+
+        for (; i < 64; i++) {
+            s0 = X[(i + 1) & 0x0f];
+            s0 = sigma0(s0);
+            s1 = X[(i + 14) & 0x0f];
+            s1 = sigma1(s1);
+
+            T1 = X[i & 0xf] += s0 + s1 + X[(i + 9) & 0xf];
+            T1 += h + Sigma1(e) + Ch(e, f, g) + K256[i];
+            T2 = Sigma0(a) + Maj(a, b, c);
+            h = g;
+            g = f;
+            f = e;
+            e = d + T1;
+            d = c;
+            c = b;
+            b = a;
+            a = T1 + T2;
+        }
+
+        ctx->h[0] += a;
+        ctx->h[1] += b;
+        ctx->h[2] += c;
+        ctx->h[3] += d;
+        ctx->h[4] += e;
+        ctx->h[5] += f;
+        ctx->h[6] += g;
+        ctx->h[7] += h;
+
+    }
+}
+
+#  else
+
+#   define ROUND_00_15(i,a,b,c,d,e,f,g,h)          do {    \
+        T1 += h + Sigma1(e) + Ch(e,f,g) + K256[i];      \
+        h = Sigma0(a) + Maj(a,b,c);                     \
+        d += T1;        h += T1;                } while (0)
+
+#   define ROUND_16_63(i,a,b,c,d,e,f,g,h,X)        do {    \
+        s0 = X[(i+1)&0x0f];     s0 = sigma0(s0);        \
+        s1 = X[(i+14)&0x0f];    s1 = sigma1(s1);        \
+        T1 = X[(i)&0x0f] += s0 + s1 + X[(i+9)&0x0f];    \
+        ROUND_00_15(i,a,b,c,d,e,f,g,h);         } while (0)
+
+static void sha256_block_data_order(SHA256_CTX *ctx, const void *in,
+                                    size_t num)
+{
+    unsigned MD32_REG_T a, b, c, d, e, f, g, h, s0, s1, T1;
+    SHA_LONG X[16];
+    int i;
+    const unsigned char *data = (const unsigned char *)in;
+    const union {
+        long one;
+        char little;
+    } is_endian = {
+        1
+    };
+
+    while (num--) {
+
+        a = ctx->h[0];
+        b = ctx->h[1];
+        c = ctx->h[2];
+        d = ctx->h[3];
+        e = ctx->h[4];
+        f = ctx->h[5];
+        g = ctx->h[6];
+        h = ctx->h[7];
+
+        if (!is_endian.little && sizeof(SHA_LONG) == 4
+            && ((size_t)in % 4) == 0) {
+            const SHA_LONG *W = (const SHA_LONG *)data;
+
+            T1 = X[0] = W[0];
+            ROUND_00_15(0, a, b, c, d, e, f, g, h);
+            T1 = X[1] = W[1];
+            ROUND_00_15(1, h, a, b, c, d, e, f, g);
+            T1 = X[2] = W[2];
+            ROUND_00_15(2, g, h, a, b, c, d, e, f);
+            T1 = X[3] = W[3];
+            ROUND_00_15(3, f, g, h, a, b, c, d, e);
+            T1 = X[4] = W[4];
+            ROUND_00_15(4, e, f, g, h, a, b, c, d);
+            T1 = X[5] = W[5];
+            ROUND_00_15(5, d, e, f, g, h, a, b, c);
+            T1 = X[6] = W[6];
+            ROUND_00_15(6, c, d, e, f, g, h, a, b);
+            T1 = X[7] = W[7];
+            ROUND_00_15(7, b, c, d, e, f, g, h, a);
+            T1 = X[8] = W[8];
+            ROUND_00_15(8, a, b, c, d, e, f, g, h);
+            T1 = X[9] = W[9];
+            ROUND_00_15(9, h, a, b, c, d, e, f, g);
+            T1 = X[10] = W[10];
+            ROUND_00_15(10, g, h, a, b, c, d, e, f);
+            T1 = X[11] = W[11];
+            ROUND_00_15(11, f, g, h, a, b, c, d, e);
+            T1 = X[12] = W[12];
+            ROUND_00_15(12, e, f, g, h, a, b, c, d);
+            T1 = X[13] = W[13];
+            ROUND_00_15(13, d, e, f, g, h, a, b, c);
+            T1 = X[14] = W[14];
+            ROUND_00_15(14, c, d, e, f, g, h, a, b);
+            T1 = X[15] = W[15];
+            ROUND_00_15(15, b, c, d, e, f, g, h, a);
+
+            data += SHA256_CBLOCK;
+        } else {
+            SHA_LONG l;
+
+            HOST_c2l(data, l);
+            T1 = X[0] = l;
+            ROUND_00_15(0, a, b, c, d, e, f, g, h);
+            HOST_c2l(data, l);
+            T1 = X[1] = l;
+            ROUND_00_15(1, h, a, b, c, d, e, f, g);
+            HOST_c2l(data, l);
+            T1 = X[2] = l;
+            ROUND_00_15(2, g, h, a, b, c, d, e, f);
+            HOST_c2l(data, l);
+            T1 = X[3] = l;
+            ROUND_00_15(3, f, g, h, a, b, c, d, e);
+            HOST_c2l(data, l);
+            T1 = X[4] = l;
+            ROUND_00_15(4, e, f, g, h, a, b, c, d);
+            HOST_c2l(data, l);
+            T1 = X[5] = l;
+            ROUND_00_15(5, d, e, f, g, h, a, b, c);
+            HOST_c2l(data, l);
+            T1 = X[6] = l;
+            ROUND_00_15(6, c, d, e, f, g, h, a, b);
+            HOST_c2l(data, l);
+            T1 = X[7] = l;
+            ROUND_00_15(7, b, c, d, e, f, g, h, a);
+            HOST_c2l(data, l);
+            T1 = X[8] = l;
+            ROUND_00_15(8, a, b, c, d, e, f, g, h);
+            HOST_c2l(data, l);
+            T1 = X[9] = l;
+            ROUND_00_15(9, h, a, b, c, d, e, f, g);
+            HOST_c2l(data, l);
+            T1 = X[10] = l;
+            ROUND_00_15(10, g, h, a, b, c, d, e, f);
+            HOST_c2l(data, l);
+            T1 = X[11] = l;
+            ROUND_00_15(11, f, g, h, a, b, c, d, e);
+            HOST_c2l(data, l);
+            T1 = X[12] = l;
+            ROUND_00_15(12, e, f, g, h, a, b, c, d);
+            HOST_c2l(data, l);
+            T1 = X[13] = l;
+            ROUND_00_15(13, d, e, f, g, h, a, b, c);
+            HOST_c2l(data, l);
+            T1 = X[14] = l;
+            ROUND_00_15(14, c, d, e, f, g, h, a, b);
+            HOST_c2l(data, l);
+            T1 = X[15] = l;
+            ROUND_00_15(15, b, c, d, e, f, g, h, a);
+        }
+
+        for (i = 16; i < 64; i += 8) {
+            ROUND_16_63(i + 0, a, b, c, d, e, f, g, h, X);
+            ROUND_16_63(i + 1, h, a, b, c, d, e, f, g, X);
+            ROUND_16_63(i + 2, g, h, a, b, c, d, e, f, X);
+            ROUND_16_63(i + 3, f, g, h, a, b, c, d, e, X);
+            ROUND_16_63(i + 4, e, f, g, h, a, b, c, d, X);
+            ROUND_16_63(i + 5, d, e, f, g, h, a, b, c, X);
+            ROUND_16_63(i + 6, c, d, e, f, g, h, a, b, X);
+            ROUND_16_63(i + 7, b, c, d, e, f, g, h, a, X);
+        }
+
+        ctx->h[0] += a;
+        ctx->h[1] += b;
+        ctx->h[2] += c;
+        ctx->h[3] += d;
+        ctx->h[4] += e;
+        ctx->h[5] += f;
+        ctx->h[6] += g;
+        ctx->h[7] += h;
+
+    }
+}
+
+#  endif
+# endif                         /* SHA256_ASM */

