Add LBFactory::beginMasterChanges() for doing DBO_TRX rounds

This is in intended to replace the DataUpdate transaction round logic.
It could also be useful for doing transaction rounds in maintenance
scripts.

Also renamed $db => $conn in a few LB methods for consistency.

Change-Id: If21c2ba5e8bac48c250b96137279e7edaa8289f7

diff --git a/includes/db/DBConnRef.php b/includes/db/DBConnRef.php
index e5b6d05..790a073 100644 (file)
--- a/includes/db/DBConnRef.php
+++ b/includes/db/DBConnRef.php
@@ -115,11 +115,15 @@ class DBConnRef implements IDatabase {
                return $this->__call( __FUNCTION__, func_get_args() );
        }
 
-       public function setFlag( $flag ) {
+       public function setFlag( $flag, $remember = self::REMEMBER_NOTHING ) {
                return $this->__call( __FUNCTION__, func_get_args() );
        }
 
-       public function clearFlag( $flag ) {
+       public function clearFlag( $flag, $remember = self::REMEMBER_NOTHING ) {
+               return $this->__call( __FUNCTION__, func_get_args() );
+       }
+
+       public function restoreFlags( $state = self::RESTORE_PRIOR ) {
                return $this->__call( __FUNCTION__, func_get_args() );
        }
 

diff --git a/includes/db/Database.php b/includes/db/Database.php
index 6ddc9f7..59c1207 100644 (file)
--- a/includes/db/Database.php
+++ b/includes/db/Database.php
@@ -198,6 +198,9 @@ abstract class DatabaseBase implements IDatabase {
        /** @var float UNIX timestamp */
        protected $lastPing = 0.0;
 
+       /** @var int[] Prior mFlags values */
+       private $priorFlags = [];
+
        /** @var TransactionProfiler */
        protected $trxProfiler;
 
@@ -430,14 +433,33 @@ abstract class DatabaseBase implements IDatabase {
                return $this->mOpened;
        }
 
-       public function setFlag( $flag ) {
+       public function setFlag( $flag, $remember = self::REMEMBER_NOTHING ) {
+               if ( $remember === self::REMEMBER_PRIOR ) {
+                       array_push( $this->priorFlags, $this->mFlags );
+               }
                $this->mFlags |= $flag;
        }
 
-       public function clearFlag( $flag ) {
+       public function clearFlag( $flag, $remember = self::REMEMBER_NOTHING ) {
+               if ( $remember === self::REMEMBER_PRIOR ) {
+                       array_push( $this->priorFlags, $this->mFlags );
+               }
                $this->mFlags &= ~$flag;
        }
 
+       public function restoreFlags( $state = self::RESTORE_PRIOR ) {
+               if ( !$this->priorFlags ) {
+                       return;
+               }
+
+               if ( $state === self::RESTORE_INITIAL ) {
+                       $this->mFlags = reset( $this->priorFlags );
+                       $this->priorFlags = [];
+               } else {
+                       $this->mFlags = array_pop( $this->priorFlags );
+               }
+       }
+
        public function getFlag( $flag ) {
                return !!( $this->mFlags & $flag );
        }

diff --git a/includes/db/IDatabase.php b/includes/db/IDatabase.php
index 25100db..1aa931e 100644 (file)
--- a/includes/db/IDatabase.php
+++ b/includes/db/IDatabase.php
@@ -50,6 +50,15 @@ interface IDatabase {
        /** @var string Transaction operation comes from the database class internally */
        const FLUSHING_INTERNAL = 'flush';
 
+       /** @var string No not remember the prior flags */
+       const REMEMBER_NOTHING = '';
+       /** @var string Remember the prior flags */
+       const REMEMBER_PRIOR = 'remember';
+       /** @var string Restore to the prior flag state */
+       const RESTORE_PRIOR = 'prior';
+       /** @var string Restore to the initial flag state */
+       const RESTORE_INITIAL = 'initial';
+
        /**
         * A string describing the current software version, and possibly
         * other details in a user-friendly way. Will be listed on Special:Version, etc.
@@ -230,8 +239,9 @@ interface IDatabase {
         *   - DBO_DEFAULT: automatically sets DBO_TRX if not in command line mode
         *       and removes it in command line mode
         *   - DBO_PERSISTENT: use persistant database connection
+        * @param string $remember IDatabase::REMEMBER_* constant [default: REMEMBER_NOTHING]
         */
-       public function setFlag( $flag );
+       public function setFlag( $flag, $remember = self::REMEMBER_NOTHING );
 
