Merge "Use adaptive CDN TTLs for page views"

[lhc/web/wiklou.git] / includes / OutputPage.php

diff --git a/includes/OutputPage.php b/includes/OutputPage.php
index dea5292..863a426 100644 (file)
--- a/includes/OutputPage.php
+++ b/includes/OutputPage.php
@@ -1933,6 +1933,36 @@ class OutputPage extends ContextSource {
                $this->setCdnMaxage( $this->mCdnMaxage );
        }
 
+       /**
+        * Get TTL in [$minTTL,$maxTTL] in pass it to lowerCdnMaxage()
+        *
+        * This sets and returns $minTTL if $mtime is false or null. Otherwise,
+        * the TTL is higher the older the $mtime timestamp is. Essentially, the
+        * TTL is 90% of the age of the object, subject to the min and max.
+        *
+        * @param string|integer|float|bool|null $mtime Last-Modified timestamp
+        * @param integer $minTTL Mimimum TTL in seconds [default: 1 minute]
+        * @param integer $maxTTL Maximum TTL in seconds [default: $wgSquidMaxage]
+        * @return integer TTL in seconds
+        * @since 1.28
+        */
+       public function adaptCdnTTL( $mtime, $minTTL = 0, $maxTTL = 0 ) {
+               $minTTL = $minTTL ?: IExpiringStore::TTL_MINUTE;
+               $maxTTL = $maxTTL ?: $this->getConfig()->get( 'SquidMaxage' );
+
+               if ( $mtime === null || $mtime === false ) {
+                       return $minTTL; // entity does not exist
+               }
+
+               $age = time() - wfTimestamp( TS_UNIX, $mtime );
+               $adaptiveTTL = max( .9 * $age, $minTTL );
+               $adaptiveTTL = min( $adaptiveTTL, $maxTTL );
+
+               $this->lowerCdnMaxage( (int)$adaptiveTTL );
+
+               return $adaptiveTTL;
+       }
+
        /**
         * Use enableClientCache(false) to force it to send nocache headers
         *