// ChunkDataSerializer.cpp
// Implements the cChunkDataSerializer class representing the object that can:
// - serialize chunk data to different protocol versions
// - cache such serialized data for multiple clients
#include "Globals.h"
#include "ChunkDataSerializer.h"
#include "zlib.h"
cChunkDataSerializer::cChunkDataSerializer(
const cChunkDef::BlockTypes & a_BlockTypes,
const cChunkDef::BlockNibbles & a_BlockMetas,
const cChunkDef::BlockNibbles & a_BlockLight,
const cChunkDef::BlockNibbles & a_BlockSkyLight,
const unsigned char * a_BiomeData
) :
m_BlockTypes(a_BlockTypes),
m_BlockMetas(a_BlockMetas),
m_BlockLight(a_BlockLight),
m_BlockSkyLight(a_BlockSkyLight),
m_BiomeData(a_BiomeData)
{
}
const AString & cChunkDataSerializer::Serialize(int a_Version)
{
Serializations::const_iterator itr = m_Serializations.find(a_Version);
if (itr != m_Serializations.end())
{
return itr->second;
}
AString data;
switch (a_Version)
{
case RELEASE_1_2_5: Serialize29(data); break;
case RELEASE_1_3_2: Serialize39(data); break;
// TODO: Other protocol versions may serialize the data differently; implement here
default:
{
LOGERROR("cChunkDataSerializer::Serialize(): Unknown version: %d", a_Version);
ASSERT(!"Unknown chunk data serialization version");
break;
}
}
m_Serializations[a_Version] = data;
return m_Serializations[a_Version];
}
void cChunkDataSerializer::Serialize29(AString & a_Data)
{
// TODO: Do not copy data and then compress it; rather, compress partial blocks of data (zlib *can* stream)
const int BiomeDataSize = cChunkDef::Width * cChunkDef::Width;
const int MetadataOffset = sizeof(m_BlockTypes);
const int BlockLightOffset = MetadataOffset + sizeof(m_BlockMetas);
const int SkyLightOffset = BlockLightOffset + sizeof(m_BlockLight);
const int BiomeOffset = SkyLightOffset + sizeof(m_BlockSkyLight);
const int DataSize = BiomeOffset + BiomeDataSize;
// Temporary buffer for the composed data:
char AllData [DataSize];
memcpy(AllData, m_BlockTypes, sizeof(m_BlockTypes));
memcpy(AllData + MetadataOffset, m_BlockMetas, sizeof(m_BlockMetas));
memcpy(AllData + BlockLightOffset, m_BlockLight, sizeof(m_BlockLight));
memcpy(AllData + SkyLightOffset, m_BlockSkyLight, sizeof(m_BlockSkyLight));
memcpy(AllData + BiomeOffset, m_BiomeData, BiomeDataSize);
// Compress the data:
// In order not to use allocation, use a fixed-size buffer, with the size
// that uses the same calculation as compressBound():
const uLongf CompressedMaxSize = DataSize + (DataSize >> 12) + (DataSize >> 14) + (DataSize >> 25) + 16;
char CompressedBlockData[CompressedMaxSize];
uLongf CompressedSize = compressBound(DataSize);
// Run-time check that our compile-time guess about CompressedMaxSize was enough:
ASSERT(CompressedSize <= CompressedMaxSize);
compress2((Bytef*)CompressedBlockData, &CompressedSize, (const Bytef*)AllData, sizeof(AllData), Z_DEFAULT_COMPRESSION);
// Now put all those data into a_Data:
// "Ground-up continuous", or rather, "biome data present" flag:
a_Data.push_back('\x01');
// Two bitmaps; we're aways sending the full chunk with no additional data, so the bitmaps are 0xffff and 0, respectively
// Also, no endian flipping is needed because of the const values
unsigned short BitMap1 = 0xffff;
unsigned short BitMap2 = 0;
a_Data.append((const char *)&BitMap1, sizeof(short));
a_Data.append((const char *)&BitMap2, sizeof(short));
Int32 CompressedSizeBE = htonl(CompressedSize);
a_Data.append((const char *)&CompressedSizeBE, sizeof(CompressedSizeBE));
Int32 UnusedInt32 = 0;
a_Data.append((const char *)&UnusedInt32, sizeof(UnusedInt32));
a_Data.append(CompressedBlockData, CompressedSize);
}
void cChunkDataSerializer::Serialize39(AString & a_Data)
{
// TODO: Do not copy data and then compress it; rather, compress partial blocks of data (zlib *can* stream)
const int BiomeDataSize = cChunkDef::Width * cChunkDef::Width;
const int MetadataOffset = sizeof(m_BlockTypes);
const int BlockLightOffset = MetadataOffset + sizeof(m_BlockMetas);
const int SkyLightOffset = BlockLightOffset + sizeof(m_BlockLight);
const int BiomeOffset = SkyLightOffset + sizeof(m_BlockSkyLight);
const int DataSize = BiomeOffset + BiomeDataSize;
// Temporary buffer for the composed data:
char AllData [DataSize];
memcpy(AllData, m_BlockTypes, sizeof(m_BlockTypes));
memcpy(AllData + MetadataOffset, m_BlockMetas, sizeof(m_BlockMetas));
memcpy(AllData + BlockLightOffset, m_BlockLight, sizeof(m_BlockLight));
memcpy(AllData + SkyLightOffset, m_BlockSkyLight, sizeof(m_BlockSkyLight));
memcpy(AllData + BiomeOffset, m_BiomeData, BiomeDataSize);
// Compress the data:
// In order not to use allocation, use a fixed-size buffer, with the size
// that uses the same calculation as compressBound():
const uLongf CompressedMaxSize = DataSize + (DataSize >> 12) + (DataSize >> 14) + (DataSize >> 25) + 16;
char CompressedBlockData[CompressedMaxSize];
uLongf CompressedSize = compressBound(DataSize);
// Run-time check that our compile-time guess about CompressedMaxSize was enough:
ASSERT(CompressedSize <= CompressedMaxSize);
compress2((Bytef*)CompressedBlockData, &CompressedSize, (const Bytef*)AllData, sizeof(AllData), Z_DEFAULT_COMPRESSION);
// Now put all those data into a_Data:
// "Ground-up continuous", or rather, "biome data present" flag:
a_Data.push_back('\x01');
// Two bitmaps; we're aways sending the full chunk with no additional data, so the bitmaps are 0xffff and 0, respectively
// Also, no endian flipping is needed because of the const values
unsigned short BitMap1 = 0xffff;
unsigned short BitMap2 = 0;
a_Data.append((const char *)&BitMap1, sizeof(short));
a_Data.append((const char *)&BitMap2, sizeof(short));
Int32 CompressedSizeBE = htonl(CompressedSize);
a_Data.append((const char *)&CompressedSizeBE, sizeof(CompressedSizeBE));
// Unlike 29, 39 doesn't have the "unused" int
a_Data.append(CompressedBlockData, CompressedSize);
}
