ChunkDataSerializer.cpp

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#include "Globals.h"
#include "ChunkDataSerializer.h"
#include "zlib/zlib.h"
#include "Protocol_1_8.h"
#include "Protocol_1_9.h"
#include "../ByteBuffer.h"





template <class Func>
void ForEachSection(const cChunkData & a_Data, Func a_Func)
{
    for (size_t SectionIdx = 0; SectionIdx < cChunkData::NumSections; ++SectionIdx)
    {
        auto Section = a_Data.GetSection(SectionIdx);
        if (Section != nullptr)
        {
            a_Func(*Section);
        }
    }
}





// cChunkDataSerializer:

cChunkDataSerializer::cChunkDataSerializer(
    const cChunkData &    a_Data,
    const unsigned char * a_BiomeData,
    const eDimension      a_Dimension
):
    m_Data(a_Data),
    m_BiomeData(a_BiomeData),
    m_Dimension(a_Dimension)
{
}





const AString & cChunkDataSerializer::Serialize(int a_Version, int a_ChunkX, int a_ChunkZ, const std::map<UInt32, UInt32> & a_BlockTypeMap)
{
    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_8_0: Serialize47 (data, a_ChunkX, a_ChunkZ); break;
        case RELEASE_1_9_0: Serialize107(data, a_ChunkX, a_ChunkZ); break;
        case RELEASE_1_9_4: Serialize110(data, a_ChunkX, a_ChunkZ); break;
        case RELEASE_1_13:  Serialize393(data, a_ChunkX, a_ChunkZ, a_BlockTypeMap); break;

        default:
        {
            LOGERROR("cChunkDataSerializer::Serialize(): Unknown version: %d", a_Version);
            ASSERT(!"Unknown chunk data serialization version");
            break;
        }
    }
    if (!data.empty())
    {
        m_Serializations[a_Version] = data;
    }
    return m_Serializations[a_Version];
}





void cChunkDataSerializer::Serialize47(AString & a_Data, int a_ChunkX, int a_ChunkZ)
{
    // This function returns the fully compressed packet (including packet size), not the raw packet!

    // Create the packet:
    cByteBuffer Packet(512 KiB);
    Packet.WriteVarInt32(0x21);  // Packet id (Chunk Data packet)
    Packet.WriteBEInt32(a_ChunkX);
    Packet.WriteBEInt32(a_ChunkZ);
    Packet.WriteBool(true);      // "Ground-up continuous", or rather, "biome data present" flag
    Packet.WriteBEUInt16(m_Data.GetSectionBitmask());

    // Write the chunk size:
    const int BiomeDataSize = cChunkDef::Width * cChunkDef::Width;
    UInt32 ChunkSize = (
        m_Data.NumPresentSections() * cChunkData::SectionBlockCount * 3 +  // Blocks and lighting
        BiomeDataSize    // Biome data
    );
    Packet.WriteVarInt32(ChunkSize);

    // Chunk written as seperate arrays of (blocktype + meta), blocklight and skylight
    // each array stores all present sections of the same kind packed together

    // Write the block types to the packet:
    ForEachSection(m_Data, [&](const cChunkData::sChunkSection & a_Section)
        {
            for (size_t BlockIdx = 0; BlockIdx != cChunkData::SectionBlockCount; ++BlockIdx)
            {
                BLOCKTYPE BlockType = a_Section.m_BlockTypes[BlockIdx] & 0xFF;
                NIBBLETYPE BlockMeta = a_Section.m_BlockMetas[BlockIdx / 2] >> ((BlockIdx & 1) * 4) & 0x0f;
                Packet.WriteBEUInt8(static_cast<unsigned char>(BlockType << 4) | BlockMeta);
                Packet.WriteBEUInt8(static_cast<unsigned char>(BlockType >> 4));
            }
        }
    );

    // Write the block lights:
    ForEachSection(m_Data, [&](const cChunkData::sChunkSection & a_Section)
        {
            Packet.WriteBuf(a_Section.m_BlockLight, sizeof(a_Section.m_BlockLight));
        }
    );

    // Write the sky lights:
    ForEachSection(m_Data, [&](const cChunkData::sChunkSection & a_Section)
        {
            Packet.WriteBuf(a_Section.m_BlockSkyLight, sizeof(a_Section.m_BlockSkyLight));
        }
    );

