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| Rev | Author | Line No. | Line |
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| 14 | pmbaty | 1 | //===-- llvm/Support/Compression.h ---Compression----------------*- C++ -*-===// |
| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | // |
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| 9 | // This file contains basic functions for compression/decompression. |
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| 10 | // |
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| 11 | //===----------------------------------------------------------------------===// |
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| 12 | |||
| 13 | #ifndef LLVM_SUPPORT_COMPRESSION_H |
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| 14 | #define LLVM_SUPPORT_COMPRESSION_H |
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| 15 | |||
| 16 | #include "llvm/ADT/ArrayRef.h" |
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| 17 | #include "llvm/Support/DataTypes.h" |
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| 18 | |||
| 19 | namespace llvm { |
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| 20 | template <typename T> class SmallVectorImpl; |
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| 21 | class Error; |
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| 22 | |||
| 23 | // None indicates no compression. The other members are a subset of |
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| 24 | // compression::Format, which is used for compressed debug sections in some |
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| 25 | // object file formats (e.g. ELF). This is a separate class as we may add new |
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| 26 | // compression::Format members for non-debugging purposes. |
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| 27 | enum class DebugCompressionType { |
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| 28 | None, ///< No compression |
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| 29 | Zlib, ///< zlib |
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| 30 | Zstd, ///< Zstandard |
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| 31 | }; |
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| 32 | |||
| 33 | namespace compression { |
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| 34 | namespace zlib { |
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| 35 | |||
| 36 | constexpr int NoCompression = 0; |
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| 37 | constexpr int BestSpeedCompression = 1; |
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| 38 | constexpr int DefaultCompression = 6; |
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| 39 | constexpr int BestSizeCompression = 9; |
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| 40 | |||
| 41 | bool isAvailable(); |
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| 42 | |||
| 43 | void compress(ArrayRef<uint8_t> Input, |
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| 44 | SmallVectorImpl<uint8_t> &CompressedBuffer, |
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| 45 | int Level = DefaultCompression); |
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| 46 | |||
| 47 | Error decompress(ArrayRef<uint8_t> Input, uint8_t *Output, |
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| 48 | size_t &UncompressedSize); |
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| 49 | |||
| 50 | Error decompress(ArrayRef<uint8_t> Input, SmallVectorImpl<uint8_t> &Output, |
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| 51 | size_t UncompressedSize); |
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| 52 | |||
| 53 | } // End of namespace zlib |
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| 54 | |||
| 55 | namespace zstd { |
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| 56 | |||
| 57 | constexpr int NoCompression = -5; |
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| 58 | constexpr int BestSpeedCompression = 1; |
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| 59 | constexpr int DefaultCompression = 5; |
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| 60 | constexpr int BestSizeCompression = 12; |
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| 61 | |||
| 62 | bool isAvailable(); |
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| 63 | |||
| 64 | void compress(ArrayRef<uint8_t> Input, |
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| 65 | SmallVectorImpl<uint8_t> &CompressedBuffer, |
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| 66 | int Level = DefaultCompression); |
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| 67 | |||
| 68 | Error decompress(ArrayRef<uint8_t> Input, uint8_t *Output, |
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| 69 | size_t &UncompressedSize); |
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| 70 | |||
| 71 | Error decompress(ArrayRef<uint8_t> Input, SmallVectorImpl<uint8_t> &Output, |
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| 72 | size_t UncompressedSize); |
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| 73 | |||
| 74 | } // End of namespace zstd |
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| 75 | |||
| 76 | enum class Format { |
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| 77 | Zlib, |
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| 78 | Zstd, |
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| 79 | }; |
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| 80 | |||
| 81 | inline Format formatFor(DebugCompressionType Type) { |
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| 82 | switch (Type) { |
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| 83 | case DebugCompressionType::None: |
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| 84 | llvm_unreachable("not a compression type"); |
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| 85 | case DebugCompressionType::Zlib: |
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| 86 | return Format::Zlib; |
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| 87 | case DebugCompressionType::Zstd: |
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| 88 | return Format::Zstd; |
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| 89 | } |
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| 90 | llvm_unreachable(""); |
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| 91 | } |
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| 92 | |||
| 93 | struct Params { |
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| 94 | constexpr Params(Format F) |
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| 95 | : format(F), level(F == Format::Zlib ? zlib::DefaultCompression |
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| 96 | : zstd::DefaultCompression) {} |
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| 97 | Params(DebugCompressionType Type) : Params(formatFor(Type)) {} |
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| 98 | |||
| 99 | Format format; |
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| 100 | int level; |
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| 101 | // This may support multi-threading for zstd in the future. Note that |
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| 102 | // different threads may produce different output, so be careful if certain |
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| 103 | // output determinism is desired. |
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| 104 | }; |
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| 105 | |||
| 106 | // Return nullptr if LLVM was built with support (LLVM_ENABLE_ZLIB, |
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| 107 | // LLVM_ENABLE_ZSTD) for the specified compression format; otherwise |
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| 108 | // return a string literal describing the reason. |
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| 109 | const char *getReasonIfUnsupported(Format F); |
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| 110 | |||
| 111 | // Compress Input with the specified format P.Format. If Level is -1, use |
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| 112 | // *::DefaultCompression for the format. |
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| 113 | void compress(Params P, ArrayRef<uint8_t> Input, |
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| 114 | SmallVectorImpl<uint8_t> &Output); |
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| 115 | |||
| 116 | // Decompress Input. The uncompressed size must be available. |
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| 117 | Error decompress(DebugCompressionType T, ArrayRef<uint8_t> Input, |
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| 118 | uint8_t *Output, size_t UncompressedSize); |
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| 119 | Error decompress(Format F, ArrayRef<uint8_t> Input, |
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| 120 | SmallVectorImpl<uint8_t> &Output, size_t UncompressedSize); |
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| 121 | Error decompress(DebugCompressionType T, ArrayRef<uint8_t> Input, |
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| 122 | SmallVectorImpl<uint8_t> &Output, size_t UncompressedSize); |
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| 123 | |||
| 124 | } // End of namespace compression |
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| 125 | |||
| 126 | } // End of namespace llvm |
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| 127 | |||
| 128 | #endif |