abstract class DatabaseBase implements IDatabase {
/** Number of times to re-try an operation in case of deadlock */
const DEADLOCK_TRIES = 4;
-
/** Minimum time to wait before retry, in microseconds */
const DEADLOCK_DELAY_MIN = 500000;
-
/** Maximum time to wait before retry */
const DEADLOCK_DELAY_MAX = 1500000;
+ /** How long before it is worth doing a dummy query to test the connection */
+ const PING_TTL = 1.0;
+
+ /** @var string SQL query */
protected $mLastQuery = '';
+ /** @var bool */
protected $mDoneWrites = false;
+ /** @var string|bool */
protected $mPHPError = false;
-
- protected $mServer, $mUser, $mPassword, $mDBname;
+ /** @var string */
+ protected $mServer;
+ /** @var string */
+ protected $mUser;
+ /** @var string */
+ protected $mPassword;
+ /** @var string */
+ protected $mDBname;
/** @var BagOStuff APC cache */
protected $srvCache;
/** @var resource Database connection */
protected $mConn = null;
+ /** @var bool */
protected $mOpened = false;
/** @var array[] List of (callable, method name) */
/** @var bool Whether to suppress triggering of post-commit callbacks */
protected $suppressPostCommitCallbacks = false;
+ /** @var string */
protected $mTablePrefix;
+ /** @var string */
protected $mSchema;
+ /** @var integer */
protected $mFlags;
+ /** @var bool */
protected $mForeign;
+ /** @var array */
protected $mLBInfo = [];
+ /** @var bool|null */
protected $mDefaultBigSelects = null;
+ /** @var array|bool */
protected $mSchemaVars = false;
/** @var array */
protected $mSessionVars = [];
-
+ /** @var array|null */
protected $preparedArgs;
-
+ /** @var string|bool|null Stashed value of html_errors INI setting */
protected $htmlErrors;
-
+ /** @var string */
protected $delimiter = ';';
/**
*/
protected $allViews = null;
+ /** @var float UNIX timestamp */
+ protected $lastPing = 0.0;
+
+ /** @var int[] Prior mFlags values */
+ private $priorFlags = [];
+
/** @var TransactionProfiler */
protected $trxProfiler;
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 );
}
$priorWritesPending = $this->writesOrCallbacksPending();
$this->mLastQuery = $sql;
- $isWriteQuery = $this->isWriteQuery( $sql );
- if ( $isWriteQuery ) {
+ $isWrite = $this->isWriteQuery( $sql );
+ if ( $isWrite ) {
$reason = $this->getReadOnlyReason();
if ( $reason !== false ) {
throw new DBReadOnlyError( $this, "Database is read-only: $reason" );
if ( !$this->mTrxLevel && $this->getFlag( DBO_TRX )
&& $this->isTransactableQuery( $sql )
) {
- $this->begin( __METHOD__ . " ($fname)" );
+ $this->begin( __METHOD__ . " ($fname)", self::TRANSACTION_INTERNAL );
$this->mTrxAutomatic = true;
}
# Keep track of whether the transaction has write queries pending
- if ( $this->mTrxLevel && !$this->mTrxDoneWrites && $isWriteQuery ) {
+ if ( $this->mTrxLevel && !$this->mTrxDoneWrites && $isWrite ) {
$this->mTrxDoneWrites = true;
$this->getTransactionProfiler()->transactionWritingIn(
$this->mServer, $this->mDBname, $this->mTrxShortId );
}
- $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 ( $isMaster ) {
- $queryProf = 'query-m: ' . substr( DatabaseBase::generalizeSQL( $sql ), 0, 255 );
- $totalProf = 'DatabaseBase::query-master';
- } else {
- $queryProf = 'query: ' . substr( DatabaseBase::generalizeSQL( $sql ), 0, 255 );
- $totalProf = 'DatabaseBase::query';
- }
- # Include query transaction state
- $queryProf .= $this->mTrxShortId ? " [TRX#{$this->mTrxShortId}]" : "";
-
- $profiler = Profiler::instance();
- if ( !$profiler instanceof ProfilerStub ) {
- $totalProfSection = $profiler->scopedProfileIn( $totalProf );
- $queryProfSection = $profiler->scopedProfileIn( $queryProf );
