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/SmallVector.h" 16#include "llvm/ADT/StringRef.h" 17#include "llvm/Config/config.h" 18#include "llvm/Support/Compiler.h" 19#include "llvm/Support/ErrorHandling.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 llvm_unreachable("Invalid zlib::CompressionLevel!"); 35} 36 37static zlib::Status encodeZlibReturnValue(int ReturnValue) { 38 switch (ReturnValue) { 39 case Z_OK: return zlib::StatusOK; 40 case Z_MEM_ERROR: return zlib::StatusOutOfMemory; 41 case Z_BUF_ERROR: return zlib::StatusBufferTooShort; 42 case Z_STREAM_ERROR: return zlib::StatusInvalidArg; 43 case Z_DATA_ERROR: return zlib::StatusInvalidData; 44 default: llvm_unreachable("unknown zlib return status!"); 45 } 46} 47 48bool zlib::isAvailable() { return true; } 49zlib::Status zlib::compress(StringRef InputBuffer, 50 SmallVectorImpl<char> &CompressedBuffer, 51 CompressionLevel Level) { 52 unsigned long CompressedSize = ::compressBound(InputBuffer.size()); 53 CompressedBuffer.resize(CompressedSize); 54 int CLevel = encodeZlibCompressionLevel(Level); 55 Status Res = encodeZlibReturnValue(::compress2( 56 (Bytef *)CompressedBuffer.data(), &CompressedSize, 57 (const Bytef *)InputBuffer.data(), InputBuffer.size(), CLevel)); 58 // Tell MemorySanitizer that zlib output buffer is fully initialized. 59 // This avoids a false report when running LLVM with uninstrumented ZLib. 60 __msan_unpoison(CompressedBuffer.data(), CompressedSize); 61 CompressedBuffer.resize(CompressedSize); 62 return Res; 63} 64 65zlib::Status zlib::uncompress(StringRef InputBuffer, 66 SmallVectorImpl<char> &UncompressedBuffer, 67 size_t UncompressedSize) { 68 UncompressedBuffer.resize(UncompressedSize); 69 Status Res = encodeZlibReturnValue(::uncompress( 70 (Bytef *)UncompressedBuffer.data(), (uLongf *)&UncompressedSize, 71 (const Bytef *)InputBuffer.data(), InputBuffer.size())); 72 // Tell MemorySanitizer that zlib output buffer is fully initialized. 73 // This avoids a false report when running LLVM with uninstrumented ZLib. 74 __msan_unpoison(UncompressedBuffer.data(), UncompressedSize); 75 UncompressedBuffer.resize(UncompressedSize); 76 return Res; 77} 78 79uint32_t zlib::crc32(StringRef Buffer) { 80 return ::crc32(0, (const Bytef *)Buffer.data(), Buffer.size()); 81} 82 83#else 84bool zlib::isAvailable() { return false; } 85zlib::Status zlib::compress(StringRef InputBuffer, 86 SmallVectorImpl<char> &CompressedBuffer, 87 CompressionLevel Level) { 88 return zlib::StatusUnsupported; 89} 90zlib::Status zlib::uncompress(StringRef InputBuffer, 91 SmallVectorImpl<char> &UncompressedBuffer, 92 size_t UncompressedSize) { 93 return zlib::StatusUnsupported; 94} 95uint32_t zlib::crc32(StringRef Buffer) { 96 llvm_unreachable("zlib::crc32 is unavailable"); 97} 98#endif 99 100