/*
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
licenses@blazegraph.com
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* Created on Apr 1, 2009
*/
package com.bigdata.service.ndx;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import com.bigdata.btree.IndexMetadata;
import com.bigdata.btree.proc.AbstractKeyArrayIndexProcedureConstructor;
import com.bigdata.btree.proc.IKeyArrayIndexProcedure;
import com.bigdata.btree.proc.IKeyRangeIndexProcedure;
import com.bigdata.btree.proc.IParallelizableIndexProcedure;
import com.bigdata.btree.proc.IResultHandler;
import com.bigdata.btree.proc.ISimpleIndexProcedure;
import com.bigdata.journal.ITx;
import com.bigdata.mdi.IMetadataIndex;
import com.bigdata.mdi.PartitionLocator;
import com.bigdata.resources.StaleLocatorException;
import com.bigdata.service.AbstractScaleOutFederation;
import com.bigdata.service.Split;
/**
* Abstract class encapsulating MOST of the logic for executing tasks
* corresponding to client index operations. {@link StaleLocatorException}s are
* handled by the recursive application of the various <code>submit()</code>
* methods.
* <p>
* A concrete subclass must implement {@link #runTasks(boolean, ArrayList)}.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
*/
abstract public class AbstractScaleOutClientIndexView2 extends
AbstractScaleOutClientIndexView {
/**
* Create a view on a scale-out index.
*
* @param fed
* The federation containing the index.
* @param name
* The index name.
* @param timestamp
* A transaction identifier, {@link ITx#UNISOLATED} for the
* unisolated index view, {@link ITx#READ_COMMITTED}, or
* <code>timestamp</code> for a historical view no later than
* the specified timestamp.
* @param metadataIndex
* The {@link IMetadataIndex} for the named scale-out index as of
* that timestamp. Note that the {@link IndexMetadata} on this
* object contains the template {@link IndexMetadata} for the
* scale-out index partitions.
*/
public AbstractScaleOutClientIndexView2(AbstractScaleOutFederation fed,
String name, long timestamp, IMetadataIndex metadataIndex) {
super(fed, name, timestamp, metadataIndex);
}
/**
*
* @see #getRecursionDepth()
*/
final private ThreadLocal<AtomicInteger> recursionDepth = new ThreadLocal<AtomicInteger>() {
protected synchronized AtomicInteger initialValue() {
return new AtomicInteger();
}
};
final public AtomicInteger getRecursionDepth() {
return recursionDepth.get();
}
/**
* Runs set of tasks.
*
* @param parallel
* <code>true</code> iff the tasks MAY be run in parallel.
* @param tasks
* The tasks to be executed.
*/
abstract protected void runTasks(final boolean parallel,
final ArrayList<AbstractDataServiceProcedureTask> tasks);
/**
* Variant uses the caller's timestamp.
*
* @param ts
* @param key
* @param proc
* @return
*/
protected Object submit(final long ts, final byte[] key,
final ISimpleIndexProcedure proc) {
// Find the index partition spanning that key.
final PartitionLocator locator = fed.getMetadataIndex(name, ts).find(
key);
/*
* Submit procedure to that data service.
*/
try {
if (log.isInfoEnabled()) {
log.info("Submitting " + proc.getClass() + " to partition"
+ locator);
}
// required to get the result back from the procedure.
final IResultHandler resultHandler = new IdentityHandler();
final SimpleDataServiceProcedureTask task = new SimpleDataServiceProcedureTask(
this, key, ts, new Split(locator, 0, 0), proc,
resultHandler);
// submit procedure and await completion.
getThreadPool().submit(task).get(taskTimeout, TimeUnit.MILLISECONDS);
// the singleton result.
final Object result = resultHandler.getResult();
return result;
} catch (Exception ex) {
throw new RuntimeException(ex);
}
}
/**
* Variant uses the caller's timestamp.
