filebackend: throw exceptions during file iteration.

* This lets calling code be far more robust rather than just
  silently ignoring entries due to some temporary problem.

Change-Id: I3ce2ae34f6cff5e40a80b8da5688503a387ce2a6

diff --git a/includes/AutoLoader.php b/includes/AutoLoader.php
index 02c92df..38b27e6 100644 (file)
--- a/includes/AutoLoader.php
+++ b/includes/AutoLoader.php
@@ -551,6 +551,7 @@ $wgAutoloadLocalClasses = array(
        # includes/filebackend
        'FileBackendGroup' => 'includes/filebackend/FileBackendGroup.php',
        'FileBackend' => 'includes/filebackend/FileBackend.php',
+       'FileBackendError' => 'includes/filebackend/FileBackend.php',
        'FileBackendStore' => 'includes/filebackend/FileBackendStore.php',
        'FileBackendStoreShardListIterator' => 'includes/filebackend/FileBackendStore.php',
        'FileBackendStoreShardDirIterator' => 'includes/filebackend/FileBackendStore.php',

diff --git a/includes/filebackend/FSFileBackend.php b/includes/filebackend/FSFileBackend.php
index dfc5192..6d64216 100644 (file)
--- a/includes/filebackend/FSFileBackend.php
+++ b/includes/filebackend/FSFileBackend.php
@@ -854,8 +854,8 @@ abstract class FSFileBackendList implements Iterator {
                try {
                        $this->iter->next();
                        $this->filterViaNext();
-               } catch ( UnexpectedValueException $e ) {
-                       $this->iter = null;
+               } catch ( UnexpectedValueException $e ) { // bad permissions? deleted?
+                       throw new FileBackendError( "File iterator gave UnexpectedValueException." );
                }
                ++$this->pos;
        }
@@ -869,8 +869,8 @@ abstract class FSFileBackendList implements Iterator {
                try {
                        $this->iter->rewind();
                        $this->filterViaNext();
-               } catch ( UnexpectedValueException $e ) {
-                       $this->iter = null;
+               } catch ( UnexpectedValueException $e ) { // bad permissions? deleted?
+                       throw new FileBackendError( "File iterator gave UnexpectedValueException." );
                }
        }
 

diff --git a/includes/filebackend/FileBackend.php b/includes/filebackend/FileBackend.php
index 29af88d..9b4760a 100644 (file)
--- a/includes/filebackend/FileBackend.php
+++ b/includes/filebackend/FileBackend.php
@@ -1061,6 +1061,8 @@ abstract class FileBackend {
         *
         * Storage backends with eventual consistency might return stale data.
         *
+        * Failures during iteration can result in FileBackendError exceptions (since 1.22).
+        *
         * @param array $params
         * $params include:
         *   - dir     : storage directory
@@ -1076,6 +1078,8 @@ abstract class FileBackend {
         *
         * Storage backends with eventual consistency might return stale data.
         *
+        * Failures during iteration can result in FileBackendError exceptions (since 1.22).
+        *
         * @param array $params
         * $params include:
         *   - dir : storage directory
@@ -1096,6 +1100,8 @@ abstract class FileBackend {
         *
         * Storage backends with eventual consistency might return stale data.
         *
+        * Failures during iteration can result in FileBackendError exceptions (since 1.22).
+        *
         * @param array $params
         * $params include:
         *   - dir        : storage directory
@@ -1111,6 +1117,8 @@ abstract class FileBackend {
         *
         * Storage backends with eventual consistency might return stale data.
         *
+        * Failures during iteration can result in FileBackendError exceptions (since 1.22).
+        *
         * @param array $params
         * $params include:
         *   - dir        : storage directory
@@ -1379,3 +1387,9 @@ abstract class FileBackend {
                return $path;
        }
 }
+
+/**
+ * @ingroup FileBackend
+ * @since 1.22
+ */
+class FileBackendError extends MWException {}

