rdbms: Add ATOMIC_CANCELABLE flag for micro-optimization

[lhc/web/wiklou.git] / includes / libs / rdbms / database / Database.php

diff --git a/includes/libs/rdbms/database/Database.php b/includes/libs/rdbms/database/Database.php
index c3e36da..118e714 100644 (file)
--- a/includes/libs/rdbms/database/Database.php
+++ b/includes/libs/rdbms/database/Database.php
@@ -2518,7 +2518,7 @@ abstract class Database implements IDatabase, IMaintainableDatabase, LoggerAware
                }
 
                try {
-                       $this->startAtomic( $fname );
+                       $this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
                        $affectedRowCount = 0;
                        foreach ( $rows as $row ) {
                                // Delete rows which collide with this one
@@ -2623,7 +2623,7 @@ abstract class Database implements IDatabase, IMaintainableDatabase, LoggerAware
 
                $affectedRowCount = 0;
                try {
-                       $this->startAtomic( $fname );
+                       $this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
                        # Update any existing conflicting row(s)
                        if ( $where !== false ) {
                                $ok = $this->update( $table, $set, $where, $fname );
@@ -2779,7 +2779,7 @@ abstract class Database implements IDatabase, IMaintainableDatabase, LoggerAware
 
                try {
                        $affectedRowCount = 0;
-                       $this->startAtomic( $fname );
+                       $this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
                        $rows = [];
                        $ok = true;
                        foreach ( $res as $row ) {
@@ -3095,7 +3095,7 @@ abstract class Database implements IDatabase, IMaintainableDatabase, LoggerAware
                        $this->trxPreCommitCallbacks[] = [ $callback, $fname ];
                } else {
                        // No transaction is active nor will start implicitly, so make one for this callback
-                       $this->startAtomic( __METHOD__ );
+                       $this->startAtomic( __METHOD__, self::ATOMIC_CANCELABLE );
                        try {
                                call_user_func( $callback );
                                $this->endAtomic( __METHOD__ );
@@ -3279,7 +3279,10 @@ abstract class Database implements IDatabase, IMaintainableDatabase, LoggerAware
                $this->query( 'ROLLBACK TO SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
        }
 
-       final public function startAtomic( $fname = __METHOD__ ) {
+       final public function startAtomic(
+               $fname = __METHOD__, $cancelable = self::ATOMIC_NOT_CANCELABLE
+       ) {
+               $savepointId = $cancelable === self::ATOMIC_CANCELABLE ? 'n/a' : null;
                if ( !$this->trxLevel ) {
                        $this->begin( $fname, self::TRANSACTION_INTERNAL );
                        // If DBO_TRX is set, a series of startAtomic/endAtomic pairs will result
@@ -3287,8 +3290,7 @@ abstract class Database implements IDatabase, IMaintainableDatabase, LoggerAware
                        if ( !$this->getFlag( self::DBO_TRX ) ) {
                                $this->trxAutomaticAtomic = true;
                        }
-                       $savepointId = null;
-               } else {
+               } elseif ( $cancelable === self::ATOMIC_CANCELABLE ) {
                        $savepointId = 'wikimedia_rdbms_atomic' . ++$this->trxAtomicCounter;
                        if ( strlen( $savepointId ) > 30 ) { // 30 == Oracle's identifier length limit (pre 12c)
                                $this->queryLogger->warning(
@@ -3316,9 +3318,9 @@ abstract class Database implements IDatabase, IMaintainableDatabase, LoggerAware
                        throw new DBUnexpectedError( $this, "Invalid atomic section ended (got $fname)." );
                }
 
-               if ( !$savepointId ) {
+               if ( !$this->trxAtomicLevels && $this->trxAutomaticAtomic ) {
                        $this->commit( $fname, self::FLUSHING_INTERNAL );
-               } else {
+               } elseif ( $savepointId && $savepointId !== 'n/a' ) {
                        $this->doReleaseSavepoint( $savepointId, $fname );
                }
        }
@@ -3333,10 +3335,13 @@ abstract class Database implements IDatabase, IMaintainableDatabase, LoggerAware
                if ( $savedFname !== $fname ) {
                        throw new DBUnexpectedError( $this, "Invalid atomic section ended (got $fname)." );
                }
-
                if ( !$savepointId ) {
+                       throw new DBUnexpectedError( $this, "Uncancelable atomic section canceled (got $fname)." );
+               }
+
+               if ( !$this->trxAtomicLevels && $this->trxAutomaticAtomic ) {
                        $this->rollback( $fname, self::FLUSHING_INTERNAL );
-               } else {
+               } elseif ( $savepointId !== 'n/a' ) {
                        $this->doRollbackToSavepoint( $savepointId, $fname );
                }
 
@@ -3344,7 +3349,7 @@ abstract class Database implements IDatabase, IMaintainableDatabase, LoggerAware
        }
 
        final public function doAtomicSection( $fname, callable $callback ) {
-               $this->startAtomic( $fname );
+               $this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
                try {
                        $res = call_user_func_array( $callback, [ $this, $fname ] );
                } catch ( Exception $e ) {