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#include "slang-lz4-compression-system.h"
#include "slang-com-helper.h"
#include "slang-com-ptr.h"
#include "slang-blob.h"
#include <lz4.h>
namespace Slang
{
// Allocate static const storage for the various interface IDs that the Slang API needs to expose
class LZ4CompressionSystemImpl : public RefObject, public ICompressionSystem
{
public:
// ISlangUnknown
// override ref counting, as singleton
SLANG_IUNKNOWN_QUERY_INTERFACE
SLANG_NO_THROW uint32_t SLANG_MCALL addRef() SLANG_OVERRIDE { return 1; }
SLANG_NO_THROW uint32_t SLANG_MCALL release() SLANG_OVERRIDE { return 1; }
// ICompressionSystem
virtual SLANG_NO_THROW CompressionSystemType SLANG_MCALL getSystemType() SLANG_OVERRIDE { return CompressionSystemType::LZ4; }
virtual SLANG_NO_THROW SlangResult SLANG_MCALL compress(const CompressionStyle* style, const void* src, size_t srcSizeInBytes, ISlangBlob** outBlob) SLANG_OVERRIDE;
virtual SLANG_NO_THROW SlangResult SLANG_MCALL decompress(const void* compressed, size_t compressedSizeInBytes, size_t decompressedSizeInBytes, void* outDecompressed) SLANG_OVERRIDE;
protected:
ICompressionSystem* getInterface(const Guid& guid);
};
ICompressionSystem* LZ4CompressionSystemImpl::getInterface(const Guid& guid)
{
return (guid == ISlangUnknown::getTypeGuid() || guid == ICompressionSystem::getTypeGuid()) ? static_cast<ICompressionSystem*>(this) : nullptr;
}
SlangResult LZ4CompressionSystemImpl::compress(const CompressionStyle* style, const void* src, size_t srcSizeInBytes, ISlangBlob** outBlob)
{
SLANG_UNUSED(style);
const size_t compressedBound = LZ4_compressBound(int(srcSizeInBytes));
ScopedAllocation alloc;
void* compressedData = alloc.allocate(compressedBound);
const int compressedSize = LZ4_compress_default((const char*)src, (char*)compressedData, int(srcSizeInBytes), int(compressedBound));
alloc.reallocate(compressedSize);
auto blob = RawBlob::moveCreate(alloc);
*outBlob = blob.detach();
return SLANG_OK;
}
SlangResult LZ4CompressionSystemImpl::decompress(const void* compressed, size_t compressedSizeInBytes, size_t decompressedSizeInBytes, void* outDecompressed)
{
const int decompressedSize = LZ4_decompress_safe((const char*)compressed, (char*)outDecompressed, int(compressedSizeInBytes), int(decompressedSizeInBytes));
SLANG_UNUSED(decompressedSize);
SLANG_ASSERT(size_t(decompressedSize) == decompressedSizeInBytes);
return SLANG_OK;
}
/* static */ICompressionSystem* LZ4CompressionSystem::getSingleton()
{
static LZ4CompressionSystemImpl impl;
return &impl;
}
} // namespace Slang
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