/** @var int No transaction is active */
const STATUS_TRX_NONE = 3;
+ /** @var int Writes to this temporary table do not affect lastDoneWrites() */
+ const TEMP_NORMAL = 1;
+ /** @var int Writes to this temporary table effect lastDoneWrites() */
+ const TEMP_PSEUDO_PERMANENT = 2;
+
/**
* @note exceptions for missing libraries/drivers should be thrown in initConnection()
* @param array $params Parameters passed from Database::factory()
final public function close() {
$exception = null; // error to throw after disconnecting
+ $wasOpen = $this->opened;
+ // This should mostly do nothing if the connection is already closed
if ( $this->conn ) {
// Roll back any dangling transaction first
if ( $this->trxLevel ) {
// Close the actual connection in the binding handle
$closed = $this->closeConnection();
- $this->conn = false;
} else {
$closed = true; // already closed; nothing to do
}
+ $this->conn = false;
$this->opened = false;
// Throw any unexpected errors after having disconnected
throw $exception;
}
- // Sanity check that no callbacks are dangling
- $fnames = $this->pendingWriteAndCallbackCallers();
- if ( $fnames ) {
- throw new RuntimeException(
- "Transaction callbacks are still pending:\n" . implode( ', ', $fnames )
- );
+ // Note that various subclasses call close() at the start of open(), which itself is
+ // called by replaceLostConnection(). In that case, just because onTransactionResolution()
+ // callbacks are pending does not mean that an exception should be thrown. Rather, they
+ // will be executed after the reconnection step.
+ if ( $wasOpen ) {
+ // Sanity check that no callbacks are dangling
+ $fnames = $this->pendingWriteAndCallbackCallers();
+ if ( $fnames ) {
+ throw new RuntimeException(
+ "Transaction callbacks are still pending:\n" . implode( ', ', $fnames )
+ );
+ }
}
return $closed;
}
/**
- * Make sure isOpen() returns true as a sanity check
+ * Make sure there is an open connection handle (alive or not) as a sanity check
+ *
+ * This guards against fatal errors to the binding handle not being defined
+ * in cases where open() was never called or close() was already called
*
* @throws DBUnexpectedError
*/
- protected function assertOpen() {
+ protected function assertHasConnectionHandle() {
if ( !$this->isOpen() ) {
throw new DBUnexpectedError( $this, "DB connection was already closed." );
}
}
+ /**
+ * Make sure that this server is not marked as a replica nor read-only as a sanity check
+ *
+ * @throws DBUnexpectedError
+ */
+ protected function assertIsWritableMaster() {
+ if ( $this->getLBInfo( 'replica' ) === true ) {
+ throw new DBUnexpectedError(
+ $this,
+ 'Write operations are not allowed on replica database connections.'
