From: Aaron Schulz <aschulz@wikimedia.org>
Date: Thu, 22 Feb 2018 08:48:42 +0000 (-0800)
Subject: Make LocalFile check early if the revision store is available
X-Git-Tag: 1.31.0-rc.0~530
X-Git-Url: https://git.heureux-cyclage.org/?p=lhc%2Fweb%2Fwiklou.git;a=commitdiff_plain;h=d9ba7cd0050d531c4f016fda285793568fa133c7

Make LocalFile check early if the revision store is available

This reduces the odds of having files without corresponding
wiki pages, given that the later is done in a deferred update.

Also made some documentation cleanups.

Bug: T187942
Change-Id: Iff516669f535713d37e0011e2d7ed285c667f1c5
---

diff --git a/includes/Storage/BlobStore.php b/includes/Storage/BlobStore.php
index 28caf3a412..8b1112b277 100644
--- a/includes/Storage/BlobStore.php
+++ b/includes/Storage/BlobStore.php
@@ -110,4 +110,10 @@ interface BlobStore {
 	 */
 	public function storeBlob( $data, $hints = [] );
 
+	/**
+	 * Check if the blob metadata or backing blob data store is read-only
+	 *
+	 * @return bool
+	 */
+	public function isReadOnly();
 }
diff --git a/includes/Storage/RevisionStore.php b/includes/Storage/RevisionStore.php
index 2992211630..db06afee7e 100644
--- a/includes/Storage/RevisionStore.php
+++ b/includes/Storage/RevisionStore.php
@@ -132,6 +132,13 @@ class RevisionStore
 		$this->logger = $logger;
 	}
 
+	/**
+	 * @return bool Whether the store is read-only
+	 */
+	public function isReadOnly() {
+		return $this->blobStore->isReadOnly();
+	}
+
 	/**
 	 * @return bool
 	 */
diff --git a/includes/Storage/SqlBlobStore.php b/includes/Storage/SqlBlobStore.php
index b890e5acaa..0ff7c13343 100644
--- a/includes/Storage/SqlBlobStore.php
+++ b/includes/Storage/SqlBlobStore.php
@@ -590,4 +590,11 @@ class SqlBlobStore implements IDBAccessObject, BlobStore {
 		return [ $schema, $id, $parameters ];
 	}
 
+	public function isReadOnly() {
+		if ( $this->useExternalStore && ExternalStore::defaultStoresAreReadOnly() ) {
+			return true;
+		}
+
+		return ( $this->getDBLoadBalancer()->getReadOnlyReason() !== false );
+	}
 }
diff --git a/includes/externalstore/ExternalStore.php b/includes/externalstore/ExternalStore.php
index 2ac6f7e82f..de7d1a4c48 100644
--- a/includes/externalstore/ExternalStore.php
+++ b/includes/externalstore/ExternalStore.php
@@ -158,7 +158,7 @@ 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
 	 */
@@ -176,7 +176,7 @@ 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
 	 */
@@ -219,6 +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
diff --git a/includes/externalstore/ExternalStoreMedium.php b/includes/externalstore/ExternalStoreMedium.php
index f1eaa93b9f..da7752b745 100644
--- a/includes/externalstore/ExternalStoreMedium.php
+++ b/includes/externalstore/ExternalStoreMedium.php
@@ -32,7 +32,8 @@ abstract class ExternalStoreMedium {
 	protected $params = [];
 
 	/**
-	 * @param array $params Options
+	 * @param array $params Usage context options:
+	 *   - wiki: the domain ID of the wiki this is being used for [optional]
 	 */
 	public function __construct( array $params = [] ) {
 		$this->params = $params;
diff --git a/includes/filerepo/file/LocalFile.php b/includes/filerepo/file/LocalFile.php
index 7cf2749f00..263e45b015 100644
--- a/includes/filerepo/file/LocalFile.php
+++ b/includes/filerepo/file/LocalFile.php
@@ -24,6 +24,7 @@
 use MediaWiki\Logger\LoggerFactory;
 use Wikimedia\Rdbms\Database;
 use Wikimedia\Rdbms\IDatabase;
+use MediaWiki\MediaWikiServices;
 
 /**
  * Class to represent a local file in the wiki's own database
@@ -1275,6 +1276,10 @@ class LocalFile extends File {
 	) {
 		if ( $this->getRepo()->getReadOnlyReason() !== false ) {
 			return $this->readOnlyFatalStatus();
+		} elseif ( MediaWikiServices::getInstance()->getRevisionStore()->isReadOnly() ) {
+			// Check this in advance to avoid writing to FileBackend and the file tables,
+			// only to fail on insert the revision due to the text store being unavailable.
+			return $this->readOnlyFatalStatus();
 		}
 
 		$srcPath = ( $src instanceof FSFile ) ? $src->getPath() : $src;