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#include "slang-lz4-compression-system.h"
#include "slang-blob.h"
#include "slang-com-helper.h"
#include "slang-com-ptr.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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