src/util/srp.h

@@ -0,0 +1,191 @@
+/*
+ * Secure Remote Password 6a implementation
+ * https://github.com/est31/csrp-gmp
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2010, 2013 Tom Cocagne, 2015 est31 <MTest31@outlook.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is furnished to do
+ * so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ */
+
+/*
+ *
+ * Purpose:       This is a direct implementation of the Secure Remote Password
+ *                Protocol version 6a as described by
+ *                http://srp.stanford.edu/design.html
+ *
+ * Author:        tom.cocagne@gmail.com (Tom Cocagne)
+ *
+ * Dependencies:  LibGMP
+ *
+ * Usage:         Refer to test_srp.c for a demonstration
+ *
+ * Notes:
+ *    This library allows multiple combinations of hashing algorithms and
+ *    prime number constants. For authentication to succeed, the hash and
+ *    prime number constants must match between
+ *    srp_create_salted_verification_key(), srp_user_new(),
+ *    and srp_verifier_new(). A recommended approach is to determine the
+ *    desired level of security for an application and globally define the
+ *    hash and prime number constants to the predetermined values.
+ *
+ *    As one might suspect, more bits means more security. As one might also
+ *    suspect, more bits also means more processing time. The test_srp.c
+ *    program can be easily modified to profile various combinations of
+ *    hash & prime number pairings.
+ */
+
+#pragma once
+
+struct SRPVerifier;
+struct SRPUser;
+
+typedef enum {
+	SRP_NG_1024,
+	SRP_NG_2048,
+	SRP_NG_4096,
+	SRP_NG_8192,
+	SRP_NG_CUSTOM
+} SRP_NGType;
+
+typedef enum {
+	/*SRP_SHA1,*/
+	/*SRP_SHA224,*/
+	SRP_SHA256,
+	/*SRP_SHA384,
+	SRP_SHA512*/
+} SRP_HashAlgorithm;
+
+typedef enum {
+	SRP_ERR,
+	SRP_OK,
+} SRP_Result;
+
+// clang-format off
+
+/* Sets the memory functions used by srp.
+ * Note: this doesn't set the memory functions used by gmp,
+ * but it is supported to have different functions for srp and gmp.
+ * Don't call this after you have already allocated srp structures.
+ */
+void srp_set_memory_functions(
+	void *(*new_srp_alloc) (size_t),
+	void *(*new_srp_realloc) (void *, size_t),
+	void (*new_srp_free) (void *));
+
+/* Out: bytes_v, len_v
+ *
+ * The caller is responsible for freeing the memory allocated for bytes_v
+ *
+ * The n_hex and g_hex parameters should be 0 unless SRP_NG_CUSTOM is used for ng_type.
+ * If provided, they must contain ASCII text of the hexidecimal notation.
+ *
+ * If bytes_s == NULL, it is filled with random data.
+ * The caller is responsible for freeing.
+ *
+ * Returns SRP_OK on success, and SRP_ERR on error.
+ * bytes_s might be in this case invalid, don't free it.
+ */
+SRP_Result srp_create_salted_verification_key(SRP_HashAlgorithm alg,
+	SRP_NGType ng_type, const char *username_for_verifier,
+	const unsigned char *password, size_t len_password,
+	unsigned char **bytes_s,  size_t *len_s,
+	unsigned char **bytes_v, size_t *len_v,
+	const char *n_hex, const char *g_hex);
+
+/* Out: bytes_B, len_B.
+ *
+ * On failure, bytes_B will be set to NULL and len_B will be set to 0
+ *
+ * The n_hex and g_hex parameters should be 0 unless SRP_NG_CUSTOM is used for ng_type
+ *
+ * If bytes_b == NULL, random data is used for b.
+ *
+ * Returns pointer to SRPVerifier on success, and NULL on error.
+ */
+struct SRPVerifier* srp_verifier_new(SRP_HashAlgorithm alg, SRP_NGType ng_type,
+	const char *username,
+	const unsigned char *bytes_s, size_t len_s,
+	const unsigned char *bytes_v, size_t len_v,
+	const unsigned char *bytes_A, size_t len_A,
+	const unsigned char *bytes_b, size_t len_b,
+	unsigned char** bytes_B, size_t *len_B,
+	const char* n_hex, const char* g_hex);
+
+// clang-format on
+
+void srp_verifier_delete(struct SRPVerifier *ver);
+
+// srp_verifier_verify_session must have been called before
+int srp_verifier_is_authenticated(struct SRPVerifier *ver);
+
+const char *srp_verifier_get_username(struct SRPVerifier *ver);
+
+/* key_length may be null */
+const unsigned char *srp_verifier_get_session_key(
+	struct SRPVerifier *ver, size_t *key_length);
+
+size_t srp_verifier_get_session_key_length(struct SRPVerifier *ver);
+
+/* Verifies session, on success, it writes bytes_HAMK.
+ * user_M must be exactly srp_verifier_get_session_key_length() bytes in size
+ */
+void srp_verifier_verify_session(
+	struct SRPVerifier *ver, const unsigned char *user_M, unsigned char **bytes_HAMK);
+
+/*******************************************************************************/
+
+/* The n_hex and g_hex parameters should be 0 unless SRP_NG_CUSTOM is used for ng_type */
+struct SRPUser *srp_user_new(SRP_HashAlgorithm alg, SRP_NGType ng_type,
+	const char *username, const char *username_for_verifier,
+	const unsigned char *bytes_password, size_t len_password, const char *n_hex,
+	const char *g_hex);
+
+void srp_user_delete(struct SRPUser *usr);
+
+int srp_user_is_authenticated(struct SRPUser *usr);
+
+const char *srp_user_get_username(struct SRPUser *usr);
+
+/* key_length may be null */
+const unsigned char *srp_user_get_session_key(struct SRPUser *usr, size_t *key_length);
+
+size_t srp_user_get_session_key_length(struct SRPUser *usr);
+
+// clang-format off
+
+/* Output: username, bytes_A, len_A.
+ * If you don't want it get written, set username to NULL.
+ * If bytes_a == NULL, random data is used for a. */
+SRP_Result srp_user_start_authentication(struct SRPUser* usr, char **username,
+	const unsigned char *bytes_a, size_t len_a,
+	unsigned char **bytes_A, size_t* len_A);
+
+/* Output: bytes_M, len_M  (len_M may be null and will always be
+ *                          srp_user_get_session_key_length() bytes in size) */
+void srp_user_process_challenge(struct SRPUser *usr,
+	const unsigned char *bytes_s, size_t len_s,
+	const unsigned char *bytes_B, size_t len_B,
+	unsigned char **bytes_M, size_t *len_M);
+// clang-format on
+
+/* bytes_HAMK must be exactly srp_user_get_session_key_length() bytes in size */
+void srp_user_verify_session(struct SRPUser *usr, const unsigned char *bytes_HAMK);

src/util/stream.h

@@ -0,0 +1,70 @@
+/*
+Minetest
+Copyright (C) 2022 Minetest Authors
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#pragma once
+
+#include <iostream>
+#include <string>
+#include <functional>
+
+template<int BufferLength, typename Emitter = std::function<void(const std::string &)> >
+class StringStreamBuffer : public std::streambuf {
+public:
+	StringStreamBuffer(Emitter emitter) : m_emitter(emitter) {
+		buffer_index = 0;
+	}
+
+	int overflow(int c) {
+		push_back(c);
+		return c;
+	}
+
+	void push_back(char c) {
+		if (c == '\n' || c == '\r') {
+			if (buffer_index)
+				m_emitter(std::string(buffer, buffer_index));
+			buffer_index = 0;
+		} else {
+			buffer[buffer_index++] = c;
+			if (buffer_index >= BufferLength) {
+				m_emitter(std::string(buffer, buffer_index));
+				buffer_index = 0;
+			}
+		}
+	}
+
+	std::streamsize xsputn(const char *s, std::streamsize n) {
+		for (int i = 0; i < n; ++i)
+			push_back(s[i]);
+		return n;
+	}
+private:
+	Emitter m_emitter;
+	char buffer[BufferLength];
+	int buffer_index;
+};
+
+class DummyStreamBuffer : public std::streambuf {
+	int overflow(int c) {
+		return c;
+	}
+	std::streamsize xsputn(const char *s, std::streamsize n) {
+		return n;
+	}
+};

src/util/strfnd.h

@@ -0,0 +1,78 @@
+/*
+Minetest
+Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#pragma once
+
+#include <string>
+
+template <typename T>
+class BasicStrfnd {
+	typedef std::basic_string<T> String;
+	String str;
+	size_t pos;
+public:
+	BasicStrfnd(const String &s) : str(s), pos(0) {}
+	void start(const String &s) { str = s; pos = 0; }
+	size_t where() { return pos; }
+	void to(size_t i) { pos = i; }
+	bool at_end() { return pos >= str.size(); }
+	String what() { return str; }
+
+	String next(const String &sep)
+	{
+		if (pos >= str.size())
+			return String();
+
+		size_t n;
+		if (sep.empty() || (n = str.find(sep, pos)) == String::npos) {
+			n = str.size();
+		}
+		String ret = str.substr(pos, n - pos);
+		pos = n + sep.size();
+		return ret;
+	}
+
+	// Returns substr up to the next occurence of sep that isn't escaped with esc ('\\')
+	String next_esc(const String &sep, T esc=static_cast<T>('\\'))
+	{
+		if (pos >= str.size())
+			return String();
+
+		size_t n, old_p = pos;
+		do {
+			if (sep.empty() || (n = str.find(sep, pos)) == String::npos) {
+				pos = n = str.size();
+				break;
+			}
+			pos = n + sep.length();
+		} while (n > 0 && str[n - 1] == esc);
+
+		return str.substr(old_p, n - old_p);
+	}
+
+	void skip_over(const String &chars)
+	{
+		size_t p = str.find_first_not_of(chars, pos);
+		if (p != String::npos)
+			pos = p;
+	}
+};
+
+typedef BasicStrfnd<char> Strfnd;
+typedef BasicStrfnd<wchar_t> WStrfnd;

