[FileBackend] Set ignore_user_abort() in file operations.

* This reduces the change of partial operations. WMF sites already
  set ignore_user_abort() in configuration, but this makes sure that
  it always happens during file changes.

Change-Id: I702c27fc3c19aca0cdd39b793a3250ead40bfe71

diff --git a/includes/filebackend/FileBackend.php b/includes/filebackend/FileBackend.php
index 0e61d0c..a3e1de3 100644 (file)
--- a/includes/filebackend/FileBackend.php
+++ b/includes/filebackend/FileBackend.php
@@ -314,6 +314,7 @@ abstract class FileBackend {
                if ( empty( $opts['force'] ) ) { // sanity
                        unset( $opts['nonLocking'] );
                }
+               $scope = $this->getScopedPHPBehaviorForOps(); // try to ignore client aborts
                return $this->doOperationsInternal( $ops, $opts );
        }
 
@@ -544,6 +545,7 @@ abstract class FileBackend {
                foreach ( $ops as &$op ) {
                        $op['overwrite'] = true; // avoids RTTs in key/value stores
                }
+               $scope = $this->getScopedPHPBehaviorForOps(); // try to ignore client aborts
                return $this->doQuickOperationsInternal( $ops );
        }
 
@@ -687,6 +689,7 @@ abstract class FileBackend {
                if ( empty( $params['bypassReadOnly'] ) && $this->isReadOnly() ) {
                        return Status::newFatal( 'backend-fail-readonly', $this->name, $this->readOnly );
                }
+               $scope = $this->getScopedPHPBehaviorForOps(); // try to ignore client aborts
                return $this->doPrepare( $params );
        }
 
@@ -714,6 +717,7 @@ abstract class FileBackend {
                if ( empty( $params['bypassReadOnly'] ) && $this->isReadOnly() ) {
                        return Status::newFatal( 'backend-fail-readonly', $this->name, $this->readOnly );
                }
+               $scope = $this->getScopedPHPBehaviorForOps(); // try to ignore client aborts
                return $this->doSecure( $params );
        }
 
@@ -742,6 +746,7 @@ abstract class FileBackend {
                if ( empty( $params['bypassReadOnly'] ) && $this->isReadOnly() ) {
                        return Status::newFatal( 'backend-fail-readonly', $this->name, $this->readOnly );
                }
+               $scope = $this->getScopedPHPBehaviorForOps(); // try to ignore client aborts
                return $this->doPublish( $params );
        }
 
@@ -766,6 +771,7 @@ abstract class FileBackend {
                if ( empty( $params['bypassReadOnly'] ) && $this->isReadOnly() ) {
                        return Status::newFatal( 'backend-fail-readonly', $this->name, $this->readOnly );
                }
+               $scope = $this->getScopedPHPBehaviorForOps(); // try to ignore client aborts
                return $this->doClean( $params );
        }
 
@@ -774,6 +780,21 @@ abstract class FileBackend {
         */
        abstract protected function doClean( array $params );
 
+       /**
+        * Enter file operation scope.
+        * This just makes PHP ignore user aborts/disconnects until the return
+        * value leaves scope. This returns null and does nothing in CLI mode.
+        *
+        * @return ScopedCallback|null
+        */
+       final protected function getScopedPHPBehaviorForOps() {
+               if ( php_sapi_name() != 'cli' ) { // http://bugs.php.net/bug.php?id=47540
+                       $old = ignore_user_abort( true ); // avoid half-finished operations
+                       return new ScopedCallback( function() use ( $old ) { ignore_user_abort( $old ); } );
+               }
+               return null;
+       }
+
        /**
         * Check if a file exists at a storage path in the backend.
         * This returns false if only a directory exists at the path.