LLVM 19.0.0git
Compression.h
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1//===-- llvm/Support/Compression.h ---Compression----------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file contains basic functions for compression/decompression.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_SUPPORT_COMPRESSION_H
14#define LLVM_SUPPORT_COMPRESSION_H
15
16#include "llvm/ADT/ArrayRef.h"
18
19namespace llvm {
20template <typename T> class SmallVectorImpl;
21class Error;
22
23// None indicates no compression. The other members are a subset of
24// compression::Format, which is used for compressed debug sections in some
25// object file formats (e.g. ELF). This is a separate class as we may add new
26// compression::Format members for non-debugging purposes.
28 None, ///< No compression
29 Zlib, ///< zlib
30 Zstd, ///< Zstandard
31};
32
33namespace compression {
34namespace zlib {
35
36constexpr int NoCompression = 0;
37constexpr int BestSpeedCompression = 1;
38constexpr int DefaultCompression = 6;
39constexpr int BestSizeCompression = 9;
40
41bool isAvailable();
42
44 SmallVectorImpl<uint8_t> &CompressedBuffer,
45 int Level = DefaultCompression);
46
47Error decompress(ArrayRef<uint8_t> Input, uint8_t *Output,
48 size_t &UncompressedSize);
49
51 size_t UncompressedSize);
52
53} // End of namespace zlib
54
55namespace zstd {
56
57constexpr int NoCompression = -5;
58constexpr int BestSpeedCompression = 1;
59constexpr int DefaultCompression = 5;
60constexpr int BestSizeCompression = 12;
61
62bool isAvailable();
63
65 SmallVectorImpl<uint8_t> &CompressedBuffer,
66 int Level = DefaultCompression);
67
68Error decompress(ArrayRef<uint8_t> Input, uint8_t *Output,
69 size_t &UncompressedSize);
70
72 size_t UncompressedSize);
73
74} // End of namespace zstd
75
76enum class Format {
77 Zlib,
78 Zstd,
79};
80
82 switch (Type) {
84 llvm_unreachable("not a compression type");
86 return Format::Zlib;
88 return Format::Zstd;
89 }
91}
92
93struct Params {
94 constexpr Params(Format F)
95 : format(F), level(F == Format::Zlib ? zlib::DefaultCompression
96 : zstd::DefaultCompression) {}
98
100 int level;
101 // This may support multi-threading for zstd in the future. Note that
102 // different threads may produce different output, so be careful if certain
103 // output determinism is desired.
104};
105
106// Return nullptr if LLVM was built with support (LLVM_ENABLE_ZLIB,
107// LLVM_ENABLE_ZSTD) for the specified compression format; otherwise
108// return a string literal describing the reason.
109const char *getReasonIfUnsupported(Format F);
110
111// Compress Input with the specified format P.Format. If Level is -1, use
112// *::DefaultCompression for the format.
115
116// Decompress Input. The uncompressed size must be available.
118 uint8_t *Output, size_t UncompressedSize);
120 SmallVectorImpl<uint8_t> &Output, size_t UncompressedSize);
122 SmallVectorImpl<uint8_t> &Output, size_t UncompressedSize);
123
124} // End of namespace compression
125
126} // End of namespace llvm
127
128#endif
#define F(x, y, z)
Definition: MD5.cpp:55
#define P(N)
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory),...
Definition: ArrayRef.h:41
Lightweight error class with error context and mandatory checking.
Definition: Error.h:160
This class consists of common code factored out of the SmallVector class to reduce code duplication b...
Definition: SmallVector.h:586
The instances of the Type class are immutable: once they are created, they are never changed.
Definition: Type.h:45
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
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)
constexpr int NoCompression
Definition: Compression.h:36
constexpr int BestSizeCompression
Definition: Compression.h:39
constexpr int DefaultCompression
Definition: Compression.h:38
constexpr int BestSpeedCompression
Definition: Compression.h:37
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)
constexpr int NoCompression
Definition: Compression.h:57
constexpr int BestSpeedCompression
Definition: Compression.h:58
constexpr int DefaultCompression
Definition: Compression.h:59
constexpr int BestSizeCompression
Definition: Compression.h:60
const char * getReasonIfUnsupported(Format F)
Definition: Compression.cpp:30
Error decompress(DebugCompressionType T, ArrayRef< uint8_t > Input, uint8_t *Output, size_t UncompressedSize)
Definition: Compression.cpp:58
Format formatFor(DebugCompressionType Type)
Definition: Compression.h:81
void compress(Params P, ArrayRef< uint8_t > Input, SmallVectorImpl< uint8_t > &Output)
Definition: Compression.cpp:46
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
DebugCompressionType
Definition: Compression.h:27
@ None
Not a recurrence.
Params(DebugCompressionType Type)
Definition: Compression.h:97
constexpr Params(Format F)
Definition: Compression.h:94