src/util/string.cpp

@@ -0,0 +1,908 @@
+/*
+Minetest
+Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "string.h"
+#include "pointer.h"
+#include "numeric.h"
+#include "log.h"
+
+#include "hex.h"
+#include "porting.h"
+#include "translation.h"
+
+#include <algorithm>
+#include <array>
+#include <sstream>
+#include <iomanip>
+#include <unordered_map>
+
+#ifndef _WIN32
+	#include <iconv.h>
+#else
+	#define _WIN32_WINNT 0x0501
+	#include <windows.h>
+#endif
+
+#ifndef _WIN32
+
+static bool convert(const char *to, const char *from, char *outbuf,
+		size_t *outbuf_size, char *inbuf, size_t inbuf_size)
+{
+	iconv_t cd = iconv_open(to, from);
+
+	char *inbuf_ptr = inbuf;
+	char *outbuf_ptr = outbuf;
+
+	size_t *inbuf_left_ptr = &inbuf_size;
+
+	const size_t old_outbuf_size = *outbuf_size;
+	size_t old_size = inbuf_size;
+	while (inbuf_size > 0) {
+		iconv(cd, &inbuf_ptr, inbuf_left_ptr, &outbuf_ptr, outbuf_size);
+		if (inbuf_size == old_size) {
+			iconv_close(cd);
+			return false;
+		}
+		old_size = inbuf_size;
+	}
+
+	iconv_close(cd);
+	*outbuf_size = old_outbuf_size - *outbuf_size;
+	return true;
+}
+
+#ifdef __ANDROID__
+// On Android iconv disagrees how big a wchar_t is for whatever reason
+const char *DEFAULT_ENCODING = "UTF-32LE";
+#elif defined(__NetBSD__) || defined(__OpenBSD__)
+	// NetBSD does not allow "WCHAR_T" as a charset input to iconv.
+	#include <sys/endian.h>
+	#if BYTE_ORDER == BIG_ENDIAN
+	const char *DEFAULT_ENCODING = "UTF-32BE";
+	#else
+	const char *DEFAULT_ENCODING = "UTF-32LE";
+	#endif
+#else
+const char *DEFAULT_ENCODING = "WCHAR_T";
+#endif
+
+std::wstring utf8_to_wide(const std::string &input)
+{
+	const size_t inbuf_size = input.length();
+	// maximum possible size, every character is sizeof(wchar_t) bytes
+	size_t outbuf_size = input.length() * sizeof(wchar_t);
+
+	char *inbuf = new char[inbuf_size]; // intentionally NOT null-terminated
+	memcpy(inbuf, input.c_str(), inbuf_size);
+	std::wstring out;
+	out.resize(outbuf_size / sizeof(wchar_t));
+
+#if defined(__ANDROID__) || defined(__NetBSD__) || defined(__OpenBSD__)
+	static_assert(sizeof(wchar_t) == 4, "Unexpected wide char size");
+#endif
+
+	char *outbuf = reinterpret_cast<char*>(&out[0]);
+	if (!convert(DEFAULT_ENCODING, "UTF-8", outbuf, &outbuf_size, inbuf, inbuf_size)) {
+		infostream << "Couldn't convert UTF-8 string 0x" << hex_encode(input)
+			<< " into wstring" << std::endl;
+		delete[] inbuf;
+		return L"<invalid UTF-8 string>";
+	}
+	delete[] inbuf;
+
+	out.resize(outbuf_size / sizeof(wchar_t));
+	return out;
+}
+
+std::string wide_to_utf8(const std::wstring &input)
+{
+	const size_t inbuf_size = input.length() * sizeof(wchar_t);
+	// maximum possible size: utf-8 encodes codepoints using 1 up to 4 bytes
+	size_t outbuf_size = input.length() * 4;
+
+	char *inbuf = new char[inbuf_size]; // intentionally NOT null-terminated
+	memcpy(inbuf, input.c_str(), inbuf_size);
+	std::string out;
+	out.resize(outbuf_size);
+
+	if (!convert("UTF-8", DEFAULT_ENCODING, &out[0], &outbuf_size, inbuf, inbuf_size)) {
+		infostream << "Couldn't convert wstring 0x" << hex_encode(inbuf, inbuf_size)
+			<< " into UTF-8 string" << std::endl;
+		delete[] inbuf;
+		return "<invalid wide string>";
+	}
+	delete[] inbuf;
+
+	out.resize(outbuf_size);
+	return out;
+}
+
+#else // _WIN32
+
+std::wstring utf8_to_wide(const std::string &input)
+{
+	size_t outbuf_size = input.size() + 1;
+	wchar_t *outbuf = new wchar_t[outbuf_size];
+	memset(outbuf, 0, outbuf_size * sizeof(wchar_t));
+	MultiByteToWideChar(CP_UTF8, 0, input.c_str(), input.size(),
+		outbuf, outbuf_size);
+	std::wstring out(outbuf);
+	delete[] outbuf;
+	return out;
+}
+
+std::string wide_to_utf8(const std::wstring &input)
+{
+	size_t outbuf_size = (input.size() + 1) * 6;
+	char *outbuf = new char[outbuf_size];
+	memset(outbuf, 0, outbuf_size);
+	WideCharToMultiByte(CP_UTF8, 0, input.c_str(), input.size(),
+		outbuf, outbuf_size, NULL, NULL);
+	std::string out(outbuf);
+	delete[] outbuf;
+	return out;
+}
+
+#endif // _WIN32
+
+wchar_t *utf8_to_wide_c(const char *str)
+{
+	std::wstring ret = utf8_to_wide(std::string(str));
+	size_t len = ret.length();
+	wchar_t *ret_c = new wchar_t[len + 1];
+	memcpy(ret_c, ret.c_str(), (len + 1) * sizeof(wchar_t));
+	return ret_c;
+}
+
+
+std::string urlencode(const std::string &str)
+{
+	// Encodes non-unreserved URI characters by a percent sign
+	// followed by two hex digits. See RFC 3986, section 2.3.
+	static const char url_hex_chars[] = "0123456789ABCDEF";
+	std::ostringstream oss(std::ios::binary);
+	for (unsigned char c : str) {
+		if (isalnum(c) || c == '-' || c == '.' || c == '_' || c == '~') {
+			oss << c;
+		} else {
+			oss << "%"
+				<< url_hex_chars[(c & 0xf0) >> 4]
+				<< url_hex_chars[c & 0x0f];
+		}
+	}
+	return oss.str();
+}
+
+std::string urldecode(const std::string &str)
+{
+	// Inverse of urlencode
+	std::ostringstream oss(std::ios::binary);
+	for (u32 i = 0; i < str.size(); i++) {
+		unsigned char highvalue, lowvalue;
+		if (str[i] == '%' &&
+				hex_digit_decode(str[i+1], highvalue) &&
+				hex_digit_decode(str[i+2], lowvalue)) {
+			oss << (char) ((highvalue << 4) | lowvalue);
+			i += 2;
+		} else {
+			oss << str[i];
+		}
+	}
+	return oss.str();
+}
+
+u32 readFlagString(std::string str, const FlagDesc *flagdesc, u32 *flagmask)
+{
+	u32 result = 0;
+	u32 mask = 0;
+	char *s = &str[0];
+	char *flagstr;
+	char *strpos = nullptr;
+
+	while ((flagstr = strtok_r(s, ",", &strpos))) {
+		s = nullptr;
+
+		while (*flagstr == ' ' || *flagstr == '\t')
+			flagstr++;
+
+		bool flagset = true;
+		if (!strncasecmp(flagstr, "no", 2)) {
+			flagset = false;
+			flagstr += 2;
+		}
+
+		for (int i = 0; flagdesc[i].name; i++) {
+			if (!strcasecmp(flagstr, flagdesc[i].name)) {
+				mask |= flagdesc[i].flag;
+				if (flagset)
+					result |= flagdesc[i].flag;
+				break;
+			}
+		}
+	}
+
+	if (flagmask)
+		*flagmask = mask;
+
+	return result;
+}
+
+std::string writeFlagString(u32 flags, const FlagDesc *flagdesc, u32 flagmask)
+{
+	std::string result;
+
+	for (int i = 0; flagdesc[i].name; i++) {
+		if (flagmask & flagdesc[i].flag) {
+			if (!(flags & flagdesc[i].flag))
+				result += "no";
+
+			result += flagdesc[i].name;
+			result += ", ";
+		}
+	}
+
+	size_t len = result.length();
+	if (len >= 2)
+		result.erase(len - 2, 2);
+
+	return result;
+}
+
+size_t mystrlcpy(char *dst, const char *src, size_t size)
+{
+	size_t srclen  = strlen(src) + 1;
+	size_t copylen = MYMIN(srclen, size);
+
+	if (copylen > 0) {
+		memcpy(dst, src, copylen);
+		dst[copylen - 1] = '\0';
+	}
+
+	return srclen;
+}
+
+char *mystrtok_r(char *s, const char *sep, char **lasts)
+{
+	char *t;
+
+	if (!s)
+		s = *lasts;
+
+	while (*s && strchr(sep, *s))
+		s++;
+
+	if (!*s)
+		return nullptr;
+
+	t = s;
+	while (*t) {
+		if (strchr(sep, *t)) {
+			*t++ = '\0';
+			break;
+		}
+		t++;
+	}
+
+	*lasts = t;
+	return s;
+}
+
+u64 read_seed(const char *str)
+{
+	char *endptr;
+	u64 num;
+
+	if (str[0] == '0' && str[1] == 'x')
+		num = strtoull(str, &endptr, 16);
+	else
+		num = strtoull(str, &endptr, 10);
+
+	if (*endptr)
+		num = murmur_hash_64_ua(str, (int)strlen(str), 0x1337);
+
+	return num;
+}
+
+static bool parseHexColorString(const std::string &value, video::SColor &color,
+		unsigned char default_alpha)
+{
+	u8 components[] = {0x00, 0x00, 0x00, default_alpha}; // R,G,B,A
+
+	size_t len = value.size();
+	bool short_form;
+
+	if (len == 9 || len == 7) // #RRGGBBAA or #RRGGBB
+		short_form = false;
+	else if (len == 5 || len == 4) // #RGBA or #RGB
+		short_form = true;
+	else
+		return false;
+
+	for (size_t pos = 1, cc = 0; pos < len; pos++, cc++) {
+		if (short_form) {
+			u8 d;
+			if (!hex_digit_decode(value[pos], d))
+				return false;
+
+			components[cc] = (d & 0xf) << 4 | (d & 0xf);
+		} else {
+			u8 d1, d2;
+			if (!hex_digit_decode(value[pos], d1) ||
+					!hex_digit_decode(value[pos+1], d2))
+				return false;
+
+			components[cc] = (d1 & 0xf) << 4 | (d2 & 0xf);
+			pos++; // skip the second digit -- it's already used
+		}
+	}
+
+	color.setRed(components[0]);
+	color.setGreen(components[1]);
+	color.setBlue(components[2]);
+	color.setAlpha(components[3]);
+
+	return true;
+}
+
+const static std::unordered_map<std::string, u32> s_named_colors = {
+	{"aliceblue",            0xf0f8ff},
+	{"antiquewhite",         0xfaebd7},