- }
-
if ( $this->debug() ) {
wfDebugLog( 'queries', sprintf( "%s: %s", $this->mDBname, $commentedSql ) );
}
- $queryId = MWDebug::query( $sql, $fname, $isMaster );
-
# Avoid fatals if close() was called
$this->assertOpen();
- # Do the query and handle errors
- $startTime = microtime( true );
- $ret = $this->doQuery( $commentedSql );
- $queryRuntime = microtime( true ) - $startTime;
- # Log the query time and feed it into the DB trx profiler
- $this->getTransactionProfiler()->recordQueryCompletion(
- $queryProf, $startTime, $isWriteQuery, $this->affectedRows() );
-
- MWDebug::queryTime( $queryId );
+ # Send the query to the server
+ $ret = $this->doProfiledQuery( $sql, $commentedSql, $isWrite, $fname );
# Try reconnecting if the connection was lost
if ( false === $ret && $this->wasErrorReissuable() ) {
$this->reportQueryError( $lastError, $lastErrno, $sql, $fname );
} else {
# Should be safe to silently retry the query
- $startTime = microtime( true );
- $ret = $this->doQuery( $commentedSql );
- $queryRuntime = microtime( true ) - $startTime;
- # Log the query time and feed it into the DB trx profiler
- $this->getTransactionProfiler()->recordQueryCompletion(
- $queryProf, $startTime, $isWriteQuery, $this->affectedRows() );
+ $ret = $this->doProfiledQuery( $sql, $commentedSql, $isWrite, $fname );
}
} else {
wfDebug( "Failed\n" );
$res = $this->resultObject( $ret );
- // Destroy profile sections in the opposite order to their creation
- ScopedCallback::consume( $queryProfSection );
- ScopedCallback::consume( $totalProfSection );
+ return $res;
+ }
+
+ private function doProfiledQuery( $sql, $commentedSql, $isWrite, $fname ) {
+ $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 ( $isMaster ) {
+ $queryProf = 'query-m: ' . substr( DatabaseBase::generalizeSQL( $sql ), 0, 255 );
+ } else {
+ $queryProf = 'query: ' . substr( DatabaseBase::generalizeSQL( $sql ), 0, 255 );
+ }
- if ( $isWriteQuery && $this->mTrxLevel ) {
- $this->mTrxWriteDuration += $queryRuntime;
- $this->mTrxWriteCallers[] = $fname;
+ # Include query transaction state
+ $queryProf .= $this->mTrxShortId ? " [TRX#{$this->mTrxShortId}]" : "";
+
+ $profiler = Profiler::instance();
+ if ( !( $profiler instanceof ProfilerStub ) ) {
+ $queryProfSection = $profiler->scopedProfileIn( $queryProf );
}
- return $res;
+ $startTime = microtime( true );
+ $ret = $this->doQuery( $commentedSql );
+ $queryRuntime = microtime( true ) - $startTime;
+
+ unset( $queryProfSection ); // profile out (if set)
+
+ if ( $ret !== false ) {
+ $this->lastPing = $startTime;
+ if ( $isWrite && $this->mTrxLevel ) {
+ $this->mTrxWriteDuration += $queryRuntime;
+ $this->mTrxWriteCallers[] = $fname;
+ }
+ }
+
+ $this->getTransactionProfiler()->recordQueryCompletion(
+ $queryProf, $startTime, $isWrite, $this->affectedRows()
+ );
+ MWDebug::query( $sql, $fname, $isMaster, $queryRuntime );
+
+ return $ret;
}
private function canRecoverFromDisconnect( $sql, $priorWritesPending ) {
$useTrx = !$this->mTrxLevel;
if ( $useTrx ) {
- $this->begin( $fname );
+ $this->begin( $fname, self::TRANSACTION_INTERNAL );
}
try {
# Update any existing conflicting row(s)
throw $e;
}
if ( $useTrx ) {
- $this->commit( $fname );
+ $this->commit( $fname, self::TRANSACTION_INTERNAL );
}
return $ok;
$this->mTrxPreCommitCallbacks[] = [ $callback, wfGetCaller() ];
} else {
// If no transaction is active, then make one for this callback
- $this->begin( __METHOD__ );
+ $this->begin( __METHOD__, self::TRANSACTION_INTERNAL );
try {
call_user_func( $callback );
$this->commit( __METHOD__ );
$autoTrx = $this->getFlag( DBO_TRX ); // automatic begin() enabled?
