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/* 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);
}
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