rdbms: Remove support for PostgreSQL < 9.2, and improve INSERT IGNORE for 9.5

[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 5bffcea..51d5466 100644 (file)
--- a/includes/libs/rdbms/database/Database.php
+++ b/includes/libs/rdbms/database/Database.php
@@ -658,6 +658,20 @@ abstract class Database implements IDatabase, IMaintainableDatabase, LoggerAware
                );
        }
 
+       /**
+        * @return string|null
+        */
+       final protected function getTransactionRoundId() {
+               // If transaction round participation is enabled, see if one is active
+               if ( $this->getFlag( self::DBO_TRX ) ) {
+                       $id = $this->getLBInfo( 'trxRoundId' );
+
+                       return is_string( $id ) ? $id : null;
+               }
+
+               return null;
+       }
+
        public function pendingWriteQueryDuration( $type = self::ESTIMATE_TOTAL ) {
                if ( !$this->trxLevel ) {
                        return false;
@@ -1131,15 +1145,10 @@ abstract class Database implements IDatabase, IMaintainableDatabase, LoggerAware
                                        # In the first case, the only options going forward are (a) ROLLBACK, or
                                        # (b) ROLLBACK TO SAVEPOINT (if one was set). If the later case, the only
                                        # option is ROLLBACK, since the snapshots would have been released.
-                                       if ( is_object( $tempIgnore ) ) {
-                                               // Ugly hack to know that savepoints are in use for postgres
-                                               // FIXME: remove this and make DatabasePostgres use ATOMIC_CANCELABLE
-                                       } else {
-                                               $this->trxStatus = self::STATUS_TRX_ERROR;
-                                               $this->trxStatusCause =
-                                                       $this->makeQueryException( $lastError, $lastErrno, $sql, $fname );
-                                               $tempIgnore = false; // cannot recover
-                                       }
+                                       $this->trxStatus = self::STATUS_TRX_ERROR;
+                                       $this->trxStatusCause =
+                                               $this->makeQueryException( $lastError, $lastErrno, $sql, $fname );
+                                       $tempIgnore = false; // cannot recover
                                } else {
                                        # Nothing prior was there to lose from the transaction
                                        $this->trxStatus = self::STATUS_TRX_OK;
@@ -1304,7 +1313,7 @@ abstract class Database implements IDatabase, IMaintainableDatabase, LoggerAware
        private function handleSessionLoss() {
                // Clean up tracking of session-level things...
                // https://dev.mysql.com/doc/refman/5.7/en/implicit-commit.html
-               // https://www.postgresql.org/docs/9.1/static/sql-createtable.html (ignoring ON COMMIT)
+               // https://www.postgresql.org/docs/9.2/static/sql-createtable.html (ignoring ON COMMIT)
                $this->sessionTempTables = [];
                // https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_get-lock
                // https://www.postgresql.org/docs/9.4/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKS
@@ -3180,6 +3189,12 @@ abstract class Database implements IDatabase, IMaintainableDatabase, LoggerAware
        }
 
        final public function onTransactionIdle( callable $callback, $fname = __METHOD__ ) {
+               if ( !$this->trxLevel && $this->getTransactionRoundId() ) {
+                       // Start an implicit transaction similar to how query() does
+                       $this->begin( __METHOD__, self::TRANSACTION_INTERNAL );
+                       $this->trxAutomatic = true;
+               }
+
                $this->trxIdleCallbacks[] = [ $callback, $fname ];
                if ( !$this->trxLevel ) {
                        $this->runOnTransactionIdleCallbacks( self::TRIGGER_IDLE );
@@ -3187,10 +3202,13 @@ abstract class Database implements IDatabase, IMaintainableDatabase, LoggerAware
        }
 
        final public function onTransactionPreCommitOrIdle( callable $callback, $fname = __METHOD__ ) {
-               if ( $this->trxLevel || $this->getFlag( self::DBO_TRX ) ) {
-                       // As long as DBO_TRX is set, writes will accumulate until the load balancer issues
-                       // an implicit commit of all peer databases. This is true even if a transaction has
-                       // not yet been triggered by writes; make sure $callback runs *after* any such writes.
+               if ( !$this->trxLevel && $this->getTransactionRoundId() ) {
+                       // Start an implicit transaction similar to how query() does
+                       $this->begin( __METHOD__, self::TRANSACTION_INTERNAL );
+                       $this->trxAutomatic = true;
+               }
+
+               if ( $this->trxLevel ) {
                        $this->trxPreCommitCallbacks[] = [ $callback, $fname ];
                } else {
                        // No transaction is active nor will start implicitly, so make one for this callback
@@ -3500,6 +3518,7 @@ abstract class Database implements IDatabase, IMaintainableDatabase, LoggerAware
                $this->trxWriteCallers = [];
                // First SELECT after BEGIN will establish the snapshot in REPEATABLE-READ.
                // Get an estimate of the replication lag before any such queries.
+               $this->trxReplicaLag = null; // clear cached value first
                $this->trxReplicaLag = $this->getApproximateLagStatus()['lag'];
                // T147697: make explicitTrxActive() return true until begin() finishes. This way, no
                // caller will think its OK to muck around with the transaction just because startAtomic()
@@ -3789,7 +3808,7 @@ abstract class Database implements IDatabase, IMaintainableDatabase, LoggerAware
        }
 
        public function getSessionLagStatus() {
-               return $this->getTransactionLagStatus() ?: $this->getApproximateLagStatus();
+               return $this->getRecordedTransactionLagStatus() ?: $this->getApproximateLagStatus();
        }
 
        /**
@@ -3800,11 +3819,13 @@ abstract class Database implements IDatabase, IMaintainableDatabase, LoggerAware
         * is this lag plus transaction duration. If they don't, it is still
         * safe to be pessimistic. This returns null if there is no transaction.
         *
+        * This returns null if the lag status for this transaction was not yet recorded.
+        *
         * @return array|null ('lag': seconds or false on error, 'since': UNIX timestamp of BEGIN)
         * @since 1.27
         */
-       final protected function getTransactionLagStatus() {
-               return $this->trxLevel
+       final protected function getRecordedTransactionLagStatus() {
+               return ( $this->trxLevel && $this->trxReplicaLag !== null )
                        ? [ 'lag' => $this->trxReplicaLag, 'since' => $this->trxTimestamp() ]
                        : null;
        }