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