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/* quirc -- QR-code recognition library
* Copyright (C) 2010-2012 Daniel Beer <dlbeer@gmail.com>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#ifndef DTHASH_H_
#define DTHASH_H_
#include <stdint.h>
#include <time.h>
#include "quirc.h"
/* Detector hash.
*
* This structure keeps track of codes that have been seen within the
* last N seconds, and allows us to print out codes at a reasonable
* rate as we see them.
*/
#define DTHASH_MAX_CODES 32
struct dthash_code {
uint32_t hash;
time_t when;
};
struct dthash {
struct dthash_code codes[DTHASH_MAX_CODES];
int count;
int timeout;
};
#ifdef __cplusplus
extern "C" {
#endif
/* Initialise a detector hash with the given timeout. */
void dthash_init(struct dthash *d, int timeout);
/* When a code is discovered, this function should be called to see if
* it should be printed. The hash will record having seen the code, and
* return non-zero if it's the first time we've seen it within the
* configured timeout period.
*/
int dthash_seen(struct dthash *d, const struct quirc_data *data);
#ifdef __cplusplus
}
#endif
#endif
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