* Add serialized version number to image metadata cache records

diff --git a/RELEASE-NOTES b/RELEASE-NOTES
index e03b3eb..f436287 100644 (file)
--- a/RELEASE-NOTES
+++ b/RELEASE-NOTES
@@ -557,6 +557,7 @@ of MediaWiki:Newpagetext) to &action=edit, if page is new.
 * Finally fixed Special:Disambiguations that was broke since SCHEMA_WORK
 * (bug 2761) fix capitalization of "i" in Turkish
 * (bug 2789) memcached image metadata now cleared after deletion
+* Add serialized version number to image metadata cache records
 
 
 === Caveats ===

diff --git a/includes/Image.php b/includes/Image.php
index 01222e2..02424dc 100644 (file)
--- a/includes/Image.php
+++ b/includes/Image.php
@@ -15,6 +15,10 @@
 if ($wgShowEXIF)
        require_once('Exif.php');
 
+/**
+ * Bump this number when serialized cache records may be incompatible.
+ */
+define( 'MW_IMAGE_VERSION', 1 );
 
 /**
  * Class to represent an image
@@ -116,7 +120,8 @@ class Image
                $cachedValues = $wgMemc->get( $keys[0] );
 
                // Check if the key existed and belongs to this version of MediaWiki
-               if (!empty($cachedValues) && is_array($cachedValues) && isset($cachedValues['width']) 
+               if (!empty($cachedValues) && is_array($cachedValues)
+                 && isset($cachedValues['version']) && ( $cachedValues['version'] == MW_IMAGE_VERSION )
                  && $cachedValues['fileExists'] && isset( $cachedValues['mime'] ) && isset( $cachedValues['metadata'] ) ) 
                {
                        if ( $wgUseSharedUploads && $cachedValues['fromShared']) {
@@ -124,7 +129,11 @@ class Image
                                # in shared repository has not changed
                                if ( isset( $keys[1] ) ) {
                                        $commonsCachedValues = $wgMemc->get( $keys[1] );
-                                       if (!empty($commonsCachedValues) && is_array($commonsCachedValues) && isset($commonsCachedValues['mime'])) {
+                                       if (!empty($commonsCachedValues) && is_array($commonsCachedValues)
+                                         && isset($commonsCachedValues['version'])
+                                         && ( $commonsCachedValues['version'] == MW_IMAGE_VERSION )
+                                         && isset($commonsCachedValues['mime'])) {
+                                               wfDebug( "Pulling image metadata from shared repository cache\n" );
                                                $this->name = $commonsCachedValues['name'];
                                                $this->imagePath = $commonsCachedValues['imagePath'];
                                                $this->fileExists = $commonsCachedValues['fileExists'];
@@ -140,8 +149,8 @@ class Image
                                                $this->imagePath = $this->getFullPath(true);
                                        }
                                }
-                       }
-                       else {
+                       } else {
+                               wfDebug( "Pulling image metadata from local cache\n" );
                                $this->name = $cachedValues['name'];
                                $this->imagePath = $cachedValues['imagePath'];
                                $this->fileExists = $cachedValues['fileExists'];
@@ -178,17 +187,19 @@ class Image
                        // We can't cache negative metadata for non-existent files,
                        // because if the file later appears in commons, the local
                        // keys won't be purged.
-                       $cachedValues = array('name' => $this->name,
-                                                                 'imagePath' => $this->imagePath,
-                                                                 'fileExists' => $this->fileExists,
-                                                                 'fromShared' => $this->fromSharedDirectory,
-                                                                 'width' => $this->width,
-                                                                 'height' => $this->height,
-                                                                 'bits' => $this->bits,
-                                                                 'type' => $this->type,
-                                                                 'mime' => $this->mime,
-                                                                 'metadata' => $this->metadata,
-                                                                 'size' => $this->size);
+                       $cachedValues = array(
+                               'version'    => MW_IMAGE_VERSION,
+                               'name'       => $this->name,
+                               'imagePath'  => $this->imagePath,
+                               'fileExists' => $this->fileExists,
+                               'fromShared' => $this->fromSharedDirectory,
+                               'width'      => $this->width,
+                               'height'     => $this->height,
+                               'bits'       => $this->bits,
+                               'type'       => $this->type,
+                               'mime'       => $this->mime,
+                               'metadata'   => $this->metadata,
+                               'size'       => $this->size );
 
                        $wgMemc->set( $keys[0], $cachedValues );
                } else {