001/*
002 * (C) Copyright 2006-2011 Nuxeo SA (http://nuxeo.com/) and others.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 *
016 * Contributors:
017 *     Nuxeo - initial API and implementation
018 * $Id$
019 */
020
021package org.nuxeo.osgi;
022
023import java.io.BufferedInputStream;
024import java.io.BufferedOutputStream;
025import java.io.DataInputStream;
026import java.io.DataOutputStream;
027import java.io.File;
028import java.io.FileInputStream;
029import java.io.FileNotFoundException;
030import java.io.FileOutputStream;
031import java.io.IOException;
032import java.util.HashMap;
033import java.util.Map;
034
035import org.apache.commons.logging.Log;
036import org.apache.commons.logging.LogFactory;
037
038/**
039 * @author <a href="mailto:bs@nuxeo.com">Bogdan Stefanescu</a>
040 */
041public class BundleIdGenerator {
042
043    private static final Log log = LogFactory.getLog(BundleIdGenerator.class);
044
045    private final Map<String, Long> ids = new HashMap<String, Long>();
046
047    private long count = 0;
048
049    public synchronized void load(File file) {
050        DataInputStream in = null;
051        try {
052            in = new DataInputStream(new BufferedInputStream(new FileInputStream(file)));
053            count = in.readLong();
054            int size = in.readInt();
055            for (int i = 0; i < size; i++) {
056                String key = in.readUTF();
057                long id = in.readLong();
058                ids.put(key, id);
059            }
060        } catch (FileNotFoundException e) {
061            // do nothing - this is the first time the runtime is started
062        } catch (IOException e) {
063            // may be the file is corrupted
064            file.delete();
065            log.error("The bundle.ids file is corrupted. reseting bundle ids.");
066        } finally {
067            if (in != null) {
068                try {
069                    in.close();
070                } catch (IOException e) {
071                }
072            }
073        }
074    }
075
076    public synchronized void store(File file) throws IOException {
077        DataOutputStream out = null;
078        try {
079            out = new DataOutputStream(new BufferedOutputStream(new FileOutputStream(file)));
080            out.writeLong(count);
081            int size = ids.size();
082            out.writeInt(size);
083            for (Map.Entry<String, Long> entry : ids.entrySet()) {
084                out.writeUTF(entry.getKey());
085                out.writeLong(entry.getValue());
086            }
087        } finally {
088            if (out != null) {
089                out.close();
090            }
091        }
092    }
093
094    public synchronized long getBundleId(String name) {
095        Long id = ids.get(name);
096        if (id == null) {
097            id = count++;
098            ids.put(name, id);
099        }
100        return id;
101    }
102
103    public synchronized long addBundle(String name) {
104        long id = count++;
105        ids.put(name, id);
106        return id;
107    }
108
109    public synchronized boolean contains(String name) {
110        return ids.containsKey(name);
111    }
112
113}