MongoCursor::awaitData

(PECL mongo >=1.2.11)

MongoCursor::awaitDataSets whether this cursor will wait for a while for a tailable cursor to return more data

Description

public MongoCursor::awaitData(bool $wait = true): MongoCursor

This method is to be used with tailable cursors. If we are at the end of the data, block for a while rather than returning no data. After a timeout period, we do return as normal.

Parameters

wait

If the cursor should wait for more data to become available.

Return Values

Returns this cursor.

Errors/Exceptions

Throws MongoCursorException if this cursor has started iterating.

Examples

Example #1 MongoCursor::awaitData() example

In this example we tail the "oplog" and instead of sleeping during every iteration, we set the MongoCursor::awaitData() option. MongoCursor::hasNext() will now block until there is more data available.

<?php
$m 
= new MongoClient'mongodb://localhost:13000', array( 'replSet' => 'seta' ) );
$c $m->local->selectCollection'oplog.rs' );
$cursor $c->find( array( 'ns' => 'demo.article''op' => 'i' ) );
$cursor->tailabletrue );
$cursor->awaitDatatrue );

while (
true) {
    if (!
$cursor->hasNext()) {
        
// we've read all the results, exit
        
if ($cursor->dead()) {
            break;
        }
    } else {
        
var_dump$cursor->getNext() );
    }
}
?>

See Also

MongoDB core docs on » tailable cursors.