org.apache.solr.cloud
Class DistributedQueue

java.lang.Object
  org.apache.solr.cloud.DistributedQueue

public class DistributedQueue
extends Object

A distributed queue from zk recipes.

Nested Class Summary

static class

DistributedQueue.QueueEvent

Constructor Summary

DistributedQueue(SolrZkClient zookeeper, String dir, List<org.apache.zookeeper.data.ACL> acl)

Method Summary

boolean	offer(byte[] data) Inserts data into queue.
DistributedQueue.QueueEvent	offer(byte[] data, long timeout) Offer the data and wait for the response
byte[]	peek() Returns the data at the first element of the queue, or null if the queue is empty.
DistributedQueue.QueueEvent	peek(boolean block) Returns the data at the first element of the queue, or null if the queue is empty and block is false.
DistributedQueue.QueueEvent	peek(long wait) Returns the data at the first element of the queue, or null if the queue is empty after wait ms.
byte[]	poll() Attempts to remove the head of the queue and return it.
byte[]	remove() Attempts to remove the head of the queue and return it.
byte[]	remove(DistributedQueue.QueueEvent event) Remove the event and save the response into the other path.
byte[]	take() Removes the head of the queue and returns it, blocks until it succeeds.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DistributedQueue

public DistributedQueue(SolrZkClient zookeeper,
                        String dir,
                        List<org.apache.zookeeper.data.ACL> acl)

Method Detail

remove

public byte[] remove()
              throws NoSuchElementException,
                     org.apache.zookeeper.KeeperException,
                     InterruptedException

Attempts to remove the head of the queue and return it.

Returns:

The former head of the queue

Throws:

NoSuchElementException

org.apache.zookeeper.KeeperException

InterruptedException

remove

public byte[] remove(DistributedQueue.QueueEvent event)
              throws org.apache.zookeeper.KeeperException,
                     InterruptedException

Remove the event and save the response into the other path.

Throws:

org.apache.zookeeper.KeeperException

InterruptedException

take

public byte[] take()
            throws org.apache.zookeeper.KeeperException,
                   InterruptedException

Removes the head of the queue and returns it, blocks until it succeeds.

Returns:

The former head of the queue

Throws:

org.apache.zookeeper.KeeperException

InterruptedException

offer

public boolean offer(byte[] data)
              throws org.apache.zookeeper.KeeperException,
                     InterruptedException

Inserts data into queue.

Returns:

true if data was successfully added

Throws:

org.apache.zookeeper.KeeperException

InterruptedException

offer

public DistributedQueue.QueueEvent offer(byte[] data,
                                         long timeout)
                                  throws org.apache.zookeeper.KeeperException,
                                         InterruptedException

Offer the data and wait for the response

Throws:

org.apache.zookeeper.KeeperException

InterruptedException

peek

public byte[] peek()
            throws org.apache.zookeeper.KeeperException,
                   InterruptedException

Returns the data at the first element of the queue, or null if the queue is empty.

Returns:

data at the first element of the queue, or null.

Throws:

org.apache.zookeeper.KeeperException

InterruptedException

peek

public DistributedQueue.QueueEvent peek(boolean block)
                                 throws org.apache.zookeeper.KeeperException,
                                        InterruptedException

Returns the data at the first element of the queue, or null if the queue is empty and block is false.

Parameters:

block - if true, blocks until an element enters the queue

Returns:

data at the first element of the queue, or null.

Throws:

org.apache.zookeeper.KeeperException

InterruptedException

peek

public DistributedQueue.QueueEvent peek(long wait)
                                 throws org.apache.zookeeper.KeeperException,
                                        InterruptedException

Returns the data at the first element of the queue, or null if the queue is empty after wait ms.

Parameters:

wait - max wait time in ms.

Returns:

data at the first element of the queue, or null.

Throws:

org.apache.zookeeper.KeeperException

InterruptedException

poll

public byte[] poll()
            throws org.apache.zookeeper.KeeperException,
                   InterruptedException

Attempts to remove the head of the queue and return it. Returns null if the queue is empty.

Returns:

Head of the queue or null.

Throws:

org.apache.zookeeper.KeeperException

InterruptedException