        /**
         * Clear a flag for this connection
@@ -243,8 +253,17 @@ interface IDatabase {
         *   - DBO_DEFAULT: automatically sets DBO_TRX if not in command line mode
         *       and removes it in command line mode
         *   - DBO_PERSISTENT: use persistant database connection
+        * @param string $remember IDatabase::REMEMBER_* constant [default: REMEMBER_NOTHING]
+        */
+       public function clearFlag( $flag, $remember = self::REMEMBER_NOTHING );
+
+       /**
+        * Restore the flags to their prior state before the last setFlag/clearFlag call
+        *
+        * @param string $state IDatabase::RESTORE_* constant. [default: RESTORE_PRIOR]
+        * @since 1.28
         */
-       public function clearFlag( $flag );
+       public function restoreFlags( $state = self::RESTORE_PRIOR );
 
        /**
         * Returns a boolean whether the flag $flag is set for this connection

diff --git a/includes/db/loadbalancer/LBFactory.php b/includes/db/loadbalancer/LBFactory.php
index b320544..f560cf1 100644 (file)
--- a/includes/db/loadbalancer/LBFactory.php
+++ b/includes/db/loadbalancer/LBFactory.php
@@ -216,6 +216,22 @@ abstract class LBFactory implements DestructibleService {
                );
        }
 
+       /**
+        * Flush any master transaction snapshots and set DBO_TRX (if DBO_DEFAULT is set)
+        *
+        * The DBO_TRX setting will be reverted to the default in each of these methods:
+        *   - commitMasterChanges()
+        *   - rollbackMasterChanges()
+        *   - commitAll()
+        * This allows for custom transaction rounds from any outer transaction scope.
+        *
+        * @param string $fname
+        * @since 1.28
+        */
+       public function beginMasterChanges( $fname = __METHOD__ ) {
+               $this->forEachLBCallMethod( 'beginMasterChanges', [ $fname ] );
+       }
+
        /**
         * Commit on all connections. Done for two reasons:
         * 1. To commit changes to the masters.

diff --git a/includes/db/loadbalancer/LoadBalancer.php b/includes/db/loadbalancer/LoadBalancer.php
index 13a0879..65cd3b3 100644 (file)
--- a/includes/db/loadbalancer/LoadBalancer.php
+++ b/includes/db/loadbalancer/LoadBalancer.php
@@ -1062,7 +1062,7 @@ class LoadBalancer {
         */
        public function commitAll( $fname = __METHOD__ ) {
                $this->forEachOpenConnection( function ( DatabaseBase $conn ) use ( $fname ) {
-                       $conn->commit( $fname, IDatabase::FLUSHING_ALL_PEERS );
+                       $conn->commit( $fname, $conn::FLUSHING_ALL_PEERS );
                } );
        }
 
@@ -1119,6 +1119,42 @@ class LoadBalancer {
                } );
        }
 
+       /**
+        * Flush any master transaction snapshots and set DBO_TRX (if DBO_DEFAULT is set)
+        *
+        * The DBO_TRX setting will be reverted to the default in each of these methods:
+        *   - commitMasterChanges()
+        *   - rollbackMasterChanges()
+        *   - commitAll()
+        * This allows for custom transaction rounds from any outer transaction scope.
+        *
+        * @param string $fname
+        * @since 1.28
+        */
+       public function beginMasterChanges( $fname = __METHOD__ ) {
+               $this->forEachOpenMasterConnection( function ( DatabaseBase $conn ) use ( $fname ) {
+                       if ( $conn->writesOrCallbacksPending() ) {
+                               throw new DBTransactionError(
+                                       $conn,
+                                       "Transaction with pending writes still active."
+                               );
+                       } elseif ( $conn->trxLevel() ) {
+                               $conn->commit( $fname, $conn::FLUSHING_ALL_PEERS );
+                       }
+                       if ( $conn->getFlag( DBO_DEFAULT ) ) {
+                               // DBO_TRX is controlled entirely by CLI mode presence with DBO_DEFAULT.
+                               // Force DBO_TRX even in CLI mode since a commit round is expected soon.
+                               $conn->setFlag( DBO_TRX, $conn::REMEMBER_PRIOR );
+                               $conn->onTransactionResolution( function () use ( $conn ) {
+                                       $conn->restoreFlags( $conn::RESTORE_PRIOR );
+                               } );
+                       } else {
+                               // Config has explicitly requested DBO_TRX be either on or off; respect that.
+                               // This is useful for things like blob stores which use auto-commit mode.
+                       }
+               } );
+       }
+
        /**
         * Issue COMMIT on all master connections where writes where done
         * @param string $fname Caller name
@@ -1126,7 +1162,7 @@ class LoadBalancer {
        public function commitMasterChanges( $fname = __METHOD__ ) {
                $this->forEachOpenMasterConnection( function ( DatabaseBase $conn ) use ( $fname ) {
                        if ( $conn->writesOrCallbacksPending() ) {
-                               $conn->commit( $fname, IDatabase::FLUSHING_ALL_PEERS );
+                               $conn->commit( $fname, $conn::FLUSHING_ALL_PEERS );
                        }
                } );
        }
@@ -1138,10 +1174,10 @@ class LoadBalancer {
         */
        public function runMasterPostCommitCallbacks() {
                $e = null; // first exception
-               $this->forEachOpenMasterConnection( function ( DatabaseBase $db ) use ( &$e ) {
-                       $db->setPostCommitCallbackSupression( false );
+               $this->forEachOpenMasterConnection( function ( DatabaseBase $conn ) use ( &$e ) {
+                       $conn->setPostCommitCallbackSupression( false );
                        try {
-                               $db->runOnTransactionIdleCallbacks( IDatabase::TRIGGER_COMMIT );
+                               $conn->runOnTransactionIdleCallbacks( $conn::TRIGGER_COMMIT );
                        } catch ( Exception $ex ) {
                                $e = $e ?: $ex;
                        }
@@ -1168,7 +1204,7 @@ class LoadBalancer {
                        foreach ( $conns2[$masterIndex] as $conn ) {
                                if ( $conn->trxLevel() && $conn->writesOrCallbacksPending() ) {
                                        try {
-                                               $conn->rollback( $fname, IDatabase::FLUSHING_ALL_PEERS );
+                                               $conn->rollback( $fname, $conn::FLUSHING_ALL_PEERS );
                                        } catch ( DBError $e ) {
                                                MWExceptionHandler::logException( $e );
                                                $failedServers[] = $conn->getServer();

