com.bigdata.relation.rule.eval
Class QueryTask

java.lang.Object
  com.bigdata.service.FederationCallable<T>
      com.bigdata.service.DataServiceCallable<RuleStats>
          com.bigdata.relation.rule.eval.AbstractStepTask
              com.bigdata.relation.rule.eval.QueryTask

All Implemented Interfaces:

IStepTask, IDataServiceCallable, IFederationCallable, Serializable, Cloneable, Callable<RuleStats>

public class QueryTask
extends AbstractStepTask

A task that executes a query operation.

Version:

$Id: QueryTask.java 3041 2010-06-18 15:41:10Z thompsonbry $

Author:

Bryan Thompson

See Also:

Serialized Form

Field Summary

Fields inherited from class com.bigdata.relation.rule.eval.AbstractStepTask

action, indexManager, joinNexusFactory, log, step

Constructor Summary

QueryTask(IStep step, IJoinNexusFactory joinNexusFactory, IBlockingBuffer<ISolution[]> buffer, IIndexManager indexManager, DataService dataService)

Method Summary

RuleStats	call() Run the task (invoked once we are in the target execution context).
protected List<Callable<RuleStats>>	newQueryTasks(IStep step, IJoinNexus joinNexus, IBlockingBuffer<ISolution[]> buffer) Builds a set of tasks for the program.
protected RuleStats	runTasks(IJoinNexus joinNexus, List<Callable<RuleStats>> tasks) Run the task(s) and wait for them to complete.

Methods inherited from class com.bigdata.relation.rule.eval.AbstractStepTask

clone, getIndexNames, getMutationBuffers, getReadRelations, getWriteRelationNames, getWriteRelations, runOne, runParallel, runSequential, submit, toString

Methods inherited from class com.bigdata.service.DataServiceCallable

getDataService, isDataService, setDataService

Methods inherited from class com.bigdata.service.FederationCallable

getFederation, setFederation

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.bigdata.service.IFederationCallable

getFederation, setFederation

Constructor Detail

QueryTask

public QueryTask(IStep step,
                 IJoinNexusFactory joinNexusFactory,
                 IBlockingBuffer<ISolution[]> buffer,
                 IIndexManager indexManager,
                 DataService dataService)

Parameters:

buffer - The IBlockingBuffer on which the ISolutions will be written.

Method Detail

call

public RuleStats call()
               throws Exception

Run the task (invoked once we are in the target execution context).

Throws:

Exception

runTasks

protected RuleStats runTasks(IJoinNexus joinNexus,
                             List<Callable<RuleStats>> tasks)
                      throws InterruptedException,
                             ExecutionException

Run the task(s) and wait for them to complete.

Returns:

The RuleStats

Throws:

ExecutionException

InterruptedException

newQueryTasks

protected List<Callable<RuleStats>> newQueryTasks(IStep step,
                                                  IJoinNexus joinNexus,
                                                  IBlockingBuffer<ISolution[]> buffer)

Builds a set of tasks for the program. Each task is assigned its own UnsynchronizedArrayBuffer. Each task will flush that UnsynchronizedArrayBuffer onto the given IBuffer when it completes.

Parameters:

step - The IStep.

joinNexus - The IJoinNexus.

buffer - The thread-safe buffer onto which the individual tasks emit chunks.

Returns:

The list of tasks to run.