diff --git a/includes/filebackend/SwiftFileBackend.php b/includes/filebackend/SwiftFileBackend.php
index a57bf59..f3aa145 100644 (file)
--- a/includes/filebackend/SwiftFileBackend.php
+++ b/includes/filebackend/SwiftFileBackend.php
@@ -926,6 +926,7 @@ class SwiftFileBackend extends FileBackendStore {
         * @param integer $limit Max number of items to list
         * @param array $params Parameters for getDirectoryList()
         * @return Array List of resolved paths of directories directly under $dir
+        * @throws FileBackendError
         */
        public function getDirListPageInternal( $fullCont, $dir, &$after, $limit, array $params ) {
                $dirs = array();
@@ -933,7 +934,7 @@ class SwiftFileBackend extends FileBackendStore {
                        return $dirs; // nothing more
                }
 
-               wfProfileIn( __METHOD__ . '-' . $this->name );
+               $section = new ProfileSection( __METHOD__ . '-' . $this->name );
                try {
                        $container = $this->getContainer( $fullCont );
                        $prefix = ( $dir == '' ) ? null : "{$dir}/";
@@ -981,8 +982,8 @@ class SwiftFileBackend extends FileBackendStore {
                } catch ( CloudFilesException $e ) { // some other exception?
                        $this->handleException( $e, null, __METHOD__,
                                array( 'cont' => $fullCont, 'dir' => $dir ) );
+                       throw new FileBackendError( "Got " . get_class( $e ) . " exception." );
                }
-               wfProfileOut( __METHOD__ . '-' . $this->name );
 
                return $dirs;
        }
@@ -1000,6 +1001,7 @@ class SwiftFileBackend extends FileBackendStore {
         * @param integer $limit Max number of items to list
         * @param array $params Parameters for getDirectoryList()
         * @return Array List of resolved paths of files under $dir
+        * @throws FileBackendError
         */
        public function getFileListPageInternal( $fullCont, $dir, &$after, $limit, array $params ) {
                $files = array();
@@ -1007,7 +1009,7 @@ class SwiftFileBackend extends FileBackendStore {
                        return $files; // nothing more
                }
 
-               wfProfileIn( __METHOD__ . '-' . $this->name );
+               $section = new ProfileSection( __METHOD__ . '-' . $this->name );
                try {
                        $container = $this->getContainer( $fullCont );
                        $prefix = ( $dir == '' ) ? null : "{$dir}/";
@@ -1048,8 +1050,8 @@ class SwiftFileBackend extends FileBackendStore {
                } catch ( CloudFilesException $e ) { // some other exception?
                        $this->handleException( $e, null, __METHOD__,
                                array( 'cont' => $fullCont, 'dir' => $dir ) );
+                       throw new FileBackendError( "Got " . get_class( $e ) . " exception." );
                }
-               wfProfileOut( __METHOD__ . '-' . $this->name );
 
                return $files;
        }
@@ -1653,7 +1655,7 @@ abstract class SwiftFileBackendList implements Iterator {
         * @param string $after|null
         * @param integer $limit
         * @param array $params
-        * @return Traversable|Array|null Returns null on failure
+        * @return Traversable|Array
         */
        abstract protected function pageFromList( $container, $dir, &$after, $limit, array $params );
 }
@@ -1672,7 +1674,7 @@ class SwiftFileBackendDirList extends SwiftFileBackendList {
 
        /**
         * @see SwiftFileBackendList::pageFromList()
-        * @return Array|null
+        * @return Array
         */
        protected function pageFromList( $container, $dir, &$after, $limit, array $params ) {
                return $this->backend->getDirListPageInternal( $container, $dir, $after, $limit, $params );
@@ -1693,7 +1695,7 @@ class SwiftFileBackendFileList extends SwiftFileBackendList {
 
        /**
         * @see SwiftFileBackendList::pageFromList()
-        * @return Array|null
+        * @return Array
         */
        protected function pageFromList( $container, $dir, &$after, $limit, array $params ) {
                return $this->backend->getFileListPageInternal( $container, $dir, $after, $limit, $params );