diff --git a/tests/phpunit/includes/db/DatabaseTest.php b/tests/phpunit/includes/db/DatabaseTest.php
index 7e55a73..0751409 100644 (file)
--- a/tests/phpunit/includes/db/DatabaseTest.php
+++ b/tests/phpunit/includes/db/DatabaseTest.php
@@ -23,6 +23,7 @@ class DatabaseTest extends MediaWikiTestCase {
                        $this->dropFunctions();
                        $this->functionTest = false;
                }
+               $this->db->restoreFlags( IDatabase::RESTORE_INITIAL );
        }
        /**
         * @covers DatabaseBase::dropTable
@@ -323,4 +324,42 @@ class DatabaseTest extends MediaWikiTestCase {
                $db->begin( __METHOD__ );
                throw new RunTimeException( "Uh oh!" );
        }
+
+       /**
+        * @covers DatabaseBase::getFlag(
+        * @covers DatabaseBase::setFlag()
+        * @covers DatabaseBase::restoreFlags()
+        */
+       public function testFlagSetting() {
+               $db = $this->db;
+               $origTrx = $db->getFlag( DBO_TRX );
+               $origSsl = $db->getFlag( DBO_SSL );
+
+               if ( $origTrx ) {
+                       $db->clearFlag( DBO_TRX, $db::REMEMBER_PRIOR );
+               } else {
+                       $db->setFlag( DBO_TRX, $db::REMEMBER_PRIOR );
+               }
+               $this->assertEquals( !$origTrx, $db->getFlag( DBO_TRX ) );
+
+               if ( $origSsl ) {
+                       $db->clearFlag( DBO_SSL, $db::REMEMBER_PRIOR );
+               } else {
+                       $db->setFlag( DBO_SSL, $db::REMEMBER_PRIOR );
+               }
+               $this->assertEquals( !$origSsl, $db->getFlag( DBO_SSL ) );
+
+               $db2 = clone $db;
+               $db2->restoreFlags( $db::RESTORE_INITIAL );
+               $this->assertEquals( $origTrx, $db2->getFlag( DBO_TRX ) );
+               $this->assertEquals( $origSsl, $db2->getFlag( DBO_SSL ) );
+
+               $db->restoreFlags();
+               $this->assertEquals( $origSsl, $db->getFlag( DBO_SSL ) );
+               $this->assertEquals( !$origTrx, $db->getFlag( DBO_TRX ) );
+
+               $db->restoreFlags();
+               $this->assertEquals( $origSsl, $db->getFlag( DBO_SSL ) );
+               $this->assertEquals( $origTrx, $db->getFlag( DBO_TRX ) );
+       }
 }

diff --git a/tests/phpunit/includes/installer/DatabaseUpdaterTest.php b/tests/phpunit/includes/installer/DatabaseUpdaterTest.php
index 09d31fc..81c9faf 100644 (file)
--- a/tests/phpunit/includes/installer/DatabaseUpdaterTest.php
+++ b/tests/phpunit/includes/installer/DatabaseUpdaterTest.php
@@ -23,10 +23,10 @@ class FakeDatabase extends DatabaseBase {
        function __construct() {
        }
 
-       function clearFlag( $arg ) {
+       function clearFlag( $arg, $remember = self::REMEMBER_NOTHING ) {
        }
 
-       function setFlag( $arg ) {
+       function setFlag( $arg, $remember = self::REMEMBER_NOTHING ) {
        }
 
        public function insert( $table, $a, $fname = __METHOD__, $options = [] ) {