/**
* ob_callback()
*
* @param string $buffer
* @return string $buffer
**/
static function ob_callback($buffer)
{
if (!class_exists('sem_cache')) {
return $buffer;
}
if (DONOTCACHEPAGE) {
return $buffer;
}
# some things just shouldn't be cached
if (self::$nocache && !in_array(self::$status_code, array(301, 302, 404)) || !in_array(self::$status_code, array(200, 301, 302, 404))) {
return $buffer;
}
# sanity check on cookies
global $sem_cache_cookies;
if (!$sem_cache_cookies || $sem_cache_cookies != sem_cache::get_cookies()) {
return $buffer;
}
# only cache visitor requests
if (array_intersect(array_keys($_COOKIE), $sem_cache_cookies)) {
return $buffer;
}
# bail on valid but rarely served pages
if (self::$status_code == 200 && !(!is_feed() && is_singular() || !is_feed() && (is_home() || is_category()) && !is_paged() || is_feed() && (!is_archive() && !is_singular() || is_category()))) {
return $buffer;
}
#don't cache a contact form page due to spam prevention techniques
// if ( preg_match("/(\bsem_contact_form\b)/i",$buffer) )
// return $buffer;
#don't cache a page due if a sem_no_cache flag is found. Provide manual way to exclude a page
if (preg_match("/(\\bsem_do_not_cache\\b)/i", $buffer)) {
return $buffer;
}
$permalink_structure = get_option('permalink_structure');
# statically cache only when relevant
self::$static &= strpos($_SERVER['REQUEST_URI'], './') === false && self::$status_code == 200 && !is_feed() && empty($_GET) && $permalink_structure && strpos($permalink_structure, "|/index\\.php/|") === false;
# sanity check on the base folder
$host = get_option('home');
if (preg_match("|^([^/]+://[^/]+)/|", $host, $_host)) {
$host = end($_host);
}
if ($host != self::$host) {
return $buffer;
}
# sanity check on incomplete files
if (!in_array(self::$status_code, array(301, 302)) && !preg_match("/(?:<\\/html>|<\\/rss>|<\\/feed>)/i", $buffer)) {
return $buffer;
}
# sanity check on mobile users
global $sem_mobile_agents;
if ($sem_mobile_agents != sem_cache::get_mobile_agents()) {
return $buffer;
}
$mobile_agents = $sem_mobile_agents;
// $mobile_agents = array_map('preg_quote', (array) $mobile_agents);
$mobile_agents = implode("|", $mobile_agents);
if (preg_match("{({$mobile_agents})}i", $_SERVER['HTTP_USER_AGENT'])) {
return $buffer;
}
if (preg_match("/(?=.*?\\bandroid\\b)(?=.*?\\bmobile\\b).*\$/i", $_SERVER['HTTP_USER_AGENT'])) {
return $buffer;
}
// made it through all the checks. Let's minify the html now
// $buffer = self::minify_html( $buffer );
if (self::$static) {
$file = preg_replace("/#.*/", '', $_SERVER['REQUEST_URI']);
$file = '/static/' . trim($file, '/');
if (!preg_match("/\\.html\$/", $file)) {
global $wp_rewrite;
if ($wp_rewrite->use_trailing_slashes) {
$file = $file . '/index.html';
} else {
$file = $file . '.html';
}
}
cache_fs::put_contents($file, $buffer);
} elseif (self::$memory) {
$cache_id = $host . preg_replace("/#.*/", '', $_SERVER['REQUEST_URI']);
$cache_id = md5($cache_id);
$headers = headers_list();
if (self::$status_header) {
array_unshift($headers, self::$status_header);
}
wp_cache_add($cache_id, $headers, 'cached_headers', cache_timeout);
if ($buffer && !in_array(self::$status_code, array(301, 302))) {
wp_cache_add($cache_id, $buffer, 'cached_buffers', cache_timeout);
}
} elseif (!(function_exists('is_multisite') && is_multisite())) {
