bundlestorageimpl.java

OSGI这是一个中间件,与UPNP齐名,是用于移植到嵌入式平台之上

/*
 * Copyright (c) 2003-2004, KNOPFLERFISH project
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials
 *   provided with the distribution.
 *
 * - Neither the name of the KNOPFLERFISH project nor the names of its
 *   contributors may be used to endorse or promote products derived
 *   from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.knopflerfish.framework.bundlestorage.file;

import org.knopflerfish.framework.*;
import java.io.*;
import java.util.*;

/**
 * Storage of all bundles jar content.
 *
 * @author Jan Stein
 * @version $Revision: 1.1.1.1 $
 */
public class BundleStorageImpl implements BundleStorage {

  /**
   * Top directory for storing all jar data for bundles.
   */
  private FileTree bundlesDir;

  /**
   * Next available bundle id.
   */
  private long nextFreeId = 1;

  /**
   * Bundle id sorted list of all active bundle archives.
   */
  private ArrayList /* BundleArchive */ archives = new ArrayList();

  /**
   * Create a container for all bundle data in this framework.
   * Try to restore all saved bundle archive state.
   *
   */
  public BundleStorageImpl() {
    // See if we have a storage directory
    bundlesDir = Util.getFileStorage("bs");
    if (bundlesDir == null) {
      throw new RuntimeException("No bundle storage area available!");
    }
    // Restore all saved bundles
    String [] list = bundlesDir.list();
    for (int i = 0; list != null & i < list.length; i++) {
      long id;
      try {
	id = Long.parseLong(list[i]);
      } catch (NumberFormatException e) {
	continue;
      }
      if (id == 0) {
	System.err.println("Saved bundle with illegal id 0 is ignored.");
      }
      int pos = find(id);
      if (pos < archives.size() && ((BundleArchive)archives.get(pos)).getBundleId() == id) {
	System.err.println("There are two bundle directories with id: " + id);
	break;
      }
      FileTree dir = new FileTree(bundlesDir, list[i]);
      if (dir.isDirectory()) {
	try {
	  boolean bUninstalled = BundleArchiveImpl.isUninstalled(dir);
	  if(bUninstalled) {
	    // silently remove any bundle marked as uninstalled
	    dir.delete();
	  } else {
	    BundleArchive ba = new BundleArchiveImpl(this, dir, id);
	    archives.add(pos, ba);
	  }
	  if (id >= nextFreeId) {
	    nextFreeId = id + 1;
	  }
	} catch (Exception e) {
	  dir.delete();
	  System.err.println("Removed corrupt bundle dir (" + e.getMessage() + "): " + dir);
	}
      }
    }
  }

  /**
   * Insert bundle into persistent storage
   *
   * @param location Location of bundle.
   * @param is Inputstrem with bundle content.
   * @return Bundle archive object.
   */
  public BundleArchive insertBundleJar(String location, InputStream is)
    throws Exception
  {
    long id = nextFreeId++;
    FileTree dir = new FileTree(bundlesDir, String.valueOf(id));
    if (dir.exists()) {
      // remove any old garbage
      dir.delete();
    }
    dir.mkdir();
    try {
      BundleArchive ba = new BundleArchiveImpl(this, dir, is, location, id);
      archives.add(ba);
      return ba;
    } catch (Exception e) {
      dir.delete();
      throw e;
    }
  }

  /**
   * Replace jar content for bundle in persistent storage.
   *
   * @param old BundleArchive to be replaced.
   * @param is Inputstrem with bundle content.
   * @return Bundle archive object.
   */
  public BundleArchive replaceBundleJar(BundleArchive old, InputStream is)
    throws Exception
  {
    int pos;
    long id = old.getBundleId();
    synchronized (archives) {
      pos = find(id);
      if (pos >= archives.size() || archives.get(pos) != old) {
	throw new Exception("No such bundle archive exists");
      }
    }
    BundleArchive ba = new BundleArchiveImpl((BundleArchiveImpl)old, is);
    synchronized (archives) {
      if (archives.get(pos) != old) {
	pos = find(id);
	if (pos >= archives.size() || archives.get(pos) != old) {
	  throw new Exception("Bundle removed during update");
	}
      }
      archives.set(pos, ba);
    }
    return ba;
  }

  /**
   * Get all bundle archive objects.
   *
   * @return Private array of all BundleArchives.
   */
  public BundleArchive [] getAllBundleArchives() {
    synchronized (archives) {
      return (BundleArchive [])archives.toArray(new BundleArchive[archives.size()]);
    }
  }

  /**
   * Get all bundles tagged to start at next launch of framework.
   * This list is sorted in increasing bundle id order.
   *
   * @return Private copy of a List with bundle id's.
   */
  public List getStartOnLaunchBundles() {
    ArrayList res = new ArrayList();
    for (Iterator i = archives.iterator(); i.hasNext(); ) {
      BundleArchive ba = (BundleArchive)i.next();
      if (ba.getStartOnLaunchFlag()) {
	res.add(ba.getBundleLocation());
      }
    }
    return res;
  }

  //
  // Package methods
  //

  /**
   * Remove bundle archive from archives list.
   *
   * @param id Bundle archive id to find.
   * @return true if element was removed.
   */
  boolean removeArchive(BundleArchive ba) {
    synchronized (archives) {
      int pos = find(ba.getBundleId());
      if (archives.get(pos) == ba) {
	archives.remove(pos);
	return true;
      } else {
	return false;
      }
    }
  }


  //
  // Private methods
  //

  /**
   * Find posisition for BundleArchive with specified id
   *
   * @param id Bundle archive id to find.
   * @return String to write
   */
  private int find(long id) {
    int lb = 0;
    int ub = archives.size();
    int x = 0;
    while (lb != ub) {
      x = (lb + ub) / 2;
      long xid = ((BundleArchive)archives.get(x)).getBundleId();
      if (id <= xid) {
	ub = x;
      } else {
	lb = x+1;
      }
    }
    return lb;
  }

}