lz4.h

// Copyright (c) 2014 The Trident Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//
// 

/*
   LZ4 - Fast LZ compression algorithm
   Header File
   Copyright (C) 2011-2012, Yann Collet.
   BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)

   Redistribution and use in source and binary forms, with or without
   modification, are permitted provided that the following conditions are
   met:

       * Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.
       * Redistributions in binary form must reproduce the above
   copyright notice, this list of conditions and the following disclaimer
   in the documentation and/or other materials provided with the
   distribution.

   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

   You can contact the author at :
   - LZ4 homepage : http://fastcompression.blogspot.com/p/lz4.html
   - LZ4 source repository : http://code.google.com/p/lz4/
*/

#ifndef _TRIDENT_LZ4_H_
#define _TRIDENT_LZ4_H_

namespace trident {


//****************************
// Simple Functions
//****************************

int LZ4_compress   (const char* source, char* dest, int isize);
int LZ4_uncompress (const char* source, char* dest, int osize);

/*
LZ4_compress() :
	isize  : is the input size. Max supported value is ~1.9GB
	return : the number of bytes written in buffer dest
			 or 0 if the compression fails (if LZ4_COMPRESSMIN is set)
	note : destination buffer must be already allocated.
		destination buffer must be sized to handle worst cases situations (input data not compressible)
		worst case size evaluation is provided by function LZ4_compressBound()

LZ4_uncompress() :
	osize  : is the output size, therefore the original size
	return : the number of bytes read in the source buffer
			 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 beyond dest + osize, and is therefore protected against malicious data packets
	note : destination buffer must be already allocated
*/


//****************************
// Advanced Functions
//****************************

int LZ4_compressBound(int isize);

/*
LZ4_compressBound() :
	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.

	isize  : is the input size. Max supported value is ~1.9GB
	return : maximum output size in a "worst case" scenario
	note : this function is limited by "int" range (2^31-1)
*/


int LZ4_uncompress_unknownOutputSize (const char* source, char* dest, int isize, int maxOutputSize);

/*
LZ4_uncompress_unknownOutputSize() :
	isize  : is the input size, therefore the compressed size
	maxOutputSize : is the size of the destination buffer (which must be already allocated)
	return : the number of bytes decoded in the destination buffer (necessarily <= maxOutputSize)
			 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 beyond dest + maxOutputSize, and is therefore protected against malicious data packets
	note   : Destination buffer must be already allocated.
	         This version is slightly slower than LZ4_uncompress()
*/


int LZ4_compressCtx(void** ctx, const char* source,  char* dest, int isize);
int LZ4_compress64kCtx(void** ctx, const char* source,  char* dest, int isize);

/*
LZ4_compressCtx() :
	This function explicitly handles the CTX memory structure.
	It avoids allocating/deallocating memory between each call, improving performance when malloc is heavily invoked.
	This function is only useful when memory is allocated into the heap (HASH_LOG value beyond STACK_LIMIT)
	Performance difference will be noticeable only when repetitively calling the compression function over many small segments.
	Note : by default, memory is allocated into the stack, therefore "malloc" is not invoked.
LZ4_compress64kCtx() :
	Same as LZ4_compressCtx(), but specific to small inputs (<64KB).
	isize *Must* be <64KB, otherwise the output will be corrupted.

	On first call : provide a *ctx=NULL; It will be automatically allocated.
	On next calls : reuse the same ctx pointer.
	Use different pointers for different threads when doing multi-threading.

*/


} // namespace trident

#endif // _TRIDENT_LZ4_H_

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