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#include "lzma.h"
#include "private.h"
#include <yt/yt/core/misc/finally.h>
extern "C" {
////////////////////////////////////////////////////////////////////////////////
#include <contrib/libs/lzmasdk/LzmaEnc.h>
#include <contrib/libs/lzmasdk/LzmaDec.h>
////////////////////////////////////////////////////////////////////////////////
} // extern "C"
namespace NYT::NCompression::NDetail {
////////////////////////////////////////////////////////////////////////////////
namespace {
const auto& Logger = CompressionLogger;
// ISzAlloc is an interface containing alloc/free functions (with its own signatures)
// required by lzma API.
class TSzAlloc
: public ISzAlloc
{
public:
TSzAlloc()
{
Alloc = &MallocWrap;
Free = &FreeWrap;
}
static void* MallocWrap(const ISzAlloc*, size_t len)
{
return malloc(len);
}
static void FreeWrap(const ISzAlloc*, void* ptr)
{
free(ptr);
}
};
TSzAlloc Alloc;
class TLzmaSinkWrapper
: public ISeqOutStream
{
public:
explicit TLzmaSinkWrapper(TBlob* output)
: Output_(output)
{
Write = &TLzmaSinkWrapper::WriteDataProc;
}
size_t WriteData(const void* buffer, size_t size)
{
Output_->Append(buffer, size);
return size;
}
static size_t WriteDataProc(const ISeqOutStream* lzmaWriteWrapper, const void* buffer, size_t size)
{
TLzmaSinkWrapper* pThis = const_cast<TLzmaSinkWrapper*>(static_cast<const TLzmaSinkWrapper*>(lzmaWriteWrapper));
return pThis->WriteData(buffer, size);
}
private:
TBlob* const Output_;
};
class TLzmaSourceWrapper
: public ISeqInStream
{
public:
explicit TLzmaSourceWrapper(TSource* source)
: Source_(source)
{
Read = ReadDataProc;
}
SRes ReadData(void* buffer, size_t* size)
{
size_t peekedSize;
const void* peekedData = Source_->Peek(&peekedSize);
peekedSize = std::min(*size, peekedSize);
peekedSize = std::min(peekedSize, Source_->Available());
memcpy(buffer, peekedData, peekedSize);
Source_->Skip(peekedSize);
*size = peekedSize;
return SZ_OK;
}
static SRes ReadDataProc(const ISeqInStream* lzmaReadWrapper, void* buffer, size_t* size)
{
TLzmaSourceWrapper* pThis = const_cast<TLzmaSourceWrapper*>(static_cast<const TLzmaSourceWrapper*>(lzmaReadWrapper));
return pThis->ReadData(buffer, size);
}
private:
TSource* const Source_;
};
} // namespace
void LzmaCompress(int level, TSource* source, TBlob* output)
{
YT_VERIFY(0 <= level && level <= 9);
TLzmaSourceWrapper reader(source);
TLzmaSinkWrapper writer(output);
auto handle = LzmaEnc_Create(&Alloc);
YT_VERIFY(handle);
auto finallyGuard = Finally([&] {
LzmaEnc_Destroy(handle, &Alloc, &Alloc);
});
auto checkError = [] (SRes result) {
YT_LOG_FATAL_IF(result != SZ_OK, "Lzma compression failed (Error: %v)",
result);
};
{
// Set properties.
CLzmaEncProps props;
LzmaEncProps_Init(&props);
props.level = level;
props.writeEndMark = 1;
checkError(LzmaEnc_SetProps(handle, &props));
}
{
// Write properties.
Byte propsBuffer[LZMA_PROPS_SIZE];
size_t propsBufferSize = LZMA_PROPS_SIZE;
checkError(LzmaEnc_WriteProperties(handle, propsBuffer, &propsBufferSize));
writer.WriteData(propsBuffer, sizeof(propsBuffer));
}
// Compress data.
checkError(LzmaEnc_Encode(handle, &writer, &reader, nullptr, &Alloc, &Alloc));
}
void LzmaDecompress(TSource* source, TBlob* output)
{
Byte propsBuffer[LZMA_PROPS_SIZE];
ReadRef(*source, TMutableRef(reinterpret_cast<char*>(propsBuffer), sizeof(propsBuffer)));
CLzmaDec handle;
LzmaDec_Construct(&handle);
{
auto result = LzmaDec_Allocate(&handle, propsBuffer, LZMA_PROPS_SIZE, &Alloc);
if(result != SZ_OK) {
THROW_ERROR_EXCEPTION("Lzma decompression failed: LzmaDec_Allocate returned an error")
<< TErrorAttribute("error", result);
}
}
auto finallyGuard = Finally([&] {
LzmaDec_Free(&handle, &Alloc);
});
LzmaDec_Init(&handle);
auto status = LZMA_STATUS_NOT_FINISHED;
while (source->Available() > 0) {
size_t sourceDataSize;
const Byte* sourceData = reinterpret_cast<const Byte*>(source->Peek(&sourceDataSize));
sourceDataSize = std::min(sourceDataSize, source->Available());
size_t oldDicPos = handle.dicPos;
size_t bufferSize = sourceDataSize;
{
auto result = LzmaDec_DecodeToDic(
&handle,
handle.dicBufSize,
sourceData,
&bufferSize, // It's input buffer size before call, read byte count afterwards.
LZMA_FINISH_ANY,
&status);
if(result != SZ_OK) {
THROW_ERROR_EXCEPTION("Lzma decompression failed: LzmaDec_DecodeToDic returned an error")
<< TErrorAttribute("error", result);
}
}
output->Append(handle.dic + oldDicPos, handle.dicPos - oldDicPos);
sourceData += bufferSize;
sourceDataSize -= bufferSize;
// Strange lzma api requires us to update this index by hand.
if (handle.dicPos == handle.dicBufSize) {
handle.dicPos = 0;
}
source->Skip(bufferSize);
}
if (status != LZMA_STATUS_FINISHED_WITH_MARK) {
THROW_ERROR_EXCEPTION("Lzma decompression failed: unexpected final status")
<< TErrorAttribute("status", static_cast<int>(status));
}
}
////////////////////////////////////////////////////////////////////////////////
} // namespace NYT::NCompression::NDetail
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