[FileBackend] Worked around Akamai CDN purge limits.

* Added swiftCDNTTL to let the cache TTL be configurable
* Also added swiftCDNPurgable option to disable purges

Change-Id: Ic8e779c20f7501a5a55f4a49fc612923d0dc268c

diff --git a/includes/filerepo/backend/SwiftFileBackend.php b/includes/filerepo/backend/SwiftFileBackend.php
index 36d4334..dc6cd44 100644 (file)
--- a/includes/filerepo/backend/SwiftFileBackend.php
+++ b/includes/filerepo/backend/SwiftFileBackend.php
@@ -42,6 +42,9 @@ class SwiftFileBackend extends FileBackendStore {
        protected $authTTL; // integer seconds
        protected $swiftAnonUser; // string; username to handle unauthenticated requests
        protected $swiftUseCDN; // boolean; whether CloudFiles CDN is enabled
+       protected $swiftCDNExpiry; // integer; how long to cache things in the CDN
+       protected $swiftCDNPurgable; // boolean; whether object CDN purging is enabled
+
        protected $maxContCacheSize = 300; // integer; max containers with entries
 
        /** @var CF_Connection */
@@ -59,6 +62,11 @@ class SwiftFileBackend extends FileBackendStore {
         *    swiftAuthTTL       : Swift authentication TTL (seconds)
         *    swiftAnonUser      : Swift user used for end-user requests (account:username)
         *    swiftUseCDN        : Whether a Cloud Files Content Delivery Network is set up
+        *    swiftCDNExpiry     : How long (in seconds) to store content in the CDN.
+        *                         If files may likely change, this should probably not exceed
+        *                         a few days. For example, deletions may take this long to apply.
+        *                         If object purging is enabled, however, this is not an issue.
+        *    swiftCDNPurgable   : Whether object purge requests are allowed by the CDN.
         *    shardViaHashLevels : Map of container names to sharding config with:
         *                         'base'   : base of hash characters, 16 or 36
         *                         'levels' : the number of hash levels (and digits)
@@ -90,6 +98,12 @@ class SwiftFileBackend extends FileBackendStore {
                $this->swiftUseCDN = isset( $config['swiftUseCDN'] )
                        ? $config['swiftUseCDN']
                        : false;
+               $this->swiftCDNExpiry = isset( $config['swiftCDNExpiry'] )
+                       ? $config['swiftCDNExpiry']
+                       : 3600; // hour
+               $this->swiftCDNPurgable = isset( $config['swiftCDNPurgable'] )
+                       ? $config['swiftCDNPurgable']
+                       : true;
                // Cache container info to mask latency
                $this->memCache = wfGetMainCache();
        }
@@ -519,7 +533,7 @@ class SwiftFileBackend extends FileBackendStore {
                                ) );
                        }
                        if ( $this->swiftUseCDN ) { // Rackspace style CDN
-                               $contObj->make_public();
+                               $contObj->make_public( $this->swiftCDNExpiry );
                        }
                } catch ( CDNNotEnabledException $e ) {
                        // CDN not enabled; nothing to see here
@@ -1018,13 +1032,14 @@ class SwiftFileBackend extends FileBackendStore {
        }
 
        /**
-        * Purge the CDN cache of affected objects if CDN caching is enabled
+        * Purge the CDN cache of affected objects if CDN caching is enabled.
+        * This is for Rackspace/Akamai CDNs.
         *
         * @param $objects Array List of CF_Object items
         * @return void
         */
        public function purgeCDNCache( array $objects ) {
-               if ( $this->swiftUseCDN ) { // Rackspace style CDN
+               if ( $this->swiftUseCDN && $this->swiftCDNPurgable ) {
                        foreach ( $objects as $object ) {
                                try {
                                        $object->purge_from_cdn();