ad_weight_probability.inc in Advertisement 5.2

A plug in for the ad.module, allowing an admin to set the probability that a given advertisement will be displayed.

Copyright (c) 2008. Jeremy Andrews <[e-mail]>.

File

weight/probability/ad_weight_probability.inc

<?php

/**
 * @file
 * A plug in for the ad.module, allowing an admin to set the probability that
 * a given advertisement will be displayed.
 *
 * Copyright (c) 2008.
 *  Jeremy Andrews <[e-mail]>.
 */
function ad_weight_probability_cache_filter($ads) {
  $display = array();
  if (is_array($ads)) {
    $probability = array();
    $cache = adserve_cache('get_cache', 'weight');
    foreach ($ads as $aid) {
      $probability[] = $cache['probability'][$aid];
    }
    $gcd = ad_weight_probability_gcd($probability);
    _debug_echo("ad_weight_probability cache_filter gcd({$gcd})");
    foreach ($ads as $aid) {
      $weight = $cache['probability'][$aid] / $gcd;
      _debug_echo("ad_weight_probability cache_filter aid({$aid}) weight({$weight})");
      for ($i = 1; $i <= $weight; $i++) {
        $display[] = $aid;
      }
    }
  }
  return $display;
}

/**
 * Returns the greatest common divisor of an array of integers.
 */
function ad_weight_probability_gcd($integers) {
  $gcd = array_shift($integers);
  while (!empty($integers)) {
    $gcd = _ad_weight_probability_gcd($gcd, array_shift($integers));
  }
  return $gcd;
}

/**
 * Helper function to calculate the greatest common divisor using the Euclidean
 * algorithm (http://en.wikipedia.org/wiki/Euclidean_algorithm).
 */
function _ad_weight_probability_gcd($a, $b) {
  if ($b == 0) {
    return $a;
  }
  else {
    return _ad_weight_probability_gcd($b, $a % $b);
  }
}

Functions

Name	Description
ad_weight_probability_cache_filter	@file A plug in for the ad.module, allowing an admin to set the probability that a given advertisement will be displayed.
ad_weight_probability_gcd	Returns the greatest common divisor of an array of integers.
_ad_weight_probability_gcd	Helper function to calculate the greatest common divisor using the Euclidean algorithm (http://en.wikipedia.org/wiki/Euclidean_algorithm).