ad_channel.inc in Advertisement 6.2

Ad Channel include file.

Copyright (c) 2008-2009. Jeremy Andrews <[e-mail]>.

File

channel/ad_channel.inc

<?php

/**
 * @file
 * Ad Channel include file.
 *
 * Copyright (c) 2008-2009.
 *   Jeremy Andrews <[e-mail]>.
 */

/**
 * Filter advertisements not in an appropriate channel, from cache.
 */
function ad_channel_cache_filter($ads) {
  _debug_echo("ad_channel_cache: adserve_cache_filter");

  // get channel array from cache
  $channels = adserve_cache('get_cache', 'channel');

  // 0 = only display advertisements not assigned to any channel if no matching
  // ads in selected channel; 1 = always display advertisements not assigned to
  // any channel; 2 = never display advertisements not assigned to any channel
  $nochannel_display = $channels['display'];
  $valid_ads = array();
  $nochannel_fallback_ads = array();
  $nochannel_percent = array();

  // determine which channels each advertisement is assigned to
  foreach ($ads as $aid) {
    _debug_echo("ad_channel_cache: checking aid({$aid})");
    if (is_array($channels['ads']) && isset($channels['ads'][$aid]) && is_array($channels['ads'][$aid])) {
      foreach ($channels['ads'][$aid] as $chid) {
        $channel = $channels['channels'][$chid];
        $display_by_url = $channel->display;
        $urls = unserialize($channel->urls);
        $frontpage = variable_get('site_frontpage', 'node');
        $regexp = '/^(' . preg_replace(array(
          '/(\\r\\n?|\\n)/',
          '/\\\\\\*/',
          '/(^|\\|)\\\\<front\\\\>($|\\|)/',
        ), array(
          '|',
          '.*',
          '\\1' . preg_quote($frontpage, '/') . '\\2',
        ), preg_quote($urls, '/')) . ')$/';
        foreach (array(
          'url',
          'alias',
        ) as $search) {
          $match = preg_match($regexp, adserve_variable($search));
          _debug_echo("ad_channel_cache: checking aid({$aid}) against channel({$chid}) path(" . adserve_variable($search) . ") regexp({$regexp}) match({$match}) display[{$display_by_url}]");

          // display ad on all except matching urls
          if ($display_by_url == 0) {
            if (empty($urls) || !$match) {
              _debug_echo("ad_channel_cache: aid({$aid}) is valid");
              $valid_ads[$chid][] = $aid;
              if ($nochannel_display == 1) {
                $nochannel_percent[$chid] = $channel->no_channel_percent;
                _debug_echo("ad_channel_cache: channel({$chid}) no_channel_percent({$nochannel_percent[$chid]})");
              }
              else {
                _debug_echo("ad_channel_cache: channel({$chid})");
              }
              break;
            }
          }
          else {
            if (!empty($urls) && $match) {
              _debug_echo("ad_channel_cache: aid({$aid}) is valid");
              $valid_ads[$chid][] = $aid;
              if ($nochannel_display == 1) {
                $nochannel_percent[$chid] = $channel->no_channel_percent;
                _debug_echo("ad_channel_cache: channel({$chid}) no_channel_percent({$nochannel_percent[$chid]})");
              }
              else {
                _debug_echo("ad_channel_cache: channel({$chid})");
              }
              break;
            }
          }

          // no match so we didn't hit a break, ad is not valid
          _debug_echo("ad_channel_cache: aid({$aid}) is not valid");
        }
      }
    }
    else {

      // no channel information for ad
      _debug_echo("ad_channel_cache: aid({$aid}) has no channel info, nochannel_display({$nochannel_display})");
      switch ($nochannel_display) {
        case 0:
          $nochannel_fallback_ads[] = $aid;
          _debug_echo("ad_channel_cache: non-channel aid({$aid}) is valid if no valid ads are assigned to current channel");
          break;
        case 1:
          $valid_ads[0][] = $aid;
          _debug_echo("ad_channel_cache: non-channel aid({$aid}) is valid");
          break;
        case 2:
          _debug_echo("ad_channel_cache: aid({$aid}) is not valid");
          break;
      }
    }
  }

  // Apply frequencies, applicable to all channels
  if (!empty($valid_ads) && !empty($nochannel_percent)) {
    $frequencies = array();
    foreach (array_keys($valid_ads) as $chid) {
      if ($chid) {
        if (isset($nochannel_percent[$chid])) {
          $frequencies[$chid] = $nochannel_percent[$chid];
          _debug_echo("ad_channel_cache: channel {$chid} has a non-channel ad frequency of " . $nochannel_percent[$chid] . "%");
        }
        else {

          // by default, channels return 'non-channel ads' with a frequency
          // of 10%
          $frequencies[$chid] = 10;
          _debug_echo("ad_channel_cache: channel {$chid} assigned a default non-channel ad frequency of 10%");
        }
      }
      else {

        // frequency for non-channel ads is not meaningful
      }
    }
    if (!empty($frequencies)) {
      $balanced_channels = array();
      $num_channels = sizeof($valid_ads);
      foreach (array_keys($valid_ads) as $chid) {

