PersistedQueue (OpenDJ account change notification handler for OpenIDM 4.4.14 API)

java.lang.Object
- org.forgerock.openidm.accountchange.PersistedQueue

```
@ThreadSafe
public class PersistedQueue
extends Object
```
Fast request queue implementation on top of Berkley DB Java Edition. The queue uses the canonalised dn for key and store only the last password change for each dn.

Constructor Summary

Constructors
Constructor Description

PersistedQueue(File queueEnvPath, String queueName, int cacheSize)
Creates instance of persistent queue.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`close()`	Closes this queue and frees up all resources associated to it.
`String`	`getQueueName()`	Returns this queue name.
`String[]`	`poll()`	Retrieves and returns element from the head of this queue.
`void`	`push(String dn, String element)`	Pushes element to the queue.
`long`	`size()`	Returns the size of this queue.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - PersistedQueue
```
public PersistedQueue(File queueEnvPath,
                      String queueName,
                      int cacheSize)
```
    Creates instance of persistent queue.
    
    Parameters:
    
    queueEnvPath - queue database environment directory path
    
    queueName - descriptive queue name
    
    cacheSize - how often to sync the queue to disk
- Method Detail
  - poll
```
public String[] poll()
              throws IOException
```
    Retrieves and returns element from the head of this queue.
    
    Returns:
    
    element from the head of the queue or null if queue is empty
    
    Throws:
    
    IOException - in case of disk IO failure
  - push
```
public void push(String dn,
                 String element)
          throws IOException
```
    Pushes element to the queue.
    The entries are sorted in natural order and not in order of time when they were added.
    
    Parameters:
    
    dn - The entry DN
    
    element - element
    
    Throws:
    
    IOException - in case of disk IO failure
  - size
```
public long size()
```
    Returns the size of this queue.
    
    Returns:
    
    the size of the queue
  - getQueueName
```
public String getQueueName()
```
    Returns this queue name.
    
    Returns:
    
    this queue name
  - close
```
public void close()
```
    Closes this queue and frees up all resources associated to it.