+	{"aqua",                 0x00ffff},
+	{"aquamarine",           0x7fffd4},
+	{"azure",                0xf0ffff},
+	{"beige",                0xf5f5dc},
+	{"bisque",               0xffe4c4},
+	{"black",                00000000},
+	{"blanchedalmond",       0xffebcd},
+	{"blue",                 0x0000ff},
+	{"blueviolet",           0x8a2be2},
+	{"brown",                0xa52a2a},
+	{"burlywood",            0xdeb887},
+	{"cadetblue",            0x5f9ea0},
+	{"chartreuse",           0x7fff00},
+	{"chocolate",            0xd2691e},
+	{"coral",                0xff7f50},
+	{"cornflowerblue",       0x6495ed},
+	{"cornsilk",             0xfff8dc},
+	{"crimson",              0xdc143c},
+	{"cyan",                 0x00ffff},
+	{"darkblue",             0x00008b},
+	{"darkcyan",             0x008b8b},
+	{"darkgoldenrod",        0xb8860b},
+	{"darkgray",             0xa9a9a9},
+	{"darkgreen",            0x006400},
+	{"darkgrey",             0xa9a9a9},
+	{"darkkhaki",            0xbdb76b},
+	{"darkmagenta",          0x8b008b},
+	{"darkolivegreen",       0x556b2f},
+	{"darkorange",           0xff8c00},
+	{"darkorchid",           0x9932cc},
+	{"darkred",              0x8b0000},
+	{"darksalmon",           0xe9967a},
+	{"darkseagreen",         0x8fbc8f},
+	{"darkslateblue",        0x483d8b},
+	{"darkslategray",        0x2f4f4f},
+	{"darkslategrey",        0x2f4f4f},
+	{"darkturquoise",        0x00ced1},
+	{"darkviolet",           0x9400d3},
+	{"deeppink",             0xff1493},
+	{"deepskyblue",          0x00bfff},
+	{"dimgray",              0x696969},
+	{"dimgrey",              0x696969},
+	{"dodgerblue",           0x1e90ff},
+	{"firebrick",            0xb22222},
+	{"floralwhite",          0xfffaf0},
+	{"forestgreen",          0x228b22},
+	{"fuchsia",              0xff00ff},
+	{"gainsboro",            0xdcdcdc},
+	{"ghostwhite",           0xf8f8ff},
+	{"gold",                 0xffd700},
+	{"goldenrod",            0xdaa520},
+	{"gray",                 0x808080},
+	{"green",                0x008000},
+	{"greenyellow",          0xadff2f},
+	{"grey",                 0x808080},
+	{"honeydew",             0xf0fff0},
+	{"hotpink",              0xff69b4},
+	{"indianred",            0xcd5c5c},
+	{"indigo",               0x4b0082},
+	{"ivory",                0xfffff0},
+	{"khaki",                0xf0e68c},
+	{"lavender",             0xe6e6fa},
+	{"lavenderblush",        0xfff0f5},
+	{"lawngreen",            0x7cfc00},
+	{"lemonchiffon",         0xfffacd},
+	{"lightblue",            0xadd8e6},
+	{"lightcoral",           0xf08080},
+	{"lightcyan",            0xe0ffff},
+	{"lightgoldenrodyellow", 0xfafad2},
+	{"lightgray",            0xd3d3d3},
+	{"lightgreen",           0x90ee90},
+	{"lightgrey",            0xd3d3d3},
+	{"lightpink",            0xffb6c1},
+	{"lightsalmon",          0xffa07a},
+	{"lightseagreen",        0x20b2aa},
+	{"lightskyblue",         0x87cefa},
+	{"lightslategray",       0x778899},
+	{"lightslategrey",       0x778899},
+	{"lightsteelblue",       0xb0c4de},
+	{"lightyellow",          0xffffe0},
+	{"lime",                 0x00ff00},
+	{"limegreen",            0x32cd32},
+	{"linen",                0xfaf0e6},
+	{"magenta",              0xff00ff},
+	{"maroon",               0x800000},
+	{"mediumaquamarine",     0x66cdaa},
+	{"mediumblue",           0x0000cd},
+	{"mediumorchid",         0xba55d3},
+	{"mediumpurple",         0x9370db},
+	{"mediumseagreen",       0x3cb371},
+	{"mediumslateblue",      0x7b68ee},
+	{"mediumspringgreen",    0x00fa9a},
+	{"mediumturquoise",      0x48d1cc},
+	{"mediumvioletred",      0xc71585},
+	{"midnightblue",         0x191970},
+	{"mintcream",            0xf5fffa},
+	{"mistyrose",            0xffe4e1},
+	{"moccasin",             0xffe4b5},
+	{"navajowhite",          0xffdead},
+	{"navy",                 0x000080},
+	{"oldlace",              0xfdf5e6},
+	{"olive",                0x808000},
+	{"olivedrab",            0x6b8e23},
+	{"orange",               0xffa500},
+	{"orangered",            0xff4500},
+	{"orchid",               0xda70d6},
+	{"palegoldenrod",        0xeee8aa},
+	{"palegreen",            0x98fb98},
+	{"paleturquoise",        0xafeeee},
+	{"palevioletred",        0xdb7093},
+	{"papayawhip",           0xffefd5},
+	{"peachpuff",            0xffdab9},
+	{"peru",                 0xcd853f},
+	{"pink",                 0xffc0cb},
+	{"plum",                 0xdda0dd},
+	{"powderblue",           0xb0e0e6},
+	{"purple",               0x800080},
+	{"rebeccapurple",        0x663399},
+	{"red",                  0xff0000},
+	{"rosybrown",            0xbc8f8f},
+	{"royalblue",            0x4169e1},
+	{"saddlebrown",          0x8b4513},
+	{"salmon",               0xfa8072},
+	{"sandybrown",           0xf4a460},
+	{"seagreen",             0x2e8b57},
+	{"seashell",             0xfff5ee},
+	{"sienna",               0xa0522d},
+	{"silver",               0xc0c0c0},
+	{"skyblue",              0x87ceeb},
+	{"slateblue",            0x6a5acd},
+	{"slategray",            0x708090},
+	{"slategrey",            0x708090},
+	{"snow",                 0xfffafa},
+	{"springgreen",          0x00ff7f},
+	{"steelblue",            0x4682b4},
+	{"tan",                  0xd2b48c},
+	{"teal",                 0x008080},
+	{"thistle",              0xd8bfd8},
+	{"tomato",               0xff6347},
+	{"turquoise",            0x40e0d0},
+	{"violet",               0xee82ee},
+	{"wheat",                0xf5deb3},
+	{"white",                0xffffff},
+	{"whitesmoke",           0xf5f5f5},
+	{"yellow",               0xffff00},
+	{"yellowgreen",          0x9acd32}
+};
+
+static bool parseNamedColorString(const std::string &value, video::SColor &color)
+{
+	std::string color_name;
+	std::string alpha_string;
+
+	/* If the string has a # in it, assume this is the start of a specified
+	 * alpha value (if it isn't the string is invalid and the error will be
+	 * caught later on, either because the color name won't be found or the
+	 * alpha value will fail conversion)
+	 */
+	size_t alpha_pos = value.find('#');
+	if (alpha_pos != std::string::npos) {
+		color_name = value.substr(0, alpha_pos);
+		alpha_string = value.substr(alpha_pos + 1);
+	} else {
+		color_name = value;
+	}
+
+	color_name = lowercase(color_name);
+
+	auto it = s_named_colors.find(color_name);
+	if (it == s_named_colors.end())
+		return false;
+
+	u32 color_temp = it->second;
+
+	/* An empty string for alpha is ok (none of the color table entries
+	 * have an alpha value either). Color strings without an alpha specified
+	 * are interpreted as fully opaque
+	 */
+	if (!alpha_string.empty()) {
+		if (alpha_string.size() == 1) {
+			u8 d;
+			if (!hex_digit_decode(alpha_string[0], d))
+				return false;
+
+			color_temp |= ((d & 0xf) << 4 | (d & 0xf)) << 24;
+		} else if (alpha_string.size() == 2) {
+			u8 d1, d2;
+			if (!hex_digit_decode(alpha_string[0], d1)
+					|| !hex_digit_decode(alpha_string[1], d2))
+				return false;
+
+			color_temp |= ((d1 & 0xf) << 4 | (d2 & 0xf)) << 24;
+		} else {
+			return false;
+		}
+	} else {
+		color_temp |= 0xff << 24; // Fully opaque
+	}
+
+	color = video::SColor(color_temp);
+
+	return true;
+}
+
+bool parseColorString(const std::string &value, video::SColor &color, bool quiet,
+		unsigned char default_alpha)
+{
+	bool success;
+
+	if (value[0] == '#')
+		success = parseHexColorString(value, color, default_alpha);
+	else
+		success = parseNamedColorString(value, color);
+
+	if (!success && !quiet)
+		errorstream << "Invalid color: \"" << value << "\"" << std::endl;
+
+	return success;
+}
+
+void str_replace(std::string &str, char from, char to)
+{
+	std::replace(str.begin(), str.end(), from, to);
+}
+
+/* Translated strings have the following format:
+ * \x1bT marks the beginning of a translated string
+ * \x1bE marks its end
+ *
+ * \x1bF marks the beginning of an argument, and \x1bE its end.
+ *
+ * Arguments are *not* translated, as they may contain escape codes.
+ * Thus, if you want a translated argument, it should be inside \x1bT/\x1bE tags as well.
+ *
+ * This representation is chosen so that clients ignoring escape codes will
+ * see untranslated strings.
+ *
+ * For instance, suppose we have a string such as "@1 Wool" with the argument "White"
+ * The string will be sent as "\x1bT\x1bF\x1bTWhite\x1bE\x1bE Wool\x1bE"
+ * To translate this string, we extract what is inside \x1bT/\x1bE tags.