+ );
+ }
+ $reason = $this->getReadOnlyReason();
+ if ( $reason !== false ) {
+ throw new DBReadOnlyError( $this, "Database is read-only: $reason" );
+ }
+ }
+
/**
* Closes underlying database connection
* @since 1.20
/**
* @param string $sql A SQL query
- * @return bool Whether $sql is SQL for TEMPORARY table operation
+ * @param bool $pseudoPermanent Treat any table from CREATE TEMPORARY as pseudo-permanent
+ * @return int|null A self::TEMP_* constant for temp table operations or null otherwise
*/
- protected function registerTempTableOperation( $sql ) {
+ protected function registerTempTableWrite( $sql, $pseudoPermanent ) {
+ static $qt = '[`"\']?(\w+)[`"\']?'; // quoted table
+
if ( preg_match(
- '/^CREATE\s+TEMPORARY\s+TABLE\s+(?:IF\s+NOT\s+EXISTS\s+)?[`"\']?(\w+)[`"\']?/i',
+ '/^CREATE\s+TEMPORARY\s+TABLE\s+(?:IF\s+NOT\s+EXISTS\s+)?' . $qt . '/i',
$sql,
$matches
) ) {
- $this->sessionTempTables[$matches[1]] = 1;
+ $type = $pseudoPermanent ? self::TEMP_PSEUDO_PERMANENT : self::TEMP_NORMAL;
+ $this->sessionTempTables[$matches[1]] = $type;
- return true;
+ return $type;
} elseif ( preg_match(
- '/^DROP\s+(?:TEMPORARY\s+)?TABLE\s+(?:IF\s+EXISTS\s+)?[`"\']?(\w+)[`"\']?/i',
+ '/^DROP\s+(?:TEMPORARY\s+)?TABLE\s+(?:IF\s+EXISTS\s+)?' . $qt . '/i',
$sql,
$matches
) ) {
- $isTemp = isset( $this->sessionTempTables[$matches[1]] );
+ $type = $this->sessionTempTables[$matches[1]] ?? null;
unset( $this->sessionTempTables[$matches[1]] );
- return $isTemp;
+ return $type;
} elseif ( preg_match(
- '/^TRUNCATE\s+(?:TEMPORARY\s+)?TABLE\s+(?:IF\s+EXISTS\s+)?[`"\']?(\w+)[`"\']?/i',
+ '/^TRUNCATE\s+(?:TEMPORARY\s+)?TABLE\s+(?:IF\s+EXISTS\s+)?' . $qt . '/i',
$sql,
$matches
) ) {
- return isset( $this->sessionTempTables[$matches[1]] );
+ return $this->sessionTempTables[$matches[1]] ?? null;
} elseif ( preg_match(
- '/^(?:INSERT\s+(?:\w+\s+)?INTO|UPDATE|DELETE\s+FROM)\s+[`"\']?(\w+)[`"\']?/i',
+ '/^(?:(?:INSERT|REPLACE)\s+(?:\w+\s+)?INTO|UPDATE|DELETE\s+FROM)\s+' . $qt . '/i',
$sql,
$matches
) ) {
- return isset( $this->sessionTempTables[$matches[1]] );
+ return $this->sessionTempTables[$matches[1]] ?? null;
}
- return false;
+ return null;
}
- public function query( $sql, $fname = __METHOD__, $tempIgnore = false ) {
+ public function query( $sql, $fname = __METHOD__, $flags = 0 ) {
$this->assertTransactionStatus( $sql, $fname );
+ $this->assertHasConnectionHandle();
- # Avoid fatals if close() was called
- $this->assertOpen();
+ $flags = (int)$flags; // b/c; this field used to be a bool
+ $ignoreErrors = $this->hasFlags( $flags, self::QUERY_SILENCE_ERRORS );
+ $pseudoPermanent = $this->hasFlags( $flags, self::QUERY_PSEUDO_PERMANENT );
+ $priorTransaction = $this->trxLevel;
$priorWritesPending = $this->writesOrCallbacksPending();
$this->lastQuery = $sql;
- $isWrite = $this->isWriteQuery( $sql );
- if ( $isWrite ) {
- $isNonTempWrite = !$this->registerTempTableOperation( $sql );
- } else {
- $isNonTempWrite = false;
- }
-
- if ( $isWrite ) {
- if ( $this->getLBInfo( 'replica' ) === true ) {
- throw new DBError(
- $this,
- 'Write operations are not allowed on replica database connections.'
- );
- }
+ if ( $this->isWriteQuery( $sql ) ) {
# In theory, non-persistent writes are allowed in read-only mode, but due to things
# like https://bugs.mysql.com/bug.php?id=33669 that might not work anyway...
- $reason = $this->getReadOnlyReason();
- if ( $reason !== false ) {
- throw new DBReadOnlyError( $this, "Database is read-only: $reason" );
- }
- # Set a flag indicating that writes have been done
- $this->lastWriteTime = microtime( true );
+ $this->assertIsWritableMaster();
+ # Do not treat temporary table writes as "meaningful writes" that need committing.
