/*
* 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.jackrabbit.core.journal;
import java.io.ByteArrayInputStream;
import java.io.DataInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.NoSuchElementException;
import java.util.List;
import java.util.Collections;
import org.apache.jackrabbit.spi.commons.namespace.NamespaceResolver;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Memory-based journal, useful for testing purposes only.
*/
public class MemoryJournal extends AbstractJournal {
/**
* Default read delay: none.
*/
private static final long DEFAULT_READ_DELAY = 0;
/**
* Default write delay: none.
*/
private static final long DEFAULT_WRITE_DELAY = 0;
/**
* Logger.
*/
private static Logger log = LoggerFactory.getLogger(MemoryJournal.class);
/**
* Revision.
*/
private InstanceRevision revision = new MemoryRevision();
/**
* List of records.
*/
private List<MemoryRecord> records = Collections.synchronizedList(new ArrayList<MemoryRecord>());
/**
* Set the read delay, i.e. the time in ms to wait before returning
* a record.
*/
private long readDelay = DEFAULT_READ_DELAY;
/**
* Set the write delay, i.e. the time in ms to wait before appending
* a record.
*/
private long writeDelay = DEFAULT_WRITE_DELAY;
/**
* Flag indicating whether this journal is closed.
*/
private boolean closed;
/**
* {@inheritDoc}
*/
public InstanceRevision getInstanceRevision() throws JournalException {
return revision;
}
/**
* {@inheritDoc}
*/
public void init(String id, NamespaceResolver resolver)
throws JournalException {
super.init(id, resolver);
}
/**
* {@inheritDoc}
*/
protected void doLock() throws JournalException {
checkState();
}
@Override
protected void appending(AppendRecord record) {
record.setRevision(records.size()+1);
}
/**
* {@inheritDoc}
*/
protected void append(AppendRecord record, InputStream in, int length)
throws JournalException {
checkState();
byte[] data = new byte[length];
int off = 0;
while (off < data.length) {
try {
int len = in.read(data, off, data.length - off);
if (len < 0) {
String msg = "Unexpected end of record after " + off + " bytes.";
throw new JournalException(msg);
}
off += len;
} catch (IOException e) {
String msg = "I/O error after " + off + " bytes.";
throw new JournalException(msg, e);
}
}
try {
Thread.sleep(writeDelay);
} catch (InterruptedException e) {
throw new JournalException("Interrupted in append().");
}
records.add(new MemoryRecord(getId(), record.getProducerId(), data));
}
/**
* {@inheritDoc}
*/
protected void doUnlock(boolean successful) {
try {
checkState();
} catch (JournalException e) {
log.warn("Journal already closed while unlocking.");
}
}
/**
* {@inheritDoc}
*/
public RecordIterator getRecords(long startRevision)
throws JournalException {
checkState();
startRevision = Math.max(startRevision, 0);
long stopRevision = records.size();
return new MemoryRecordIterator(startRevision, stopRevision);
}
/**
* {@inheritDoc}
*/
public RecordIterator getRecords() throws JournalException {
return new MemoryRecordIterator(0, records.size());
}
/**
* Set records. Used to share records between two journal implementations.
*
* @param records array list that should back up this memory journal
*/
public void setRecords(List<MemoryRecord> records) {
this.records = records;
}
/**
* Return the read delay in milliseconds.
*
* @return read delay
*/
public long getReadDelay() {
return readDelay;
}
/**
* Set the read delay in milliseconds.
*
* @param readDelay read delay
*/
public void setReadDelay(long readDelay) {
this.readDelay = readDelay;
}
/**
* Return the write delay in milliseconds.
*
* @return write delay
*/
public long getWriteDelay() {
return writeDelay;
}
/**
* Set the write delay in milliseconds.
*
* @param writeDelay write delay
*/
public void setWriteDelay(long writeDelay) {
this.writeDelay = writeDelay;
}
/**
* {@inheritDoc}
*/
public void close() {
closed = true;
}
/**
* Check state of this journal.
*/
private void checkState() throws JournalException {
if (closed) {
throw new JournalException("Journal closed.");
}
}
/**
* Memory record.
*/
public static class MemoryRecord {
/**
* Journal id.
*/
private String journalId;
/**
* Producer id.
*/
private String producerId;
/**
* Data.
*/
private byte[] data;
/**
* Create a new instance of this class
*
* @param journalId journal id
* @param producerId producer id
* @param data data
*/
public MemoryRecord(String journalId, String producerId, byte[] data) {
this.journalId = journalId;
this.producerId = producerId;
this.data = data;
}
/**
* Return the journal id.
*
* @return the journal id
*/
public String getJournalId() {
return journalId;
}
/**
* Return the producer id.
*
* @return the producer id
*/
public String getProducerId() {
return producerId;
}
/**
* Return the data.
*
* @return data
*/
public byte[] getData() {
return data;
}
}
/**
* Record iterator implementation.
*/
public class MemoryRecordIterator implements RecordIterator {
/**
* Current revision.
*/
private long revision;
/**
* Last revision.
*/
private final long stopRevision;
/**
* Create a new instance of this class.
*
* @param startRevision start revision
* @param stopRevision stop revision
*/
public MemoryRecordIterator(long startRevision, long stopRevision) {
this.revision = startRevision;
this.stopRevision = stopRevision;
}
/**
* {@inheritDoc}
*/
public boolean hasNext() {
return revision < stopRevision;
}
/**
* {@inheritDoc}
*/
public Record nextRecord() throws NoSuchElementException,
JournalException {
int index = (int) revision;
MemoryRecord record = records.get(index);
checkState();
byte[] data = record.getData();
DataInputStream dataIn = new DataInputStream(
new ByteArrayInputStream(data));
try {
Thread.sleep(readDelay);
} catch (InterruptedException e) {
throw new JournalException("Interrupted in read().");
}
return new ReadRecord(record.getJournalId(), record.getProducerId(),
++revision, dataIn, data.length,
getResolver(), getNamePathResolver());
}
/**
* {@inheritDoc}
*/
public void close() {
// nothing to be done here
}
}
}