Make LocalFile check early if the revision store is available

[lhc/web/wiklou.git] / includes / externalstore / ExternalStore.php

diff --git a/includes/externalstore/ExternalStore.php b/includes/externalstore/ExternalStore.php
index ea04cc8..de7d1a4 100644 (file)
--- a/includes/externalstore/ExternalStore.php
+++ b/includes/externalstore/ExternalStore.php
@@ -3,6 +3,8 @@
  * @defgroup ExternalStorage ExternalStorage
  */
 
+use MediaWiki\MediaWikiServices;
+
 /**
  * Interface for data storage in external repositories.
  *
@@ -51,17 +53,10 @@ class ExternalStore {
         * @param array $params Associative array of ExternalStoreMedium parameters
         * @return ExternalStoreMedium|bool The store class or false on error
         */
-       public static function getStoreObject( $proto, array $params = array() ) {
-               global $wgExternalStores;
-
-               if ( !$wgExternalStores || !in_array( $proto, $wgExternalStores ) ) {
-                       return false; // protocol not enabled
-               }
-
-               $class = 'ExternalStore' . ucfirst( $proto );
-
-               // Any custom modules should be added to $wgAutoLoadClasses for on-demand loading
-               return class_exists( $class ) ? new $class( $params ) : false;
+       public static function getStoreObject( $proto, array $params = [] ) {
+               return MediaWikiServices::getInstance()
+                       ->getExternalStoreFactory()
+                       ->getStoreObject( $proto, $params );
        }
 
        /**
@@ -72,7 +67,7 @@ class ExternalStore {
         * @return string|bool The text stored or false on error
         * @throws MWException
         */
-       public static function fetchFromURL( $url, array $params = array() ) {
+       public static function fetchFromURL( $url, array $params = [] ) {
                $parts = explode( '://', $url, 2 );
                if ( count( $parts ) != 2 ) {
                        return false; // invalid URL
@@ -97,16 +92,17 @@ class ExternalStore {
         * @param array $urls The URLs of the text to get
         * @return array Map from url to its data.  Data is either string when found
         *     or false on failure.
+        * @throws MWException
         */
        public static function batchFetchFromURLs( array $urls ) {
-               $batches = array();
+               $batches = [];
                foreach ( $urls as $url ) {
                        $scheme = parse_url( $url, PHP_URL_SCHEME );
                        if ( $scheme ) {
                                $batches[$scheme][] = $url;
                        }
                }
-               $retval = array();
+               $retval = [];
                foreach ( $batches as $proto => $batchedUrls ) {
                        $store = self::getStoreObject( $proto );
                        if ( $store === false ) {
@@ -136,7 +132,7 @@ class ExternalStore {
         * @return string|bool The URL of the stored data item, or false on error
         * @throws MWException
         */
-       public static function insert( $url, $data, array $params = array() ) {
+       public static function insert( $url, $data, array $params = [] ) {
                $parts = explode( '://', $url, 2 );
                if ( count( $parts ) != 2 ) {
                        return false; // invalid URL
@@ -162,11 +158,11 @@ class ExternalStore {
         * provided by $wgDefaultExternalStore.
         *
         * @param string $data
-        * @param array $params Associative array of ExternalStoreMedium parameters
+        * @param array $params Map of ExternalStoreMedium::__construct context parameters
         * @return string|bool The URL of the stored data item, or false on error
         * @throws MWException
         */
-       public static function insertToDefault( $data, array $params = array() ) {
+       public static function insertToDefault( $data, array $params = [] ) {
                global $wgDefaultExternalStore;
 
                return self::insertWithFallback( (array)$wgDefaultExternalStore, $data, $params );
@@ -180,11 +176,11 @@ class ExternalStore {
         *
         * @param array $tryStores Refer to $wgDefaultExternalStore
         * @param string $data
-        * @param array $params Associative array of ExternalStoreMedium parameters
+        * @param array $params Map of ExternalStoreMedium::__construct context parameters
         * @return string|bool The URL of the stored data item, or false on error
         * @throws MWException
         */
-       public static function insertWithFallback( array $tryStores, $data, array $params = array() ) {
+       public static function insertWithFallback( array $tryStores, $data, array $params = [] ) {
                $error = false;
                while ( count( $tryStores ) > 0 ) {
                        $index = mt_rand( 0, count( $tryStores ) - 1 );
@@ -195,19 +191,25 @@ class ExternalStore {
                        if ( $store === false ) {
                                throw new MWException( "Invalid external storage protocol - $storeUrl" );
                        }
+
                        try {
-                               $url = $store->store( $path, $data ); // Try to save the object
+                               if ( $store->isReadOnly( $path ) ) {
+                                       $msg = 'read only';
+                               } else {
+                                       $url = $store->store( $path, $data );
+                                       if ( strlen( $url ) ) {
+                                               return $url; // a store accepted the write; done!
+                                       }
+                                       $msg = 'operation failed';
+                               }
                        } catch ( Exception $error ) {
-                               $url = false;
-                       }
-                       if ( strlen( $url ) ) {
-                               return $url; // Done!
-                       } else {
-                               unset( $tryStores[$index] ); // Don't try this one again!
-                               $tryStores = array_values( $tryStores ); // Must have consecutive keys
-                               wfDebugLog( 'ExternalStorage',
-                                       "Unable to store text to external storage $storeUrl" );
+                               $msg = 'caught exception';
                        }
+
+                       unset( $tryStores[$index] ); // Don't try this one again!
+                       $tryStores = array_values( $tryStores ); // Must have consecutive keys
+                       wfDebugLog( 'ExternalStorage',
+                               "Unable to store text to external storage $storeUrl ($msg)" );
                }
                // All stores failed
                if ( $error ) {
@@ -217,6 +219,29 @@ class ExternalStore {
                }
        }
 
+       /**
+        * @return bool Whether all the default insertion stores are marked as read-only
+        * @since 1.31
+        */
+       public static function defaultStoresAreReadOnly() {
+               global $wgDefaultExternalStore;
+
+               $tryStores = (array)$wgDefaultExternalStore;
+               if ( !$tryStores ) {
+                       return false; // no stores exists which can be "read only"
+               }
+
+               foreach ( $tryStores as $storeUrl ) {
+                       list( $proto, $path ) = explode( '://', $storeUrl, 2 );
+                       $store = self::getStoreObject( $proto, [] );
+                       if ( !$store->isReadOnly( $path ) ) {
+                               return false; // at least one store is not read-only
+                       }
+               }
+
+               return true; // all stores are read-only
+       }
+
        /**
         * @param string $data
         * @param string $wiki
@@ -224,6 +249,6 @@ class ExternalStore {
         * @throws MWException
         */
        public static function insertToForeignDefault( $data, $wiki ) {
-               return self::insertToDefault( $data, array( 'wiki' => $wiki ) );
+               return self::insertToDefault( $data, [ 'wiki' => $wiki ] );
        }
 }