ad_cache_file.inc in Advertisement 5
Same filename and directory in other branches
A plug in for the ad.module, providing a file cache mechanism for improved performance when displaying ads.
TODO: Add support for tracking views/clicks with group-level granularity.
Copyright (c) 2007-2008. Jeremy Andrews <jeremy@kerneltrap.org>. All rights reserved.
File
cache/file/ad_cache_file.incView source
<?php
/**
* @file
* A plug in for the ad.module, providing a file cache mechanism for improved
* performance when displaying ads.
*
* TODO: Add support for tracking views/clicks with group-level granularity.
*
* Copyright (c) 2007-2008.
* Jeremy Andrews <jeremy@kerneltrap.org>. All rights reserved.
*/
/**
* This is the actual cache function called by adserve.php that displays ads
* without bootstrapping Drupal.
*/
function ad_cache_file() {
static $displayed_count = 0;
_debug_echo('File cache: entering.');
$cache_file = ad_cache_file_get_lock();
$output = '';
if ($cache_file) {
// Read entire cache file into memory.
$cache = unserialize(fread(adserve_variable('fd'), filesize($cache_file)));
// Store cache in a static variable for re-use by other functions.
ad_cache_file_ro_cache($cache);
/**
* The cache structure looks like this:
* $cache['ad'][$aid]['display'] = $ad
* $cache['hostid'][$hostid] = TRUE
* $cache['ad'][$aid][$hostid]['counts'][$action][$timestamp] = $counter
* $cache['last_sync'] = $timestamp
*/
/**
* Initial support for over-riding default functionality when serving ads.
*/
$includes = array(
'include_file_init',
'include_file_select',
);
foreach ($includes as $include) {
if (isset($cache[$include])) {
$include_file = adserve_variable('root_dir') . '/' . $cache[$include];
if (file_exists($include_file) && is_file($include_file)) {
_debug_echo("File cache: including external file: '{$include_file}'.");
include_once $include_file;
}
else {
_debug_echo("File cache: unable to find external file: '{$include_file}'.");
}
switch ($include) {
case 'include_file_init':
$include_func_init = $cache['include_func_init'];
_debug_echo("File cache: include_func_init: '{$include_func_init}'.");
break;
case 'include_file_select':
adserve_variable('include_func_select', $cache['include_func_select']);
_debug_echo("File cache: include_func_select: '" . adserve_variable('include_func_select') . "'");
break;
}
}
}
$hostid = adserve_variable('hostid') ? adserve_variable('hostid') : 'none';
_debug_echo("File cache: using hostid: '{$hostid}'.");
if ($hostid != 'none' && !isset($cache['hostid'][$hostid])) {
_debug_echo("File cache: invalid hostid: '{$hostid}'.");
$output = 'You do not have permission to display ads.';
}
else {
$last_sync = $cache['last_sync'];
$lifetime = $cache['lifetime'];
$time = time();
$timestamp = date('YmdH');
// Allow external plug-ins to initialize these values...
if (function_exists($include_func_init)) {
$init = $include_func_init($cache, $hostid);
}
if (!empty($init)) {
_debug_echo('File cache: initialized externally.');
$quantity = $init['quantity'];
$id = $init['id'];
$type = $init['type'];
$aids = explode(',', $id);
$cache_size = sizeof($aids);
}
else {
$quantity = adserve_variable('quantity');
if (isset($cache['hostid'][$hostid]['aids'])) {
$id = $cache['hostid'][$hostid]['aids'];
$type = 'host';
$aids = explode(',', $id);
$cache_size = sizeof($aids);
}
else {
if (adserve_variable('nids')) {
$id = adserve_variable('nids');
$type = 'nids';
$aids = explode(',', $id);
$cache_size = sizeof($aids);
}
else {
if (adserve_variable('tids')) {
$id = adserve_variable('tids');
$type = 'tids';
if (!isset($cache['tids'][$id])) {
$cache['tids'][$id] = array();
$tids = explode(',', $id);
foreach ($tids as $tid) {
if (is_array($cache['tid'][$tid]['aid'])) {
$cache['tids'][$id] += $cache['tid'][$tid]['aid'];
}
}
// Rebuild keys from 0, cache it for re-use on next ad display
$cache['tids'][$id] = array_values($cache['tids'][$id]);
}
$cache_size = sizeof($cache['tids'][$id]);
$aids = $cache['tids'][$id];
}
else {
$id = 0;
$type = 'default';
$cache_size = sizeof($cache['tid'][0]['aid']);
$aids = $cache['tid'][0]['aid'];
}
}
}
}
if (adserve_variable('debug')) {
echo "File cache: last sync: {$last_sync}<br />\n";
echo "File cache: current time: {$time}<br />\n";
if ($time - $lifetime >= $last_sync) {
echo "File cache: will rebuild cache now.<br />\n";
}
else {
$seconds = $last_sync - $time + $lifetime;
echo "File cache: will rebuild cache in {$seconds} seconds.<br/>\n";
}
echo "File cache: timestamp: {$timestamp}<br />\n";
echo "File cache: cache_size({$cache_size})<br />\n";
}
$ids = adserve_variable("{$type}-ids");
if ($ids == NULL) {
$ids = array();
}
_debug_echo('File cache: size of $ids: ' . sizeof($ids));
// Only include aids that are in our cache, others are not valid in our
// context.
