package com.bigdata.relation.rule.eval;
import java.io.Serializable;
import org.apache.log4j.Logger;
import com.bigdata.relation.accesspath.IBuffer;
import com.bigdata.relation.rule.IRule;
/**
* Helper class is used for sequential {@link IRule} step execution. It runs
* an {@link IStepTask} and then {@link IBuffer#flush()}s the
* {@link IBuffer} on which the {@link IStepTask} wrote its
* {@link ISolution}s.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
* @version $Id$
*/
public class RunRuleAndFlushBufferTask implements IStepTask, Serializable {
protected static final Logger log = Logger.getLogger(RunRuleAndFlushBufferTask.class);
protected static final boolean DEBUG = log.isDebugEnabled();
/**
*
*/
private static final long serialVersionUID = -2910127641227561854L;
private final IStepTask stepTask;
private final IBuffer<ISolution[]> buffer;
/**
*
* @param stepTask
* A task.
* @param buffer
* A thread-safe buffer containing chunks of {@link ISolution}s
* computed by that task.
*/
public RunRuleAndFlushBufferTask(final IStepTask stepTask,
final IBuffer<ISolution[]> buffer) {
if (stepTask == null)
throw new IllegalArgumentException();
if (buffer == null)
throw new IllegalArgumentException();
this.stepTask = stepTask;
this.buffer = buffer;
}
public RuleStats call() throws Exception {
// run the rule.
final RuleStats ruleStats = stepTask.call();
if (DEBUG) {
log.debug("Flushing buffer: size=" + buffer.size() + ", class="
+ buffer.getClass().getName());
}
final long mutationCount = buffer.flush();
// if (!ruleStats.mutationCount.compareAndSet(0L, mutationCount)) {
//
// /*
// * Since buffer#flush() reports the total #of solutions flushed so
// * far, the mutation count should only be set once the rule has
// * completed its execution. Otherwise solutions will be double
// * counted.
// */
//
// throw new AssertionError("Already set: mutationCount="
// + ruleStats.mutationCount+", task="+stepTask);
//
// }
if(DEBUG) {
log.debug("Flushed buffer: mutationCount=" + mutationCount);
// + ", stats=" + ruleStats);
}
return ruleStats;
}
}