+ * When we notice the \x1bF tag, we recursively extract what is there up to the \x1bE end tag,
+ * translating it as well.
+ * We get the argument "White", translated, and create a template string with "@1" instead of it.
+ * We finally get the template "@1 Wool" that was used in the beginning, which we translate
+ * before filling it again.
+ */
+
+void translate_all(const std::wstring &s, size_t &i,
+		Translations *translations, std::wstring &res);
+
+void translate_string(const std::wstring &s, Translations *translations,
+		const std::wstring &textdomain, size_t &i, std::wstring &res)
+{
+	std::wostringstream output;
+	std::vector<std::wstring> args;
+	int arg_number = 1;
+	while (i < s.length()) {
+		// Not an escape sequence: just add the character.
+		if (s[i] != '\x1b') {
+			output.put(s[i]);
+			// The character is a literal '@'; add it twice
+			// so that it is not mistaken for an argument.
+			if (s[i] == L'@')
+				output.put(L'@');
+			++i;
+			continue;
+		}
+
+		// We have an escape sequence: locate it and its data
+		// It is either a single character, or it begins with '('
+		// and extends up to the following ')', with '\' as an escape character.
+		++i;
+		size_t start_index = i;
+		size_t length;
+		if (i == s.length()) {
+			length = 0;
+		} else if (s[i] == L'(') {
+			++i;
+			++start_index;
+			while (i < s.length() && s[i] != L')') {
+				if (s[i] == L'\\')
+					++i;
+				++i;
+			}
+			length = i - start_index;
+			++i;
+			if (i > s.length())
+				i = s.length();
+		} else {
+			++i;
+			length = 1;
+		}
+		std::wstring escape_sequence(s, start_index, length);
+
+		// The escape sequence is now reconstructed.
+		std::vector<std::wstring> parts = split(escape_sequence, L'@');
+		if (parts[0] == L"E") {
+			// "End of translation" escape sequence. We are done locating the string to translate.
+			break;
+		} else if (parts[0] == L"F") {
+			// "Start of argument" escape sequence.
+			// Recursively translate the argument, and add it to the argument list.
+			// Add an "@n" instead of the argument to the template to translate.
+			if (arg_number >= 10) {
+				errorstream << "Ignoring too many arguments to translation" << std::endl;
+				std::wstring arg;
+				translate_all(s, i, translations, arg);
+				args.push_back(arg);
+				continue;
+			}
+			output.put(L'@');
+			output << arg_number;
+			++arg_number;
+			std::wstring arg;
+			translate_all(s, i, translations, arg);
+			args.push_back(arg);
+		} else {
+			// This is an escape sequence *inside* the template string to translate itself.
+			// This should not happen, show an error message.
+			errorstream << "Ignoring escape sequence '"
+				<< wide_to_utf8(escape_sequence) << "' in translation" << std::endl;
+		}
+	}
+
+	std::wstring toutput;
+	// Translate the template.
+	if (translations != nullptr)
+		toutput = translations->getTranslation(
+				textdomain, output.str());
+	else
+		toutput = output.str();
+
+	// Put back the arguments in the translated template.
+	std::wostringstream result;
+	size_t j = 0;
+	while (j < toutput.length()) {
+		// Normal character, add it to output and continue.
+		if (toutput[j] != L'@' || j == toutput.length() - 1) {
+			result.put(toutput[j]);
+			++j;
+			continue;
+		}
+
+		++j;
+		// Literal escape for '@'.
+		if (toutput[j] == L'@') {
+			result.put(L'@');
+			++j;
+			continue;
+		}
+
+		// Here we have an argument; get its index and add the translated argument to the output.
+		int arg_index = toutput[j] - L'1';
+		++j;
+		if (0 <= arg_index && (size_t)arg_index < args.size()) {
+			result << args[arg_index];
+		} else {
+			// This is not allowed: show an error message
+			errorstream << "Ignoring out-of-bounds argument escape sequence in translation" << std::endl;
+		}
+	}
+	res = result.str();
+}
+
+void translate_all(const std::wstring &s, size_t &i,
+		Translations *translations, std::wstring &res)
+{
+	std::wostringstream output;
+	while (i < s.length()) {
+		// Not an escape sequence: just add the character.
+		if (s[i] != '\x1b') {
+			output.put(s[i]);
+			++i;
+			continue;
+		}
+
+		// We have an escape sequence: locate it and its data
+		// It is either a single character, or it begins with '('
+		// and extends up to the following ')', with '\' as an escape character.
+		size_t escape_start = i;
+		++i;
+		size_t start_index = i;
+		size_t length;
+		if (i == s.length()) {
+			length = 0;
+		} else if (s[i] == L'(') {
+			++i;
+			++start_index;
+			while (i < s.length() && s[i] != L')') {
+				if (s[i] == L'\\') {
+					++i;
+				}
+				++i;
+			}
+			length = i - start_index;
+			++i;
+			if (i > s.length())
+				i = s.length();
+		} else {
+			++i;
+			length = 1;
+		}
+		std::wstring escape_sequence(s, start_index, length);
+
+		// The escape sequence is now reconstructed.
+		std::vector<std::wstring> parts = split(escape_sequence, L'@');
+		if (parts[0] == L"E") {
+			// "End of argument" escape sequence. Exit.
+			break;
+		} else if (parts[0] == L"T") {
+			// Beginning of translated string.
+			std::wstring textdomain;
+			if (parts.size() > 1)
+				textdomain = parts[1];
+			std::wstring translated;
+			translate_string(s, translations, textdomain, i, translated);
+			output << translated;
+		} else {
+			// Another escape sequence, such as colors. Preserve it.
+			output << std::wstring(s, escape_start, i - escape_start);
+		}
+	}
+
+	res = output.str();
+}
+
+// Translate string server side
+std::wstring translate_string(const std::wstring &s, Translations *translations)
+{
+	size_t i = 0;
+	std::wstring res;
+	translate_all(s, i, translations, res);
+	return res;
+}
+
+// Translate string client side
+std::wstring translate_string(const std::wstring &s)
+{
+#ifdef SERVER
+	return translate_string(s, nullptr);
+#else
+	return translate_string(s, g_client_translations);
+#endif
+}
+
+static const std::array<std::wstring, 30> disallowed_dir_names = {
+	// Problematic filenames from here:
+	// https://docs.microsoft.com/en-us/windows/win32/fileio/naming-a-file#file-and-directory-names
+	// Plus undocumented values from here:
+	// https://googleprojectzero.blogspot.com/2016/02/the-definitive-guide-on-win32-to-nt.html
+	L"CON",
+	L"PRN",
+	L"AUX",
+	L"NUL",
+	L"COM1",
+	L"COM2",
+	L"COM3",
+	L"COM4",
+	L"COM5",
+	L"COM6",
+	L"COM7",
+	L"COM8",
+	L"COM9",
+	L"COM\u00B2",
+	L"COM\u00B3",
+	L"COM\u00B9",
+	L"LPT1",
+	L"LPT2",
+	L"LPT3",
+	L"LPT4",
+	L"LPT5",
+	L"LPT6",
+	L"LPT7",
+	L"LPT8",
+	L"LPT9",
+	L"LPT\u00B2",
+	L"LPT\u00B3",
+	L"LPT\u00B9",
+	L"CONIN$",
+	L"CONOUT$",
+};
+
+/**
+ * List of characters that are blacklisted from created directories
+ */
+static const std::wstring disallowed_path_chars = L"<>:\"/\\|?*.";
+
+
+std::string sanitizeDirName(const std::string &str, const std::string &optional_prefix)
+{
+	std::wstring safe_name = utf8_to_wide(str);
+
+	for (std::wstring disallowed_name : disallowed_dir_names) {
+		if (str_equal(safe_name, disallowed_name, true)) {
+			safe_name = utf8_to_wide(optional_prefix) + safe_name;
+			break;
+		}
+	}
+
+	// Replace leading and trailing spaces with underscores.
+	size_t start = safe_name.find_first_not_of(L' ');
+	size_t end = safe_name.find_last_not_of(L' ');
+	if (start == std::wstring::npos || end == std::wstring::npos)
+		start = end = safe_name.size();
+	for (size_t i = 0; i < start; i++)
+		safe_name[i] = L'_';
+	for (size_t i = end + 1; i < safe_name.size(); i++)
+		safe_name[i] = L'_';
+
+	// Replace other disallowed characters with underscores
+	for (size_t i = 0; i < safe_name.length(); i++) {
+		bool is_valid = true;
+
+		// Unlikely, but control characters should always be blacklisted
+		if (safe_name[i] < 32) {
+			is_valid = false;
+		} else if (safe_name[i] < 128) {
+			is_valid = disallowed_path_chars.find_first_of(safe_name[i])
+					== std::wstring::npos;
+		}
+
+		if (!is_valid)
+			safe_name[i] = L'_';
+	}
+
+	return wide_to_utf8(safe_name);
+}
+
+
+void safe_print_string(std::ostream &os, const std::string &str)
+{
+	std::ostream::fmtflags flags = os.flags();
+	os << std::hex;
+	for (const char c : str) {
+		if (IS_ASCII_PRINTABLE_CHAR(c) || IS_UTF8_MULTB_START(c) ||
+				IS_UTF8_MULTB_INNER(c) || c == '\n' || c == '\t') {
+			os << c;
+		} else {
+			os << '<' << std::setw(2) << (int)c << '>';
+		}
+	}
+	os.setf(flags);
+}

