1 //===--- Compression.cpp - Compression implementation ---------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements compression functions.
12 //===----------------------------------------------------------------------===//
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
26 #if LLVM_ENABLE_ZLIB == 1 && HAVE_LIBZ
27 static int encodeZlibCompressionLevel(zlib::CompressionLevel 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;
34 llvm_unreachable("Invalid zlib::CompressionLevel!");
37 static 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!");
48 bool zlib::isAvailable() { return true; }
49 zlib::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);
65 zlib::Status zlib::uncompress(StringRef InputBuffer, char *UncompressedBuffer,
66 size_t &UncompressedSize) {
67 Status Res = encodeZlibReturnValue(
68 ::uncompress((Bytef *)UncompressedBuffer, (uLongf *)&UncompressedSize,
69 (const Bytef *)InputBuffer.data(), InputBuffer.size()));
70 // Tell MemorySanitizer that zlib output buffer is fully initialized.
71 // This avoids a false report when running LLVM with uninstrumented ZLib.
72 __msan_unpoison(UncompressedBuffer, UncompressedSize);
76 zlib::Status zlib::uncompress(StringRef InputBuffer,
77 SmallVectorImpl<char> &UncompressedBuffer,
78 size_t UncompressedSize) {
79 UncompressedBuffer.resize(UncompressedSize);
81 uncompress(InputBuffer, UncompressedBuffer.data(), UncompressedSize);
82 UncompressedBuffer.resize(UncompressedSize);
86 uint32_t zlib::crc32(StringRef Buffer) {
87 return ::crc32(0, (const Bytef *)Buffer.data(), Buffer.size());
91 bool zlib::isAvailable() { return false; }
92 zlib::Status zlib::compress(StringRef InputBuffer,
93 SmallVectorImpl<char> &CompressedBuffer,
94 CompressionLevel Level) {
95 return zlib::StatusUnsupported;
97 zlib::Status zlib::uncompress(StringRef InputBuffer, char *UncompressedBuffer,
98 size_t &UncompressedSize) {
99 return zlib::StatusUnsupported;
101 zlib::Status zlib::uncompress(StringRef InputBuffer,
102 SmallVectorImpl<char> &UncompressedBuffer,
103 size_t UncompressedSize) {
104 return zlib::StatusUnsupported;
106 uint32_t zlib::crc32(StringRef Buffer) {
107 llvm_unreachable("zlib::crc32 is unavailable");