From 756c2e98fe1f30a2b6cf9fc73744be93c2d257c0 Mon Sep 17 00:00:00 2001
From: mrkubax10 <mrkubax10@onet.pl>
Date: Fri, 17 May 2024 11:33:11 +0200
Subject: [PATCH] Reset R/W mode during map file operations in server
 ChunkManager

---
 src/server/chunk_manager.cpp | 17 ++++++++++++-----
 src/server/chunk_manager.hpp |  1 +
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/src/server/chunk_manager.cpp b/src/server/chunk_manager.cpp
index 80aa908..9a24497 100644
--- a/src/server/chunk_manager.cpp
+++ b/src/server/chunk_manager.cpp
@@ -84,7 +84,6 @@ void ChunkManager::load_map_from_file(const std::string& name) {
 			m_map_read_only = false;
 			LOG_INFO("Created new map '%s'", name.c_str());
 			write_empty_map_header();
-			get_chunk(math::Vector3i(0)).add_node(1, math::Vector3i(0));
 			return;
 		}
 	}
@@ -133,14 +132,13 @@ polygun::world::Chunk& ChunkManager::get_chunk(const math::Vector3i& pos) {
 
 	uint32_t dummy;
 	if(find_chunk_header_offset(pos, dummy)) {
-		char temp[2];
-		char temp2[8];
+		char temp[8];
 		uint8_t compression_mode;
 		fread(reinterpret_cast<char*>(&compression_mode), 1, 1, m_map_file);
 		fread(temp, 2, 1, m_map_file);
 		const uint16_t data_size = utils::bytes_to_uint16(temp);
-		fread(temp2, 8, 1, m_map_file);
-		const uint64_t data_offset = utils::bytes_to_uint64(temp2);
+		fread(temp, 8, 1, m_map_file);
+		const uint64_t data_offset = utils::bytes_to_uint64(temp);
 		load_chunk(pos[0], pos[1], pos[2], compression_mode, data_size, data_offset);
 		LOG_VERBOSE("Loaded chunk at position %d %d %d (offset in map file: %lu)", pos[0], pos[1], pos[2], data_offset);
 		return *m_loaded_chunks.back();
@@ -241,9 +239,13 @@ void ChunkManager::write_chunk(const world::Chunk& chunk) {
 	char temp2[8];
 	uint32_t chunk_index;
 	if(find_chunk_header_offset(chunk.get_pos(), chunk_index)) {
+		reset_rw_mode();
+
 		uint64_t chunk_header_offset = ftell(m_map_file);
 		fwrite(reinterpret_cast<const char*>(&compression_mode), 1, 1, m_map_file);
 
+		reset_rw_mode();
+
 		fread(temp, 2, 1, m_map_file);
 		const uint16_t prev_data_size = utils::bytes_to_uint16(temp);
 
@@ -344,4 +346,9 @@ void ChunkManager::close_map() {
 			write_chunk(*chunk);
 	}
 	fclose(m_map_file);
+}
+
+void ChunkManager::reset_rw_mode() {
+	// Use dummy fseek to reset file R/W mode
+	fseek(m_map_file, 0, SEEK_CUR);
 }
\ No newline at end of file
diff --git a/src/server/chunk_manager.hpp b/src/server/chunk_manager.hpp
index 5e2e8f6..849a1f3 100644
--- a/src/server/chunk_manager.hpp
+++ b/src/server/chunk_manager.hpp
@@ -61,6 +61,7 @@ namespace polygun::server {
 		void write_empty_map_header();
 		void write_chunk(const world::Chunk& chunk);
 		void close_map();
+		void reset_rw_mode();
 	};
 }