/* 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);

}