/** @var Exception $e */
- $e = $ePrior = null; // last exception
+ $e = null; // first exception
do { // callbacks may add callbacks :)
$callbacks = array_merge(
$this->mTrxIdleCallbacks,
} else {
$this->clearFlag( DBO_TRX ); // restore auto-commit
}
- } catch ( Exception $e ) {
- if ( $ePrior ) {
- MWExceptionHandler::logException( $ePrior );
- }
- $ePrior = $e;
+ } catch ( Exception $ex ) {
+ MWExceptionHandler::logException( $ex );
+ $e = $e ?: $ex;
// Some callbacks may use startAtomic/endAtomic, so make sure
// their transactions are ended so other callbacks don't fail
if ( $this->trxLevel() ) {
} while ( count( $this->mTrxIdleCallbacks ) );
if ( $e instanceof Exception ) {
- throw $e; // re-throw any last exception
+ throw $e; // re-throw any first exception
}
}
* This method should not be used outside of Database/LoadBalancer
*
* @since 1.22
+ * @throws Exception
*/
public function runOnTransactionPreCommitCallbacks() {
- $e = $ePrior = null; // last exception
+ $e = null; // first exception
do { // callbacks may add callbacks :)
$callbacks = $this->mTrxPreCommitCallbacks;
$this->mTrxPreCommitCallbacks = []; // consumed (and recursion guard)
try {
list( $phpCallback ) = $callback;
call_user_func( $phpCallback );
- } catch ( Exception $e ) {
- if ( $ePrior ) {
- MWExceptionHandler::logException( $ePrior );
- }
- $ePrior = $e;
+ } catch ( Exception $ex ) {
+ MWExceptionHandler::logException( $ex );
+ $e = $e ?: $ex;
}
}
} while ( count( $this->mTrxPreCommitCallbacks ) );
if ( $e instanceof Exception ) {
- throw $e; // re-throw any last exception
+ throw $e; // re-throw any first exception
}
}
final public function startAtomic( $fname = __METHOD__ ) {
if ( !$this->mTrxLevel ) {
- $this->begin( $fname );
+ $this->begin( $fname, self::TRANSACTION_INTERNAL );
$this->mTrxAutomatic = true;
// If DBO_TRX is set, a series of startAtomic/endAtomic pairs will result
// in all changes being in one transaction to keep requests transactional.
final public function doAtomicSection( $fname, callable $callback ) {
$this->startAtomic( $fname );
try {
- call_user_func_array( $callback, [ $this, $fname ] );
+ $res = call_user_func_array( $callback, [ $this, $fname ] );
} catch ( Exception $e ) {
$this->rollback( $fname );
throw $e;
}
$this->endAtomic( $fname );
+
+ return $res;
}
- final public function begin( $fname = __METHOD__ ) {
- if ( $this->mTrxLevel ) { // implicit commit
+ final public function begin( $fname = __METHOD__, $mode = self::TRANSACTION_EXPLICIT ) {
+ // Protect against mismatched atomic section, transaction nesting, and snapshot loss
+ if ( $this->mTrxLevel ) {
if ( $this->mTrxAtomicLevels ) {
- // If the current transaction was an automatic atomic one, then we definitely have
- // a problem. Same if there is any unclosed atomic level.
$levels = implode( ', ', $this->mTrxAtomicLevels );
- throw new DBUnexpectedError(
- $this,
- "Got explicit BEGIN from $fname while atomic section(s) $levels are open."
- );
+ $msg = "$fname: Got explicit BEGIN while atomic section(s) $levels are open.";
+ throw new DBUnexpectedError( $this, $msg );
} elseif ( !$this->mTrxAutomatic ) {
- // We want to warn about inadvertently nested begin/commit pairs, but not about
- // auto-committing implicit transactions that were started by query() via DBO_TRX
- throw new DBUnexpectedError(
- $this,
- "$fname: Transaction already in progress (from {$this->mTrxFname}), " .
- " performing implicit commit!"
- );
- } elseif ( $this->mTrxDoneWrites ) {
- // The transaction was automatic and has done write operations
- throw new DBUnexpectedError(
- $this,
- "$fname: Automatic transaction with writes in progress" .
- " (from {$this->mTrxFname}), performing implicit commit!\n"
- );
- }
-
- $this->runOnTransactionPreCommitCallbacks();
- $writeTime = $this->pendingWriteQueryDuration();
- $this->doCommit( $fname );
- if ( $this->mTrxDoneWrites ) {
- $this->mDoneWrites = microtime( true );
- $this->getTransactionProfiler()->transactionWritingOut(
- $this->mServer, $this->mDBname, $this->mTrxShortId, $writeTime );
+ $msg = "$fname: Explicit transaction already active (from {$this->mTrxFname}).";
+ throw new DBUnexpectedError( $this, $msg );
+ } else {
+ // @TODO: make this an exception at some point
+ $msg = "$fname: Implicit transaction already active (from {$this->mTrxFname}).";
+ wfLogDBError( $msg );
+ return; // join the main transaction set
}
-
- $this->runOnTransactionIdleCallbacks( self::TRIGGER_COMMIT );
+ } elseif ( $this->getFlag( DBO_TRX ) && $mode !== self::TRANSACTION_INTERNAL ) {
+ // @TODO: make this an exception at some point
+ wfLogDBError( "$fname: Implicit transaction expected (DBO_TRX set)." );
+ return; // let any writes be in the main transaction
}
// Avoid fatals if close() was called
$levels = implode( ', ', $this->mTrxAtomicLevels );
throw new DBUnexpectedError(
$this,
- "Got COMMIT while atomic sections $levels are still open"
+ "$fname: Got COMMIT while atomic sections $levels are still open."