    // Write the biome data:
    Packet.WriteBuf(m_BiomeData, BiomeDataSize);

    AString PacketData;
    Packet.ReadAll(PacketData);
    Packet.CommitRead();

    cByteBuffer Buffer(20);
    if (PacketData.size() >= 256)
    {
        if (!cProtocol_1_8_0::CompressPacket(PacketData, a_Data))
        {
            ASSERT(!"Packet compression failed.");
            a_Data.clear();
            return;
        }
    }
    else
    {
        AString PostData;
        Buffer.WriteVarInt32(static_cast<UInt32>(Packet.GetUsedSpace() + 1));
        Buffer.WriteVarInt32(0);
        Buffer.ReadAll(PostData);
        Buffer.CommitRead();

        a_Data.clear();
        a_Data.reserve(PostData.size() + PacketData.size());
        a_Data.append(PostData.data(), PostData.size());
        a_Data.append(PacketData.data(), PacketData.size());
    }
}





void cChunkDataSerializer::Serialize107(AString & a_Data, int a_ChunkX, int a_ChunkZ)
{
    // This function returns the fully compressed packet (including packet size), not the raw packet!

    // Create the packet:
    cByteBuffer Packet(512 KiB);
    Packet.WriteVarInt32(0x20);  // Packet id (Chunk Data packet)
    Packet.WriteBEInt32(a_ChunkX);
    Packet.WriteBEInt32(a_ChunkZ);
    Packet.WriteBool(true);        // "Ground-up continuous", or rather, "biome data present" flag
    Packet.WriteVarInt32(m_Data.GetSectionBitmask());
    // Write the chunk size:
    const size_t BitsPerEntry = 13;
    const size_t Mask = (1 << BitsPerEntry) - 1;  // Creates a mask that is 13 bits long, ie 0b1111111111111
    const size_t ChunkSectionDataArraySize = (cChunkData::SectionBlockCount * BitsPerEntry) / 8 / 8;  // Convert from bit count to long count
    size_t ChunkSectionSize = (
        1 +                                // Bits per block - set to 13, so the global palette is used and the palette has a length of 0
        1 +                                // Palette length
        2 +                                // Data array length VarInt - 2 bytes for the current value
        ChunkSectionDataArraySize * 8 +    // Actual block data - multiplied by 8 because first number is longs
        cChunkData::SectionBlockCount / 2  // Block light
    );

    if (m_Dimension == dimOverworld)
    {
        // Sky light is only sent in the overworld.
        ChunkSectionSize += cChunkData::SectionBlockCount / 2;
    }

    const size_t BiomeDataSize = cChunkDef::Width * cChunkDef::Width;
    size_t ChunkSize = (
        ChunkSectionSize * m_Data.NumPresentSections() +
        BiomeDataSize
    );
    Packet.WriteVarInt32(static_cast<UInt32>(ChunkSize));

    // Write each chunk section...
    ForEachSection(m_Data, [&](const cChunkData::sChunkSection & a_Section)
        {
            Packet.WriteBEUInt8(static_cast<UInt8>(BitsPerEntry));
            Packet.WriteVarInt32(0);  // Palette length is 0
            Packet.WriteVarInt32(static_cast<UInt32>(ChunkSectionDataArraySize));

            UInt64 TempLong = 0;  // Temporary value that will be stored into
            UInt64 CurrentlyWrittenIndex = 0;  // "Index" of the long that would be written to

            for (size_t Index = 0; Index < cChunkData::SectionBlockCount; Index++)
            {
                UInt64 Value = static_cast<UInt64>(a_Section.m_BlockTypes[Index] << 4);
                if (Index % 2 == 0)
                {
                    Value |= a_Section.m_BlockMetas[Index / 2] & 0x0f;
                }
                else
                {
                    Value |= a_Section.m_BlockMetas[Index / 2] >> 4;
                }
                Value &= Mask;  // It shouldn't go out of bounds, but it's still worth being careful

                // Painful part where we write data into the long array.  Based off of the normal code.
                size_t BitPosition = Index * BitsPerEntry;
                size_t FirstIndex = BitPosition / 64;
                size_t SecondIndex = ((Index + 1) * BitsPerEntry - 1) / 64;
                size_t BitOffset = BitPosition % 64;

                if (FirstIndex != CurrentlyWrittenIndex)
                {
                    // Write the current data before modifiying it.
                    Packet.WriteBEUInt64(TempLong);
                    TempLong = 0;
                    CurrentlyWrittenIndex = FirstIndex;
                }