src/util/string.h

@@ -0,0 +1,763 @@
+/*
+Minetest
+Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#pragma once
+
+#include "irrlichttypes_bloated.h"
+#include "irrString.h"
+#include <cstdlib>
+#include <string>
+#include <cstring>
+#include <vector>
+#include <map>
+#include <sstream>
+#include <iomanip>
+#include <cctype>
+#include <unordered_map>
+
+class Translations;
+
+#define STRINGIFY(x) #x
+#define TOSTRING(x) STRINGIFY(x)
+
+// Checks whether a value is an ASCII printable character
+#define IS_ASCII_PRINTABLE_CHAR(x)   \
+	(((unsigned int)(x) >= 0x20) &&  \
+	( (unsigned int)(x) <= 0x7e))
+
+// Checks whether a byte is an inner byte for an utf-8 multibyte sequence
+#define IS_UTF8_MULTB_INNER(x)       \
+	(((unsigned char)(x) >= 0x80) && \
+	( (unsigned char)(x) <= 0xbf))
+
+// Checks whether a byte is a start byte for an utf-8 multibyte sequence
+#define IS_UTF8_MULTB_START(x)       \
+	(((unsigned char)(x) >= 0xc2) && \
+	( (unsigned char)(x) <= 0xf4))
+
+// Given a start byte x for an utf-8 multibyte sequence
+// it gives the length of the whole sequence in bytes.
+#define UTF8_MULTB_START_LEN(x)            \
+	(((unsigned char)(x) < 0xe0) ? 2 :     \
+	(((unsigned char)(x) < 0xf0) ? 3 : 4))
+
+typedef std::unordered_map<std::string, std::string> StringMap;
+
+struct FlagDesc {
+	const char *name;
+	u32 flag;
+};
+
+// Try to avoid converting between wide and UTF-8 unless you need to
+// input/output stuff via Irrlicht
+std::wstring utf8_to_wide(const std::string &input);
+std::string wide_to_utf8(const std::wstring &input);
+
+// You must free the returned string!
+// The returned string is allocated using new[]
+wchar_t *utf8_to_wide_c(const char *str);
+
+std::string urlencode(const std::string &str);
+std::string urldecode(const std::string &str);
+u32 readFlagString(std::string str, const FlagDesc *flagdesc, u32 *flagmask);
+std::string writeFlagString(u32 flags, const FlagDesc *flagdesc, u32 flagmask);
+size_t mystrlcpy(char *dst, const char *src, size_t size);
+char *mystrtok_r(char *s, const char *sep, char **lasts);
+u64 read_seed(const char *str);
+bool parseColorString(const std::string &value, video::SColor &color, bool quiet,
+		unsigned char default_alpha = 0xff);
+
+
+/**
+ * Returns a copy of \p str with spaces inserted at the right hand side to ensure
+ * that the string is \p len characters in length. If \p str is <= \p len then the
+ * returned string will be identical to str.
+ */
+inline std::string padStringRight(std::string str, size_t len)
+{
+	if (len > str.size())
+		str.insert(str.end(), len - str.size(), ' ');
+
+	return str;
+}
+
+/**
+ * Returns a version of \p str with the first occurrence of a string
+ * contained within ends[] removed from the end of the string.
+ *
+ * @param str
+ * @param ends A NULL- or ""- terminated array of strings to remove from s in
+ *	the copy produced.  Note that once one of these strings is removed
+ *	that no further postfixes contained within this array are removed.
+ *
+ * @return If no end could be removed then "" is returned.
+ */
+inline std::string removeStringEnd(const std::string &str,
+		const char *ends[])
+{
+	const char **p = ends;
+
+	for (; *p && (*p)[0] != '\0'; p++) {
+		std::string end = *p;
+		if (str.size() < end.size())
+			continue;
+		if (str.compare(str.size() - end.size(), end.size(), end) == 0)
+			return str.substr(0, str.size() - end.size());
+	}
+
+	return "";
+}
+
+
+/**
+ * Check two strings for equivalence.  If \p case_insensitive is true
+ * then the case of the strings is ignored (default is false).
+ *
+ * @param s1
+ * @param s2
+ * @param case_insensitive
+ * @return true if the strings match
+ */
+template <typename T>
+inline bool str_equal(const std::basic_string<T> &s1,
+		const std::basic_string<T> &s2,
+		bool case_insensitive = false)
+{
+	if (!case_insensitive)
+		return s1 == s2;
+
+	if (s1.size() != s2.size())
+		return false;
+
+	for (size_t i = 0; i < s1.size(); ++i)
+		if(tolower(s1[i]) != tolower(s2[i]))
+			return false;
+
+	return true;
+}
+
+
+/**
+ * Check whether \p str begins with the string prefix. If \p case_insensitive
+ * is true then the check is case insensitve (default is false; i.e. case is
+ * significant).
+ *
+ * @param str
+ * @param prefix
+ * @param case_insensitive
+ * @return true if the str begins with prefix
+ */
+template <typename T>
+inline bool str_starts_with(const std::basic_string<T> &str,
+		const std::basic_string<T> &prefix,
+		bool case_insensitive = false)
+{
+	if (str.size() < prefix.size())
+		return false;
+
+	if (!case_insensitive)
+		return str.compare(0, prefix.size(), prefix) == 0;
+
+	for (size_t i = 0; i < prefix.size(); ++i)
+		if (tolower(str[i]) != tolower(prefix[i]))
+			return false;
+	return true;
+}
+
+/**
+ * Check whether \p str begins with the string prefix. If \p case_insensitive
+ * is true then the check is case insensitve (default is false; i.e. case is
+ * significant).
+ *
+ * @param str
+ * @param prefix
+ * @param case_insensitive
+ * @return true if the str begins with prefix
+ */
+template <typename T>
+inline bool str_starts_with(const std::basic_string<T> &str,
+		const T *prefix,
+		bool case_insensitive = false)
+{
+	return str_starts_with(str, std::basic_string<T>(prefix),
+			case_insensitive);
+}
+
+
+/**
+ * Check whether \p str ends with the string suffix. If \p case_insensitive
+ * is true then the check is case insensitve (default is false; i.e. case is
+ * significant).
+ *
+ * @param str
+ * @param suffix
+ * @param case_insensitive
+ * @return true if the str begins with suffix
+ */
+template <typename T>
+inline bool str_ends_with(const std::basic_string<T> &str,
+		const std::basic_string<T> &suffix,
+		bool case_insensitive = false)
+{
+	if (str.size() < suffix.size())
+		return false;
+
+	size_t start = str.size() - suffix.size();
+	if (!case_insensitive)
+		return str.compare(start, suffix.size(), suffix) == 0;
+
+	for (size_t i = 0; i < suffix.size(); ++i)
+		if (tolower(str[start + i]) != tolower(suffix[i]))
+			return false;
+	return true;
+}
+
+
+/**
+ * Check whether \p str ends with the string suffix. If \p case_insensitive
+ * is true then the check is case insensitve (default is false; i.e. case is
+ * significant).
+ *
+ * @param str
+ * @param suffix
+ * @param case_insensitive
+ * @return true if the str begins with suffix
+ */
+template <typename T>
+inline bool str_ends_with(const std::basic_string<T> &str,
+		const T *suffix,
+		bool case_insensitive = false)
+{
+	return str_ends_with(str, std::basic_string<T>(suffix),
+			case_insensitive);
+}
+
+
+/**
+ * Splits a string into its component parts separated by the character
+ * \p delimiter.
+ *
+ * @return An std::vector<std::basic_string<T> > of the component parts
+ */
+template <typename T>
+inline std::vector<std::basic_string<T> > str_split(
+		const std::basic_string<T> &str,
+		T delimiter)
+{
+	std::vector<std::basic_string<T> > parts;
+	std::basic_stringstream<T> sstr(str);
+	std::basic_string<T> part;
+
+	while (std::getline(sstr, part, delimiter))
+		parts.push_back(part);
+
+	return parts;
+}
+
+
+/**
+ * @param str
+ * @return A copy of \p str converted to all lowercase characters.
+ */
+inline std::string lowercase(const std::string &str)
+{
+	std::string s2;
+
+	s2.reserve(str.size());
+
+	for (char i : str)
+		s2 += tolower(i);
+
+	return s2;
+}
+
+
+/**
+ * @param str
+ * @return A copy of \p str with leading and trailing whitespace removed.
+ */
+inline std::string trim(const std::string &str)
+{
+	size_t front = 0;
+	size_t back = str.size();
+
+	while (front < back && std::isspace(str[front]))
+		++front;
+
+	while (back > front && std::isspace(str[back - 1]))
+		--back;
+
+	return str.substr(front, back - front);
+}
+
+
+/**
+ * Returns whether \p str should be regarded as (bool) true.  Case and leading
+ * and trailing whitespace are ignored.  Values that will return
+ * true are "y", "yes", "true" and any number that is not 0.
+ * @param str
+ */
+inline bool is_yes(const std::string &str)
+{
+	std::string s2 = lowercase(trim(str));
+
+	return s2 == "y" || s2 == "yes" || s2 == "true" || atoi(s2.c_str()) != 0;
+}
+
+
+/**
+ * Converts the string \p str to a signed 32-bit integer. The converted value
+ * is constrained so that min <= value <= max.
+ *
+ * @see atoi(3) for limitations
+ *
+ * @param str
+ * @param min Range minimum
+ * @param max Range maximum
+ * @return The value converted to a signed 32-bit integer and constrained
+ *	within the range defined by min and max (inclusive)
+ */
+inline s32 mystoi(const std::string &str, s32 min, s32 max)
+{
+	s32 i = atoi(str.c_str());
+
+	if (i < min)
+		i = min;
+	if (i > max)
+		i = max;
+
+	return i;
+}
+
+/**
+ * Returns a 32-bit value reprensented by the string \p str (decimal).
+ * @see atoi(3) for further limitations
+ */
+inline s32 mystoi(const std::string &str)
+{
+	return atoi(str.c_str());
+}
+
+/**
+ * Returns a float reprensented by the string \p str (decimal).
+ * @see atof(3)
+ */
+inline float mystof(const std::string &str)
+{
+	return atof(str.c_str());
+}
+
+#define stoi mystoi
+#define stof mystof
+
+/// Returns a value represented by the string \p val.
+template <typename T>
+inline T from_string(const std::string &str)
+{
+	std::stringstream tmp(str);
+	T t;
+	tmp >> t;
+	return t;
+}
+
+/// Returns a 64-bit signed value represented by the string \p str (decimal).
+inline s64 stoi64(const std::string &str) { return from_string<s64>(str); }
+
+#if __cplusplus < 201103L
+namespace std {
+
+/// Returns a string representing the value \p val.
