[FileBackend] Improved stat caching by reducing cache salting.

Change-Id: Ieec6515fcf1c2f147b52eceec1f6c55a681115c5

diff --git a/includes/filebackend/FileBackendStore.php b/includes/filebackend/FileBackendStore.php
index 9bec145..d53f7b3 100644 (file)
--- a/includes/filebackend/FileBackendStore.php
+++ b/includes/filebackend/FileBackendStore.php
@@ -105,7 +105,9 @@ abstract class FileBackendStore extends FileBackend {
                } else {
                        $status = $this->doCreateInternal( $params );
                        $this->clearCache( array( $params['dst'] ) );
-                       $this->deleteFileCache( $params['dst'] ); // persistent cache
+                       if ( !empty( $params['overwrite'] ) ) { // file possibly mutated
+                               $this->deleteFileCache( $params['dst'] ); // persistent cache
+                       }
                }
                wfProfileOut( __METHOD__ . '-' . $this->name );
                wfProfileOut( __METHOD__ );
@@ -141,7 +143,9 @@ abstract class FileBackendStore extends FileBackend {
                } else {
                        $status = $this->doStoreInternal( $params );
                        $this->clearCache( array( $params['dst'] ) );
-                       $this->deleteFileCache( $params['dst'] ); // persistent cache
+                       if ( !empty( $params['overwrite'] ) ) { // file possibly mutated
+                               $this->deleteFileCache( $params['dst'] ); // persistent cache
+                       }
                }
                wfProfileOut( __METHOD__ . '-' . $this->name );
                wfProfileOut( __METHOD__ );
@@ -173,7 +177,9 @@ abstract class FileBackendStore extends FileBackend {
                wfProfileIn( __METHOD__ . '-' . $this->name );
                $status = $this->doCopyInternal( $params );
                $this->clearCache( array( $params['dst'] ) );
-               $this->deleteFileCache( $params['dst'] ); // persistent cache
+               if ( !empty( $params['overwrite'] ) ) { // file possibly mutated
+                       $this->deleteFileCache( $params['dst'] ); // persistent cache
+               }
                wfProfileOut( __METHOD__ . '-' . $this->name );
                wfProfileOut( __METHOD__ );
                return $status;
@@ -235,7 +241,9 @@ abstract class FileBackendStore extends FileBackend {
                $status = $this->doMoveInternal( $params );
                $this->clearCache( array( $params['src'], $params['dst'] ) );
                $this->deleteFileCache( $params['src'] ); // persistent cache
-               $this->deleteFileCache( $params['dst'] ); // persistent cache
+               if ( !empty( $params['overwrite'] ) ) { // file possibly mutated
+                       $this->deleteFileCache( $params['dst'] ); // persistent cache
+               }
                wfProfileOut( __METHOD__ . '-' . $this->name );
                wfProfileOut( __METHOD__ );
                return $status;
@@ -1460,7 +1468,9 @@ abstract class FileBackendStore extends FileBackend {
        }
 
        /**
-        * Set the cached stat info for a file path
+        * Set the cached stat info for a file path.
+        * Negatives (404s) are not cached. By not caching negatives, we can skip cache
+        * salting for the case when a file is created at a path were there was none before.
         *
         * @param $path string Storage path
         * @param $val mixed Information to cache