com.bigdata.service
Class DataService.GetIndexMetadataTask

java.lang.Object
  com.bigdata.journal.AbstractTask
      com.bigdata.service.DataService.GetIndexMetadataTask

All Implemented Interfaces:

ITask, Callable

Enclosing class:

DataService

public static class DataService.GetIndexMetadataTask
extends AbstractTask

Retrieves the IndexMetadata for the named index as of the specified timestamp.

Version:

$Id: DataService.java 2265 2009-10-26 12:51:06Z thompsonbry $

Author:

Bryan Thompson

Nested Class Summary

Nested classes/interfaces inherited from class com.bigdata.journal.AbstractTask

AbstractTask.DelegateTask<T>, AbstractTask.InnerReadWriteTxServiceCallable, AbstractTask.InnerWriteServiceCallable<T>, AbstractTask.ResubmitException

Field Summary

Fields inherited from class com.bigdata.journal.AbstractTask

checkpointNanoTime, concurrencyManager, DEBUG, INFO, isReadWriteTx, log, nanoTime_assignedWorker, nanoTime_beginWork, nanoTime_finishedWork, nanoTime_submitTask, readOnly, resourceManager, taskCounters, timestamp, transactionManager, tx

Constructor Summary

DataService.GetIndexMetadataTask(ConcurrencyManager concurrencyManager, long startTime, String name)

Method Summary

protected IndexMetadata

doTask() Implement the task behavior here.

Methods inherited from class com.bigdata.journal.AbstractTask

assertResource, assertRunning, assertUnisolated, call, clearLoggingContext, dropIndex, getCommitTime, getIndex, getJournal, getOnlyResource, getResource, getResourceManager, getTaskCounters, getTaskName, getTimestamp, isResource, registerIndex, setupLoggingContext, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

DataService.GetIndexMetadataTask

public DataService.GetIndexMetadataTask(ConcurrencyManager concurrencyManager,
                                        long startTime,
                                        String name)

Method Detail

doTask

protected IndexMetadata doTask()
                        throws Exception

Description copied from class: AbstractTask

Implement the task behavior here.

Note: Long-running implementations MUST periodically test Thread.interrupted() and MUST throw an exception, such as InterruptedException, if they are interrupted. This behavior allows tasks to be canceled in a timely manner.

If you ignore or fail to test Thread.interrupted() then your task CAN NOT be aborted. If it is Future.cancel(boolean) with false then the task will run to completion even though it has been cancelled (but the Future will appear to have been cancelled).

If you simply return rather than throwing an exception then the WriteExecutorService will assume that your task completed and your (partial) results will be made restart-safe at the next commit!

Specified by:

doTask in class AbstractTask

Returns:

The object that will be returned by AbstractTask.call() iff the operation succeeds.

Throws:

Exception - The exception that will be thrown by AbstractTask.call() iff the operation fails.

InterruptedException - This exception SHOULD be thrown if Thread.interrupted() becomes true during execution.