        // if there are no non-channel ads, there is no need to balance
        if (count($valid_ads[0]) > 0) {
          if (isset($frequencies[$chid])) {

            // for a given channel, ensure the proper ratio to non-channel ads
            if ($frequencies[$chid] <= 50) {

              // increase occurrences of $chid
              $balanced_channels[] = 0;
              $frequency = round(100 / $frequencies[$chid]) - 1;
              _debug_echo("ad_channel_cache: adjusting ratio of channel({$chid}) to {$frequency}:1 relative non-channel ads");
              for ($i = 1; $i <= $frequency; $i++) {
                $balanced_channels[] = $chid;
              }
            }
            else {

              // add $chid and additional non-channel ads
              $balanced_channels[] = $chid;
              $frequency = round(100 / (100 - $frequencies[$chid])) - 1;
              _debug_echo("ad_channel_cache: adjusting ratio of channel({$chid}) to 1:{$frequency} relative non-channel ads");
              for ($i = 1; $i <= $frequency; $i++) {
                $balanced_channels[] = 0;
              }
            }
          }
        }
        else {
          _debug_echo("ad_channel_cache: NOT adjusting ratio of channel({$chid}) to relative non-channel ads as there are no non-channel ads");
          $balanced_channels[] = $chid;
        }
      }
      _debug_echo('ad_channel_cache: channel 0 contains all non-channel ads');
      if (adserve_variable('debug') >= 2) {
        foreach ($balanced_channels as $key => $chid) {
          _debug_echo("ad_channel_cache: channel {$chid} => index {$key}");
        }
      }
    }
    $random_channel = _select_channel_id($balanced_channels);
  }
  else {
    if (!empty($valid_ads)) {
      foreach ($valid_ads as $chid => $ads) {
        $chids[$chid] = $chid;
      }
      shuffle($chids);
      $random_channel = array_pop($chids);
    }
    else {
      if (empty($valid_ads) && !empty($nochannel_fallback_ads)) {
        _debug_echo("ad_channel_cache: using ads with no channel info");
        $valid_ads[0] = $nochannel_fallback_ads;
        $random_channel = 0;
      }
    }
  }
  $premiere = adserve_cache('get_cache', 'premiere');
  if (is_array($premiere)) {
    $premieres = array();
    foreach (array_keys($valid_ads) as $chid) {
      foreach ($valid_ads[$chid] as $aid) {
        if (in_array($aid, $premiere)) {
          _debug_echo("ad_channel_cache: aid({$aid}) is premiere advertisement");
          $premieres[$aid] = $aid;
        }
        else {
          _debug_echo("ad_channel_cache: aid({$aid}) is not a premiere advertisement");
        }
      }
    }
    if (!empty($premieres)) {
      _debug_echo("ad_channel_cache: returning premiere advertisements");
      return $premieres;
    }
  }
  _debug_echo("ad_channel_cache: returning non-premiere advertisements from randomly selected channel {$random_channel}");
  if (isset($valid_ads[$random_channel])) {
    return ad_channel_enforce_inventory_level($random_channel, $valid_ads[$random_channel]);
  }
}

/**
 * Randomly select a valid channel id from an array channel ids
 * @param array, valid array.
 */
function _select_channel_id($choices) {
  $selected = 0;
  if (is_array($choices)) {
    $available = sizeof($choices);
    _debug_echo("ad_channel_cache: randomly selecting from {$available} indexes.");
    $selected = $available > 1 ? $choices[mt_rand(0, $available - 1)] : $choices[0];
    _debug_echo("ad_channel_cache: randomly selected channel {$selected}.");
  }
  return $selected;
}

/*
 * Augment the selected channel with 'remnant' ads to ensure that any specified
 * inventory level is honored
 * @param int, channel id
 * @param array, valid array.
 */
function ad_channel_enforce_inventory_level($chid, $ads) {
  if ($chid > 0) {
    $channels = adserve_cache('get_cache', 'channel');
    $channel = $channels['channels'][$chid];
    $level = $channel->inventory;
    $num_ads = count($ads);
    if ($num_ads < $level) {
      _debug_echo("ad_channel_enforce_inventory_level: channel({$chid}) has {$num_ads} and needs {$level}");
      $remnants = array_values(adserve_cache('get_cache', 'remnant'));
      $available = count($remnants);
      if ($available > 0) {
        _debug_echo("ad_channel_enforce_inventory_level: randomly selecting from {$available} remnants.");
        while (count($ads) < $level) {
          shuffle($remnants);
          $selected = array_pop($remnants);
          _debug_echo("ad_channel_enforce_inventory_level: selected {$selected}.");
          $ads[] = $selected;
        }
      }
      else {
        _debug_echo("ad_channel_enforce_inventory_level: no remnants to choose from.");
      }
    }
    else {
      _debug_echo("ad_channel_enforce_inventory_level: channel({$chid}) no inventory level assigned");
    }
  }
  else {
    _debug_echo("ad_channel_enforce_inventory_level: not needed for channel({$chid})");
  }
  return $ads;
}

Functions

Name	Description
ad_channel_cache_filter	Filter advertisements not in an appropriate channel, from cache.
ad_channel_enforce_inventory_level
_select_channel_id	Randomly select a valid channel id from an array channel ids