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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-15 03:34:50 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-15 03:34:50 +0000 |
commit | def92d1b8e9d373e2f6f27c366d578d97d8960c6 (patch) | |
tree | 2ef34b9ad8bb9a9220e05d60352558b15f513894 /other-licenses/snappy/src/snappy.h | |
parent | Adding debian version 125.0.3-1. (diff) | |
download | firefox-def92d1b8e9d373e2f6f27c366d578d97d8960c6.tar.xz firefox-def92d1b8e9d373e2f6f27c366d578d97d8960c6.zip |
Merging upstream version 126.0.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'other-licenses/snappy/src/snappy.h')
-rw-r--r-- | other-licenses/snappy/src/snappy.h | 56 |
1 files changed, 46 insertions, 10 deletions
diff --git a/other-licenses/snappy/src/snappy.h b/other-licenses/snappy/src/snappy.h index e4fdad3354..9e0572dcc8 100644 --- a/other-licenses/snappy/src/snappy.h +++ b/other-licenses/snappy/src/snappy.h @@ -50,13 +50,36 @@ namespace snappy { class Source; class Sink; + struct CompressionOptions { + // Compression level. + // Level 1 is the fastest + // Level 2 is a little slower but provides better compression. Level 2 is + // **EXPERIMENTAL** for the time being. It might happen that we decide to + // fall back to level 1 in the future. + // Levels 3+ are currently not supported. We plan to support levels up to + // 9 in the future. + // If you played with other compression algorithms, level 1 is equivalent to + // fast mode (level 1) of LZ4, level 2 is equivalent to LZ4's level 2 mode + // and compresses somewhere around zstd:-3 and zstd:-2 but generally with + // faster decompression speeds than snappy:1 and zstd:-3. + int level = DefaultCompressionLevel(); + + constexpr CompressionOptions() = default; + constexpr explicit CompressionOptions(int compression_level) + : level(compression_level) {} + static constexpr int MinCompressionLevel() { return 1; } + static constexpr int MaxCompressionLevel() { return 2; } + static constexpr int DefaultCompressionLevel() { return 1; } + }; + // ------------------------------------------------------------------------ // Generic compression/decompression routines. // ------------------------------------------------------------------------ - // Compress the bytes read from "*source" and append to "*sink". Return the + // Compress the bytes read from "*reader" and append to "*writer". Return the // number of bytes written. - size_t Compress(Source* source, Sink* sink); + size_t Compress(Source* reader, Sink* writer, + CompressionOptions options = {}); // Find the uncompressed length of the given stream, as given by the header. // Note that the true length could deviate from this; the stream could e.g. @@ -71,14 +94,22 @@ namespace snappy { // Higher-level string based routines (should be sufficient for most users) // ------------------------------------------------------------------------ - // Sets "*compressed" to the compressed version of "input[0,input_length-1]". + // Sets "*compressed" to the compressed version of "input[0..input_length-1]". // Original contents of *compressed are lost. // // REQUIRES: "input[]" is not an alias of "*compressed". size_t Compress(const char* input, size_t input_length, - std::string* compressed); + std::string* compressed, CompressionOptions options = {}); + + // Same as `Compress` above but taking an `iovec` array as input. Note that + // this function preprocesses the inputs to compute the sum of + // `iov[0..iov_cnt-1].iov_len` before reading. To avoid this, use + // `RawCompressFromIOVec` below. + size_t CompressFromIOVec(const struct iovec* iov, size_t iov_cnt, + std::string* compressed, + CompressionOptions options = {}); - // Decompresses "compressed[0,compressed_length-1]" to "*uncompressed". + // Decompresses "compressed[0..compressed_length-1]" to "*uncompressed". // Original contents of "*uncompressed" are lost. // // REQUIRES: "compressed[]" is not an alias of "*uncompressed". @@ -119,10 +150,15 @@ namespace snappy { // RawCompress(input, input_length, output, &output_length); // ... Process(output, output_length) ... // delete [] output; - void RawCompress(const char* input, - size_t input_length, - char* compressed, - size_t* compressed_length); + void RawCompress(const char* input, size_t input_length, char* compressed, + size_t* compressed_length, CompressionOptions options = {}); + + // Same as `RawCompress` above but taking an `iovec` array as input. Note that + // `uncompressed_length` is the total number of bytes to be read from the + // elements of `iov` (_not_ the number of elements in `iov`). + void RawCompressFromIOVec(const struct iovec* iov, size_t uncompressed_length, + char* compressed, size_t* compressed_length, + CompressionOptions options = {}); // Given data in "compressed[0..compressed_length-1]" generated by // calling the Snappy::Compress routine, this routine @@ -202,7 +238,7 @@ namespace snappy { static constexpr int kMinHashTableBits = 8; static constexpr size_t kMinHashTableSize = 1 << kMinHashTableBits; - static constexpr int kMaxHashTableBits = 14; + static constexpr int kMaxHashTableBits = 15; static constexpr size_t kMaxHashTableSize = 1 << kMaxHashTableBits; } // end namespace snappy |