com.bigdata.relation.rule.eval

Class DefaultRuleTaskFactory

java.lang.Object

com.bigdata.relation.rule.eval.DefaultRuleTaskFactory

All Implemented Interfaces:

IRuleTaskFactory, Externalizable, Serializable

public class DefaultRuleTaskFactory
extends Object
implements IRuleTaskFactory, Externalizable

Default factory for tasks to execute IRules.

Version:

$Id$

Author:

Bryan Thompson

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected static org.apache.log4j.Logger	log
static IRuleTaskFactory	PIPELINE Pipeline join strategy.

Constructor Summary

Constructors

Constructor and Description
DefaultRuleTaskFactory() De-serialization ctor.
DefaultRuleTaskFactory(boolean subquery)

Method Summary

Methods

Modifier and Type	Method and Description
IStepTask	newTask(IRule rule, IJoinNexus joinNexus, IBuffer<ISolution[]> buffer) The object will be used to evaluate the rule for the IRule.
void	readExternal(ObjectInput in)
void	writeExternal(ObjectOutput out)

Methods inherited from class java.lang.Object

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

Field Detail

log

protected static final org.apache.log4j.Logger log

PIPELINE

public static final transient IRuleTaskFactory PIPELINE

Pipeline join strategy.

Note: This join strategy was designed for scale-out evaluation but does better for local deployments as well. It starts a JoinTask per index partition on which the join must read while evaluating the rule. This gives it access to the local index objects for each index partition of interest. Intermediate IBindingSets are streamed in chunks to the downstream JoinTask(s). Therefore, all index operations are local and only the intermediate IBindingSets and the final ISolutions are moved using RMI.

See Also:

JoinMasterTask, LocalJoinMasterTask, DistributedJoinMasterTask

Constructor Detail

DefaultRuleTaskFactory

public DefaultRuleTaskFactory()

De-serialization ctor.

DefaultRuleTaskFactory

public DefaultRuleTaskFactory(boolean subquery)

Method Detail

newTask

public IStepTask newTask(IRule rule,
                IJoinNexus joinNexus,
                IBuffer<ISolution[]> buffer)

Description copied from interface: IRuleTaskFactory

The object will be used to evaluate the rule for the IRule.

Specified by:

newTask in interface IRuleTaskFactory

Parameters:

rule - The rule (MAY have been specialized since it was declared).

joinNexus - Encapsulates various important information required for join operations.

buffer - The buffer onto which chunks of computed ISolutions for the IRule must be written.

Returns:

null unless custom evaluation is desired.

readExternal

public void readExternal(ObjectInput in)
                  throws IOException,
                         ClassNotFoundException

Specified by:

readExternal in interface Externalizable

Throws:

IOException

ClassNotFoundException

writeExternal

public void writeExternal(ObjectOutput out)
                   throws IOException

Specified by:

writeExternal in interface Externalizable

Throws:

IOException