Zookeeper::get

(PECL zookeeper >= 0.1.0)

Zookeeper::getGets the data associated with a node synchronously

说明

public Zookeeper::get ( string $path , callable $watcher_cb = null , array &$stat = null , int $max_size = 0 ) : string

参数

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.

stat

If not NULL, will hold the value of stat for the path on return.

max_size

Max size of the data. If 0 is used, this method will return the whole data.

返回值

Returns the data on success, and false on failure.

错误/异常

This method emits PHP error/warning when parameters count or types are wrong or fail to get value from node.

Caution

Since version 0.3.0, this method emits ZookeeperException and it's derivatives.

范例

Example #1 Zookeeper::get() example

Get value from node.

<?php
$zookeeper 
= new Zookeeper('locahost:2181');
$path '/path/to/node';
$value 'nodevalue';
$zookeeper->set($path$value);

$r $zookeeper->get($path);
if (
$r)
  echo 
$r;
else
  echo 
'ERR';
?>

以上例程会输出:

nodevalue

Example #2 Zookeeper::get() stat example

Get node stat info.

<?php
$zookeeper 
= new Zookeeper('localhost:2181');
$path '/path/to/node';
$stat = [];
$zookeeper->get($pathnull$stat);
var_dump($stat);
?>

以上例程会输出:

array(11) {
  ["czxid"]=>
  float(0)
  ["mzxid"]=>
  float(0)
  ["ctime"]=>
  float(0)
  ["mtime"]=>
  float(0)
  ["version"]=>
  int(0)
  ["cversion"]=>
  int(-2)
  ["aversion"]=>
  int(0)
  ["ephemeralOwner"]=>
  float(0)
  ["dataLength"]=>
  int(0)
  ["numChildren"]=>
  int(2)
  ["pzxid"]=>
  float(0)
}

参见

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