                TempLong |= (Value << BitOffset);

                if (FirstIndex != SecondIndex)
                {
                    // Part of the data is now in the second long; write the first one first
                    Packet.WriteBEUInt64(TempLong);
                    CurrentlyWrittenIndex = SecondIndex;

                    TempLong = (Value >> (64 - BitOffset));
                }
            }
            // The last long will generally not be written
            Packet.WriteBEUInt64(TempLong);

            // Write lighting:
            Packet.WriteBuf(a_Section.m_BlockLight, sizeof(a_Section.m_BlockLight));
            if (m_Dimension == dimOverworld)
            {
                // Skylight is only sent in the overworld; the nether and end do not use it
                Packet.WriteBuf(a_Section.m_BlockSkyLight, sizeof(a_Section.m_BlockSkyLight));
            }
        }
    );

    // Write the biome data
    Packet.WriteBuf(m_BiomeData, BiomeDataSize);

    AString PacketData;
    Packet.ReadAll(PacketData);
    Packet.CommitRead();

    cByteBuffer Buffer(20);
    if (PacketData.size() >= 256)
    {
        if (!cProtocol_1_9_0::CompressPacket(PacketData, a_Data))
        {
            ASSERT(!"Packet compression failed.");
            a_Data.clear();
            return;
        }
    }
    else
    {
        AString PostData;
        Buffer.WriteVarInt32(static_cast<UInt32>(Packet.GetUsedSpace() + 1));
        Buffer.WriteVarInt32(0);
        Buffer.ReadAll(PostData);
        Buffer.CommitRead();

        a_Data.clear();
        a_Data.reserve(PostData.size() + PacketData.size());
        a_Data.append(PostData.data(), PostData.size());
        a_Data.append(PacketData.data(), PacketData.size());
    }
}





void cChunkDataSerializer::Serialize110(AString & a_Data, int a_ChunkX, int a_ChunkZ)
{
    // This function returns the fully compressed packet (including packet size), not the raw packet!

    // Create the packet:
    cByteBuffer Packet(512 KiB);
    Packet.WriteVarInt32(0x20);  // Packet id (Chunk Data packet)
    Packet.WriteBEInt32(a_ChunkX);
    Packet.WriteBEInt32(a_ChunkZ);
    Packet.WriteBool(true);        // "Ground-up continuous", or rather, "biome data present" flag
    Packet.WriteVarInt32(m_Data.GetSectionBitmask());
    // Write the chunk size:
    const size_t BitsPerEntry = 13;
    const size_t Mask = (1 << BitsPerEntry) - 1;  // Creates a mask that is 13 bits long, ie 0b1111111111111
    const size_t ChunkSectionDataArraySize = (cChunkData::SectionBlockCount * BitsPerEntry) / 8 / 8;  // Convert from bit count to long count
    size_t ChunkSectionSize = (
        1 +                                // Bits per block - set to 13, so the global palette is used and the palette has a length of 0
        1 +                                // Palette length
        2 +                                // Data array length VarInt - 2 bytes for the current value
        ChunkSectionDataArraySize * 8 +    // Actual block data - multiplied by 8 because first number is longs
        cChunkData::SectionBlockCount / 2  // Block light
    );

    if (m_Dimension == dimOverworld)
    {
        // Sky light is only sent in the overworld.
        ChunkSectionSize += cChunkData::SectionBlockCount / 2;
    }

    const size_t BiomeDataSize = cChunkDef::Width * cChunkDef::Width;
    size_t ChunkSize = (
        ChunkSectionSize * m_Data.NumPresentSections() +
        BiomeDataSize
    );
    Packet.WriteVarInt32(static_cast<UInt32>(ChunkSize));

    // Write each chunk section...
    ForEachSection(m_Data, [&](const cChunkData::sChunkSection & a_Section)
        {
            Packet.WriteBEUInt8(static_cast<UInt8>(BitsPerEntry));
            Packet.WriteVarInt32(0);  // Palette length is 0
            Packet.WriteVarInt32(static_cast<UInt32>(ChunkSectionDataArraySize));