# poor man's memcached
$cache_id = $host . preg_replace("/#.*/", '', $_SERVER['REQUEST_URI']);
$cache_id = md5($cache_id);
$file = '/semi-static/' . $cache_id;
$headers = headers_list();
if (self::$status_header) {
array_unshift($headers, self::$status_header);
}
cache_fs::put_contents($file . '.meta', serialize($headers));
if ($buffer && !in_array(self::$status_code, array(301, 302))) {
cache_fs::put_contents($file . '.html', $buffer);
}
}
return $buffer;
}
/**
* enable_static()
*
* @return bool $success
**/
static function enable_static()
{
if (!self::can_static() && !self::can_memory()) {
return false;
}
$static_cache = (bool) get_option('static_cache');
$memory_cache = (bool) get_option('memory_cache');
wp_clear_scheduled_hook('cache_timeout');
wp_clear_scheduled_hook('static_cache_timeout');
# sanity check
if (!$static_cache && !$memory_cache) {
return self::disable_static();
}
if (!wp_mkdir_p(WP_CONTENT_DIR . '/cache')) {
echo '<div class="error">' . '<p>' . sprintf(__('Error: Failed to create %s.', 'sem-cache'), 'wp-content/cache') . '</p>' . '</div>' . "\n";
return false;
}
$use_static_cache = $static_cache ? 'true' : 'false';
$use_memory_cache = $memory_cache ? 'true' : 'false';
$sem_cache_cookies = var_export(sem_cache::get_cookies(), true);
$sem_mobile_agents = var_export(sem_cache::get_mobile_agents(), true);
$sem_cache_file = dirname(__FILE__) . '/static-cache.php';
$contents = <<<EOS
<?php
define('static_cache', {$use_static_cache});
define('memory_cache', {$use_memory_cache});
\$sem_cache_cookies = {$sem_cache_cookies};
\$sem_mobile_agents = {$sem_mobile_agents};
include '{$sem_cache_file}';
?>
EOS;
$file = WP_CONTENT_DIR . '/advanced-cache.php';
$perms = stat(WP_CONTENT_DIR);
$perms = $perms['mode'] & 0666;
if (!file_put_contents($file, $contents) || !chmod($file, $perms)) {
echo '<div class="error">' . '<p>' . sprintf(__('Error: Failed to write %s.', 'sem-cache'), 'wp-content/advanced-cache.php') . '</p>' . '</div>' . "\n";
return false;
}
# Enable the static cache
if (!function_exists('save_mod_rewrite_rules') || !function_exists('get_home_path')) {
include_once ABSPATH . 'wp-admin/includes/admin.php';
}
if (!isset($GLOBALS['wp_rewrite'])) {
$GLOBALS['wp_rewrite'] = new WP_Rewrite();
}
# prevent mass-flushing when the permalink structure hasn't changed
remove_action('generate_rewrite_rules', array('sem_cache', 'flush_cache'));
global $wp_rewrite;
$wp_rewrite->flush_rules();
# Enable the memory cache
if ($memory_cache && !self::enable_memcached()) {
return false;
}
# Enable the cache
$file = ABSPATH . 'wp-config.php';
if (!defined('WP_CACHE') || !WP_CACHE) {
$contents = file_get_contents($file);
$line = "define('WP_CACHE', true);";
if (stristr($contents, "'WP_CACHE'")) {
$contents = preg_replace("/\n\t\t\t\t\t(?!(?:\\/\\/|\\#)\\s*)\n\t\t\t\t\tdefine\\s*\\(\\s*\n\t\t\t\t\t\t(['\"])WP_CACHE\\1\n\t\t\t\t\t\t.*?;\n\t\t\t\t\t/x", $line, $contents);
} else {
$contents = preg_replace("/^<\\?php\\s*/", "<?php" . PHP_EOL . PHP_EOL . $line . PHP_EOL . PHP_EOL, $contents);
}
if (!$contents || !file_put_contents($file, $contents)) {
echo '<div class="error">' . '<p>' . __('Error: Failed to override the WP_CACHE define in wp-config.php.', 'sem-cache') . '</p>' . '</div>' . "\n";
return false;
}
}
return true;
}
