tikhomirov@695: /*
tikhomirov@695:  * Copyright (c) 2013 TMate Software Ltd
tikhomirov@695:  *  
tikhomirov@695:  * This program is free software; you can redistribute it and/or modify
tikhomirov@695:  * it under the terms of the GNU General Public License as published by
tikhomirov@695:  * the Free Software Foundation; version 2 of the License.
tikhomirov@695:  *
tikhomirov@695:  * This program is distributed in the hope that it will be useful,
tikhomirov@695:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
tikhomirov@695:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
tikhomirov@695:  * GNU General Public License for more details.
tikhomirov@695:  *
tikhomirov@695:  * For information on how to redistribute this software under
tikhomirov@695:  * the terms of a license other than GNU General Public License
tikhomirov@695:  * contact TMate Software at support@hg4j.com
tikhomirov@695:  */
tikhomirov@695: package org.tmatesoft.hg.internal;
tikhomirov@695: 
tikhomirov@695: import org.tmatesoft.hg.core.Nodeid;
tikhomirov@695: import org.tmatesoft.hg.internal.RevlogStream.Inspector;
tikhomirov@695: import org.tmatesoft.hg.repo.HgRepository;
tikhomirov@695: import org.tmatesoft.hg.repo.HgRuntimeException;
tikhomirov@695: 
tikhomirov@695: /**
tikhomirov@695:  * Does almost nothing, facilitates chains of inspectors and sharing certain information between them 
tikhomirov@695:  * 
tikhomirov@695:  * @author Artem Tikhomirov
tikhomirov@695:  * @author TMate Software Ltd.
tikhomirov@695:  */
tikhomirov@695: public abstract class RevlogDelegate implements RevlogStream.Inspector {
tikhomirov@695: 	
tikhomirov@695: 	private final Inspector next;
tikhomirov@695: 	private Nodeid nid;
tikhomirov@695: 	private final RevlogDelegate nextAsRD;
tikhomirov@695: 	
tikhomirov@695: 	protected RevlogDelegate(RevlogStream.Inspector nextInChain) {
tikhomirov@695: 		next = nextInChain;
tikhomirov@695: 		if (nextInChain instanceof RevlogDelegate) {
tikhomirov@695: 			// additional benefits
tikhomirov@695: 			nextAsRD = (RevlogDelegate) nextInChain;
tikhomirov@695: 		} else {
tikhomirov@695: 			nextAsRD = null;
tikhomirov@695: 		}
tikhomirov@695: 	}
tikhomirov@695: 
tikhomirov@695: 	/**
tikhomirov@695: 	 * iterates index only and ensures pre/post processing is invoked for the chain
tikhomirov@695: 	 */
tikhomirov@695: 	public void walk(HgRepository hgRepo, RevlogStream stream, int from, int to) {
tikhomirov@695: 		// hgRepo is handy for present uses, but is generally not appropriate, 
tikhomirov@695: 		// it's ok to refactor and let subclasses get what they need through e.g. a cons 
tikhomirov@695: 		stream.iterate(from, to, false, this);
tikhomirov@695: 		postWalk(hgRepo);
tikhomirov@695: 	}
tikhomirov@695: 	
tikhomirov@695: 	// does nothing but gives a chance to delegate to handle the same
tikhomirov@695: 	protected void postWalk(HgRepository hgRepo) {
tikhomirov@695: 		if (nextAsRD != null) {
tikhomirov@695: 			nextAsRD.postWalk(hgRepo);
tikhomirov@695: 		}
tikhomirov@695: 	}
tikhomirov@695: 
tikhomirov@695: 	/**
tikhomirov@695: 	 * @return Nodeid of current revision if already known, or a new instance otherwise. 
tikhomirov@695: 	 * The value will propagate to subsequent {@link RevlogDelegate RevlogDelegates}, if any
tikhomirov@695: 	 */
tikhomirov@695: 	protected Nodeid getRevision(byte[] nodeid) {
tikhomirov@695: 		if (nid == null) {
tikhomirov@695: 			nid = Nodeid.fromBinary(nodeid, 0);
tikhomirov@695: 		}
tikhomirov@695: 		return nid;
tikhomirov@695: 	}
tikhomirov@695: 	
tikhomirov@695: 	protected void setRevision(Nodeid nodeid) {
tikhomirov@695: 		nid = nodeid;
tikhomirov@695: 	}
tikhomirov@695: 	
tikhomirov@695: 	public void next(int revisionIndex, int actualLen, int baseRevision, int linkRevision, int parent1Revision, int parent2Revision, byte[] nodeid, DataAccess data) throws HgRuntimeException {
tikhomirov@695: 		if (next != null) {
tikhomirov@695: 			if (nextAsRD != null) {
tikhomirov@695: 				nextAsRD.setRevision(nid); // null is fine
tikhomirov@695: 			}
tikhomirov@695: 			next.next(revisionIndex, actualLen, baseRevision, linkRevision, parent1Revision, parent2Revision, nodeid, data);
tikhomirov@695: 		}
tikhomirov@695: 		nid = null; // forget it, get ready for the next iteration
tikhomirov@695: 	}
tikhomirov@695: }