            UInt64 TempLong = 0;  // Temporary value that will be stored into
            UInt64 CurrentlyWrittenIndex = 0;  // "Index" of the long that would be written to

            for (size_t Index = 0; Index < cChunkData::SectionBlockCount; Index++)
            {
                UInt64 Value = static_cast<UInt64>(a_Section.m_BlockTypes[Index] << 4);
                if (Index % 2 == 0)
                {
                    Value |= a_Section.m_BlockMetas[Index / 2] & 0x0f;
                }
                else
                {
                    Value |= a_Section.m_BlockMetas[Index / 2] >> 4;
                }
                Value &= Mask;  // It shouldn't go out of bounds, but it's still worth being careful

                // Painful part where we write data into the long array.  Based off of the normal code.
                size_t BitPosition = Index * BitsPerEntry;
                size_t FirstIndex = BitPosition / 64;
                size_t SecondIndex = ((Index + 1) * BitsPerEntry - 1) / 64;
                size_t BitOffset = BitPosition % 64;

                if (FirstIndex != CurrentlyWrittenIndex)
                {
                    // Write the current data before modifiying it.
                    Packet.WriteBEUInt64(TempLong);
                    TempLong = 0;
                    CurrentlyWrittenIndex = FirstIndex;
                }

                TempLong |= (Value << BitOffset);

                if (FirstIndex != SecondIndex)
                {
                    // Part of the data is now in the second long; write the first one first
                    Packet.WriteBEUInt64(TempLong);
                    CurrentlyWrittenIndex = SecondIndex;

                    TempLong = (Value >> (64 - BitOffset));
                }
            }
            // The last long will generally not be written
            Packet.WriteBEUInt64(TempLong);

            // Write lighting:
            Packet.WriteBuf(a_Section.m_BlockLight, sizeof(a_Section.m_BlockLight));
            if (m_Dimension == dimOverworld)
            {
                // Skylight is only sent in the overworld; the nether and end do not use it
                Packet.WriteBuf(a_Section.m_BlockSkyLight, sizeof(a_Section.m_BlockSkyLight));
            }
        }
    );

    // Write the biome data
    Packet.WriteBuf(m_BiomeData, BiomeDataSize);

    // Identify 1.9.4's tile entity list as empty
    Packet.WriteBEUInt8(0);

    AString PacketData;
    Packet.ReadAll(PacketData);
    Packet.CommitRead();

    cByteBuffer Buffer(20);
    if (PacketData.size() >= 256)
    {
        if (!cProtocol_1_9_0::CompressPacket(PacketData, a_Data))
        {
            ASSERT(!"Packet compression failed.");
            a_Data.clear();
            return;
        }
    }
    else
    {
        AString PostData;
        Buffer.WriteVarInt32(static_cast<UInt32>(Packet.GetUsedSpace() + 1));
        Buffer.WriteVarInt32(0);
        Buffer.ReadAll(PostData);
        Buffer.CommitRead();

        a_Data.clear();
        a_Data.reserve(PostData.size() + PacketData.size());
        a_Data.append(PostData.data(), PostData.size());
        a_Data.append(PacketData.data(), PacketData.size());
    }
}





void cChunkDataSerializer::Serialize393(AString & a_Data, int a_ChunkX, int a_ChunkZ, const std::map<UInt32, UInt32> & a_BlockTypeMap)
{
    // This function returns the fully compressed packet (including packet size), not the raw packet!

    ASSERT(!a_BlockTypeMap.empty());  // We need a protocol-specific translation map

    // Create the packet:
    cByteBuffer Packet(512 KiB);
    Packet.WriteVarInt32(0x22);  // Packet id (Chunk Data packet)
    Packet.WriteBEInt32(a_ChunkX);
    Packet.WriteBEInt32(a_ChunkZ);
    Packet.WriteBool(true);  // "Ground-up continuous", or rather, "biome data present" flag
    Packet.WriteVarInt32(m_Data.GetSectionBitmask());

