AckReceiverWindow

java.lang.Object
- org.jgroups.stack.AckReceiverWindow

```
public class AckReceiverWindow
extends java.lang.Object
```
Counterpart of AckSenderWindow. Simple FIFO buffer. Every message received is ACK'ed (even duplicates) and added to a hashmap keyed by seqno. The next seqno to be received is stored in next_to_remove. When a message with a seqno less than next_to_remove is received, it will be discarded. The remove() method removes and returns a message whose seqno is equal to next_to_remove, or null if not found.
Change May 28 2002 (bela): replaced TreeSet with HashMap. Keys do not need to be sorted, and adding a key to a sorted set incurs overhead.

Version:

$Id: AckReceiverWindow.java,v 1.25.2.4.2.2 2009/04/28 11:31:50 belaban Exp $

Author:

Bela Ban

Constructor Summary

Constructors
Constructor Description

AckReceiverWindow(long initial_seqno)

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`boolean`	`add(long seqno, Message msg)`	Adds a new message.
`java.util.concurrent.locks.ReentrantLock`	`getLock()`
`boolean`	`hasMessagesToRemove()`
`java.lang.String`	`printDetails()`
`Message`	`remove()`	Removes a message whose seqno is equal to `next_to_remove`, increments the latter.
`Message`	`removeOOBMessage()`
`void`	`reset()`
`int`	`size()`
`boolean`	`smallerThanNextToRemove(long seqno)`
`java.lang.String`	`toString()`

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

- Constructor Detail
  - AckReceiverWindow
```
public AckReceiverWindow(long initial_seqno)
```
- Method Detail
  - getLock
```
public java.util.concurrent.locks.ReentrantLock getLock()
```
  - add
```
public boolean add(long seqno,
                   Message msg)
```
    Adds a new message. Message cannot be null
    
    Returns:
    
    True if the message was added, false if not (e.g. duplicate, message was already present)
  - remove
```
public Message remove()
```
    Removes a message whose seqno is equal to next_to_remove, increments the latter. Returns message that was removed, or null, if no message can be removed. Messages are thus removed in order.
  - removeOOBMessage
```
public Message removeOOBMessage()
```
  - hasMessagesToRemove
```
public boolean hasMessagesToRemove()
```
  - smallerThanNextToRemove
```
public boolean smallerThanNextToRemove(long seqno)
```
  - reset
```
public void reset()
```
  - size
```
public int size()
```
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object
  - printDetails
```
public java.lang.String printDetails()
```