llvm-mirror/lib/Support/Compression.cpp
Ahmed Charles 52ce0c101e Replace OwningPtr<T> with std::unique_ptr<T>.
This compiles with no changes to clang/lld/lldb with MSVC and includes
overloads to various functions which are used by those projects and llvm
which have OwningPtr's as parameters. This should allow out of tree
projects some time to move. There are also no changes to libs/Target,
which should help out of tree targets have time to move, if necessary.

llvm-svn: 203083
2014-03-06 05:51:42 +00:00

104 lines
3.8 KiB
C++

//===--- Compression.cpp - Compression implementation ---------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements compression functions.
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/Compression.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Config/config.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MemoryBuffer.h"
#if LLVM_ENABLE_ZLIB == 1 && HAVE_ZLIB_H
#include <zlib.h>
#endif
using namespace llvm;
#if LLVM_ENABLE_ZLIB == 1 && HAVE_LIBZ
static int encodeZlibCompressionLevel(zlib::CompressionLevel Level) {
switch (Level) {
case zlib::NoCompression: return 0;
case zlib::BestSpeedCompression: return 1;
case zlib::DefaultCompression: return Z_DEFAULT_COMPRESSION;
case zlib::BestSizeCompression: return 9;
}
llvm_unreachable("Invalid zlib::CompressionLevel!");
}
static zlib::Status encodeZlibReturnValue(int ReturnValue) {
switch (ReturnValue) {
case Z_OK: return zlib::StatusOK;
case Z_MEM_ERROR: return zlib::StatusOutOfMemory;
case Z_BUF_ERROR: return zlib::StatusBufferTooShort;
case Z_STREAM_ERROR: return zlib::StatusInvalidArg;
case Z_DATA_ERROR: return zlib::StatusInvalidData;
default: llvm_unreachable("unknown zlib return status!");
}
}
bool zlib::isAvailable() { return true; }
zlib::Status zlib::compress(StringRef InputBuffer,
std::unique_ptr<MemoryBuffer> &CompressedBuffer,
CompressionLevel Level) {
unsigned long CompressedSize = ::compressBound(InputBuffer.size());
std::unique_ptr<char[]> TmpBuffer(new char[CompressedSize]);
int CLevel = encodeZlibCompressionLevel(Level);
Status Res = encodeZlibReturnValue(::compress2(
(Bytef *)TmpBuffer.get(), &CompressedSize,
(const Bytef *)InputBuffer.data(), InputBuffer.size(), CLevel));
if (Res == StatusOK) {
CompressedBuffer.reset(MemoryBuffer::getMemBufferCopy(
StringRef(TmpBuffer.get(), CompressedSize)));
// Tell MSan that memory initialized by zlib is valid.
__msan_unpoison(CompressedBuffer->getBufferStart(), CompressedSize);
}
return Res;
}
zlib::Status zlib::uncompress(StringRef InputBuffer,
std::unique_ptr<MemoryBuffer> &UncompressedBuffer,
size_t UncompressedSize) {
std::unique_ptr<char[]> TmpBuffer(new char[UncompressedSize]);
Status Res = encodeZlibReturnValue(
::uncompress((Bytef *)TmpBuffer.get(), (uLongf *)&UncompressedSize,
(const Bytef *)InputBuffer.data(), InputBuffer.size()));
if (Res == StatusOK) {
UncompressedBuffer.reset(MemoryBuffer::getMemBufferCopy(
StringRef(TmpBuffer.get(), UncompressedSize)));
// Tell MSan that memory initialized by zlib is valid.
__msan_unpoison(UncompressedBuffer->getBufferStart(), UncompressedSize);
}
return Res;
}
uint32_t zlib::crc32(StringRef Buffer) {
return ::crc32(0, (const Bytef *)Buffer.data(), Buffer.size());
}
#else
bool zlib::isAvailable() { return false; }
zlib::Status zlib::compress(StringRef InputBuffer,
std::unique_ptr<MemoryBuffer> &CompressedBuffer,
CompressionLevel Level) {
return zlib::StatusUnsupported;
}
zlib::Status zlib::uncompress(StringRef InputBuffer,
std::unique_ptr<MemoryBuffer> &UncompressedBuffer,
size_t UncompressedSize) {
return zlib::StatusUnsupported;
}
uint32_t zlib::crc32(StringRef Buffer) {
llvm_unreachable("zlib::crc32 is unavailable");
}
#endif