+ # Profile them as reads. Integration tests can override this behavior via $flags.
+ $tableType = $this->registerTempTableWrite( $sql, $pseudoPermanent );
+ $isEffectiveWrite = ( $tableType !== self::TEMP_NORMAL );
+ } else {
+ $isEffectiveWrite = false;
}
# Add trace comment to the begin of the sql string, right after the operator.
# Or, for one-word queries (like "BEGIN" or COMMIT") add it to the end (T44598)
$commentedSql = preg_replace( '/\s|$/', " /* $fname {$this->agent} */ ", $sql, 1 );
- # Start implicit transactions that wrap the request if DBO_TRX is enabled
- if ( !$this->trxLevel && $this->getFlag( self::DBO_TRX )
- && $this->isTransactableQuery( $sql )
- ) {
- $this->begin( __METHOD__ . " ($fname)", self::TRANSACTION_INTERNAL );
- $this->trxAutomatic = true;
- }
-
- # Keep track of whether the transaction has write queries pending
- if ( $this->trxLevel && !$this->trxDoneWrites && $isWrite ) {
- $this->trxDoneWrites = true;
- $this->trxProfiler->transactionWritingIn(
- $this->server, $this->getDomainID(), $this->trxShortId );
- }
-
- if ( $this->getFlag( self::DBO_DEBUG ) ) {
- $this->queryLogger->debug( "{$this->getDomainID()} {$commentedSql}" );
- }
-
# Send the query to the server and fetch any corresponding errors
- $ret = $this->doProfiledQuery( $sql, $commentedSql, $isNonTempWrite, $fname );
+ $ret = $this->attemptQuery( $sql, $commentedSql, $isEffectiveWrite, $fname );
$lastError = $this->lastError();
$lastErrno = $this->lastErrno();
- # Try reconnecting if the connection was lost
+ $recoverableSR = false; // recoverable statement rollback?
+ $recoverableCL = false; // recoverable connection loss?
+
if ( $ret === false && $this->wasConnectionLoss() ) {
- # Check if any meaningful session state was lost
- $recoverable = $this->canRecoverFromDisconnect( $sql, $priorWritesPending );
+ # Check if no meaningful session state was lost
+ $recoverableCL = $this->canRecoverFromDisconnect( $sql, $priorWritesPending );
# Update session state tracking and try to restore the connection
$reconnected = $this->replaceLostConnection( __METHOD__ );
# Silently resend the query to the server if it is safe and possible
- if ( $reconnected && $recoverable ) {
- $ret = $this->doProfiledQuery( $sql, $commentedSql, $isNonTempWrite, $fname );
+ if ( $recoverableCL && $reconnected ) {
+ $ret = $this->attemptQuery( $sql, $commentedSql, $isEffectiveWrite, $fname );
$lastError = $this->lastError();
$lastErrno = $this->lastErrno();
if ( $ret === false && $this->wasConnectionLoss() ) {
# Query probably causes disconnects; reconnect and do not re-run it
$this->replaceLostConnection( __METHOD__ );
+ } else {
+ $recoverableCL = false; // connection does not need recovering
+ $recoverableSR = $this->wasKnownStatementRollbackError();
}
}
+ } else {
+ $recoverableSR = $this->wasKnownStatementRollbackError();
}
if ( $ret === false ) {
- if ( $this->trxLevel ) {
- if ( $this->wasKnownStatementRollbackError() ) {
+ if ( $priorTransaction ) {
+ if ( $recoverableSR ) {
# We're ignoring an error that caused just the current query to be aborted.
# But log the cause so we can log a deprecation notice if a caller actually
# does ignore it.
$this->trxStatusIgnoredCause = [ $lastError, $lastErrno, $fname ];
