Compression.cpp revision a0bd5df0867e054b9740bc734325cdeabfe3825a
1//===--- Compression.cpp - Compression implementation ---------------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements compression functions. 11// 12//===----------------------------------------------------------------------===// 13 14#include "llvm/Support/Compression.h" 15#include "llvm/ADT/OwningPtr.h" 16#include "llvm/ADT/StringRef.h" 17#include "llvm/Config/config.h" 18#include "llvm/Support/ErrorHandling.h" 19#include "llvm/Support/MemoryBuffer.h" 20#if LLVM_ENABLE_ZLIB == 1 && HAVE_ZLIB_H 21#include <zlib.h> 22#endif 23 24using namespace llvm; 25 26#if LLVM_ENABLE_ZLIB == 1 && HAVE_LIBZ 27static int encodeZlibCompressionLevel(zlib::CompressionLevel Level) { 28 switch (Level) { 29 case zlib::NoCompression: return 0; 30 case zlib::BestSpeedCompression: return 1; 31 case zlib::DefaultCompression: return Z_DEFAULT_COMPRESSION; 32 case zlib::BestSizeCompression: return 9; 33 } 34} 35 36static zlib::Status encodeZlibReturnValue(int ReturnValue) { 37 switch (ReturnValue) { 38 case Z_OK: return zlib::StatusOK; 39 case Z_MEM_ERROR: return zlib::StatusOutOfMemory; 40 case Z_BUF_ERROR: return zlib::StatusBufferTooShort; 41 case Z_STREAM_ERROR: return zlib::StatusInvalidArg; 42 case Z_DATA_ERROR: return zlib::StatusInvalidData; 43 default: llvm_unreachable("unknown zlib return status!"); 44 } 45} 46 47bool zlib::isAvailable() { return true; } 48zlib::Status zlib::compress(StringRef InputBuffer, 49 OwningPtr<MemoryBuffer> &CompressedBuffer, 50 CompressionLevel Level) { 51 unsigned long CompressedSize = ::compressBound(InputBuffer.size()); 52 OwningArrayPtr<char> TmpBuffer(new char[CompressedSize]); 53 int CLevel = encodeZlibCompressionLevel(Level); 54 Status Res = encodeZlibReturnValue(::compress2( 55 (Bytef *)TmpBuffer.get(), &CompressedSize, 56 (const Bytef *)InputBuffer.data(), InputBuffer.size(), CLevel)); 57 if (Res == StatusOK) 58 CompressedBuffer.reset(MemoryBuffer::getMemBufferCopy( 59 StringRef(TmpBuffer.get(), CompressedSize))); 60 return Res; 61} 62 63zlib::Status zlib::uncompress(StringRef InputBuffer, 64 OwningPtr<MemoryBuffer> &UncompressedBuffer, 65 size_t UncompressedSize) { 66 OwningArrayPtr<char> TmpBuffer(new char[UncompressedSize]); 67 Status Res = encodeZlibReturnValue( 68 ::uncompress((Bytef *)TmpBuffer.get(), (uLongf *)&UncompressedSize, 69 (const Bytef *)InputBuffer.data(), InputBuffer.size())); 70 if (Res == StatusOK) 71 UncompressedBuffer.reset(MemoryBuffer::getMemBufferCopy( 72 StringRef(TmpBuffer.get(), UncompressedSize))); 73 return Res; 74} 75 76#else 77bool zlib::isAvailable() { return false; } 78zlib::Status zlib::compress(StringRef InputBuffer, 79 OwningPtr<MemoryBuffer> &CompressedBuffer, 80 CompressionLevel Level) { 81 return zlib::StatusUnsupported; 82} 83zlib::Status zlib::uncompress(StringRef InputBuffer, 84 OwningPtr<MemoryBuffer> &UncompressedBuffer, 85 size_t UncompressedSize) { 86 return zlib::StatusUnsupported; 87} 88#endif 89 90