$search = array();
if (is_array($aids)) {
foreach ($aids as $aid) {
if (isset($cache['ad'][$aid])) {
$search[] = $aid;
}
}
}
$selected = adserve_select_ad($search, $quantity, $ids);
adserve_variable("{$type}-ids", array_merge($selected, $ids));
foreach ($selected as $aid) {
$aid = (int) $aid;
$ad = $cache['ad'][$aid];
if (!empty($output)) {
// Add a div between ads that themers can use to arrange ads when
// displaying more than one at a time.
$displayed_count++;
$output .= "<div class=\"advertisement-space\" id=\"{$id}-{$displayed_count}\"></div>";
}
$output .= $ad['display'];
_debug_echo("File cache: displaying AID: {$aid}");
// If displaying an ad, increment appropriate view counter. Otherwise,
// simply increment a counter.
$action = $aid ? 'view' : 'count';
// Increment counter.
if (isset($cache['ad'][$aid][$hostid]) && isset($cache['ad'][$aid][$hostid]['counts'][$action]) && isset($cache['ad'][$aid][$hostid]['counts'][$action][$timestamp])) {
$cache['ad'][$aid][$hostid]['counts'][$action][$timestamp]++;
}
else {
$cache['ad'][$aid][$hostid]['counts'][$action][$timestamp] = 1;
}
}
// Write updated cache back to file and release the lock.
$cache = serialize($cache);
// Store updated cache in a static variable for re-use by other functions.
ad_cache_file_ro_cache($cache);
rewind(adserve_variable('fd'));
ftruncate(adserve_variable('fd'), 0);
fwrite(adserve_variable('fd'), $cache, strlen($cache));
flock(adserve_variable('fd'), LOCK_UN);
fclose(adserve_variable('fd'));
adserve_variable('fd', '');
// Every $lifetime seconds we flush the cache files to the database.
if ($last_sync < time() - $lifetime) {
ad_cache_file_rebuild();
}
}
}
else {
$output = 'Configuration error, failed to lock cache file.';
if (ad_cache_file_rebuild()) {
// Required function was missing, the file cache must be disabled, so
// return nothing allowing adserve.inc to use the default display method.
return;
}
}
if (empty($output)) {
adserve_variable('error', TRUE);
$output = 'No active ads were found in the ' . (empty($nids) ? 'tids' : 'nids') . " '{$id}'.";
if (adserve_variable('debug')) {
echo "{$output}<br />\n";
}
}
return $output;
}
function ad_cache_file_get_lock() {
static $lock = FALSE;
static $cache_file = '';
if ($lock) {
_debug_echo('File cache: already have lock.');
return $cache_file;
}
// We'll loop through all possible cache files until we obtain an
// exclusive lock.
for ($i = 1; $i <= adserve_variable('files'); $i++) {
// Prefix the filename with a '.' to hide it on Unix systems.
$cache_file = adserve_variable('root_dir') . '/' . adserve_variable('path') . '/.' . $i . '.ad.cache';
if (adserve_variable('debug')) {
echo "Trying cache_file '{$cache_file}'.<br />\n";
}
if (!($fd = @fopen($cache_file, 'r+'))) {
if (adserve_variable('debug')) {
echo "Failed to open cache_file '{$cache_file}'.<br />\n";
}
// We failed to open the cache file, try the next one.
continue;
}
if ($i < adserve_variable('files')) {
// This isn't the last available cache file so we'll use a
// non-blocking lock for best performance. If we fail to lock this
// cache file, we'll quickly move on to the next until we find an
// available one.
if (!flock($fd, LOCK_EX | LOCK_NB)) {
if (adserve_variable('debug')) {
echo "Failed to obtain non-blocking lock.<br />\n";
}
// We failed to obtain an exclusive lock, close the file and try the
// next one.
@fclose($fd);
continue;
}
if (adserve_variable('debug')) {
echo "Obtained lock.<br />\n";
$stat = fstat($fd);
echo 'File size: ' . $stat['size'] . '<br />';
}
$lock = TRUE;
break;
}
else {
// This is the last available cache file, we'll use a blocking lock
// as we have to wait until we have exclusive write permissions.
if (!flock($fd, LOCK_EX)) {
if (adserve_variable('debug')) {
echo "Failed to obtain blocking lock.<br />\n";
}
// A blocking exclusive lock shouldn't ever fail, so something has
// gone very wrong. Perhaps the file was deleted out from under us?