);
}
} elseif ( !$this->mTrxAutomatic ) {
throw new DBUnexpectedError(
$this,
- "$fname: Flushing an explicit transaction, getting out of sync!"
+ "$fname: Flushing an explicit transaction, getting out of sync."
);
}
} else {
if ( !$this->mTrxLevel ) {
- wfWarn( "$fname: No transaction to commit, something got out of sync!" );
+ wfWarn( "$fname: No transaction to commit, something got out of sync." );
return; // nothing to do
} elseif ( $this->mTrxAutomatic ) {
- throw new DBUnexpectedError(
- $this,
- "$fname: Explicit commit of implicit transaction."
- );
+ // @TODO: make this an exception at some point
+ wfLogDBError( "$fname: Explicit commit of implicit transaction." );
+ return; // wait for the main transaction set commit round
}
}
}
final public function rollback( $fname = __METHOD__, $flush = '' ) {
- if ( $flush !== self::FLUSHING_INTERNAL && $flush !== self::FLUSHING_ALL_PEERS ) {
+ if ( $flush === self::FLUSHING_INTERNAL || $flush === self::FLUSHING_ALL_PEERS ) {
if ( !$this->mTrxLevel ) {
- wfWarn( "$fname: No transaction to rollback, something got out of sync!" );
return; // nothing to do
}
} else {
if ( !$this->mTrxLevel ) {
+ wfWarn( "$fname: No transaction to rollback, something got out of sync." );
return; // nothing to do
+ } elseif ( $this->getFlag( DBO_TRX ) ) {
+ throw new DBUnexpectedError(
+ $this,
+ "$fname: Expected mass rollback of all peer databases (DBO_TRX set)."
+ );
}
}
}
}
- /**
- * @return bool
- */
- protected function explicitTrxActive() {
+ public function explicitTrxActive() {
return $this->mTrxLevel && ( $this->mTrxAtomicLevels || !$this->mTrxAutomatic );
}
}
public function ping() {
+ if ( $this->isOpen() && ( microtime( true ) - $this->lastPing ) < self::PING_TTL ) {
+ return true;
+ }
try {
// This will reconnect if possible, or error out if not
$this->query( "SELECT 1 AS ping", __METHOD__ );
* @return bool
*/
protected function reconnect() {
- # Stub. Not essential to override.
- return true;
+ $this->closeConnection();
+ $this->mOpened = false;
+ $this->mConn = false;
+ try {
+ $this->open( $this->mServer, $this->mUser, $this->mPassword, $this->mDBname );
+ $this->lastPing = microtime( true );
+ $ok = true;
+ } catch ( DBConnectionError $e ) {
+ $ok = false;
+ }
+
+ return $ok;
}
public function getSessionLagStatus() {
}
public function getScopedLockAndFlush( $lockKey, $fname, $timeout ) {
+ if ( $this->writesOrCallbacksPending() ) {
+ // This only flushes transactions to clear snapshots, not to write data
+ throw new DBUnexpectedError(
+ $this,
+ "$fname: Cannot COMMIT to clear snapshot because writes are pending."
+ );
+ }
+
if ( !$this->lock( $lockKey, $fname, $timeout ) ) {
return null;
}
$unlocker = new ScopedCallback( function () use ( $lockKey, $fname ) {
- $this->commit( __METHOD__, self::FLUSHING_INTERNAL );
- $this->unlock( $lockKey, $fname );
+ if ( $this->trxLevel() ) {
+ // There is a good chance an exception was thrown, causing any early return
+ // from the caller. Let any error handler get a chance to issue rollback().
+ // If there isn't one, let the error bubble up and trigger server-side rollback.
+ $this->onTransactionResolution( function () use ( $lockKey, $fname ) {
+ $this->unlock( $lockKey, $fname );
+ } );
+ } else {
+ $this->unlock( $lockKey, $fname );
+ }
} );
$this->commit( __METHOD__, self::FLUSHING_INTERNAL );
dépôts / lhc / web / wiklou.git / blobdiff