+template <typename T>
+inline string to_string(T val)
+{
+	ostringstream oss;
+	oss << val;
+	return oss.str();
+}
+#define DEFINE_STD_TOSTRING_FLOATINGPOINT(T)		\
+	template <>					\
+	inline string to_string<T>(T val)		\
+	{						\
+		ostringstream oss;			\
+		oss << std::fixed			\
+			<< std::setprecision(6)		\
+			<< val;				\
+		return oss.str();			\
+	}
+DEFINE_STD_TOSTRING_FLOATINGPOINT(float)
+DEFINE_STD_TOSTRING_FLOATINGPOINT(double)
+DEFINE_STD_TOSTRING_FLOATINGPOINT(long double)
+
+#undef DEFINE_STD_TOSTRING_FLOATINGPOINT
+
+/// Returns a wide string representing the value \p val
+template <typename T>
+inline wstring to_wstring(T val)
+{
+	return utf8_to_wide(to_string(val));
+}
+}
+#endif
+
+/// Returns a string representing the decimal value of the 32-bit value \p i.
+inline std::string itos(s32 i) { return std::to_string(i); }
+/// Returns a string representing the decimal value of the 64-bit value \p i.
+inline std::string i64tos(s64 i) { return std::to_string(i); }
+
+// std::to_string uses the '%.6f' conversion, which is inconsistent with
+// std::ostream::operator<<() and impractical too.  ftos() uses the
+// more generic and std::ostream::operator<<()-compatible '%G' format.
+/// Returns a string representing the decimal value of the float value \p f.
+inline std::string ftos(float f)
+{
+	std::ostringstream oss;
+	oss << f;
+	return oss.str();
+}
+
+
+/**
+ * Replace all occurrences of \p pattern in \p str with \p replacement.
+ *
+ * @param str String to replace pattern with replacement within.
+ * @param pattern The pattern to replace.
+ * @param replacement What to replace the pattern with.
+ */
+inline void str_replace(std::string &str, const std::string &pattern,
+		const std::string &replacement)
+{
+	std::string::size_type start = str.find(pattern, 0);
+	while (start != str.npos) {
+		str.replace(start, pattern.size(), replacement);
+		start = str.find(pattern, start + replacement.size());
+	}
+}
+
+/**
+ * Escapes characters [ ] \ , ; that can not be used in formspecs
+ */
+inline void str_formspec_escape(std::string &str)
+{
+	str_replace(str, "\\", "\\\\");
+	str_replace(str, "]", "\\]");
+	str_replace(str, "[", "\\[");
+	str_replace(str, ";", "\\;");
+	str_replace(str, ",", "\\,");
+}
+
+/**
+ * Replace all occurrences of the character \p from in \p str with \p to.
+ *
+ * @param str The string to (potentially) modify.
+ * @param from The character in str to replace.
+ * @param to The replacement character.
+ */
+void str_replace(std::string &str, char from, char to);
+
+
+/**
+ * Check that a string only contains whitelisted characters. This is the
+ * opposite of string_allowed_blacklist().
+ *
+ * @param str The string to be checked.
+ * @param allowed_chars A string containing permitted characters.
+ * @return true if the string is allowed, otherwise false.
+ *
+ * @see string_allowed_blacklist()
+ */
+inline bool string_allowed(const std::string &str, const std::string &allowed_chars)
+{
+	return str.find_first_not_of(allowed_chars) == str.npos;
+}
+
+
+/**
+ * Check that a string contains no blacklisted characters. This is the
+ * opposite of string_allowed().
+ *
+ * @param str The string to be checked.
+ * @param blacklisted_chars A string containing prohibited characters.
+ * @return true if the string is allowed, otherwise false.
+
+ * @see string_allowed()
+ */
+inline bool string_allowed_blacklist(const std::string &str,
+		const std::string &blacklisted_chars)
+{
+	return str.find_first_of(blacklisted_chars) == str.npos;
+}
+
+
+/**
+ * Create a string based on \p from where a newline is forcefully inserted
+ * every \p row_len characters.
+ *
+ * @note This function does not honour word wraps and blindy inserts a newline
+ *	every \p row_len characters whether it breaks a word or not.  It is
+ *	intended to be used for, for example, showing paths in the GUI.
+ *
+ * @note This function doesn't wrap inside utf-8 multibyte sequences and also
+ * 	counts multibyte sequences correcly as single characters.
+ *
+ * @param from The (utf-8) string to be wrapped into rows.
+ * @param row_len The row length (in characters).
+ * @return A new string with the wrapping applied.
+ */
+inline std::string wrap_rows(const std::string &from,
+		unsigned row_len)
+{
+	std::string to;
+
+	size_t character_idx = 0;
+	for (size_t i = 0; i < from.size(); i++) {
+		if (!IS_UTF8_MULTB_INNER(from[i])) {
+			// Wrap string after last inner byte of char
+			if (character_idx > 0 && character_idx % row_len == 0)
+				to += '\n';
+			character_idx++;
+		}
+		to += from[i];
+	}
+
+	return to;
+}
+
+
+/**
+ * Removes backslashes from an escaped string (FormSpec strings)
+ */
+template <typename T>
+inline std::basic_string<T> unescape_string(const std::basic_string<T> &s)
+{
+	std::basic_string<T> res;
+
+	for (size_t i = 0; i < s.length(); i++) {
+		if (s[i] == '\\') {
+			i++;
+			if (i >= s.length())
+				break;
+		}
+		res += s[i];
+	}
+
+	return res;
+}
+
+/**
+ * Remove all escape sequences in \p s.
+ *
+ * @param s The string in which to remove escape sequences.
+ * @return \p s, with escape sequences removed.
+ */
+template <typename T>
+std::basic_string<T> unescape_enriched(const std::basic_string<T> &s)
+{
+	std::basic_string<T> output;
+	size_t i = 0;
+	while (i < s.length()) {
+		if (s[i] == '\x1b') {
+			++i;
+			if (i == s.length()) continue;
+			if (s[i] == '(') {
+				++i;
+				while (i < s.length() && s[i] != ')') {
+					if (s[i] == '\\') {
+						++i;
+					}
+					++i;
+				}
+				++i;
+			} else {
+				++i;
+			}
+			continue;
+		}
+		output += s[i];
+		++i;
+	}
+	return output;
+}
+
+template <typename T>
+std::vector<std::basic_string<T> > split(const std::basic_string<T> &s, T delim)
+{
+	std::vector<std::basic_string<T> > tokens;
+
+	std::basic_string<T> current;
+	bool last_was_escape = false;
+	for (size_t i = 0; i < s.length(); i++) {
+		T si = s[i];
+		if (last_was_escape) {
+			current += '\\';
+			current += si;
+			last_was_escape = false;
+		} else {
+			if (si == delim) {
+				tokens.push_back(current);
+				current = std::basic_string<T>();
+				last_was_escape = false;
+			} else if (si == '\\') {
+				last_was_escape = true;
+			} else {
+				current += si;
+				last_was_escape = false;
+			}
+		}
+	}
+	//push last element
+	tokens.push_back(current);
+
+	return tokens;
+}
+
+std::wstring translate_string(const std::wstring &s, Translations *translations);
+
+std::wstring translate_string(const std::wstring &s);
+
+inline std::wstring unescape_translate(const std::wstring &s) {
+	return unescape_enriched(translate_string(s));
+}
+
+/**
+ * Checks that all characters in \p to_check are a decimal digits.
+ *
+ * @param to_check
+ * @return true if to_check is not empty and all characters in to_check are
+ *	decimal digits, otherwise false
+ */
+inline bool is_number(const std::string &to_check)
+{
+	for (char i : to_check)
+		if (!std::isdigit(i))
+			return false;
+
+	return !to_check.empty();
+}
+
+
+/**
+ * Returns a C-string, either "true" or "false", corresponding to \p val.
+ *
+ * @return If \p val is true, then "true" is returned, otherwise "false".
+ */
+inline const char *bool_to_cstr(bool val)
+{
+	return val ? "true" : "false";
+}
+
+/**
+ * Converts a duration in seconds to a pretty-printed duration in
+ * days, hours, minutes and seconds.
+ *
+ * @param sec duration in seconds
+ * @return pretty-printed duration
+ */
+inline const std::string duration_to_string(int sec)
+{
+	std::ostringstream ss;
+	const char *neg = "";
+	if (sec < 0) {
+		sec = -sec;
+		neg = "-";
+	}
+	int total_sec = sec;
+	int min = sec / 60;
+	sec %= 60;
+	int hour = min / 60;
+	min %= 60;
+	int day = hour / 24;
+	hour %= 24;
+
+	if (day > 0) {
+		ss << neg << day << "d";
+		if (hour > 0 || min > 0 || sec > 0)
+			ss << " ";
+	}
+
+	if (hour > 0) {
+		ss << neg << hour << "h";
+		if (min > 0 || sec > 0)
+			ss << " ";
+	}
+
+	if (min > 0) {
+		ss << neg << min << "min";
+		if (sec > 0)
+			ss << " ";
+	}
+
+	if (sec > 0 || total_sec == 0) {
+		ss << neg << sec << "s";
+	}
+
+	return ss.str();
+}
+
+/**
+ * Joins a vector of strings by the string \p delimiter.
+ *
+ * @return A std::string
+ */
+inline std::string str_join(const std::vector<std::string> &list,
+		const std::string &delimiter)
+{
+	std::ostringstream oss;
+	bool first = true;
+	for (const auto &part : list) {
+		if (!first)
+			oss << delimiter;
+		oss << part;
+		first = false;
+	}
+	return oss.str();
+}
+
+/**
+ * Create a UTF8 std::string from a irr::core::stringw.
+ */
+inline std::string stringw_to_utf8(const irr::core::stringw &input)
+{
+	std::wstring str(input.c_str());
+	return wide_to_utf8(str);
+}
+
+ /**
+  * Create a irr::core:stringw from a UTF8 std::string.
+  */
+inline irr::core::stringw utf8_to_stringw(const std::string &input)
+{
+	std::wstring str = utf8_to_wide(input);
+	return irr::core::stringw(str.c_str());
+}
+
+/**
+ * Sanitize the name of a new directory. This consists of two stages:
+ * 1. Check for 'reserved filenames' that can't be used on some filesystems
+ *    and add a prefix to them
+ * 2. Remove 'unsafe' characters from the name by replacing them with '_'
+ */
+std::string sanitizeDirName(const std::string &str, const std::string &optional_prefix);
+
+/**
+ * Prints a sanitized version of a string without control characters.
+ * '\t' and '\n' are allowed, as are UTF-8 control characters (e.g. RTL).
+ * ASCII control characters are replaced with their hex encoding in angle
+ * brackets (e.g. "a\x1eb" -> "a<1e>b").
+ */
+void safe_print_string(std::ostream &os, const std::string &str);

