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/StringRef.h" 16 #include "llvm/Config/config.h" 17 #include "llvm/Support/Compiler.h" 18 #include "llvm/Support/ErrorHandling.h" 19 #if LLVM_ENABLE_ZLIB == 1 && HAVE_ZLIB_H 20 #include <zlib.h> 21 #endif 22 23 using namespace llvm; 24 25 #if LLVM_ENABLE_ZLIB == 1 && HAVE_LIBZ 26 static int encodeZlibCompressionLevel(zlib::CompressionLevel Level) { 27 switch (Level) { 28 case zlib::NoCompression: return 0; 29 case zlib::BestSpeedCompression: return 1; 30 case zlib::DefaultCompression: return Z_DEFAULT_COMPRESSION; 31 case zlib::BestSizeCompression: return 9; 32 } 33 llvm_unreachable("Invalid zlib::CompressionLevel!"); 34 } 35 36 static 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 47 bool zlib::isAvailable() { return true; } 48 zlib::Status zlib::compress(StringRef InputBuffer, 49 SmallVectorImpl<char> &CompressedBuffer, 50 CompressionLevel Level) { 51 unsigned long CompressedSize = ::compressBound(InputBuffer.size()); 52 CompressedBuffer.resize(CompressedSize); 53 int CLevel = encodeZlibCompressionLevel(Level); 54 Status Res = encodeZlibReturnValue(::compress2( 55 (Bytef *)CompressedBuffer.data(), &CompressedSize, 56 (const Bytef *)InputBuffer.data(), InputBuffer.size(), CLevel)); 57 CompressedBuffer.resize(CompressedSize); 58 return Res; 59 } 60 61 zlib::Status zlib::uncompress(StringRef InputBuffer, 62 SmallVectorImpl<char> &UncompressedBuffer, 63 size_t UncompressedSize) { 64 UncompressedBuffer.resize(UncompressedSize); 65 Status Res = encodeZlibReturnValue(::uncompress( 66 (Bytef *)UncompressedBuffer.data(), (uLongf *)&UncompressedSize, 67 (const Bytef *)InputBuffer.data(), InputBuffer.size())); 68 UncompressedBuffer.resize(UncompressedSize); 69 return Res; 70 } 71 72 uint32_t zlib::crc32(StringRef Buffer) { 73 return ::crc32(0, (const Bytef *)Buffer.data(), Buffer.size()); 74 } 75 76 #else 77 bool zlib::isAvailable() { return false; } 78 zlib::Status zlib::compress(StringRef InputBuffer, 79 SmallVectorImpl<char> &CompressedBuffer, 80 CompressionLevel Level) { 81 return zlib::StatusUnsupported; 82 } 83 zlib::Status zlib::uncompress(StringRef InputBuffer, 84 SmallVectorImpl<char> &UncompressedBuffer, 85 size_t UncompressedSize) { 86 return zlib::StatusUnsupported; 87 } 88 uint32_t zlib::crc32(StringRef Buffer) { 89 llvm_unreachable("zlib::crc32 is unavailable"); 90 } 91 #endif 92 93
