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OpenCADC core utility library
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/*
************************************************************************
******************* CANADIAN ASTRONOMY DATA CENTRE *******************
************** CENTRE CANADIEN DE DONNÉES ASTRONOMIQUES **************
*
* (c) 2020. (c) 2020.
* Government of Canada Gouvernement du Canada
* National Research Council Conseil national de recherches
* Ottawa, Canada, K1A 0R6 Ottawa, Canada, K1A 0R6
* All rights reserved Tous droits réservés
*
* NRC disclaims any warranties, Le CNRC dénie toute garantie
* expressed, implied, or énoncée, implicite ou légale,
* statutory, of any kind with de quelque nature que ce
* respect to the software, soit, concernant le logiciel,
* including without limitation y compris sans restriction
* any warranty of merchantability toute garantie de valeur
* or fitness for a particular marchande ou de pertinence
* purpose. NRC shall not be pour un usage particulier.
* liable in any event for any Le CNRC ne pourra en aucun cas
* damages, whether direct or être tenu responsable de tout
* indirect, special or general, dommage, direct ou indirect,
* consequential or incidental, particulier ou général,
* arising from the use of the accessoire ou fortuit, résultant
* software. Neither the name de l'utilisation du logiciel. Ni
* of the National Research le nom du Conseil National de
* Council of Canada nor the Recherches du Canada ni les noms
* names of its contributors may de ses participants ne peuvent
* be used to endorse or promote être utilisés pour approuver ou
* products derived from this promouvoir les produits dérivés
* software without specific prior de ce logiciel sans autorisation
* written permission. préalable et particulière
* par écrit.
*
* This file is part of the Ce fichier fait partie du projet
* OpenCADC project. OpenCADC.
*
* OpenCADC is free software: OpenCADC est un logiciel libre ;
* you can redistribute it and/or vous pouvez le redistribuer ou le
* modify it under the terms of modifier suivant les termes de
* the GNU Affero General Public la “GNU Affero General Public
* License as published by the License” telle que publiée
* Free Software Foundation, par la Free Software Foundation
* either version 3 of the : soit la version 3 de cette
* License, or (at your option) licence, soit (à votre gré)
* any later version. toute version ultérieure.
*
* OpenCADC is distributed in the OpenCADC est distribué
* hope that it will be useful, dans l’espoir qu’il vous
* but WITHOUT ANY WARRANTY; sera utile, mais SANS AUCUNE
* without even the implied GARANTIE : sans même la garantie
* warranty of MERCHANTABILITY implicite de COMMERCIALISABILITÉ
* or FITNESS FOR A PARTICULAR ni d’ADÉQUATION À UN OBJECTIF
* PURPOSE. See the GNU Affero PARTICULIER. Consultez la Licence
* General Public License for Générale Publique GNU Affero
* more details. pour plus de détails.
*
* You should have received Vous devriez avoir reçu une
* a copy of the GNU Affero copie de la Licence Générale
* General Public License along Publique GNU Affero avec
* with OpenCADC. If not, see OpenCADC ; si ce n’est
* - rq = new LinkedBlockingQueue();
private final BlockingQueue
- wq = new LinkedBlockingQueue();
/**
* Create default instance. The default is triple-buffered with 64K buffers.
*/
public MultiBufferIO() {
this(3, 64 * 1024);
}
/**
* Create instance with non-default buffering.
*
* @param numBuffers number of buffers
* @param bufferSize size of each buffer
*/
public MultiBufferIO(int numBuffers, int bufferSize) {
if (numBuffers < 1) {
throw new IllegalArgumentException("invalid numBuffers: " + numBuffers + " (minimum: 1)");
}
if (bufferSize < 8192) {
throw new IllegalArgumentException("invalid bufferSize: " + bufferSize + " (minimum: 8192)");
}
this.numBuffers = numBuffers;
this.bufferSize = bufferSize;
}
/**
* Copy input stream to output stream.
*
* @param input source/producer
* @param output sink/consumer
* @throws InterruptedException if the main thread gets an interrupt
* @throws ReadException if input.read() fails
* @throws WriteException if output.write() fails
*/
public void copy(InputStream input, OutputStream output) throws InterruptedException, ReadException, WriteException {
for (int i = 0; i < numBuffers; i++) {
rq.put(new Item(bufferSize));
}
Worker w = new Worker(output);
Thread writer = new Thread(w, MultiBufferIO.class.getSimpleName() + "-writer");
try {
writer.start();
Throwable readFail = doit(input, w);
log.debug("reader completed: " + readFail);
if (readFail != null) {
writer.interrupt();
}
writer.join();
log.debug("writer completed: " + w.fail);
if (readFail != null) {
throw new ReadException(READ_FAIL, readFail);
}
if (w.fail != null) {
throw new WriteException(WRITE_FAIL, w.fail);
}
} finally {
if (writer.isAlive()) {
try {
log.error("BUG: " + writer.getName() + " still alive in finally - interrupting...");
writer.interrupt();
log.error("BUG: " + writer.getName() + " interrupted in finally - waiting...");
writer.join();
log.error("BUG: " + writer.getName() + " still alive in finally - finished");
} catch (Exception ex) {
log.error("OOPS: failed to kill " + writer.getName(), ex);
}
}
}
}
private Exception doit(InputStream istream, Worker w) {
Exception ret = null;
try {
while (w.fail == null) {
// check/clear interrupted flag and throw if necessary
if (Thread.interrupted()) {
throw new InterruptedException();
}
//log.debug("reader: wait for buffer...");
Item buf = rq.take();
if (buf.num == -1) {
return null; // done
}
//log.debug("reader: read from stream...");
buf.num = istream.read(buf.buffer);
//log.debug("reader: queue buffer: " + buf.num);
wq.put(buf);
if (buf.num == -1) {
return null; // done
}
}
//log.debug("reader: detected writer.fail: " + w.fail);
return null;
} catch (Exception ex) {
Item term = new Item(0);
term.num = -1;
try {
wq.put(term);
} catch (InterruptedException oops) {
log.debug("interrupted while putting terminator", oops);
}
return ex;
}
}
private class Item {
final byte[] buffer;
int num = 0;
Item(int sz) {
buffer = new byte[sz];
}
}
// take buffer from wq, write to output, recycle via rq
private class Worker implements Runnable {
private OutputStream ostream;
Exception fail;
public Worker(OutputStream ostream) {
this.ostream = ostream;
}
@Override
public void run() {
try {
while (true) {
// check/clear interrupted flag and throw if necessary
if (Thread.interrupted()) {
throw new InterruptedException();
}
//log.debug("writer: wait for buffer...");
Item buf = wq.take();
//log.debug("writer: got buffer " + buf.num);
if (buf.num == -1) {
return; // done
}
//log.debug("writer: write to stream...");
ostream.write(buf.buffer, 0, buf.num);
//log.debug("writer: recycle buffer...");
rq.put(buf);
}
} catch (Exception ex) {
this.fail = ex;
Item term = new Item(0);
term.num = -1;
try {
rq.put(term);
} catch (InterruptedException oops) {
log.debug("interrupted while putting terminator", oops);
}
return;
}
}
}
}