ZooKeeper
PHP-Handbuch

Zookeeper::exists

Checks the existence of a node in zookeeper synchronously.

Beschreibung

public bool Zookeeper::exists ( string $path [, callable $watcher_cb = null ] )

Parameter-Liste

path

The name of the node. Expressed as a file name with slashes separating ancestors of the node.

watcher_cb

if nonzero, a watch will be set at the server to notify the client if the node changes. The watch will be set even if the node does not

Rückgabewerte

Returns true/false on success, and false on failure.

Fehler/Exceptions

This method emits PHP error/warning when parameters count or types are wrong or fail to check the existence of a node.

Beispiele

Beispiel #1 Zookeeper::exists example

Check the existence of a node.

<?php
$zookeeper = new Zookeeper('locahost:2181');
$path = '/path/to/node';
$r = $zookeeper->exists($path);
if ($r)
  echo 'EXISTS';
else
  echo 'N/A or ERR';
?>

Das oben gezeigte Beispiel erzeugt folgende Ausgabe:

EXISTS

Siehe auch

  • Zookeeper::get