/*
* Copyright (c) 2008 - 2011, Jan Stender, Bjoern Kolbeck, Mikael Hoegqvist,
* Felix Hupfeld, Felix Langner Zuse Institute Berlin
*
* Licensed under the BSD License, see LICENSE file for details.
*
*/
package de.mxro.thrd.babudb05.lsmdb;
import java.io.IOException;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.Map;
import java.util.Map.Entry;
import java.util.concurrent.atomic.AtomicBoolean;
import de.mxro.thrd.babudb05.BabuDBRequestResultImpl;
import de.mxro.thrd.babudb05.api.database.UserDefinedLookup;
import de.mxro.thrd.babudb05.api.dev.BabuDBInternal;
import de.mxro.thrd.babudb05.api.exception.BabuDBException;
import de.mxro.thrd.babudb05.api.exception.BabuDBException.ErrorCode;
import de.mxro.thrd.xstreemfs.foundation.LifeCycleThread;
import de.mxro.thrd.xstreemfs.foundation.logging.Logging;
/**
* @author bjko
*/
public class LSMDBWorker extends LifeCycleThread {
public static enum RequestOperation {
INSERT, LOOKUP, PREFIX_LOOKUP, RANGE_LOOKUP, USER_DEFINED_LOOKUP, LOCK
};
private final AtomicBoolean locked = new AtomicBoolean(false);
private final BabuDBInternal dbs;
private final LinkedList<LSMDBRequest<?>> requests = new LinkedList<LSMDBRequest<?>>();
private final int maxQ;
private boolean quit = true;
private boolean graceful;
public LSMDBWorker(BabuDBInternal babuDB, int id, int maxQ) {
super("LSMDBWrkr#" + id);
setLifeCycleListener(babuDB);
this.maxQ = maxQ;
this.dbs = babuDB;
}
public synchronized void addRequest(LSMDBRequest<?> request) throws InterruptedException {
assert (request != null);
// wait for queue space to become available
if (!quit && maxQ > 0 && requests.size() >= maxQ) {
wait();
}
if (!quit) {
assert (maxQ == 0 || requests.size() < maxQ);
requests.add(request);
notifyAll();
} else {
throw new InterruptedException("Appending a request to the queue of " + getName() +
" was interrupted, due shutdown.");
}
}
public synchronized void shutdown(boolean graceful) {
this.graceful = graceful;
quit = true;
notifyAll();
}
@Override
public void shutdown() {
shutdown(true);
}
@Override
public synchronized void start() {
assert (quit);
quit = false;
super.start();
}
@Override
public void run() {
Logging.logMessage(Logging.LEVEL_DEBUG, this, "operational");
notifyStarted();
while (!quit) {
try {
final LSMDBRequest<?> r;
// wait for a request
synchronized (this) {
if (requests.isEmpty()) {
wait();
}
if (quit) {
break;
// get a request
} else {
r = requests.poll();
notify();
}
}
processRequest(r);
} catch (InterruptedException ex) {
if (!quit) {
cleanUp();
notifyCrashed(ex);
return;
}
}
}
// process pending requests on shutdown if graceful flag has not been reset
if (graceful) {
synchronized (requests) {
for (LSMDBRequest<?> rq : requests) {
processRequest(rq);
}
}
}
Logging.logMessage(Logging.LEVEL_DEBUG, this, "worker shutdown complete");
notifyStopped();
}
/**
* Closes the worker. And frees remaining requests.
*
* @throws IOException
*/
private synchronized void cleanUp() {
assert (graceful || requests.size() == 0);
// clear pending requests, if available
for (LSMDBRequest<?> rq : requests) {
rq.getListener().failed(new BabuDBException(ErrorCode.INTERRUPTED,
"Worker was shut down, before the request could be proceeded."));
}
}
@SuppressWarnings("unchecked")
protected void processRequest(LSMDBRequest<?> r) {
switch (r.getOperation()) {
case INSERT:
doInsert(r);
break;
case LOOKUP:
doLookup((LSMDBRequest<byte[]>) r);
break;
case PREFIX_LOOKUP:
doPrefixLookup((LSMDBRequest<Iterator<Entry<byte[], byte[]>>>) r);
break;
case RANGE_LOOKUP:
doRangeLookup((LSMDBRequest<Iterator<Entry<byte[], byte[]>>>) r);
break;
case USER_DEFINED_LOOKUP:
doUserLookup((LSMDBRequest<Object>) r);
break;
case LOCK:
doLock((LSMDBRequest<Object>) r);
break;
default:
Logging.logMessage(Logging.LEVEL_ERROR, this,
"UNKNOWN OPERATION REQUESTED! PROGRAMMATIC ERROR!!!! PANIC!");
System.exit(1);
}
}
protected void doUserLookup(final LSMDBRequest<Object> r) {
final UserDefinedLookup l = r.getUserDefinedLookup();
final LSMLookupInterface lif = new LSMLookupInterface(r.getDatabase());
try {
Object result = l.execute(lif);
r.getListener().finished(result);
} catch (BabuDBException ex) {
r.getListener().failed(ex);
}
}
@SuppressWarnings("unchecked")
protected void doInsert(final LSMDBRequest<?> r) {
try {
dbs.getTransactionManager().makePersistent(
dbs.getDatabaseManager().createTransaction().insertRecordGroup(
r.getDatabase().getDatabaseName(), r.getInsertData(), r.getDatabase()),
(BabuDBRequestResultImpl<Object>) r.getListener());
} catch (BabuDBException e) {
r.getListener().failed(e);
}
}
protected void doLookup(final LSMDBRequest<byte[]> r) {
final LSMDatabase db = r.getDatabase();
final int numIndices = db.getIndexCount();
if ((r.getIndexId() >= numIndices) || (r.getIndexId() < 0)) {
r.getListener().failed(
new BabuDBException(ErrorCode.NO_SUCH_INDEX, "index " + r.getIndexId() +
" does not exist"));
} else {
r.getListener().finished(db.getIndex(r.getIndexId()).lookup(r.getLookupKey()));
}
}
protected void doPrefixLookup(final LSMDBRequest<Iterator<Map.Entry<byte[], byte[]>>> r) {
final LSMDatabase db = r.getDatabase();
final int numIndices = db.getIndexCount();
if ((r.getIndexId() >= numIndices) || (r.getIndexId() < 0)) {
r.getListener().failed(
new BabuDBException(ErrorCode.NO_SUCH_INDEX, "index " + r.getIndexId() +
" does not exist"));
} else {
r.getListener().finished(db.getIndex(r.getIndexId()).prefixLookup(r.getLookupKey()));
}
}
protected void doRangeLookup(final LSMDBRequest<Iterator<Map.Entry<byte[], byte[]>>> r) {
final LSMDatabase db = r.getDatabase();
final int numIndices = db.getIndexCount();
if ((r.getIndexId() >= numIndices) || (r.getIndexId() < 0)) {
r.getListener().failed(
new BabuDBException(ErrorCode.NO_SUCH_INDEX, "index " + r.getIndexId() +
" does not exist"));
} else {
r.getListener().finished(
db.getIndex(r.getIndexId()).rangeLookup(r.getFrom(), r.getTo()));
}
}
protected void doLock(final LSMDBRequest<Object> r) {
synchronized (locked) {
r.getListener().finished(locked);
try {
if (locked.get()) {
locked.wait();
}
} catch (InterruptedException e) {
r.getListener().failed(
new BabuDBException(ErrorCode.INTERRUPTED, e.getMessage(), e));
}
}
}
}