path: root/lib/lz4/lz4.h

/*
 *  LZ4 - Fast LZ compression algorithm
 *  Header File
 *  Copyright (C) 2011-present, 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://www.lz4.org
    - LZ4 source repository : https://github.com/lz4/lz4
*/
#if defined (__cplusplus)
extern "C" {
#endif

#ifndef LZ4_H_2983827168210
#define LZ4_H_2983827168210

/* --- Dependency --- */
#include <stddef.h>   /* size_t */


/**
  Introduction

  LZ4 is lossless compression algorithm, providing compression speed >500 MB/s per core,
  scalable with multi-cores CPU. It features an extremely fast decoder, with speed in
  multiple GB/s per core, typically reaching RAM speed limits on multi-core systems.

  The LZ4 compression library provides in-memory compression and decompression functions.
  It gives full buffer control to user.
  Compression can be done in:
    - a single step (described as Simple Functions)
    - a single step, reusing a context (described in Advanced Functions)
    - unbounded multiple steps (described as Streaming compression)

  lz4.h generates and decodes LZ4-compressed blocks (doc/lz4_Block_format.md).
  Decompressing such a compressed block requires additional metadata.
  Exact metadata depends on exact decompression function.
  For the typical case of LZ4_decompress_safe(),
  metadata includes block's compressed size, and maximum bound of decompressed size.
  Each application is free to encode and pass such metadata in whichever way it wants.

  lz4.h only handle blocks, it can not generate Frames.

  Blocks are different from Frames (doc/lz4_Frame_format.md).
  Frames bundle both blocks and metadata in a specified manner.
  Embedding metadata is required for compressed data to be self-contained and portable.
  Frame format is delivered through a companion API, declared in lz4frame.h.
  The `lz4` CLI can only manage frames.
*/

/*^***************************************************************
*  Export parameters
*****************************************************************/
/*
*  LZ4_DLL_EXPORT :
*  Enable exporting of functions when building a Windows DLL
*  LZ4LIB_VISIBILITY :
*  Control library symbols visibility.
*/
#ifndef LZ4LIB_VISIBILITY
#  if defined(__GNUC__) && (__GNUC__ >= 4)
#    define LZ4LIB_VISIBILITY __attribute__ ((visibility ("hidden")))
#  else
#    define LZ4LIB_VISIBILITY
#  endif
#endif

#define LZ4LIB_API LZ4LIB_VISIBILITY

/*------   Version   ------*/
#define LZ4_QUOTE(str) #str
#define LZ4_EXPAND_AND_QUOTE(str) LZ4_QUOTE(str)
#define LZ4_VERSION_STRING LZ4_EXPAND_AND_QUOTE(LZ4_LIB_VERSION)

/*-************************************
*  Tuning parameter
**************************************/
/*!
 * LZ4_MEMORY_USAGE :
 * Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
 * Increasing memory usage improves compression ratio.
 * Reduced memory usage may improve speed, thanks to better cache locality.
 * Default value is 14, for 16KB, which nicely fits into Intel x86 L1 cache
 */
#ifndef LZ4_MEMORY_USAGE
# define LZ4_MEMORY_USAGE 14
#endif


/*-************************************
*  Simple Functions
**************************************/
/*! LZ4_compress_default() :
 *  Compresses 'srcSize' bytes from buffer 'src'
 *  into already allocated 'dst' buffer of size 'dstCapacity'.
 *  Compression is guaranteed to succeed if 'dstCapacity' >= LZ4_compressBound(srcSize).
 *  It also runs faster, so it's a recommended setting.
 *  If the function cannot compress 'src' into a more limited 'dst' budget,
 *  compression stops *immediately*, and the function result is zero.
 *  In which case, 'dst' content is undefined (invalid).
 *      srcSize : max supported value is LZ4_MAX_INPUT_SIZE.
 *      dstCapacity : size of buffer 'dst' (which must be already allocated)
 *     @return  : the number of bytes written into buffer 'dst' (necessarily <= dstCapacity)
 *                or 0 if compression fails
 * Note : This function is protected against buffer overflow scenarios (never writes outside 'dst' buffer, nor read outside 'source' buffer).
 */
LZ4LIB_API int LZ4_compress_default(const char* src, char* dst, int srcSize, int dstCapacity);

