roc_driver.c

mediastreamer2是开源的网络传输媒体流的库

/*
 * roc_driver.c
 *
 * test driver for rollover counter replay implementation
 *
 * David A. McGrew
 * Cisco Systems, Inc.
 */

/*
 *	
 * Copyright (c) 2001-2006, Cisco Systems, Inc.
 * All rights reserved.
 * 
 * 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.
 * 
 *   Neither the name of the Cisco Systems, Inc. nor the names of its
 *   contributors may be used to endorse or promote products derived
 *   from this software without specific prior written permission.
 * 
 * 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 HOLDERS 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.
 *
 */


#include <stdio.h>

/*
 * defining ROC_TEST causes small datatypes to be used in
 * xtd_seq_num_t - this allows the functions to be exhaustively tested.
 */
#if ROC_NEEDS_TO_BE_TESTED
#define ROC_TEST     
#endif

#include "rdbx.h"
#include "ut_sim.h"

err_status_t
roc_test(int num_trials);

int
main (void) {
  err_status_t status;

  printf("rollover counter test driver\n"
	 "David A. McGrew\n"
	 "Cisco Systems, Inc.\n");
  
  printf("testing index functions...");
  status = roc_test(1 << 18);
  if (status) {
    printf("failed\n");
    exit(status);
  }
  printf("passed\n");
  return 0;
}


#define ROC_VERBOSE 0

err_status_t
roc_test(int num_trials) {
  xtd_seq_num_t local, est, ref;
  ut_connection utc;
  int i, num_bad_est = 0;
  int delta;
  uint32_t ircvd;
  double failure_rate;

  index_init(&local);
  index_init(&ref);
  index_init(&est);

  printf("\n\ttesting sequential insertion...");
  for (i=0; i < 2048; i++) {
    delta = index_guess(&local, &est, (uint16_t) ref);
#if ROC_VERBOSE
    printf("%lld, %lld, %d\n", ref, est,  i);
#endif
    if (ref != est) {
#if ROC_VERBOSE
      printf(" *bad estimate*\n");
#endif
      ++num_bad_est;
    }
    index_advance(&ref, 1);
  }
  failure_rate = (double) num_bad_est / num_trials;
  if (failure_rate > 0.01) {
    printf("error: failure rate too high (%d bad estimates in %d trials)\n", 
	   num_bad_est, num_trials);
    return err_status_algo_fail;
  }
  printf("done\n");


  printf("\ttesting non-sequential insertion...");
  index_init(&local);
  index_init(&ref);
  index_init(&est);
  ut_init(&utc);
  
  for (i=0; i < num_trials; i++) {
    
    /* get next seq num from unreliable transport simulator */
    ircvd = ut_next_index(&utc);
    
    /* set ref to value of ircvd */
    ref = ircvd; 

    /* estimate index based on low bits of ircvd */
    delta = index_guess(&local, &est, (uint16_t) ref);
#if ROC_VERBOSE
    printf("ref: %lld, local: %lld, est: %lld, ircvd: %d, delta: %d\n", 
	   ref, local, est, ircvd, delta);
#endif
    
    /* now update local xtd_seq_num_t as necessary */
    if (delta > 0) 
      index_advance(&local, delta);

    if (ref != est) {
#if ROC_VERBOSE
      printf(" *bad estimate*\n");
#endif
      /* record failure event */
      ++num_bad_est;
      
      /* reset local value to correct value */
      local = ref;
    }
  }
  failure_rate = (double) num_bad_est / num_trials;
  if (failure_rate > 0.01) {
    printf("error: failure rate too high (%d bad estimates in %d trials)\n", 
	   num_bad_est, num_trials);
    return err_status_algo_fail;
  }
  printf("done\n");

  return err_status_ok;
}