1 files changed, 453 insertions, 0 deletions
diff --git a/engine/lib/cache.php b/engine/lib/cache.php
new file mode 100644
index 000000000..3116c1a9b
--- /dev/null
+++ b/engine/lib/cache.php
@@ -0,0 +1,453 @@
+<?php
+/**
+ * Elgg cache
+ * Cache file interface for caching data.
+ *
+ * @package    Elgg.Core
+ * @subpackage Cache
+ */
+
+/* Filepath Cache */
+
+/**
+ * Returns an ElggCache object suitable for caching system information
+ *
+ * @todo Can this be done in a cleaner way?
+ * @todo Swap to memcache etc?
+ *
+ * @return ElggFileCache
+ */
+function elgg_get_system_cache() {
+	global $CONFIG;
+
+	/**
+	 * A default filestore cache using the dataroot.
+	 */
+	static $FILE_PATH_CACHE;
+
+	if (!$FILE_PATH_CACHE) {
+		$FILE_PATH_CACHE = new ElggFileCache($CONFIG->dataroot . 'system_cache/');
+	}
+
+	return $FILE_PATH_CACHE;
+}
+
+/**
+ * Reset the system cache by deleting the caches
+ *
+ * @return void
+ */
+function elgg_reset_system_cache() {
+	$cache = elgg_get_system_cache();
+	$cache->clear();
+}
+
+/**
+ * Saves a system cache.
+ *
+ * @param string $type The type or identifier of the cache
+ * @param string $data The data to be saved
+ * @return bool
+ */
+function elgg_save_system_cache($type, $data) {
+	global $CONFIG;
+
+	if ($CONFIG->system_cache_enabled) {
+		$cache = elgg_get_system_cache();
+		return $cache->save($type, $data);
+	}
+
+	return false;
+}
+
+/**
+ * Retrieve the contents of a system cache.
+ *
+ * @param string $type The type of cache to load
+ * @return string
+ */
+function elgg_load_system_cache($type) {
+	global $CONFIG;
+
+	if ($CONFIG->system_cache_enabled) {
+		$cache = elgg_get_system_cache();
+		$cached_data = $cache->load($type);
+
+		if ($cached_data) {
+			return $cached_data;
+		}
+	}
+
+	return NULL;
+}
+
+/**
+ * Enables the system disk cache.
+ *
+ * Uses the 'system_cache_enabled' datalist with a boolean value.
+ * Resets the system cache.
+ *
+ * @return void
+ */
+function elgg_enable_system_cache() {
+	global $CONFIG;
+
+	datalist_set('system_cache_enabled', 1);
+	$CONFIG->system_cache_enabled = 1;
+	elgg_reset_system_cache();
+}
+
+/**
+ * Disables the system disk cache.
+ *
+ * Uses the 'system_cache_enabled' datalist with a boolean value.
+ * Resets the system cache.
+ *
+ * @return void
+ */
+function elgg_disable_system_cache() {
+	global $CONFIG;
+
+	datalist_set('system_cache_enabled', 0);
+	$CONFIG->system_cache_enabled = 0;
+	elgg_reset_system_cache();
+}
+
+/** @todo deprecate in Elgg 1.9 **/
+
+/**
+ * @access private
+ */
+function elgg_get_filepath_cache() {
+	return elgg_get_system_cache();
+}
+/**
+ * @access private
+ */
+function elgg_filepath_cache_reset() {
+	elgg_reset_system_cache();
+}
+/**
+ * @access private
+ */
+function elgg_filepath_cache_save($type, $data) {
+	return elgg_save_system_cache($type, $data);
+}
+/**
+ * @access private
+ */
+function elgg_filepath_cache_load($type) {
+	return elgg_load_system_cache($type);
+}
+/**
+ * @access private
+ */
+function elgg_enable_filepath_cache() {
+	elgg_enable_system_cache();
+}
+/**
+ * @access private
+ */
+function elgg_disable_filepath_cache() {
+	elgg_disable_system_cache();
+}
+
+/* Simplecache */
+
+/**
+ * Registers a view to simple cache.
+ *
+ * Simple cache is a caching mechanism that saves the output of
+ * views and its extensions into a file.  If the view is called
+ * by the {@link simplecache/view.php} file, the Elgg framework will
+ * not be loaded and the contents of the view will returned
+ * from file.
+ *
+ * @warning Simple cached views must take no parameters and return
+ * the same content no matter who is logged in.