- } else {
+ } elseif ( !$recoverableCL ) {
# Either the query was aborted or all queries after BEGIN where aborted.
# 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
$this->trxStatus = self::STATUS_TRX_ERROR;
$this->trxStatusCause =
$this->getQueryExceptionAndLog( $lastError, $lastErrno, $sql, $fname );
- $tempIgnore = false; // cannot recover
+ $ignoreErrors = false; // cannot recover
$this->trxStatusIgnoredCause = null;
}
}
- $this->reportQueryError( $lastError, $lastErrno, $sql, $fname, $tempIgnore );
+ $this->reportQueryError( $lastError, $lastErrno, $sql, $fname, $ignoreErrors );
}
return $this->resultObject( $ret );
*
* @param string $sql Original SQL query
* @param string $commentedSql SQL query with debugging/trace comment
- * @param bool $isWrite Whether the query is a (non-temporary) write operation
+ * @param bool $isEffectiveWrite Whether the query is a (non-temporary table) write
* @param string $fname Name of the calling function
* @return bool|ResultWrapper True for a successful write query, ResultWrapper
* object for a successful read query, or false on failure
*/
- private function doProfiledQuery( $sql, $commentedSql, $isWrite, $fname ) {
+ private function attemptQuery( $sql, $commentedSql, $isEffectiveWrite, $fname ) {
+ $this->beginIfImplied( $sql, $fname );
+
+ # Keep track of whether the transaction has write queries pending
+ if ( $isEffectiveWrite ) {
+ $this->lastWriteTime = microtime( true );
+ if ( $this->trxLevel && !$this->trxDoneWrites ) {
+ $this->trxDoneWrites = true;
+ $this->trxProfiler->transactionWritingIn(
+ $this->server, $this->getDomainID(), $this->trxShortId );
+ }
+ }
+
+ if ( $this->getFlag( self::DBO_DEBUG ) ) {
+ $this->queryLogger->debug( "{$this->getDomainID()} {$commentedSql}" );
+ }
+
$isMaster = !is_null( $this->getLBInfo( 'master' ) );
# generalizeSQL() will probably cut down the query to reasonable
# logging size most of the time. The substr is really just a sanity check.
if ( $ret !== false ) {
$this->lastPing = $startTime;
- if ( $isWrite && $this->trxLevel ) {
+ if ( $isEffectiveWrite && $this->trxLevel ) {
$this->updateTrxWriteQueryTime( $sql, $queryRuntime, $this->affectedRows() );
$this->trxWriteCallers[] = $fname;
}
$this->trxProfiler->recordQueryCompletion(
$queryProf,
$startTime,
- $isWrite,
- $isWrite ? $this->affectedRows() : $this->numRows( $ret )
+ $isEffectiveWrite,
+ $isEffectiveWrite ? $this->affectedRows() : $this->numRows( $ret )
);
$this->queryLogger->debug( $sql, [
'method' => $fname,
return $ret;
}
+ /**
+ * Start an implicit transaction if DBO_TRX is enabled and no transaction is active
+ *
+ * @param string $sql
+ * @param string $fname
+ */
+ private function beginIfImplied( $sql, $fname ) {
+ if (
+ !$this->trxLevel &&
+ $this->getFlag( self::DBO_TRX ) &&
+ $this->isTransactableQuery( $sql )
+ ) {
+ $this->begin( __METHOD__ . " ($fname)", self::TRANSACTION_INTERNAL );
+ $this->trxAutomatic = true;
+ }
+ }
+
/**
* Update the estimated run-time of a query, not counting large row lock times
*
}
/**
- * Determine whether or not it is safe to retry queries after a database
- * connection is lost
+ * Determine whether it is safe to retry queries after a database connection is lost
*
* @param string $sql SQL query
* @param bool $priorWritesPending Whether there is a transaction open with
}
/**
- * Clean things up after session (and thus transaction) loss
+ * Clean things up after session (and thus transaction) loss before reconnect
*/
- private function handleSessionLoss() {
+ private function handleSessionLossPreconnect() {
// Clean up tracking of session-level things...
