/*
* 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.id;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Properties;
import java.util.UUID;
import javax.jcr.RepositoryException;
/**
* A factory for creating new node ids.
*/
public class NodeIdFactory {
public final static String SEQUENTIAL_NODE_ID = "jackrabbit.sequentialNodeId";
private final static String NODE_ID_FILE = "nodeId.properties";
private final static String NODE_ID_FILE_TEMP = "nodeId.properties.temp";
private final static String MSB = "msb";
private final static String NEXT_LSB = "nextLsb";
private final static int DEFAULT_CACHE_SIZE = 128;
private final String repositoryHome;
private boolean createRandom;
private long msb;
private long nextLsb;
private long storedLsb;
private int cacheSize = DEFAULT_CACHE_SIZE;
public NodeIdFactory(String repositoryHome) {
this.repositoryHome = repositoryHome;
}
public void setCacheSize(int cacheSize) {
this.cacheSize = cacheSize;
}
public void open() throws RepositoryException {
String seq = System.getProperty(SEQUENTIAL_NODE_ID);
if (seq == null) {
createRandom = true;
return;
}
try {
File n = new File(repositoryHome, NODE_ID_FILE);
if (!n.exists()) {
File temp = new File(repositoryHome, NODE_ID_FILE_TEMP);
if (temp.exists()) {
temp.renameTo(n);
} else {
n.getParentFile().mkdirs();
n.createNewFile();
}
}
Properties p = new Properties();
FileInputStream in = new FileInputStream(n);
try {
p.load(in);
} finally {
in.close();
}
String defaultMsb = "", defaultLsb = "0";
int index = seq.indexOf("/");
if (index >= 0) {
defaultMsb = seq.substring(0, index);
defaultLsb = seq.substring(index + 1);
}
String m = p.getProperty(MSB, defaultMsb);
if (m.length() == 0) {
msb = UUID.randomUUID().getMostSignificantBits();
// ensure it doesn't conflict with version 1-5 UUIDs
msb &= ~0xf000;
} else {
if (m.length() == 16) {
msb = (Long.parseLong(m.substring(0, 8), 16) << 32) |
Long.parseLong(m.substring(8), 16);
} else {
msb = Long.parseLong(m, 16);
}
}
storedLsb = nextLsb = Long.parseLong(p.getProperty(NEXT_LSB, defaultLsb), 16);
} catch (Exception e) {
throw new RepositoryException("Could not open node id factory", e);
}
}
public void close() throws RepositoryException {
if (!createRandom) {
store(nextLsb);
}
}
private void store(long lsb) throws RepositoryException {
this.storedLsb = lsb;
Properties p = new Properties();
p.setProperty(MSB, Long.toHexString(msb));
p.setProperty(NEXT_LSB, Long.toHexString(lsb));
try {
File temp = new File(repositoryHome, NODE_ID_FILE_TEMP);
FileOutputStream out = new FileOutputStream(temp);
try {
p.store(out, null);
} finally {
out.close();
}
File n = new File(repositoryHome, NODE_ID_FILE);
n.delete();
temp.renameTo(n);
} catch (IOException e) {
throw new RepositoryException("Could not store next node id", e);
}
}
public NodeId newNodeId() throws RepositoryException {
if (createRandom) {
return NodeId.randomId();
}
long lsb = nextLsb++;
if (lsb >= storedLsb) {
store(lsb + cacheSize);
}
return new NodeId(msb, lsb);
}
}