+ *
+ * @example
+ * 		$blog_js = elgg_get_simplecache_url('js', 'blog/save_draft');
+ *		elgg_register_simplecache_view('js/blog/save_draft');
+ *		elgg_register_js('elgg.blog', $blog_js);
+ *		elgg_load_js('elgg.blog');
+ *
+ * @param string $viewname View name
+ *
+ * @return void
+ * @link http://docs.elgg.org/Views/Simplecache
+ * @see elgg_regenerate_simplecache()
+ * @since 1.8.0
+ */
+function elgg_register_simplecache_view($viewname) {
+	global $CONFIG;
+
+	if (!isset($CONFIG->views)) {
+		$CONFIG->views = new stdClass;
+	}
+
+	if (!isset($CONFIG->views->simplecache)) {
+		$CONFIG->views->simplecache = array();
+	}
+
+	$CONFIG->views->simplecache[] = $viewname;
+}
+
+/**
+ * Get the URL for the cached file
+ *
+ * @warning You must register the view with elgg_register_simplecache_view()
+ * for caching to work. See elgg_register_simplecache_view() for a full example.
+ *
+ * @param string $type The file type: css or js
+ * @param string $view The view name
+ * @return string
+ * @since 1.8.0
+ */
+function elgg_get_simplecache_url($type, $view) {
+	global $CONFIG;
+	$lastcache = (int)$CONFIG->lastcache;
+	$viewtype = elgg_get_viewtype();
+	elgg_register_simplecache_view("$type/$view");// see #5302
+	if (elgg_is_simplecache_enabled()) {
+		$url = elgg_get_site_url() . "cache/$type/$viewtype/$view.$lastcache.$type";
+	} else {
+		$url = elgg_get_site_url() . "$type/$view.$lastcache.$type";
+		$elements = array("view" => $viewtype);
+		$url = elgg_http_add_url_query_elements($url, $elements);
+	}
+	
+	return $url;
+}
+
+/**
+ * Regenerates the simple cache.
+ *
+ * @warning This does not invalidate the cache, but actively rebuilds it.
+ *
+ * @param string $viewtype Optional viewtype to regenerate. Defaults to all valid viewtypes.
+ *
+ * @return void
+ * @see elgg_register_simplecache_view()
+ * @since 1.8.0
+ */
+function elgg_regenerate_simplecache($viewtype = NULL) {
+	global $CONFIG;
+
+	if (!isset($CONFIG->views->simplecache) || !is_array($CONFIG->views->simplecache)) {
+		return;
+	}
+
+	$lastcached = time();
+
+	// @todo elgg_view() checks if the page set is done (isset($CONFIG->pagesetupdone)) and
+	// triggers an event if it's not. Calling elgg_view() here breaks submenus
+	// (at least) because the page setup hook is called before any
+	// contexts can be correctly set (since this is called before page_handler()).
+	// To avoid this, lie about $CONFIG->pagehandlerdone to force
+	// the trigger correctly when the first view is actually being output.
+	$CONFIG->pagesetupdone = TRUE;
+
+	if (!file_exists($CONFIG->dataroot . 'views_simplecache')) {
+		mkdir($CONFIG->dataroot . 'views_simplecache');
+	}
+
+	if (isset($viewtype)) {
+		$viewtypes = array($viewtype);
+	} else {
+		$viewtypes = $CONFIG->view_types;
+	}
+
+	$original_viewtype = elgg_get_viewtype();
+
+	// disable error reporting so we don't cache problems
+	$old_debug = elgg_get_config('debug');
+	elgg_set_config('debug', null);
+
+	foreach ($viewtypes as $viewtype) {
+		elgg_set_viewtype($viewtype);
+		foreach ($CONFIG->views->simplecache as $view) {
+			$viewcontents = elgg_view($view);
+			$viewname = md5(elgg_get_viewtype() . $view);
+			if ($handle = fopen($CONFIG->dataroot . 'views_simplecache/' . $viewname, 'w')) {
+				fwrite($handle, $viewcontents);
+				fclose($handle);
+			}
+		}
+
+		datalist_set("simplecache_lastupdate_$viewtype", $lastcached);
+		datalist_set("simplecache_lastcached_$viewtype", $lastcached);
+	}
+
+	elgg_set_config('debug', $old_debug);
+	elgg_set_viewtype($original_viewtype);
+
+	// needs to be set for links in html head
+	$CONFIG->lastcache = $lastcached;
+
+	unset($CONFIG->pagesetupdone);
+}
+
+/**
+ * Is simple cache enabled
+ *
+ * @return bool
+ * @since 1.8.0
+ */
+function elgg_is_simplecache_enabled() {
+	if (elgg_get_config('simplecache_enabled')) {
+		return true;
+	}
+
+	return false;
+}
+
+/**
+ * Enables the simple cache.
