AuroraRuntime/Source/Compression/Compressors/LZ4Decompressor.hpp

128 lines
3.6 KiB
C++

/***
Copyright (C) 2022 J Reece Wilson (a/k/a "Reece"). All rights reserved.
File: LZ4Decompressor.hpp
Date: 2022-2-15
Author: Reece
***/
#pragma once
#include "lz4.h"
#include "lz4frame.h"
namespace Aurora::Compression
{
struct LZ4Inflate : BaseStream
{
DecompressInfo meta;
LZ4Inflate(const DecompressInfo &meta) : meta(meta), BaseStream(meta.uInternalStreamSize)
{}
~LZ4Inflate()
{
if (this->lz4Stream_)
{
LZ4F_freeDecompressionContext(this->lz4Stream_);
}
}
bool Init(const AuSPtr<IO::IStreamReader> &pReader) override
{
this->pReader_ = pReader;
if (!this->IsValid())
{
SysPushErrorMem();
return false;
}
auto err = LZ4F_createDecompressionContext(&this->lz4Stream_, LZ4F_getVersion());
if (LZ4F_isError(err))
{
return {};
}
auto bufferSize = meta.uInternalStreamSize;
this->pBufferIn_ = AuSPtr<char>(new char[bufferSize], AuDefaultDeleter<char[]>());
if (!this->pBufferIn_)
{
return {};
}
this->pBufferOut_ = AuSPtr<char>(new char[bufferSize], AuDefaultDeleter<char[]>());
if (!this->pBufferOut_)
{
return {};
}
this->pReadPtr_ = this->pBufferIn_.get();
SetPointer(this->pReadPtr_, bufferSize);
return true;
}
AuStreamReadWrittenPair_t Ingest_s(AuUInt32 input) override
{
bool ret = true;
AuUInt32 inputStat = 0, outputStat = 0;
size_t bytesRemInFrame {};
LZ4F_decompressOptions_t opts {};
auto bufferSize = meta.uInternalStreamSize;
while (inputStat < input)
{
inputStat += IngestForInPointer<char, uInt>(this->pReader_, this->pReadPtr_, this->uBufferInAvail_, input - inputStat, this);
if (!this->uBufferInAvail_)
{
return {inputStat, outputStat};
}
auto frameSize = bytesRemInFrame ? bytesRemInFrame : LZ4F_MIN_SIZE_TO_KNOW_HEADER_LENGTH;
frameSize = LZ4F_MIN_SIZE_TO_KNOW_HEADER_LENGTH;
if (this->uBufferInAvail_ < frameSize)
{
return {inputStat, outputStat};
}
size_t frameSPtr = this->uBufferInAvail_;
size_t frameS2Ptr = bufferSize;
bytesRemInFrame = LZ4F_decompress(this->lz4Stream_, this->pBufferOut_.get(), &frameS2Ptr, this->pReadPtr_, &frameSPtr, &opts);
if (LZ4F_isError(bytesRemInFrame))
{
return {};
}
this->pReadPtr_ += frameSPtr;
outputStat += bytesRemInFrame;
this->uBufferInAvail_ -= frameSPtr;
if (frameS2Ptr)
{
if (!Write(this->pBufferOut_.get(), frameS2Ptr))
{
SysPushErrorIO("Compression Out of Overhead");
return {};
}
}
inputStat += frameS2Ptr;
}
return AuMakePair(inputStat, outputStat);
}
private:
AuSPtr<IO::IStreamReader> pReader_;
LZ4F_dctx* lz4Stream_ {};
AuSPtr<char> pBufferIn_;
AuSPtr<char> pBufferOut_;
char *pReadPtr_;
AuUInt32 uBufferInAvail_ {};
};
}