/*******************************************************************************
* Copyright 2012-2014 by Aerospike.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
******************************************************************************/
package com.aerospike.client.command;
import java.util.concurrent.ExecutorService;
import com.aerospike.client.AerospikeException;
import com.aerospike.client.ScanCallback;
import com.aerospike.client.cluster.Cluster;
import com.aerospike.client.cluster.Node;
import com.aerospike.client.policy.ScanPolicy;
public final class ScanExecutor {
private final ExecutorService threadPool;
private final ScanThread[] threads;
private volatile Exception exception;
private int nextThread;
private boolean completed;
public ScanExecutor(Cluster cluster, Node[] nodes, ScanPolicy policy, String namespace, String setName, ScanCallback callback, String[] binNames) {
this.threadPool = cluster.getThreadPool();
// Initialize threads.
threads = new ScanThread[nodes.length];
for (int i = 0; i < nodes.length; i++) {
ScanCommand command = new ScanCommand(nodes[i], policy, namespace, setName, callback, binNames);
threads[i] = new ScanThread(command);
}
// Initialize maximum number of nodes to query in parallel.
nextThread = (policy.maxConcurrentNodes == 0 || policy.maxConcurrentNodes >= threads.length)? threads.length : policy.maxConcurrentNodes;
}
public void scanParallel() throws AerospikeException {
// Start threads. Use separate max because threadCompleted() may modify nextThread in parallel.
int max = nextThread;
for (int i = 0; i < max; i++) {
threadPool.execute(threads[i]);
}
waitTillComplete();
// Throw an exception if an error occurred.
if (exception != null) {
if (exception instanceof AerospikeException) {
throw (AerospikeException)exception;
}
else {
throw new AerospikeException(exception);
}
}
}
private void threadCompleted() {
int index = -1;
// Determine if a new thread needs to be started.
synchronized (threads) {
if (nextThread < threads.length) {
index = nextThread++;
}
}
if (index >= 0) {
// Start new thread.
threadPool.execute(threads[index]);
}
else {
// All threads have been started. Check status.
for (ScanThread thread : threads) {
if (! thread.complete) {
// Some threads have not finished. Do nothing.
return;
}
}
// All threads complete.
notifyCompleted();
}
}
private void stopThreads(Exception cause) {
synchronized (threads) {
if (exception != null) {
return;
}
exception = cause;
}
for (ScanThread thread : threads) {
try {
thread.stop();
}
catch (Exception e) {
}
}
notifyCompleted();
}
private synchronized void waitTillComplete() {
while (! completed) {
try {
super.wait();
}
catch (InterruptedException ie) {
}
}
}
private synchronized void notifyCompleted() {
completed = true;
super.notify();
}
private final class ScanThread implements Runnable {
private final ScanCommand command;
private Thread thread;
private boolean complete;
public ScanThread(ScanCommand command) {
this.command = command;
}
public void run() {
thread = Thread.currentThread();
try {
if (command.isValid()) {
command.execute();
}
}
catch (Exception e) {
// Terminate other scan threads.
stopThreads(e);
}
complete = true;
if (exception == null) {
threadCompleted();
}
}
public void stop() {
command.stop();
if (thread != null) {
thread.interrupt();
}
}
}
}