/*! LZ4_decompress_safe() :
 *  compressedSize : is the exact complete size of the compressed block.
 *  dstCapacity : is the size of destination buffer (which must be already allocated), presumed an upper bound of decompressed size.
 * @return : the number of bytes decompressed into destination buffer (necessarily <= dstCapacity)
 *           If destination buffer is not large enough, decoding will stop and output an error code (negative value).
 *           If the source stream is detected malformed, the function will stop decoding and return a negative result.
 * Note 1 : This function is protected against malicious data packets :
 *          it will never writes outside 'dst' buffer, nor read outside 'source' buffer,
 *          even if the compressed block is maliciously modified to order the decoder to do these actions.
 *          In such case, the decoder stops immediately, and considers the compressed block malformed.
 * Note 2 : compressedSize and dstCapacity must be provided to the function, the compressed block does not contain them.
 *          The implementation is free to send / store / derive this information in whichever way is most beneficial.
 *          If there is a need for a different format which bundles together both compressed data and its metadata, consider looking at lz4frame.h instead.
 */
LZ4LIB_API int LZ4_decompress_safe (const char* src, char* dst, int compressedSize, int dstCapacity);


/*-************************************
*  Advanced Functions
**************************************/
#define LZ4_MAX_INPUT_SIZE        0x7E000000   /* 2 113 929 216 bytes */
#define LZ4_COMPRESSBOUND(isize)  ((unsigned)(isize) > (unsigned)LZ4_MAX_INPUT_SIZE ? 0 : (isize) + ((isize)/255) + 16)

/*! LZ4_compressBound() :
    Provides the maximum size that LZ4 compression may output in a "worst case" scenario (input data not compressible)
    This function is primarily useful for memory allocation purposes (destination buffer size).
    Macro LZ4_COMPRESSBOUND() is also provided for compilation-time evaluation (stack memory allocation for example).
    Note that LZ4_compress_default() compresses faster when dstCapacity is >= LZ4_compressBound(srcSize)
        inputSize  : max supported value is LZ4_MAX_INPUT_SIZE
        return : maximum output size in a "worst case" scenario
              or 0, if input size is incorrect (too large or negative)
*/
LZ4LIB_API int LZ4_compressBound(int inputSize);


/*! LZ4_compress_fast_extState() :
 *  Same as LZ4_compress_fast(), using an externally allocated memory space for its state.
 *  Use LZ4_sizeofState() to know how much memory must be allocated,
 *  and allocate it on 8-bytes boundaries (using `malloc()` typically).
 *  Then, provide this buffer as `void* state` to compression function.
 */
LZ4LIB_API int LZ4_sizeofState(void);
LZ4LIB_API int LZ4_compress_fast_extState (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration);

/*-*********************************************
*  Streaming Compression Functions
***********************************************/
typedef union LZ4_stream_u LZ4_stream_t;  /* incomplete type (defined later) */

/*-**********************************************
*  Streaming Decompression Functions
*  Bufferless synchronous API
************************************************/
typedef union LZ4_streamDecode_u LZ4_streamDecode_t;   /* tracking context */

#endif /* LZ4_H_2983827168210 */


/*^*************************************
 * !!!!!!   STATIC LINKING ONLY   !!!!!!
 ***************************************/

/*-****************************************************************************
 * Experimental section
 *
 * Symbols declared in this section must be considered unstable. Their
 * signatures or semantics may change, or they may be removed altogether in the
 * future. They are therefore only safe to depend on when the caller is
 * statically linked against the library.
 *
 * To protect against unsafe usage, not only are the declarations guarded,
 * the definitions are hidden by default
 * when building LZ4 as a shared/dynamic library.
 *
 * In order to access these declarations,
 * define LZ4_STATIC_LINKING_ONLY in your application
 * before including LZ4's headers.
 *
 * In order to make their implementations accessible dynamically, you must
 * define LZ4_PUBLISH_STATIC_FUNCTIONS when building the LZ4 library.
 ******************************************************************************/

#ifdef LZ4_STATIC_LINKING_ONLY

#ifndef LZ4_STATIC_3504398509
#define LZ4_STATIC_3504398509

#define LZ4LIB_STATIC_API LZ4LIB_API

#ifndef LZ4_DISTANCE_MAX   /* history window size; can be user-defined at compile time */
#  define LZ4_DISTANCE_MAX 65535   /* set to maximum value by default */
#endif

