Limit attempts to render the same thumbnail after failures

bug: 49118
Change-Id: I9379ec445bf2e77bd3b085c00182c5e406ed300d

diff --git a/RELEASE-NOTES-1.23 b/RELEASE-NOTES-1.23
index 86bf6b1..16bdf1e 100644 (file)
--- a/RELEASE-NOTES-1.23
+++ b/RELEASE-NOTES-1.23
@@ -220,6 +220,9 @@ changes to languages because of Bugzilla reports.
   3 headings)" was removed.
 * (bug 52810) Preference "Justify paragraphs" was removed.
 * OutputPage::showErrorPage raises a notice if arguments are incoherent.
+* Thumbnails that keep failing to render in thumb.php will be rate-limited
+  againt further render attempts for 1 hour. $wgAttemptFailureEpoch can be
+  altered to reset all rate-limited thumbnails at once.
 
 ==== Removed classes ====
 * FakeMemCachedClient (deprecated in 1.18)

diff --git a/includes/DefaultSettings.php b/includes/DefaultSettings.php
index 536c035..bb80beb 100644 (file)
--- a/includes/DefaultSettings.php
+++ b/includes/DefaultSettings.php
@@ -1031,6 +1031,14 @@ $wgTiffThumbnailType = false;
  */
 $wgThumbnailEpoch = '20030516000000';
 
+/**
+ * Certain operations are avoided if there were too many recent failures,
+ * for example, thumbnail generation. Bump this value to invalidate all
+ * memory of failed operations and thus allow further attempts to resume.
+ * This is useful when a cause for the failures has been found and fixed.
+ */
+$wgAttemptFailureEpoch = 1;
+
 /**
  * If set, inline scaled images will still produce "<img>" tags ready for
  * output instead of showing an error message.

diff --git a/languages/messages/MessagesEn.php b/languages/messages/MessagesEn.php
index 88b729d..5e92d3d 100644 (file)
--- a/languages/messages/MessagesEn.php
+++ b/languages/messages/MessagesEn.php
@@ -3577,6 +3577,7 @@ $2',
 'thumbnail_image-type'     => 'Image type not supported',
 'thumbnail_gd-library'     => 'Incomplete GD library configuration: Missing function $1',
 'thumbnail_image-missing'  => 'File seems to be missing: $1',
+'thumbnail_image-failure-limit' => 'There have been too many recent failed attempts ($1 or more) to render this thumbnail. Please try again later.',
 
 # Special:Import
 'import'                     => 'Import pages',

diff --git a/languages/messages/MessagesQqq.php b/languages/messages/MessagesQqq.php
index 8874507..b004b12 100644 (file)
--- a/languages/messages/MessagesQqq.php
+++ b/languages/messages/MessagesQqq.php
@@ -7269,6 +7269,8 @@ See also:
 *$1 is a function name of the GD library',
 'thumbnail_image-missing' => 'This is the parameter 1 of the message {{msg-mw|thumbnail error}}.
 *$1 is the path incl. filename of the missing image',
+'thumbnail_image-failure-limit' => 'This is the parameter 1 of the message {{msg-mw|thumbnail error}}.
+*$1 is the maximum allowed number of failed attempts',
 
 # Special:Import
 'import' => 'The title of the special page [[Special:Import]];',
@@ -9649,7 +9651,7 @@ Quotation marks, for quoting, sometimes titles etc., depending on the language.
 
 See: [[w:Non-English usage of quotation marks|Non-English usage of quotation marks on Wikipedia]].
 
-Parameters: 
+Parameters:
 * $1 - text to be wrapped in quotation marks',
 
 # Multipage image navigation

diff --git a/maintenance/language/messages.inc b/maintenance/language/messages.inc
index ed85223..6e6c3ed 100644 (file)
--- a/maintenance/language/messages.inc
+++ b/maintenance/language/messages.inc
@@ -2490,6 +2490,7 @@ $wgMessageStructure = array(
                'thumbnail_image-type',
                'thumbnail_gd-library',
                'thumbnail_image-missing',
+               'thumbnail_image-failure-limit'
        ),
        'import' => array(
                'import',

diff --git a/thumb.php b/thumb.php
index ad5239e..88aecbd 100644 (file)
--- a/thumb.php
+++ b/thumb.php
@@ -307,6 +307,9 @@ function wfStreamThumb( array $params ) {
        if ( $user->pingLimiter( 'renderfile' ) ) {
                wfThumbError( 500, wfMessage( 'actionthrottledtext' ) );
                return;
+       } elseif ( wfThumbIsAttemptThrottled( $img, $thumbName, 5 ) ) {
+               wfThumbError( 500, wfMessage( 'thumbnail_image-failure-limit', 5 ) );
+               return;
        }
 
        // Thumbnail isn't already there, so create the new thumbnail...
@@ -332,6 +335,7 @@ function wfStreamThumb( array $params ) {
        }
 
        if ( $errorMsg !== false ) {
+               wfThumbIncrAttemptFailures( $img, $thumbName );
                wfThumbError( 500, $errorMsg );
        } else {
                // Stream the file if there were no errors
@@ -339,6 +343,45 @@ function wfStreamThumb( array $params ) {
        }
 }
 
+/**
+ * @param File $img
+ * @param string $thumbName
+ * @param int $limit
+ * @return int|bool
+ */
+function wfThumbIsAttemptThrottled( File $img, $thumbName, $limit ) {
+       global $wgMemc;
+
+       return ( $wgMemc->get( wfThumbAttemptKey( $img, $thumbName ) ) >= $limit );
+}
+
+/**
+ * @param File $img
+ * @param string $thumbName
+ */
+function wfThumbIncrAttemptFailures( File $img, $thumbName ) {
+       global $wgMemc;
+
+       $key = wfThumbAttemptKey( $img, $thumbName );
+       if ( !$wgMemc->incr( $key, 1 ) ) {
+               if ( !$wgMemc->add( $key, 1, 3600 ) ) {
+                       $wgMemc->incr( $key, 1 );
+               }
+       }
+}
+
+/**
+ * @param File $img
+ * @param string $thumbName
+ * @return string
+ */
+function wfThumbAttemptKey( File $img, $thumbName ) {
+       global $wgAttemptFailureEpoch;
+
+       return wfMemcKey( 'attempt-failures', $wgAttemptFailureEpoch,
+               $img->getRepo()->getName(), md5( $img->getName() ), md5( $thumbName ) );
+}
+
 /**
  * Convert pathinfo type parameter, into normal request parameters
  *