*
* @param ts
* @param fromKey
* @param toKey
* @param proc
* @param resultHandler
*/
protected void submit(final long ts, final byte[] fromKey,
final byte[] toKey, final IKeyRangeIndexProcedure proc,
final IResultHandler resultHandler) {
// true iff the procedure is known to be parallelizable.
final boolean parallel = proc instanceof IParallelizableIndexProcedure;
if (log.isInfoEnabled())
log.info("Procedure " + proc.getClass().getName()
+ " will be mapped across index partitions in "
+ (parallel ? "parallel" : "sequence"));
final int poolSize = ((ThreadPoolExecutor) getThreadPool())
.getCorePoolSize();
final int maxTasksPerRequest = fed.getClient()
.getMaxParallelTasksPerRequest();
// max #of tasks to queue at once.
final int maxTasks = poolSize == 0 ? maxTasksPerRequest : Math.min(
poolSize, maxTasksPerRequest);
// verify positive or the loop below will fail to progress.
assert maxTasks > 0 : "maxTasks=" + maxTasks + ", poolSize=" + poolSize
+ ", maxTasksPerRequest=" + maxTasksPerRequest;
/*
* Scan visits index partition locators in key order.
*
* Note: We are using the caller's timestamp.
*/
final Iterator<PartitionLocator> itr = locatorScan(ts, fromKey, toKey,
false/* reverseScan */);
long nparts = 0;
while (itr.hasNext()) {
/*
* Process the remaining locators a "chunk" at a time. The chunk
* size is choosen to be the configured size of the client thread
* pool. This lets us avoid overwhelming the thread pool queue when
* mapping a procedure across a very large #of index partitions.
*
* The result is an ordered list of the tasks to be executed. The
* order of the tasks is determined by the natural order of the
* index partitions - that is, we submit the tasks in key order so
* that a non-parallelizable procedure will be mapped in the correct
* sequence.
*/
final ArrayList<AbstractDataServiceProcedureTask> tasks = new ArrayList<AbstractDataServiceProcedureTask>(
maxTasks);
for (int i = 0; i < maxTasks && itr.hasNext(); i++) {
final PartitionLocator locator = itr.next();
final Split split = new Split(locator, 0/* fromIndex */, 0/* toIndex */);
tasks.add(new KeyRangeDataServiceProcedureTask(this, fromKey, toKey,
ts, split, proc, resultHandler));
nparts++;
}
runTasks(parallel, tasks);
} // next (chunk of) locators.
if (log.isInfoEnabled())
log.info("Procedure " + proc.getClass().getName()
+ " mapped across " + nparts + " index partitions in "
+ (parallel ? "parallel" : "sequence"));
}
/**
* Variant uses the caller's timestamp.
*
* @param ts
* @param fromIndex
* @param toIndex
* @param keys
* @param vals
* @param ctor
* @param aggregator
*/
protected void submit(final long ts, final int fromIndex, final int toIndex,
final byte[][] keys, final byte[][] vals,
final AbstractKeyArrayIndexProcedureConstructor ctor,
final IResultHandler aggregator) {
/*
* Break down the data into a series of "splits", each of which will be
* applied to a different index partition.
*
* Note: We are using the caller's timestamp here so this will have
* read-consistent semantics!
*/
final LinkedList<Split> splits = splitKeys(ts, fromIndex, toIndex, keys);
final int nsplits = splits.size();
/*
* Create the instances of the procedure for each split.
*/
final ArrayList<AbstractDataServiceProcedureTask> tasks = new ArrayList<AbstractDataServiceProcedureTask>(
nsplits);
final Iterator<Split> itr = splits.iterator();
boolean parallel = false;
while (itr.hasNext()) {
final Split split = itr.next();
final IKeyArrayIndexProcedure proc = ctor.newInstance(this,
split.fromIndex, split.toIndex, keys, vals);
if (proc instanceof IParallelizableIndexProcedure) {
parallel = true;
}
tasks.add(new KeyArrayDataServiceProcedureTask(this, keys, vals, ts,
split, proc, aggregator, ctor));
}
if (log.isInfoEnabled())
log.info("Procedures created by " + ctor.getClass().getName()
+ " will run on " + nsplits + " index partitions in "
+ (parallel ? "parallel" : "sequence"));
runTasks(parallel, tasks);
}
}