Package org.apache.solr.cloud.autoscaling.sim

Class GenericDistributedQueue

java.lang.Object

org.apache.solr.cloud.autoscaling.sim.GenericDistributedQueue

All Implemented Interfaces:

DistributedQueue

public class GenericDistributedQueue
extends Object
implements DistributedQueue

A distributed queue that uses DistribStateManager as the underlying distributed store. Implementation based on ZkDistributedQueue

Constructor Summary

Constructors

Constructor	Description
GenericDistributedQueue(DistribStateManager stateManager, String dir)
GenericDistributedQueue(DistribStateManager stateManager, String dir, Stats stats)
GenericDistributedQueue(DistribStateManager stateManager, String dir, Stats stats, int maxQueueSize)

Method Summary

Modifier and Type	Method	Description
Map<String,Object>	getStats()
Stats	getZkStats()
void	offer(byte[] data)	Inserts data into queue.
byte[]	peek()	Returns the data at the first element of the queue, or null if the queue is empty.
byte[]	peek(boolean block)	Returns the data at the first element of the queue, or null if the queue is empty and block is false.
byte[]	peek(long wait)	Returns the data at the first element of the queue, or null if the queue is empty after wait ms.
Collection<Pair<String,byte[]>>	peekElements(int max, long waitMillis, Predicate<String> acceptFilter)	Return the currently-known set of elements, using child names from memory.
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.
void	remove(Collection<String> paths)
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

GenericDistributedQueue

public GenericDistributedQueue(DistribStateManager stateManager,
                               String dir)

GenericDistributedQueue

public GenericDistributedQueue(DistribStateManager stateManager,
                               String dir,
                               Stats stats)

GenericDistributedQueue

public GenericDistributedQueue(DistribStateManager stateManager,
                               String dir,
                               Stats stats,
                               int maxQueueSize)

Method Detail

peek

public byte[] peek()
            throws Exception

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

Specified by:

peek in interface DistributedQueue

Returns:

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

Throws:

Exception

peek

public byte[] peek(boolean block)
            throws Exception

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

Specified by:

peek in interface DistributedQueue

Parameters:

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

Returns:

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

Throws:

Exception

peek

public byte[] peek(long wait)
            throws Exception

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

Specified by:

peek in interface DistributedQueue

Parameters:

wait - max wait time in ms.

Returns:

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

Throws:

Exception

poll

public byte[] poll()
            throws Exception

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

Specified by:

poll in interface DistributedQueue

Returns:

Head of the queue or null.

Throws:

Exception

remove

public byte[] remove()
              throws Exception

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

Specified by:

remove in interface DistributedQueue

Returns:

The former head of the queue

Throws:

Exception

remove

public void remove(Collection<String> paths)
            throws Exception

Throws:

Exception

take

public byte[] take()
            throws Exception

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

Specified by:

take in interface DistributedQueue

Returns:

The former head of the queue

Throws:

Exception

offer

public void offer(byte[] data)
           throws Exception

Inserts data into queue. If there are no other queue consumers, the offered element will be immediately visible when this method returns.

Specified by:

offer in interface DistributedQueue

Throws:

Exception

getZkStats

public Stats getZkStats()

getStats

public Map<String,Object> getStats()

Specified by:

getStats in interface DistributedQueue

peekElements

public Collection<Pair<String,byte[]>> peekElements(int max,
                                                          long waitMillis,
                                                          Predicate<String> acceptFilter)
                                                   throws Exception

Return the currently-known set of elements, using child names from memory. If no children are found, or no children pass acceptFilter, waits up to waitMillis for at least one child to become available.

Package-private to support OverseerTaskQueue specifically.

Specified by:

peekElements in interface DistributedQueue

Throws:

Exception