Viewing file:  Compression.h (4.22 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
//===-- llvm/Support/Compression.h ---Compression----------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file contains basic functions for compression/decompression.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_SUPPORT_COMPRESSION_H
#define LLVM_SUPPORT_COMPRESSION_H
#include "llvm/ADT/ArrayRef.h"
#include "llvm/Support/DataTypes.h"
namespace llvm {
template <typename T> class SmallVectorImpl;
class Error;
// None indicates no compression. The other members are a subset of
// compression::Format, which is used for compressed debug sections in some
// object file formats (e.g. ELF). This is a separate class as we may add new
// compression::Format members for non-debugging purposes.
enum class DebugCompressionType {
None, ///< No compression
Zlib, ///< zlib
Zstd, ///< Zstandard
};
namespace compression {
namespace zlib {
constexpr int NoCompression = 0;
constexpr int BestSpeedCompression = 1;
constexpr int DefaultCompression = 6;
constexpr int BestSizeCompression = 9;
bool isAvailable();
void compress(ArrayRef<uint8_t> Input,
SmallVectorImpl<uint8_t> &CompressedBuffer,
int Level = DefaultCompression);
Error decompress(ArrayRef<uint8_t> Input, uint8_t *Output,
size_t &UncompressedSize);
Error decompress(ArrayRef<uint8_t> Input, SmallVectorImpl<uint8_t> &Output,
size_t UncompressedSize);
} // End of namespace zlib
namespace zstd {
constexpr int NoCompression = -5;
constexpr int BestSpeedCompression = 1;
constexpr int DefaultCompression = 5;
constexpr int BestSizeCompression = 12;
bool isAvailable();
void compress(ArrayRef<uint8_t> Input,
SmallVectorImpl<uint8_t> &CompressedBuffer,
int Level = DefaultCompression, bool EnableLdm = false);
Error decompress(ArrayRef<uint8_t> Input, uint8_t *Output,
size_t &UncompressedSize);
Error decompress(ArrayRef<uint8_t> Input, SmallVectorImpl<uint8_t> &Output,
size_t UncompressedSize);
} // End of namespace zstd
enum class Format {
Zlib,
Zstd,
};
inline Format formatFor(DebugCompressionType Type) {
switch (Type) {
case DebugCompressionType::None:
llvm_unreachable("not a compression type");
case DebugCompressionType::Zlib:
return Format::Zlib;
case DebugCompressionType::Zstd:
return Format::Zstd;
}
llvm_unreachable("");
}
struct Params {
constexpr Params(Format F)
: format(F), level(F == Format::Zlib ? zlib::DefaultCompression
: zstd::DefaultCompression) {}
constexpr Params(Format F, int L, bool Ldm = false)
: format(F), level(L), zstdEnableLdm(Ldm) {}
Params(DebugCompressionType Type) : Params(formatFor(Type)) {}
Format format;
int level;
bool zstdEnableLdm = false; // Enable zstd long distance matching
// This may support multi-threading for zstd in the future. Note that
// different threads may produce different output, so be careful if certain
// output determinism is desired.
};
// Return nullptr if LLVM was built with support (LLVM_ENABLE_ZLIB,
// LLVM_ENABLE_ZSTD) for the specified compression format; otherwise
// return a string literal describing the reason.
const char *getReasonIfUnsupported(Format F);
// Compress Input with the specified format P.Format. If Level is -1, use
// *::DefaultCompression for the format.
void compress(Params P, ArrayRef<uint8_t> Input,
SmallVectorImpl<uint8_t> &Output);
// Decompress Input. The uncompressed size must be available.
Error decompress(DebugCompressionType T, ArrayRef<uint8_t> Input,
uint8_t *Output, size_t UncompressedSize);
Error decompress(Format F, ArrayRef<uint8_t> Input,
SmallVectorImpl<uint8_t> &Output, size_t UncompressedSize);
Error decompress(DebugCompressionType T, ArrayRef<uint8_t> Input,
SmallVectorImpl<uint8_t> &Output, size_t UncompressedSize);
} // End of namespace compression
} // End of namespace llvm
#endif
|