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// Copyright Epic Games, Inc. All Rights Reserved.
#include <zenutil/chunkblock.h>
#include <zencore/compactbinarybuilder.h>
#include <zencore/logging.h>
#include <vector>
namespace zen {
using namespace std::literals;
ChunkBlockDescription
ParseChunkBlockDescription(const CbObjectView& BlockObject)
{
ChunkBlockDescription Result;
Result.BlockHash = BlockObject["rawHash"sv].AsHash();
if (Result.BlockHash != IoHash::Zero)
{
CbArrayView ChunksArray = BlockObject["rawHashes"sv].AsArrayView();
Result.ChunkHashes.reserve(ChunksArray.Num());
for (CbFieldView ChunkView : ChunksArray)
{
Result.ChunkHashes.push_back(ChunkView.AsHash());
}
CbArrayView ChunkRawLengthsArray = BlockObject["chunkRawLengths"sv].AsArrayView();
std::vector<uint32_t> ChunkLengths;
Result.ChunkRawLengths.reserve(ChunkRawLengthsArray.Num());
for (CbFieldView ChunkView : ChunkRawLengthsArray)
{
Result.ChunkRawLengths.push_back(ChunkView.AsUInt32());
}
}
return Result;
}
std::vector<ChunkBlockDescription>
ParseChunkBlockDescriptionList(const CbObjectView& BlocksObject)
{
if (!BlocksObject)
{
return {};
}
std::vector<ChunkBlockDescription> Result;
CbArrayView Blocks = BlocksObject["blocks"].AsArrayView();
Result.reserve(Blocks.Num());
for (CbFieldView BlockView : Blocks)
{
CbObjectView BlockObject = BlockView.AsObjectView();
Result.emplace_back(ParseChunkBlockDescription(BlockObject));
}
return Result;
}
CbObject
BuildChunkBlockDescription(const ChunkBlockDescription& Block, CbObjectView MetaData)
{
ZEN_ASSERT(Block.ChunkRawLengths.size() == Block.ChunkHashes.size());
CbObjectWriter Writer;
Writer.AddHash("rawHash"sv, Block.BlockHash);
Writer.BeginArray("rawHashes"sv);
{
for (const IoHash& ChunkHash : Block.ChunkHashes)
{
Writer.AddHash(ChunkHash);
}
}
Writer.EndArray();
Writer.BeginArray("chunkRawLengths");
{
for (uint32_t ChunkSize : Block.ChunkRawLengths)
{
Writer.AddInteger(ChunkSize);
}
}
Writer.EndArray();
Writer.AddObject("metadata", MetaData);
return Writer.Save();
}
CompressedBuffer
GenerateChunkBlock(std::vector<std::pair<IoHash, FetchChunkFunc>>&& FetchChunks, ChunkBlockDescription& OutBlock)
{
const size_t ChunkCount = FetchChunks.size();
std::vector<SharedBuffer> ChunkSegments;
ChunkSegments.resize(1);
ChunkSegments.reserve(1 + ChunkCount);
OutBlock.ChunkHashes.reserve(ChunkCount);
OutBlock.ChunkRawLengths.reserve(ChunkCount);
{
IoBuffer TempBuffer(ChunkCount * 9);
MutableMemoryView View = TempBuffer.GetMutableView();
uint8_t* BufferStartPtr = reinterpret_cast<uint8_t*>(View.GetData());
uint8_t* BufferEndPtr = BufferStartPtr;
BufferEndPtr += WriteVarUInt(gsl::narrow<uint64_t>(ChunkCount), BufferEndPtr);
for (const auto& It : FetchChunks)
{
std::pair<uint64_t, CompressedBuffer> Chunk = It.second(It.first);
uint64_t ChunkSize = 0;
std::span<const SharedBuffer> Segments = Chunk.second.GetCompressed().GetSegments();
for (const SharedBuffer& Segment : Segments)
{
ChunkSize += Segment.GetSize();
ChunkSegments.push_back(Segment);
}
BufferEndPtr += WriteVarUInt(ChunkSize, BufferEndPtr);
OutBlock.ChunkHashes.push_back(It.first);
OutBlock.ChunkRawLengths.push_back(gsl::narrow<uint32_t>(Chunk.first));
}
ZEN_ASSERT(BufferEndPtr <= View.GetDataEnd());
ptrdiff_t TempBufferLength = std::distance(BufferStartPtr, BufferEndPtr);
ChunkSegments[0] = SharedBuffer(IoBuffer(TempBuffer, 0, gsl::narrow<size_t>(TempBufferLength)));
}
CompressedBuffer CompressedBlock =
CompressedBuffer::Compress(CompositeBuffer(std::move(ChunkSegments)), OodleCompressor::Mermaid, OodleCompressionLevel::None);
OutBlock.BlockHash = CompressedBlock.DecodeRawHash();
return CompressedBlock;
}
bool
IterateChunkBlock(const SharedBuffer& BlockPayload, std::function<void(CompressedBuffer&& Chunk, const IoHash& AttachmentHash)> Visitor)
{
ZEN_ASSERT(BlockPayload);
if (BlockPayload.GetSize() < 1)
{
return false;
}
MemoryView BlockView = BlockPayload.GetView();
const uint8_t* ReadPtr = reinterpret_cast<const uint8_t*>(BlockView.GetData());
uint32_t NumberSize;
uint64_t ChunkCount = ReadVarUInt(ReadPtr, NumberSize);
ReadPtr += NumberSize;
std::vector<uint64_t> ChunkSizes;
ChunkSizes.reserve(ChunkCount);
while (ChunkCount--)
{
ChunkSizes.push_back(ReadVarUInt(ReadPtr, NumberSize));
ReadPtr += NumberSize;
}
for (uint64_t ChunkSize : ChunkSizes)
{
IoBuffer Chunk(IoBuffer::Wrap, ReadPtr, ChunkSize);
IoHash AttachmentRawHash;
uint64_t AttachmentRawSize;
CompressedBuffer CompressedChunk = CompressedBuffer::FromCompressed(SharedBuffer(Chunk), AttachmentRawHash, AttachmentRawSize);
if (!CompressedChunk)
{
ZEN_ERROR("Invalid chunk in block");
return false;
}
Visitor(std::move(CompressedChunk), AttachmentRawHash);
ReadPtr += ChunkSize;
ZEN_ASSERT(ReadPtr <= BlockView.GetDataEnd());
}
return true;
};
} // namespace zen
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