com.google.enterprise.connector.util.diffing

Class ChangeQueue

java.lang.Object

com.google.enterprise.connector.util.diffing.ChangeQueue

All Implemented Interfaces:

ChangeSource

public class ChangeQueue
extends java.lang.Object
implements ChangeSource

Bounded buffer of Change objects for buffering between the DocumentSnapshotRepositoryMonitor and the CheckpointAndChangeQueue.

Since:

2.8

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	ChangeQueue.CrawlActivityLogger Interface to log the crawl activity for each crawl.
static class	ChangeQueue.DefaultCrawlActivityLogger
static interface	ChangeQueue.QueuePropertyFetcher Interface to retrieve the properties required for ChangeQueue.

Constructor Summary

Constructors

Constructor and Description
ChangeQueue(ChangeQueue.QueuePropertyFetcher propertyFetcher, ChangeQueue.CrawlActivityLogger activityLogger)
ChangeQueue(int size, long sleepInterval, ChangeQueue.CrawlActivityLogger activityLogger) Create a new ChangeQueue.

Method Summary

Modifier and Type	Method and Description
Change	getNextChange() Gets the next available change from the ChangeQueue.
DocumentSnapshotRepositoryMonitor.Callback	newCallback()
void	setSleepInterval(long sleepInterval) Sets the sleepInterval in milliseconds, normally passed from the retry delay in a TraversalSchedule.

Methods inherited from class java.lang.Object

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

Constructor Detail

ChangeQueue

public ChangeQueue(int size,
                   long sleepInterval,
                   ChangeQueue.CrawlActivityLogger activityLogger)

Create a new ChangeQueue.

Parameters:

size - the queue size

sleepInterval - how often to look for new changes, in milliseconds

activityLogger - a CrawlActivityLogger

ChangeQueue

public ChangeQueue(ChangeQueue.QueuePropertyFetcher propertyFetcher,
                   ChangeQueue.CrawlActivityLogger activityLogger)

Method Detail

newCallback

public DocumentSnapshotRepositoryMonitor.Callback newCallback()

Returns:

the monitor callback. This is a factory method for use by Spring, which needs a Callback to create a DocumentSnapshotRepositoryMonitor.

getNextChange

public Change getNextChange()

Gets the next available change from the ChangeQueue. Will wait up to 1/4 second for a change to appear if none is immediately available.

Specified by:

getNextChange in interface ChangeSource

Returns:

the next available change, or null if no changes are available

setSleepInterval

public void setSleepInterval(long sleepInterval)

Sets the sleepInterval in milliseconds, normally passed from the retry delay in a TraversalSchedule.