Merge "Allow maintenance/cdb.php to look up keys with spaces in them."

[lhc/web/wiklou.git] / includes / filebackend / FileBackendMultiWrite.php

diff --git a/includes/filebackend/FileBackendMultiWrite.php b/includes/filebackend/FileBackendMultiWrite.php
index 1603d44..3841f2e 100644 (file)
--- a/includes/filebackend/FileBackendMultiWrite.php
+++ b/includes/filebackend/FileBackendMultiWrite.php
@@ -52,10 +52,12 @@ class FileBackendMultiWrite extends FileBackend {
 
        /** @var int Bitfield */
        protected $syncChecks = 0;
-
        /** @var string|bool */
        protected $autoResync = false;
 
+       /** @var bool */
+       protected $asyncWrites = false;
+
        /* Possible internal backend consistency checks */
        const CHECK_SIZE = 1;
        const CHECK_TIME = 2;
@@ -85,6 +87,9 @@ class FileBackendMultiWrite extends FileBackend {
         *                      Use "conservative" to limit resyncing to copying newer master
         *                      backend files over older (or non-existing) clone backend files.
         *                      Cases that cannot be handled will result in operation abortion.
+        *   - replication    : Set to 'async' to defer file operations on the non-master backends.
+        *                      This will apply such updates post-send for web requests. Note that
+        *                      any checks from "syncChecks" are still synchronous.
         *
         * @param array $config
         * @throws FileBackendError
@@ -97,6 +102,7 @@ class FileBackendMultiWrite extends FileBackend {
                $this->autoResync = isset( $config['autoResync'] )
                        ? $config['autoResync']
                        : false;
+               $this->asyncWrites = isset( $config['replication'] ) && $config['replication'] === 'async';
                // Construct backends here rather than via registration
                // to keep these backends hidden from outside the proxy.
                $namesUsed = array();
@@ -147,6 +153,7 @@ class FileBackendMultiWrite extends FileBackend {
                $mbe = $this->backends[$this->masterIndex]; // convenience
 
                // Try to lock those files for the scope of this function...
+               $scopeLock = null;
                if ( empty( $opts['nonLocking'] ) ) {
                        // Try to lock those files for the scope of this function...
                        /** @noinspection PhpUnusedLocalVariableInspection */
@@ -187,8 +194,19 @@ class FileBackendMultiWrite extends FileBackend {
                // If $ops only had one operation, this might avoid backend sync inconsistencies.
                if ( $masterStatus->isOK() && $masterStatus->successCount > 0 ) {
                        foreach ( $this->backends as $index => $backend ) {
-                               if ( $index !== $this->masterIndex ) { // not done already
-                                       $realOps = $this->substOpBatchPaths( $ops, $backend );
+                               if ( $index === $this->masterIndex ) {
+                                       continue; // done already
+                               }
+
+                               $realOps = $this->substOpBatchPaths( $ops, $backend );
+                               if ( $this->asyncWrites ) {
+                                       // Bind $scopeLock to the callback to preserve locks
+                                       DeferredUpdates::addCallableUpdate(
+                                               function() use ( $backend, $realOps, $opts, $scopeLock ) {
+                                                       $backend->doOperations( $realOps, $opts );
+                                               }
+                                       );
+                               } else {
                                        $status->merge( $backend->doOperations( $realOps, $opts ) );
                                }
                        }
@@ -457,8 +475,18 @@ class FileBackendMultiWrite extends FileBackend {
                $status->merge( $masterStatus );
                // Propagate the operations to the clone backends...
                foreach ( $this->backends as $index => $backend ) {
-                       if ( $index !== $this->masterIndex ) { // not done already
-                               $realOps = $this->substOpBatchPaths( $ops, $backend );
+                       if ( $index === $this->masterIndex ) {
+                               continue; // done already
+                       }
+
+                       $realOps = $this->substOpBatchPaths( $ops, $backend );
+                       if ( $this->asyncWrites ) {
+                               DeferredUpdates::addCallableUpdate(
+                                       function() use ( $backend, $realOps ) {
+                                               $backend->doQuickOperations( $realOps );
+                                       }
+                               );
+                       } else {
                                $status->merge( $backend->doQuickOperations( $realOps ) );
                        }
                }
@@ -473,40 +501,48 @@ class FileBackendMultiWrite extends FileBackend {
        }
 
        protected function doPrepare( array $params ) {
-               $status = Status::newGood();
-               foreach ( $this->backends as $index => $backend ) {
-                       $realParams = $this->substOpPaths( $params, $backend );
-                       $status->merge( $backend->doPrepare( $realParams ) );
-               }
-
-               return $status;
+               return $this->doDirectoryOp( 'prepare', $params );
        }
 
        protected function doSecure( array $params ) {
-               $status = Status::newGood();
-               foreach ( $this->backends as $index => $backend ) {
-                       $realParams = $this->substOpPaths( $params, $backend );
-                       $status->merge( $backend->doSecure( $realParams ) );
-               }
-
-               return $status;
+               return $this->doDirectoryOp( 'secure', $params );
        }
 
        protected function doPublish( array $params ) {
-               $status = Status::newGood();
-               foreach ( $this->backends as $index => $backend ) {
-                       $realParams = $this->substOpPaths( $params, $backend );
-                       $status->merge( $backend->doPublish( $realParams ) );
-               }
-
-               return $status;
+               return $this->doDirectoryOp( 'publish', $params );
        }
 
        protected function doClean( array $params ) {
+               return $this->doDirectoryOp( 'clean', $params );
+       }
+
+       /**
+        * @param string $method One of (doPrepare,doSecure,doPublish,doClean)
+        * @param array $params Method arguments
+        * @return Status
+        */
+       protected function doDirectoryOp( $method, array $params ) {
                $status = Status::newGood();
+
+               $realParams = $this->substOpPaths( $params, $this->backends[$this->masterIndex] );
+               $masterStatus = $this->backends[$this->masterIndex]->$method( $realParams );
+               $status->merge( $masterStatus );
+
                foreach ( $this->backends as $index => $backend ) {
+                       if ( $index === $this->masterIndex ) {
+                               continue; // already done
+                       }
+
                        $realParams = $this->substOpPaths( $params, $backend );
-                       $status->merge( $backend->doClean( $realParams ) );
+                       if ( $this->asyncWrites ) {
+                               DeferredUpdates::addCallableUpdate(
+                                       function() use ( $backend, $method, $realParams ) {
+                                               $backend->$method( $realParams );
+                                       }
+                               );
+                       } else {
+                               $status->merge( $backend->$method( $realParams ) );
+                       }
                }
 
                return $status;