function getReaderIndex()
{
+ $fname = 'LoadBalancer::getReaderIndex';
+ wfProfileIn( $fname );
+
$i = false;
if ( $this->mForce >= 0 ) {
$i = $this->mForce;
if ( $i !== false ) {
wfDebug( "Using reader #$i: {$this->mServers[$i]['host']}\n" );
- $this->getConnection( $i );
+ $this->openConnection( $i );
if ( !$this->isOpen( $i ) ) {
unset( $loads[$i] );
}
}
}
+ wfProfileOut( $fname );
return $i;
}
# If a DB_SLAVE connection has been opened already, waits
# Otherwise sets a variable telling it to wait if such a connection is opened
function waitFor( $file, $pos ) {
+ $fname = "LoadBalancer::waitFor";
+ wfProfileIn( $fname );
+
wfDebug( "User master pos: $file $pos\n" );
$this->mWaitForFile = false;
$this->mWaitForPos = false;
- if ( count( $this->mServers ) == 1 ) {
- return;
- }
-
- $this->mWaitForFile = $file;
- $this->mWaitForPos = $pos;
+ if ( count( $this->mServers ) > 1 ) {
+ $this->mWaitForFile = $file;
+ $this->mWaitForPos = $pos;
- if ( $this->mReadIndex > 0 ) {
- if ( !$this->doWait( $this->mReadIndex ) ) {
- # Use master instead
- $this->mReadIndex = 0;
- }
- }
+ if ( $this->mReadIndex > 0 ) {
+ if ( !$this->doWait( $this->mReadIndex ) ) {
+ # Use master instead
+ $this->mReadIndex = 0;
+ }
+ }
+ }
+ wfProfileOut( $fname );
}
# Wait for a given slave to catch up to the master pos stored in $this
function doWait( $index ) {
global $wgMemc;
+ $retVal = false;
+
$key = "masterpos:" . $index;
$memcPos = $wgMemc->get( $key );
if ( $memcPos ) {
list( $file, $pos ) = explode( ' ', $memcPos );
# If the saved position is later than the requested position, return now
if ( $file == $this->mWaitForFile && $this->mWaitForPos <= $pos ) {
- return true;
+ $retVal = true;
}
}
- $conn =& $this->getConnection( $index );
- wfDebug( "Waiting for slave #$index to catch up...\n" );
- $result = $conn->masterPosWait( $this->mWaitForFile, $this->mWaitForPos, MASTER_WAIT_TIMEOUT );
+ if ( !$retVal && $this->isOpen( $index ) ) {
+ $conn =& $this->mConnections( $index );
+ wfDebug( "Waiting for slave #$index to catch up...\n" );
+ $result = $conn->masterPosWait( $this->mWaitForFile, $this->mWaitForPos, MASTER_WAIT_TIMEOUT );
- if ( $result == -1 || is_null( $result ) ) {
- # Timed out waiting for slave, use master instead
- wfDebug( "Timed out waiting for slave #$index pos {$this->mWaitForFile} {$this->mWaitForPos}\n" );
- $retVal = false;
- } else {
- $retVal = true;
- wfDebug( "Done\n" );
+ if ( $result == -1 || is_null( $result ) ) {
+ # Timed out waiting for slave, use master instead
+ wfDebug( "Timed out waiting for slave #$index pos {$this->mWaitForFile} {$this->mWaitForPos}\n" );
+ $retVal = false;
+ } else {
+ $retVal = true;
+ wfDebug( "Done\n" );
+ }
}
return $retVal;
}
# Get a connection by index
function &getConnection( $i, $fail = false )
{
+ $fname = "LoadBalancer::getConnection";
+ wfProfileIn( $fname );
/*
# Task-based index
if ( $i >= DB_TASK_FIRST && $i < DB_TASK_LAST ) {
# Operation-based index
if ( $i == DB_SLAVE ) {
- # Note: re-entrant
$i = $this->getReaderIndex();
} elseif ( $i == DB_MASTER ) {
$i = $this->getWriterIndex();
$i = $this->mLastIndex;
if ( $i === -1 ) {
# Oh dear, not set, best to use the writer for safety
+ wfDebug( "Warning: DB_LAST used when there was no previous index\n" );
$i = $this->getWriterIndex();
}
- }
+ }
# Now we have an explicit index into the servers array
+ $this->openConnection( $i, $fail );
+ wfProfileOut( $fname );
+ return $this->mConnections[$i];
+ }
+
+ # Open a connection to the server given by the specified index
+ # Index must be an actual index into the array
+ /* private */ function openConnection( $i, $fail = false ) {
+ $fname = 'LoadBalancer::openConnection';
+ wfProfileIn( $fname );
+
if ( !$this->isOpen( $i ) ) {
- $this->mConnections[$i] = $this->makeConnection( $this->mServers[$i] );
+ $this->mConnections[$i] = $this->reallyOpenConnection( $this->mServers[$i] );
if ( $i != 0 && $this->mWaitForFile ) {
if ( !$this->doWait( $i ) ) {
$this->mReadIndex = 0;
$i = 0;
if ( !$this->isOpen( 0 ) ) {
- $this->mConnections[0] = $this->makeConnection( $this->mServers[0] );
+ $this->mConnections[0] = $this->reallyOpenConnection( $this->mServers[0] );
}
wfDebug( "Failed over to {$this->mConnections[0]->mServer}\n" );
}
$this->mConnections[$i] = false;
}
$this->mLastIndex = $i;
-
- return $this->mConnections[$i];
+ wfProfileOut( $fname );
}
+ # Test if the specified index represents an open connection
/* private */ function isOpen( $index ) {
if ( array_key_exists( $index, $this->mConnections ) && is_object( $this->mConnections[$index] ) &&
$this->mConnections[$index]->isOpen() )
}
}
- /* private */ function makeConnection( &$server ) {
+ # Really opens a connection
+ /* private */ function reallyOpenConnection( &$server ) {
extract( $server );
# Get class for this database type
$class = 'Database' . ucfirst( $type );
function reportConnectionError( &$conn )
{
- if ( !is_object( $conn ) ) {
- $conn = new Database;
- }
- if ( $this->mFailFunction ) {
- $conn->setFailFunction( $this->mFailFunction );
- } else {
- $conn->setFailFunction( "wfEmergencyAbort" );
+ $fname = 'LoadBalancer::reportConnectionError';
+ wfProfileIn( $fname );
+ # Prevent infinite recursion
+
+ static $reporting = false;
+ if ( !$reporting ) {
+ $reporting = true;
+ if ( !is_object( $conn ) ) {
+ $conn = new Database;
+ }
+ if ( $this->mFailFunction ) {
+ $conn->setFailFunction( $this->mFailFunction );
+ } else {
+ $conn->setFailFunction( "wfEmergencyAbort" );
+ }
+ $conn->reportConnectionError();
+ $reporting = false;
}
- $conn->reportConnectionError();
+ wfProfileOut( $fname );
}
function getWriterIndex()
dépôts / lhc / web / wiklou.git / blobdiff