src/util/thread.h

@@ -0,0 +1,228 @@
+/*
+Minetest
+Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#pragma once
+
+#include "irrlichttypes.h"
+#include "threading/thread.h"
+#include "threading/mutex_auto_lock.h"
+#include "porting.h"
+#include "log.h"
+#include "container.h"
+
+template<typename T>
+class MutexedVariable
+{
+public:
+	MutexedVariable(const T &value):
+		m_value(value)
+	{}
+
+	T get()
+	{
+		MutexAutoLock lock(m_mutex);
+		return m_value;
+	}
+
+	void set(const T &value)
+	{
+		MutexAutoLock lock(m_mutex);
+		m_value = value;
+	}
+
+	// You pretty surely want to grab the lock when accessing this
+	T m_value;
+private:
+	std::mutex m_mutex;
+};
+
+/*
+	A single worker thread - multiple client threads queue framework.
+*/
+template<typename Key, typename T, typename Caller, typename CallerData>
+class GetResult {
+public:
+	Key key;
+	T item;
+	std::pair<Caller, CallerData> caller;
+};
+
+template<typename Key, typename T, typename Caller, typename CallerData>
+class ResultQueue : public MutexedQueue<GetResult<Key, T, Caller, CallerData> > {
+};
+
+template<typename Caller, typename Data, typename Key, typename T>
+class CallerInfo {
+public:
+	Caller caller;
+	Data data;
+	ResultQueue<Key, T, Caller, Data> *dest;
+};
+
+template<typename Key, typename T, typename Caller, typename CallerData>
+class GetRequest {
+public:
+	GetRequest() = default;
+	~GetRequest() = default;
+
+	GetRequest(const Key &a_key): key(a_key)
+	{
+	}
+
+	Key key;
+	std::list<CallerInfo<Caller, CallerData, Key, T> > callers;
+};
+
+/**
+ * Notes for RequestQueue usage
+ * @param Key unique key to identify a request for a specific resource
+ * @param T ?
+ * @param Caller unique id of calling thread
+ * @param CallerData data passed back to caller
+ */
+template<typename Key, typename T, typename Caller, typename CallerData>
+class RequestQueue {
+public:
+	bool empty()
+	{
+		return m_queue.empty();
+	}
+
+	void add(const Key &key, Caller caller, CallerData callerdata,
+		ResultQueue<Key, T, Caller, CallerData> *dest)
+	{
+		typename std::deque<GetRequest<Key, T, Caller, CallerData> >::iterator i;
+		typename std::list<CallerInfo<Caller, CallerData, Key, T> >::iterator j;
+
+		{
+			MutexAutoLock lock(m_queue.getMutex());
+
+			/*
+				If the caller is already on the list, only update CallerData
+			*/
+			for (i = m_queue.getQueue().begin(); i != m_queue.getQueue().end(); ++i) {
+				GetRequest<Key, T, Caller, CallerData> &request = *i;
+				if (request.key != key)
+					continue;
+
+				for (j = request.callers.begin(); j != request.callers.end(); ++j) {
+					CallerInfo<Caller, CallerData, Key, T> &ca = *j;
+					if (ca.caller == caller) {
+						ca.data = callerdata;
+						return;
+					}
+				}
+
+				CallerInfo<Caller, CallerData, Key, T> ca;
+				ca.caller = caller;
+				ca.data = callerdata;
+				ca.dest = dest;
+				request.callers.push_back(ca);
+				return;
+			}
+		}
+
+		/*
+			Else add a new request to the queue
+		*/
+
+		GetRequest<Key, T, Caller, CallerData> request;
+		request.key = key;
+		CallerInfo<Caller, CallerData, Key, T> ca;
+		ca.caller = caller;
+		ca.data = callerdata;
+		ca.dest = dest;
+		request.callers.push_back(ca);
+
+		m_queue.push_back(request);
+	}
+
+	GetRequest<Key, T, Caller, CallerData> pop(unsigned int timeout_ms)
+	{
+		return m_queue.pop_front(timeout_ms);
+	}
+
+	GetRequest<Key, T, Caller, CallerData> pop()
+	{
+		return m_queue.pop_frontNoEx();
+	}
+
+	void pushResult(GetRequest<Key, T, Caller, CallerData> req, T res)
+	{
+		for (typename std::list<CallerInfo<Caller, CallerData, Key, T> >::iterator
+				i = req.callers.begin();
+				i != req.callers.end(); ++i) {
+			CallerInfo<Caller, CallerData, Key, T> &ca = *i;
+
+			GetResult<Key,T,Caller,CallerData> result;
+
+			result.key = req.key;
+			result.item = res;
+			result.caller.first = ca.caller;
+			result.caller.second = ca.data;
+
+			ca.dest->push_back(result);
+		}
+	}
+
+private:
+	MutexedQueue<GetRequest<Key, T, Caller, CallerData> > m_queue;
+};
+
+class UpdateThread : public Thread
+{
+public:
+	UpdateThread(const std::string &name) : Thread(name + "Update") {}
+	~UpdateThread() = default;
+
+	void deferUpdate() { m_update_sem.post(); }
+
+	void stop()
+	{
+		Thread::stop();
+
+		// give us a nudge
+		m_update_sem.post();
+	}
+
+	void *run()
+	{
+		BEGIN_DEBUG_EXCEPTION_HANDLER
+
+		while (!stopRequested()) {
+			m_update_sem.wait();
+			// Set semaphore to 0
+			while (m_update_sem.wait(0));
+
+			if (stopRequested()) break;
+
+			doUpdate();
+		}
+
+		END_DEBUG_EXCEPTION_HANDLER
+
+		return NULL;
+	}
+
+protected:
+	virtual void doUpdate() = 0;
+
+private:
+	Semaphore m_update_sem;
+};

src/util/timetaker.cpp

@@ -0,0 +1,63 @@
+/*
+Minetest
+Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "timetaker.h"
+
+#include "porting.h"
+#include "log.h"
+#include <ostream>
+
+TimeTaker::TimeTaker(const std::string &name, u64 *result, TimePrecision prec)
+{
+	m_name = name;
+	m_result = result;
+	m_precision = prec;
+	m_time1 = porting::getTime(prec);
+}
+
+u64 TimeTaker::stop(bool quiet)
+{
+	if (m_running) {
+		u64 dtime = porting::getTime(m_precision) - m_time1;
+		if (m_result != nullptr) {
+			(*m_result) += dtime;
+		} else {
+			if (!quiet) {
+				static const char* const units[] = {
+					"s"  /* PRECISION_SECONDS */,
+					"ms" /* PRECISION_MILLI */,
+					"us" /* PRECISION_MICRO */,
+					"ns" /* PRECISION_NANO */,
+				};
+				infostream << m_name << " took "
+				           << dtime << units[m_precision]
+					   << std::endl;
+			}
+		}
+		m_running = false;
+		return dtime;
+	}
+	return 0;
+}
+
+u64 TimeTaker::getTimerTime()
+{
+	return porting::getTime(m_precision) - m_time1;
+}
+

src/util/timetaker.h

@@ -0,0 +1,50 @@
+/*
+Minetest
+Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#pragma once
+
+#include "irrlichttypes.h"
+#include "gettime.h"
+
+/*
+	TimeTaker
+*/
+
+class TimeTaker
+{
+public:
+	TimeTaker(const std::string &name, u64 *result=nullptr,
+		TimePrecision prec=PRECISION_MILLI);
+
+	~TimeTaker()
+	{
+		stop();
+	}
+
+	u64 stop(bool quiet=false);
+
+	u64 getTimerTime();
+
+private:
+	std::string m_name;
+	u64 m_time1;
+	bool m_running = true;
+	TimePrecision m_precision;
+	u64 *m_result = nullptr;
+};