/*
  * 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
  */
 
 #ifndef AVUTIL_HASH_H
 #define AVUTIL_HASH_H
 
 #include <stdint.h>
 
 struct AVHashContext;
 
 /**
  * Allocate a hash context for the algorithm specified by name.
  *
  * @return  >= 0 for success, a negative error code for failure
  * @note  The context is not initialized, you must call av_hash_init().
  */
 int av_hash_alloc(struct AVHashContext **ctx, const char *name);
 
 /**
  * Get the names of available hash algorithms.
  *
  * This function can be used to enumerate the algorithms.
  *
  * @param i  index of the hash algorithm, starting from 0
  * @return   a pointer to a static string or NULL if i is out of range
  */
 const char *av_hash_names(int i);
 
 /**
  * Get the name of the algorithm corresponding to the given hash context.
  */
 const char *av_hash_get_name(const struct AVHashContext *ctx);
 
 /**

  * Maximum value that av_hash_get_size will currently return.
  *
  * You can use this if you absolutely want or need to use static allocation
  * and are fine with not supporting hashes newly added to libavutil without
  * recompilation.
  * Note that you still need to check against av_hash_get_size, adding new hashes
  * with larger sizes will not be considered an ABI change and should not cause
  * your code to overflow a buffer.
  */

 #define AV_HASH_MAX_SIZE 64

 
 /**

  * Get the size of the resulting hash value in bytes.
  *
  * The pointer passed to av_hash_final have space for at least this many bytes.
  */
 int av_hash_get_size(const struct AVHashContext *ctx);
 
 /**
  * Initialize or reset a hash context.
  */
 void av_hash_init(struct AVHashContext *ctx);
 
 /**
  * Update a hash context with additional data.
  */
 void av_hash_update(struct AVHashContext *ctx, const uint8_t *src, int len);
 
 /**
  * Finalize a hash context and compute the actual hash value.
  */
 void av_hash_final(struct AVHashContext *ctx, uint8_t *dst);
 
 /**

  * Finalize a hash context and compute the actual hash value.
  * If size is smaller than the hash size, the hash is truncated;
  * if size is larger, the buffer is padded with 0.
  */
 void av_hash_final_bin(struct AVHashContext *ctx, uint8_t *dst, int size);
 
 /**
  * Finalize a hash context and compute the actual hash value as a hex string.
  * The string is always 0-terminated.
  * If size is smaller than 2 * hash_size + 1, the hex string is truncated.
  */
 void av_hash_final_hex(struct AVHashContext *ctx, uint8_t *dst, int size);
 
 /**
  * Finalize a hash context and compute the actual hash value as a base64 string.
  * The string is always 0-terminated.
  * If size is smaller than AV_BASE64_SIZE(hash_size), the base64 string is
  * truncated.
  */
 void av_hash_final_b64(struct AVHashContext *ctx, uint8_t *dst, int size);
 
 /**

  * Free hash context.
  */
 void av_hash_freep(struct AVHashContext **ctx);
 
 #endif /* AVUTIL_HASH_H */