+ *
+ * @access private
+ * @see elgg_register_simplecache_view()
+ * @return void
+ * @since 1.8.0
+ */
+function elgg_enable_simplecache() {
+	global $CONFIG;
+
+	datalist_set('simplecache_enabled', 1);
+	$CONFIG->simplecache_enabled = 1;
+	elgg_regenerate_simplecache();
+}
+
+/**
+ * Disables the simple cache.
+ *
+ * @warning Simplecache is also purged when disabled.
+ *
+ * @access private
+ * @see elgg_register_simplecache_view()
+ * @return void
+ * @since 1.8.0
+ */
+function elgg_disable_simplecache() {
+	global $CONFIG;
+	if ($CONFIG->simplecache_enabled) {
+		datalist_set('simplecache_enabled', 0);
+		$CONFIG->simplecache_enabled = 0;
+
+		// purge simple cache
+		if ($handle = opendir($CONFIG->dataroot . 'views_simplecache')) {
+			while (false !== ($file = readdir($handle))) {
+				if ($file != "." && $file != "..") {
+					unlink($CONFIG->dataroot . 'views_simplecache/' . $file);
+				}
+			}
+			closedir($handle);
+		}
+	}
+}
+
+/**
+ * Deletes all cached views in the simplecache and sets the lastcache and
+ * lastupdate time to 0 for every valid viewtype.
+ *
+ * @return bool
+ * @since 1.7.4
+ */
+function elgg_invalidate_simplecache() {
+	global $CONFIG;
+
+	if (!isset($CONFIG->views->simplecache) || !is_array($CONFIG->views->simplecache)) {
+		return false;
+	}
+
+	$handle = opendir($CONFIG->dataroot . 'views_simplecache');
+
+	if (!$handle) {
+		return false;
+	}
+
+	// remove files.
+	$return = true;
+	while (false !== ($file = readdir($handle))) {
+		if ($file != "." && $file != "..") {
+			$return &= unlink($CONFIG->dataroot . 'views_simplecache/' . $file);
+		}
+	}
+	closedir($handle);
+
+	// reset cache times
+	$viewtypes = $CONFIG->view_types;
+
+	if (!is_array($viewtypes)) {
+		return false;
+	}
+
+	foreach ($viewtypes as $viewtype) {
+		$return &= datalist_set("simplecache_lastupdate_$viewtype", 0);
+		$return &= datalist_set("simplecache_lastcached_$viewtype", 0);
+	}
+
+	return $return;
+}
+
+/**
+ * @see elgg_reset_system_cache()
+ * @access private
+ */
+function _elgg_load_cache() {
+	global $CONFIG;
+
+	$CONFIG->system_cache_loaded = false;
+
+	$CONFIG->views = new stdClass();
+	$data = elgg_load_system_cache('view_locations');
+	if (!is_string($data)) {
+		return;
+	}
+	$CONFIG->views->locations = unserialize($data);
+	
+	$data = elgg_load_system_cache('view_types');
+	if (!is_string($data)) {
+		return;
+	}
+	$CONFIG->view_types = unserialize($data);
+
+	$CONFIG->system_cache_loaded = true;
+}
+
+/**
+ * @access private
+ */
+function _elgg_cache_init() {
+	global $CONFIG;
+
+	$viewtype = elgg_get_viewtype();
+
+	// Regenerate the simple cache if expired.
+	// Don't do it on upgrade because upgrade does it itself.
+	// @todo - move into function and perhaps run off init system event
+	if (!defined('UPGRADING')) {
+		$lastupdate = datalist_get("simplecache_lastupdate_$viewtype");
+		$lastcached = datalist_get("simplecache_lastcached_$viewtype");
+		if ($lastupdate == 0 || $lastcached < $lastupdate) {
+			elgg_regenerate_simplecache($viewtype);
+			$lastcached = datalist_get("simplecache_lastcached_$viewtype");
+		}
+		$CONFIG->lastcache = $lastcached;
+	}
+
+	// cache system data if enabled and not loaded
+	if ($CONFIG->system_cache_enabled && !$CONFIG->system_cache_loaded) {
+		elgg_save_system_cache('view_locations', serialize($CONFIG->views->locations));
+		elgg_save_system_cache('view_types', serialize($CONFIG->view_types));
+	}
+
+	if ($CONFIG->system_cache_enabled && !$CONFIG->i18n_loaded_from_cache) {
+		reload_all_translations();
+		foreach ($CONFIG->translations as $lang => $map) {
+			elgg_save_system_cache("$lang.lang", serialize($map));
+		}
+	}
+}
+
+elgg_register_event_handler('ready', 'system', '_elgg_cache_init');