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/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
25 #if LLVM_ENABLE_ZLIB == 1 && HAVE_LIBZ
26 static int encodeZlibCompressionLevel(zlib::CompressionLevel 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;
33 llvm_unreachable("Invalid zlib::CompressionLevel!");
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!");
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);
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);
72 uint32_t zlib::crc32(StringRef Buffer) {
73 return ::crc32(0, (const Bytef *)Buffer.data(), Buffer.size());
77 bool zlib::isAvailable() { return false; }
78 zlib::Status zlib::compress(StringRef InputBuffer,
79 SmallVectorImpl<char> &CompressedBuffer,
80 CompressionLevel Level) {
81 return zlib::StatusUnsupported;
83 zlib::Status zlib::uncompress(StringRef InputBuffer,
84 SmallVectorImpl<char> &UncompressedBuffer,
85 size_t UncompressedSize) {
86 return zlib::StatusUnsupported;
88 uint32_t zlib::crc32(StringRef Buffer) {
89 llvm_unreachable("zlib::crc32 is unavailable");