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Diffstat (limited to 'toolkit/components/lz4/lz4.cpp')
-rw-r--r-- | toolkit/components/lz4/lz4.cpp | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/toolkit/components/lz4/lz4.cpp b/toolkit/components/lz4/lz4.cpp new file mode 100644 index 000000000..34d568025 --- /dev/null +++ b/toolkit/components/lz4/lz4.cpp @@ -0,0 +1,73 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "mozilla/Compression.h" + +/** + * LZ4 is a very fast byte-wise compression algorithm. + * + * Compared to Google's Snappy it is faster to compress and decompress and + * generally produces output of about the same size. + * + * Compared to zlib it compresses at about 10x the speed, decompresses at about + * 4x the speed and produces output of about 1.5x the size. + * + */ + +using namespace mozilla::Compression; + +/** + * Compresses 'inputSize' bytes from 'source' into 'dest'. + * Destination buffer must be already allocated, + * and must be sized to handle worst cases situations (input data not compressible) + * Worst case size evaluation is provided by function LZ4_compressBound() + * + * @param inputSize is the input size. Max supported value is ~1.9GB + * @param return the number of bytes written in buffer dest + */ +extern "C" MOZ_EXPORT size_t +workerlz4_compress(const char* source, size_t inputSize, char* dest) { + return LZ4::compress(source, inputSize, dest); +} + +/** + * If the source stream is malformed, the function will stop decoding + * and return a negative result, indicating the byte position of the + * faulty instruction + * + * This function never writes outside of provided buffers, and never + * modifies input buffer. + * + * note : destination buffer must be already allocated. + * its size must be a minimum of 'outputSize' bytes. + * @param outputSize is the output size, therefore the original size + * @return true/false + */ +extern "C" MOZ_EXPORT int +workerlz4_decompress(const char* source, size_t inputSize, + char* dest, size_t maxOutputSize, + size_t *bytesOutput) { + return LZ4::decompress(source, inputSize, + dest, maxOutputSize, + bytesOutput); +} + + +/* + Provides the maximum size that LZ4 may output in a "worst case" + scenario (input data not compressible) primarily useful for memory + allocation of output buffer. + note : this function is limited by "int" range (2^31-1) + + @param inputSize is the input size. Max supported value is ~1.9GB + @return maximum output size in a "worst case" scenario +*/ +extern "C" MOZ_EXPORT size_t +workerlz4_maxCompressedSize(size_t inputSize) +{ + return LZ4::maxCompressedSize(inputSize); +} + + + |