// https://dev.mysql.com/doc/refman/5.7/en/implicit-commit.html
// https://www.postgresql.org/docs/9.2/static/sql-createtable.html (ignoring ON COMMIT)
// https://www.postgresql.org/docs/9.4/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKS
$this->namedLocksHeld = [];
// Session loss implies transaction loss
- $this->handleTransactionLoss();
- }
-
- /**
- * Clean things up after transaction loss
- */
- private function handleTransactionLoss() {
$this->trxLevel = 0;
$this->trxAtomicCounter = 0;
$this->trxIdleCallbacks = []; // T67263; transaction already lost
$this->trxPreCommitCallbacks = []; // T67263; transaction already lost
+ // @note: leave trxRecurringCallbacks in place
+ if ( $this->trxDoneWrites ) {
+ $this->trxProfiler->transactionWritingOut(
+ $this->server,
+ $this->getDomainID(),
+ $this->trxShortId,
+ $this->pendingWriteQueryDuration( self::ESTIMATE_TOTAL ),
+ $this->trxWriteAffectedRows
+ );
+ }
+ }
+
+ /**
+ * Clean things up after session (and thus transaction) loss after reconnect
+ */
+ private function handleSessionLossPostconnect() {
try {
// Handle callbacks in trxEndCallbacks, e.g. onTransactionResolution().
// If callback suppression is set then the array will remain unhandled.
/**
* Report a query error. Log the error, and if neither the object ignore
- * flag nor the $tempIgnore flag is set, throw a DBQueryError.
+ * flag nor the $ignoreErrors flag is set, throw a DBQueryError.
*
* @param string $error
* @param int $errno
* @param string $sql
* @param string $fname
- * @param bool $tempIgnore
+ * @param bool $ignoreErrors
* @throws DBQueryError
*/
- public function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
- if ( $tempIgnore ) {
+ public function reportQueryError( $error, $errno, $sql, $fname, $ignoreErrors = false ) {
+ if ( $ignoreErrors ) {
$this->queryLogger->debug( "SQL ERROR (ignored): $error\n" );
} else {
$exception = $this->getQueryExceptionAndLog( $error, $errno, $sql, $fname );
}
/**
- * @return bool Whether it is safe to assume the given error only caused statement rollback
+ * @return bool Whether it is known that the last query error only caused statement rollback
* @note This is for backwards compatibility for callers catching DBError exceptions in
* order to ignore problems like duplicate key errors or foriegn key violations
* @since 1.31
throw new DBUnexpectedError( $this, $msg );
}
- // Avoid fatals if close() was called
- $this->assertOpen();
+ $this->assertHasConnectionHandle();
$this->doBegin( $fname );
$this->trxStatus = self::STATUS_TRX_OK;
}
}
- // Avoid fatals if close() was called
- $this->assertOpen();
+ $this->assertHasConnectionHandle();
$this->runOnTransactionPreCommitCallbacks();
}
if ( $trxActive ) {
- // Avoid fatals if close() was called
- $this->assertOpen();
+ $this->assertHasConnectionHandle();
$this->doRollback( $fname );
$this->trxStatus = self::STATUS_TRX_NONE;
$this->closeConnection();
$this->opened = false;
$this->conn = false;
+
+ $this->handleSessionLossPreconnect();
+
try {
$this->open(
$this->server,
);
}
- $this->handleSessionLoss();
+ $this->handleSessionLossPostconnect();
return $ok;
}
$this->indexAliases = $aliases;
}
+ /**
+ * @param int $field
+ * @param int $flags
+ * @return bool
+ */
+ protected function hasFlags( $field, $flags ) {
+ return ( ( $field & $flags ) === $flags );
+ }
+
/**
* Get the underlying binding connection handle
*
$this->opened = false;
$this->conn = false;
$this->trxEndCallbacks = []; // don't copy
- $this->handleSessionLoss(); // no trx or locks anymore
+ $this->handleSessionLossPreconnect(); // no trx or locks anymore
$this->open(
$this->server,
$this->user,