ArchiveContent.java (freenet.client)

//s243a pearltree node: http://www.pearltrees.com/s243a/archivecontent-java/id12827343
/* This code is part of Freenet. It is distributed under the GNU General
 * Public License, version 2 (or at your option any later version). See
 * http://www.gnu.org/ for further details of the GPL. */
package freenet.client;

import java.util.HashSet;

import com.db4o.ObjectContainer;

import freenet.keys.FreenetURI;

/**
 * @author amphibian (Matthew Toseland)
 *
 * Object passed down a full fetch, including all the recursion.
 * Used, at present, for detecting archive fetch loops, hence the
 * name.
 */
// WARNING: THIS CLASS IS STORED IN DB4O -- THINK TWICE BEFORE ADD/REMOVE/RENAME FIELDS
public class ArchiveContext {

    private HashSet<FreenetURI> soFar;
    final int maxArchiveLevels;
    final long maxArchiveSize;

    public ArchiveContext(long maxArchiveSize, int max) {
        this.maxArchiveLevels = max;
        this.maxArchiveSize = maxArchiveSize;
    }

    /**
     * Check for a loop.
     *
     * The URI provided is expected to be a reasonably unique identifier for the archive.
     */
    public synchronized void doLoopDetection(FreenetURI key, ObjectContainer container) throws ArchiveFailureException {
        if(container != null)
            container.activate(soFar, Integer.MAX_VALUE);
        if(soFar == null) {
            soFar = new HashSet<FreenetURI>();
            if(container != null)
                container.store(soFar);
        }
        if(soFar.size() > maxArchiveLevels)
            throw new ArchiveFailureException(ArchiveFailureException.TOO_MANY_LEVELS);
        FreenetURI uri = key;
        if(container != null)
            uri = uri.clone();
        if(!soFar.add(uri)) {
            throw new ArchiveFailureException(ArchiveFailureException.ARCHIVE_LOOP_DETECTED);
        }
        if(container != null) {
            container.store(uri);
            container.store(soFar);
        }
    }

    public void removeFrom(ObjectContainer container) {
        if(soFar != null) {
            for(FreenetURI uri : soFar) {
                uri.removeFrom(container);
            }
            container.delete(soFar);
        }
        container.delete(this);
    }
}