#endif   /* LZ4_STATIC_3504398509 */
#endif   /* LZ4_STATIC_LINKING_ONLY */



#ifndef LZ4_H_98237428734687
#define LZ4_H_98237428734687

/*-************************************************************
 *  PRIVATE DEFINITIONS
 **************************************************************
 * Do not use these definitions directly.
 * They are only exposed to allow static allocation of `LZ4_stream_t` and `LZ4_streamDecode_t`.
 * Accessing members will expose code to API and/or ABI break in future versions of the library.
 **************************************************************/
#define LZ4_HASHLOG   (LZ4_MEMORY_USAGE-2)
#define LZ4_HASHTABLESIZE (1 << LZ4_MEMORY_USAGE)
#define LZ4_HASH_SIZE_U32 (1 << LZ4_HASHLOG)       /* required as macro for static allocation */

#if defined(__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
#include <stdint.h>

typedef struct LZ4_stream_t_internal LZ4_stream_t_internal;
struct LZ4_stream_t_internal {
    uint32_t hashTable[LZ4_HASH_SIZE_U32];
    uint32_t currentOffset;
    uint16_t dirty;
    uint16_t tableType;
    const uint8_t* dictionary;
    const LZ4_stream_t_internal* dictCtx;
    uint32_t dictSize;
};

typedef struct {
    const uint8_t* externalDict;
    size_t extDictSize;
    const uint8_t* prefixEnd;
    size_t prefixSize;
} LZ4_streamDecode_t_internal;

#else

typedef struct LZ4_stream_t_internal LZ4_stream_t_internal;
struct LZ4_stream_t_internal {
    unsigned int hashTable[LZ4_HASH_SIZE_U32];
    unsigned int currentOffset;
    unsigned short dirty;
    unsigned short tableType;
    const unsigned char* dictionary;
    const LZ4_stream_t_internal* dictCtx;
    unsigned int dictSize;
};

typedef struct {
    const unsigned char* externalDict;
    const unsigned char* prefixEnd;
    size_t extDictSize;
    size_t prefixSize;
} LZ4_streamDecode_t_internal;

#endif

/*! LZ4_stream_t :
 *  information structure to track an LZ4 stream.
 *  LZ4_stream_t can also be created using LZ4_createStream(), which is recommended.
 *  The structure definition can be convenient for static allocation
 *  (on stack, or as part of larger structure).
 *  Init this structure with LZ4_initStream() before first use.
 *  note : only use this definition in association with static linking !
 *    this definition is not API/ABI safe, and may change in a future version.
 */
#define LZ4_STREAMSIZE_U64 ((1 << (LZ4_MEMORY_USAGE-3)) + 4 + ((sizeof(void*)==16) ? 4 : 0) /*AS-400*/ )
#define LZ4_STREAMSIZE     (LZ4_STREAMSIZE_U64 * sizeof(unsigned long long))
union LZ4_stream_u {
    unsigned long long table[LZ4_STREAMSIZE_U64];
    LZ4_stream_t_internal internal_donotuse;
} ;  /* previously typedef'd to LZ4_stream_t */

/*! LZ4_initStream() : v1.9.0+
 *  An LZ4_stream_t structure must be initialized at least once.
 *  This is automatically done when invoking LZ4_createStream(),
 *  but it's not when the structure is simply declared on stack (for example).
 *
 *  Use LZ4_initStream() to properly initialize a newly declared LZ4_stream_t.
 *  It can also initialize any arbitrary buffer of sufficient size,
 *  and will @return a pointer of proper type upon initialization.
 *
 *  Note : initialization fails if size and alignment conditions are not respected.
 *         In which case, the function will @return NULL.
 *  Note2: An LZ4_stream_t structure guarantees correct alignment and size.
 *  Note3: Before v1.9.0, use LZ4_resetStream() instead
 */
LZ4LIB_API LZ4_stream_t* LZ4_initStream (void* buffer, size_t size);


/*! LZ4_streamDecode_t :
 *  information structure to track an LZ4 stream during decompression.
 *  init this structure  using LZ4_setStreamDecode() before first use.
 *  note : only use in association with static linking !
 *         this definition is not API/ABI safe,
 *         and may change in a future version !
 */
#define LZ4_STREAMDECODESIZE_U64 (4 + ((sizeof(void*)==16) ? 2 : 0) /*AS-400*/ )
#define LZ4_STREAMDECODESIZE     (LZ4_STREAMDECODESIZE_U64 * sizeof(unsigned long long))
union LZ4_streamDecode_u {
    unsigned long long table[LZ4_STREAMDECODESIZE_U64];
    LZ4_streamDecode_t_internal internal_donotuse;
} ;   /* previously typedef'd to LZ4_streamDecode_t */

#endif /* LZ4_H_98237428734687 */


#if defined (__cplusplus)
}
#endif