    // Write the chunk size in bytes:
    const size_t BitsPerEntry = 14;
    const size_t Mask = (1 << BitsPerEntry) - 1;
    const size_t ChunkSectionDataArraySize = (cChunkData::SectionBlockCount * BitsPerEntry) / 8 / 8;
    size_t ChunkSectionSize = (
        1 +  // Bits per entry, BEUInt8, 1 byte
        Packet.GetVarIntSize(static_cast<UInt32>(ChunkSectionDataArraySize)) +  // Field containing "size of whole section", VarInt32, variable size
        ChunkSectionDataArraySize * 8 +  // Actual section data, lots of bytes (multiplier 1 long = 8 bytes)
        cChunkData::SectionBlockCount / 2  // Size of blocklight which is always sent
    );

    if (m_Dimension == dimOverworld)
    {
        // Sky light is only sent in the overworld.
        ChunkSectionSize += cChunkData::SectionBlockCount / 2;
    }

    const size_t BiomeDataSize = cChunkDef::Width * cChunkDef::Width;
    size_t ChunkSize = (
        ChunkSectionSize * m_Data.NumPresentSections() +
        BiomeDataSize * 4  // Biome data now BE ints
    );
    Packet.WriteVarInt32(static_cast<UInt32>(ChunkSize));

    // Write each chunk section...
    ForEachSection(m_Data, [&](const cChunkData::sChunkSection & a_Section)
        {
            Packet.WriteBEUInt8(static_cast<UInt8>(BitsPerEntry));
            Packet.WriteVarInt32(static_cast<UInt32>(ChunkSectionDataArraySize));

            UInt64 TempLong = 0;  // Temporary value that will be stored into
            UInt64 CurrentlyWrittenIndex = 0;  // "Index" of the long that would be written to

            for (size_t Index = 0; Index < cChunkData::SectionBlockCount; Index++)
            {
                UInt32 blockType = a_Section.m_BlockTypes[Index];
                UInt32 blockMeta = (a_Section.m_BlockMetas[Index / 2] >> ((Index % 2) * 4)) & 0x0f;
                auto itr = a_BlockTypeMap.find(blockType * 16 | blockMeta);
                UInt64 Value = (itr == a_BlockTypeMap.end()) ? 0 :itr->second;
                Value &= Mask;  // It shouldn't go out of bounds, but it's still worth being careful

                // Painful part where we write data into the long array.  Based off of the normal code.
                size_t BitPosition = Index * BitsPerEntry;
                size_t FirstIndex = BitPosition / 64;
                size_t SecondIndex = ((Index + 1) * BitsPerEntry - 1) / 64;
                size_t BitOffset = BitPosition % 64;

                if (FirstIndex != CurrentlyWrittenIndex)
                {
                    // Write the current data before modifiying it.
                    Packet.WriteBEUInt64(TempLong);
                    TempLong = 0;
                    CurrentlyWrittenIndex = FirstIndex;
                }

                TempLong |= (Value << BitOffset);

                if (FirstIndex != SecondIndex)
                {
                    // Part of the data is now in the second long; write the first one first
                    Packet.WriteBEUInt64(TempLong);
                    CurrentlyWrittenIndex = SecondIndex;

                    TempLong = (Value >> (64 - BitOffset));
                }
            }
            // The last long will generally not be written
            Packet.WriteBEUInt64(TempLong);

            // Write lighting:
            Packet.WriteBuf(a_Section.m_BlockLight, sizeof(a_Section.m_BlockLight));
            if (m_Dimension == dimOverworld)
            {
                // Skylight is only sent in the overworld; the nether and end do not use it
                Packet.WriteBuf(a_Section.m_BlockSkyLight, sizeof(a_Section.m_BlockSkyLight));
            }
        }
    );

    // Write the biome data
    for (size_t i = 0; i != BiomeDataSize; i++)
    {
        Packet.WriteBEUInt32(static_cast<UInt32>(m_BiomeData[i]) & 0xff);
    }

    // Identify 1.9.4's tile entity list as empty
    Packet.WriteVarInt32(0);

    AString PacketData;
    Packet.ReadAll(PacketData);
    Packet.CommitRead();

    if (PacketData.size() >= 256)
    {
        if (!cProtocol_1_9_0::CompressPacket(PacketData, a_Data))
        {
            ASSERT(!"Packet compression failed.");
            a_Data.clear();
            return;
        }
    }
    else
    {
        cByteBuffer Buffer(20);
        AString PostData;

        Buffer.WriteVarInt32(static_cast<UInt32>(Packet.GetUsedSpace() + 1));
        Buffer.WriteVarInt32(0);
        Buffer.ReadAll(PostData);
        Buffer.CommitRead();

        a_Data.clear();
        a_Data.reserve(PostData.size() + PacketData.size());
        a_Data.append(PostData.data(), PostData.size());
        a_Data.append(PacketData.data(), PacketData.size());
    }
}