/*
  * Copyright (C) 2013 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 

 /**
  * @file
  * @ingroup lavu_murmur3
  * Public header for MurmurHash3 hash function implementation.
  */
 

 #ifndef AVUTIL_MURMUR3_H
 #define AVUTIL_MURMUR3_H
 
 #include <stdint.h>
 

 #include "version.h"
 

 /**
  * @defgroup lavu_murmur3 Murmur3
  * @ingroup lavu_hash
  * MurmurHash3 hash function implementation.
  *

  * MurmurHash3 is a non-cryptographic hash function, of which three
  * incompatible versions were created by its inventor Austin Appleby:
  *
  * - 32-bit output
  * - 128-bit output for 32-bit platforms
  * - 128-bit output for 64-bit platforms
  *
  * FFmpeg only implements the last variant: 128-bit output designed for 64-bit
  * platforms. Even though the hash function was designed for 64-bit platforms,
  * the function in reality works on 32-bit systems too, only with reduced
  * performance.
  *
  * @anchor lavu_murmur3_seedinfo
  * By design, MurmurHash3 requires a seed to operate. In response to this,
  * libavutil provides two functions for hash initiation, one that requires a
  * seed (av_murmur3_init_seeded()) and one that uses a fixed arbitrary integer
  * as the seed, and therefore does not (av_murmur3_init()).
  *
  * To make hashes comparable, you should provide the same seed for all calls to
  * this hash function -- if you are supplying one yourself, that is.
  *

  * @{
  */
 

 /**
  * Allocate an AVMurMur3 hash context.
  *
  * @return Uninitialized hash context or `NULL` in case of error
  */

 struct AVMurMur3 *av_murmur3_alloc(void);

 
 /**
  * Initialize or reinitialize an AVMurMur3 hash context with a seed.
  *
  * @param[out] c    Hash context
  * @param[in]  seed Random seed
  *
  * @see av_murmur3_init()
  * @see @ref lavu_murmur3_seedinfo "Detailed description" on a discussion of
  * seeds for MurmurHash3.
  */

 void av_murmur3_init_seeded(struct AVMurMur3 *c, uint64_t seed);

 
 /**
  * Initialize or reinitialize an AVMurMur3 hash context.
  *
  * Equivalent to av_murmur3_init_seeded() with a built-in seed.
  *
  * @param[out] c    Hash context
  *
  * @see av_murmur3_init_seeded()
  * @see @ref lavu_murmur3_seedinfo "Detailed description" on a discussion of
  * seeds for MurmurHash3.
  */

 void av_murmur3_init(struct AVMurMur3 *c);

 
 /**
  * Update hash context with new data.
  *
  * @param[out] c    Hash context
  * @param[in]  src  Input data to update hash with
  * @param[in]  len  Number of bytes to read from `src`
  */

 #if FF_API_CRYPTO_SIZE_T

 void av_murmur3_update(struct AVMurMur3 *c, const uint8_t *src, int len);

 #else
 void av_murmur3_update(struct AVMurMur3 *c, const uint8_t *src, size_t len);
 #endif

 
 /**
  * Finish hashing and output digest value.
  *
  * @param[in,out] c    Hash context
  * @param[out]    dst  Buffer where output digest value is stored
  */

 void av_murmur3_final(struct AVMurMur3 *c, uint8_t dst[16]);
 

 /**
  * @}
  */
 

 #endif /* AVUTIL_MURMUR3_H */