rdbms: small cleanups to session loss handling

[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 8ccccc3..014c4af 100644 (file)
--- a/includes/libs/rdbms/database/Database.php
+++ b/includes/libs/rdbms/database/Database.php
@@ -1015,12 +1015,12 @@ abstract class Database implements IDatabase, IMaintainableDatabase, LoggerAware
                                $this->queryLogger->warning( $msg, $params +
                                        [ 'trace' => ( new RuntimeException() )->getTraceAsString() ] );
 
-                               if ( !$recoverable ) {
-                                       # Callers may catch the exception and continue to use the DB
-                                       $this->reportQueryError( $lastError, $lastErrno, $sql, $fname );
-                               } else {
+                               if ( $recoverable ) {
                                        # Should be safe to silently retry the query
                                        $ret = $this->doProfiledQuery( $sql, $commentedSql, $isNonTempWrite, $fname );
+                               } else {
+                                       # Callers may catch the exception and continue to use the DB
+                                       $this->reportQueryError( $lastError, $lastErrno, $sql, $fname );
                                }
                        } else {
                                $msg = __METHOD__ . ': lost connection to {dbserver} permanently';
@@ -1181,19 +1181,29 @@ abstract class Database implements IDatabase, IMaintainableDatabase, LoggerAware
         */
        private function handleSessionLoss() {
                $this->trxLevel = 0;
-               $this->trxIdleCallbacks = []; // T67263
-               $this->trxPreCommitCallbacks = []; // T67263
+               $this->trxIdleCallbacks = []; // T67263; transaction already lost
+               $this->trxPreCommitCallbacks = []; // T67263; transaction already lost
                $this->sessionTempTables = [];
                $this->namedLocksHeld = [];
+
+               // Note: if callback suppression is set then some *Callbacks arrays are not cleared here
+               $e = null;
                try {
                        // Handle callbacks in trxEndCallbacks
                        $this->runOnTransactionIdleCallbacks( self::TRIGGER_ROLLBACK );
+               } catch ( Exception $ex ) {
+                       // Already logged; move on...
+                       $e = $e ?: $ex;
+               }
+               try {
+                       // Handle callbacks in trxRecurringCallbacks
                        $this->runTransactionListenerCallbacks( self::TRIGGER_ROLLBACK );
-                       return null;
-               } catch ( Exception $e ) {
+               } catch ( Exception $ex ) {
                        // Already logged; move on...
-                       return $e;
+                       $e = $e ?: $ex;
                }
+
+               return $e;
        }
 
        /**
@@ -1854,10 +1864,48 @@ abstract class Database implements IDatabase, IMaintainableDatabase, LoggerAware
                return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')';
        }
 
+       public function buildSubstring( $input, $startPosition, $length = null ) {
+               $this->assertBuildSubstringParams( $startPosition, $length );
+               $functionBody = "$input FROM $startPosition";
+               if ( $length !== null ) {
+                       $functionBody .= " FOR $length";
+               }
+               return 'SUBSTRING(' . $functionBody . ')';
+       }
+
+       /**
+        * Check type and bounds for parameters to self::buildSubstring()
+        *
+        * All supported databases have substring functions that behave the same for
+        * positive $startPosition and non-negative $length, but behaviors differ when
+        * given 0 or negative $startPosition or negative $length. The simplest
+        * solution to that is to just forbid those values.
+        *
+        * @param int $startPosition
+        * @param int|null $length
+        * @since 1.31
+        */
+       protected function assertBuildSubstringParams( $startPosition, $length ) {
+               if ( !is_int( $startPosition ) || $startPosition <= 0 ) {
+                       throw new InvalidArgumentException(
+                               '$startPosition must be a positive integer'
+                       );
+               }
+               if ( !( is_int( $length ) && $length >= 0 || $length === null ) ) {
+                       throw new InvalidArgumentException(
+                               '$length must be null or an integer greater than or equal to 0'
+                       );
+               }
+       }
+
        public function buildStringCast( $field ) {
                return $field;
        }
 
+       public function buildIntegerCast( $field ) {
+               return 'CAST( ' . $field . ' AS INTEGER )';
+       }
+
        public function databasesAreIndependent() {
                return false;
        }