@fclose($fd);
continue;
}
if (adserve_variable('debug')) {
echo "Obtained lock on final cache file.<br />\n";
}
$lock = TRUE;
break;
}
}
if ($lock) {
adserve_variable('fd', $fd);
return $cache_file;
}
else {
return NULL;
}
}
function ad_cache_file_increment($action = 'view') {
_debug_echo("File cache: incrementing '{$action}'.");
$cache_file = ad_cache_file_get_lock();
if ($cache_file) {
$cache = unserialize(fread(adserve_variable('fd'), filesize($cache_file)));
$hostid = adserve_variable('hostid') ? adserve_variable('hostid') : 'none';
$aid = adserve_variable('aid');
if ($action == 'view') {
if ($hostid != 'none' && !isset($cache['hostid'][$hostid])) {
_debug_echo("File cache: invalid hostid: {$hostid}");
$output = 'You do not have permission to display images.';
// TODO: We should still log this. Perhaps a new $action type?
return -1;
}
}
$last_sync = $cache['last_sync'];
$lifetime = $cache['lifetime'];
$time = time();
$timestamp = date('YmdH');
// Increment action counter.
if (isset($cache['ad'][$aid][$hostid]) && isset($cache['ad'][$aid][$hostid]['counts'][$action]) && isset($cache['ad'][$aid][$hostid]['counts'][$action][$timestamp])) {
$cache['ad'][$aid][$hostid]['counts'][$action][$timestamp]++;
}
else {
$cache['ad'][$aid][$hostid]['counts'][$action][$timestamp] = 1;
}
// Write updated cache back to file and release the lock.
$cache = serialize($cache);
rewind(adserve_variable('fd'));
ftruncate(adserve_variable('fd'), 0);
fwrite(adserve_variable('fd'), $cache, strlen($cache));
flock(adserve_variable('fd'), LOCK_UN);
fclose(adserve_variable('fd'));
adserve_variable('fd', '');
// Every $lifetime seconds we flush the cache files to the database.
if ($last_sync < time() - $lifetime) {
ad_cache_file_rebuild();
}
return 1;
}
return 0;
}
/**
* Additional variables required by the filecache.
*/
function ad_cache_file_variables() {
// paths are comprised of alphanumerics, underscores, dashes, periods and
// slashes.
$variables = array();
$variables['path'] = isset($_GET['p']) ? preg_replace('/[^_\\-\\.\\/\\0-9a-zA-Z]/', '', $_GET['p']) : 'files';
// files is an integer.
$variables['files'] = isset($_GET['f']) ? (int) $_GET['f'] : 1;
if ($variables['files'] > 15) {
echo "Invalid value 'f=" . $variables['files'] . "', exiting.<br />\n";
exit;
}
return $variables;
}
/**
* Bootstrap drupal, then run ad_cache_file_build() from ad.module which will
* rebuild all cache files.
*/
function ad_cache_file_rebuild() {
adserve_bootstrap();
if (function_exists('ad_cache_file_build')) {
ad_cache_file_build();
return 0;
}
else {
return -1;
}
}
/**
*
*/
function ad_cache_file_ro_cache($cache = array()) {
static $ro_cache = array();
if (!empty($cache)) {
$ro_cache = $cache;
}
return $ro_cache;
}
/**
*
*/
function ad_cache_file_adserve_select($ads, $invalid) {
if ($include_func_select = adserve_variable('include_func_select')) {
_debug_echo("File cache: adserve_select: invoking '{$include_func_select}()'");
if (function_exists($include_func_select)) {
$cache = ad_cache_file_ro_cache();
if (!empty($cache)) {
return $include_func_select($ads, $invalid, $cache);
}
else {
_debug_echo("File cache: unexpected error: cache variable empty.");
}
}
else {
_debug_echo("File cache: adserve_select: '{$include_func_select}()' not found");
}
}
else {
_debug_echo("File cache: adserve_select: no select function defined");
}
}Functions
Name |
Description |
|---|---|
| ad_cache_file | This is the actual cache function called by adserve.php that displays ads without bootstrapping Drupal. |
| ad_cache_file_adserve_select | |
| ad_cache_file_get_lock | |
| ad_cache_file_increment | |
| ad_cache_file_rebuild | Bootstrap drupal, then run ad_cache_file_build() from ad.module which will rebuild all cache files. |
| ad_cache_file_ro_cache | |
| ad_cache_file_variables | Additional variables required by the filecache. |