Support caching of old versions

diff --git a/includes/filerepo/FileCache.php b/includes/filerepo/FileCache.php
index 7840d1a..328cd11 100644 (file)
--- a/includes/filerepo/FileCache.php
+++ b/includes/filerepo/FileCache.php
@@ -9,7 +9,7 @@
  */
 class FileCache {
        var $repoGroup;
-       var $cache = array(), $notFound = array();
+       var $cache = array(), $oldCache = array(), $notFound = array();
 
        protected static $instance;
 
@@ -87,10 +87,10 @@ class FileCache {
        /**
         * Search the cache for a file.
         * @param mixed $title Title object or string
+        * @param string or false $time, old version time
         * @return File object or false if it is not found
-        * @todo Implement searching for old file versions(?)
         */
-       function findFile( $title ) {
+       function findFile( $title, $time = false ) {
                if( !( $title instanceof Title ) ) {
                        $title = Title::makeTitleSafe( NS_FILE, $title );
                }
@@ -99,20 +99,37 @@ class FileCache {
                }
 
                $dbkey = $title->getDBkey();
+               # Is there a current version cached?
                if( array_key_exists( $dbkey, $this->cache ) ) {
-                       wfDebug( "FileCache HIT for $dbkey\n" );
-                       return $this->cache[$dbkey];
+                       if( !$time || $this->cache[$dbkey]->getTimestamp() === $time ) {
+                               wfDebug( "FileCache HIT for $dbkey\n" );
+                               return $this->cache[$dbkey];
+                       }
                }
+               # Is there no current version? Then assume no old versions too.
                if( array_key_exists( $dbkey, $this->notFound ) ) {
                        wfDebug( "FileCache negative HIT for $dbkey\n" );
                        return false;
                }
+               # Is this old version cached?
+               if( $time && array_key_exists( $dbkey, $this->oldCache ) &&
+                       array_key_exists( $time, $this->oldCache[$dbkey] ) )
+               {
+                       wfDebug( "FileCache HIT for $dbkey on $time\n" );
+                       return $this->oldCache[$dbkey][$time];
+               }
 
                // Not in cache, fall back to a direct query
-               $file = $this->repoGroup->findFile( $title );
+               $file = $this->repoGroup->findFile( $title, $time );
                if( $file ) {
                        wfDebug( "FileCache MISS for $dbkey\n" );
-                       $this->cache[$dbkey] = $file;
+                       if( !$file->isOld() ) {
+                               $this->cache[$dbkey] = $file; // cache the current version
+                       }
+                       if( !array_key_exists( $dbkey, $this->oldCache ) ) {
+                               $this->oldCache[$dbkey] = array();
+                       }
+                       $this->oldCache[$dbkey][$file->getTimestamp()] = $file; // cache this version
                } else {
                        wfDebug( "FileCache negative MISS for $dbkey\n" );
                        $this->notFound[$dbkey] = true;