/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.activemq.store.kahadb.plist;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.util.Iterator;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Set;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicReference;
import org.apache.kahadb.index.ListIndex;
import org.apache.kahadb.journal.Location;
import org.apache.kahadb.page.Transaction;
import org.apache.kahadb.util.ByteSequence;
import org.apache.kahadb.util.LocationMarshaller;
import org.apache.kahadb.util.StringMarshaller;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class PList extends ListIndex<String, Location> {
static final Logger LOG = LoggerFactory.getLogger(PList.class);
final PListStore store;
private String name;
Object indexLock;
PList(PListStore store) {
this.store = store;
this.indexLock = store.getIndexLock();
setPageFile(store.getPageFile());
setKeyMarshaller(StringMarshaller.INSTANCE);
setValueMarshaller(LocationMarshaller.INSTANCE);
}
public void setName(String name) {
this.name = name;
}
public String getName() {
return this.name;
}
void read(DataInput in) throws IOException {
setHeadPageId(in.readLong());
}
public void write(DataOutput out) throws IOException {
out.writeLong(getHeadPageId());
}
public synchronized void destroy() throws IOException {
synchronized (indexLock) {
this.store.getPageFile().tx().execute(new Transaction.Closure<IOException>() {
public void execute(Transaction tx) throws IOException {
clear(tx);
unload(tx);
}
});
}
}
public void addLast(final String id, final ByteSequence bs) throws IOException {
final Location location = this.store.write(bs, false);
synchronized (indexLock) {
this.store.getPageFile().tx().execute(new Transaction.Closure<IOException>() {
public void execute(Transaction tx) throws IOException {
add(tx, id, location);
}
});
}
}
public void addFirst(final String id, final ByteSequence bs) throws IOException {
final Location location = this.store.write(bs, false);
synchronized (indexLock) {
this.store.getPageFile().tx().execute(new Transaction.Closure<IOException>() {
public void execute(Transaction tx) throws IOException {
addFirst(tx, id, location);
}
});
}
}
public boolean remove(final String id) throws IOException {
final AtomicBoolean result = new AtomicBoolean();
synchronized (indexLock) {
this.store.getPageFile().tx().execute(new Transaction.Closure<IOException>() {
public void execute(Transaction tx) throws IOException {
result.set(remove(tx, id) != null);
}
});
}
return result.get();
}
public boolean remove(final long position) throws IOException {
final AtomicBoolean result = new AtomicBoolean();
synchronized (indexLock) {
this.store.getPageFile().tx().execute(new Transaction.Closure<IOException>() {
public void execute(Transaction tx) throws IOException {
Iterator<Map.Entry<String, Location>> iterator = iterator(tx, position);
if (iterator.hasNext()) {
iterator.next();
iterator.remove();
result.set(true);
} else {
result.set(false);
}
}
});
}
return result.get();
}
public PListEntry get(final long position) throws IOException {
PListEntry result = null;
final AtomicReference<Map.Entry<String, Location>> ref = new AtomicReference<Map.Entry<String, Location>>();
synchronized (indexLock) {
this.store.getPageFile().tx().execute(new Transaction.Closure<IOException>() {
public void execute(Transaction tx) throws IOException {
Iterator<Map.Entry<String, Location>> iterator = iterator(tx, position);
ref.set(iterator.next());
}
});
}
if (ref.get() != null) {
ByteSequence bs = this.store.getPayload(ref.get().getValue());
result = new PListEntry(ref.get().getKey(), bs);
}
return result;
}
public PListEntry getFirst() throws IOException {
PListEntry result = null;
final AtomicReference<Map.Entry<String, Location>> ref = new AtomicReference<Map.Entry<String, Location>>();
synchronized (indexLock) {
this.store.getPageFile().tx().execute(new Transaction.Closure<IOException>() {
public void execute(Transaction tx) throws IOException {
ref.set(getFirst(tx));
}
});
}
if (ref.get() != null) {
ByteSequence bs = this.store.getPayload(ref.get().getValue());
result = new PListEntry(ref.get().getKey(), bs);
}
return result;
}
public PListEntry getLast() throws IOException {
PListEntry result = null;
final AtomicReference<Map.Entry<String, Location>> ref = new AtomicReference<Map.Entry<String, Location>>();
synchronized (indexLock) {
this.store.getPageFile().tx().execute(new Transaction.Closure<IOException>() {
public void execute(Transaction tx) throws IOException {
ref.set(getLast(tx));
}
});
}
if (ref.get() != null) {
ByteSequence bs = this.store.getPayload(ref.get().getValue());
result = new PListEntry(ref.get().getKey(), bs);
}
return result;
}
public boolean isEmpty() {
return size() == 0;
}
public PListIterator iterator() throws IOException {
return new PListIterator();
}
public final class PListIterator implements Iterator<PListEntry> {
final Iterator<Map.Entry<String, Location>> iterator;
final Transaction tx;
PListIterator() throws IOException {
tx = store.pageFile.tx();
synchronized (indexLock) {
this.iterator = iterator(tx);
}
}
@Override
public boolean hasNext() {
return iterator.hasNext();
}
@Override
public PListEntry next() {
Map.Entry<String, Location> entry = iterator.next();
ByteSequence bs = null;
try {
bs = store.getPayload(entry.getValue());
} catch (IOException unexpected) {
NoSuchElementException e = new NoSuchElementException(unexpected.getLocalizedMessage());
e.initCause(unexpected);
throw e;
}
return new PListEntry(entry.getKey(), bs);
}
@Override
public void remove() {
try {
synchronized (indexLock) {
tx.execute(new Transaction.Closure<IOException>() {
@Override
public void execute(Transaction tx) throws IOException {
iterator.remove();
}
});
}
} catch (IOException unexpected) {
IllegalStateException e = new IllegalStateException(unexpected);
e.initCause(unexpected);
throw e;
}
}
public void release() {
try {
tx.rollback();
} catch (IOException unexpected) {
IllegalStateException e = new IllegalStateException(unexpected);
e.initCause(unexpected);
throw e;
}
}
}
public void claimFileLocations(final Set<Integer> candidates) throws IOException {
synchronized (indexLock) {
if (loaded.get()) {
this.store.getPageFile().tx().execute(new Transaction.Closure<IOException>() {
public void execute(Transaction tx) throws IOException {
Iterator<Map.Entry<String,Location>> iterator = iterator(tx);
while (iterator.hasNext()) {
Location location = iterator.next().getValue();
candidates.remove(location.getDataFileId());
}
}
});
}
}
}
@Override
public String toString() {
return name + "[headPageId=" + getHeadPageId() + ",tailPageId=" + getTailPageId() + ", size=" + size() + "]";
}
}