tikhomirov@22: /*
tikhomirov@22:  * Copyright (c) 2010, 2011 Artem Tikhomirov 
tikhomirov@2:  */
tikhomirov@2: package com.tmate.hgkit.ll;
tikhomirov@2: 
tikhomirov@29: import java.util.Collection;
tikhomirov@29: import java.util.Collections;
tikhomirov@29: import java.util.HashMap;
tikhomirov@29: import java.util.LinkedHashSet;
tikhomirov@29: import java.util.Map;
tikhomirov@29: import java.util.Set;
tikhomirov@29: 
tikhomirov@2: /**
tikhomirov@2:  *
tikhomirov@2:  * @author artem
tikhomirov@2:  */
tikhomirov@2: public abstract class Revlog {
tikhomirov@2: 
tikhomirov@2: 	private final HgRepository hgRepo;
tikhomirov@21: 	protected final RevlogStream content;
tikhomirov@2: 
tikhomirov@21: 	protected Revlog(HgRepository hgRepo, RevlogStream content) {
tikhomirov@2: 		if (hgRepo == null) {
tikhomirov@2: 			throw new NullPointerException();
tikhomirov@2: 		}
tikhomirov@2: 		this.hgRepo = hgRepo;
tikhomirov@21: 		this.content = content;
tikhomirov@2: 	}
tikhomirov@2: 
tikhomirov@2: 	public final HgRepository getRepo() {
tikhomirov@2: 		return hgRepo;
tikhomirov@2: 	}
tikhomirov@2: 
tikhomirov@21: 	public int getRevisionCount() {
tikhomirov@21: 		return content.revisionCount();
tikhomirov@21: 	}
tikhomirov@37: 
tikhomirov@49: 	public int getLocalRevisionNumber(Nodeid nid) {
tikhomirov@49: 		int revision = content.findLocalRevisionNumber(nid);
tikhomirov@49: 		if (revision == Integer.MIN_VALUE) {
tikhomirov@49: 			throw new IllegalArgumentException(String.format("%s doesn't represent a revision of %s", nid.toString(), this /*XXX HgDataFile.getPath might be more suitable here*/));
tikhomirov@49: 		}
tikhomirov@49: 		return revision;
tikhomirov@49: 	}
tikhomirov@49: 
tikhomirov@39: 	// Till now, i follow approach that NULL nodeid is never part of revlog
tikhomirov@39: 	public boolean isKnown(Nodeid nodeid) {
tikhomirov@49: 		final int rn = content.findLocalRevisionNumber(nodeid);
tikhomirov@49: 		if (Integer.MIN_VALUE == rn) {
tikhomirov@39: 			return false;
tikhomirov@39: 		}
tikhomirov@49: 		if (rn < 0 || rn >= content.revisionCount()) {
tikhomirov@49: 			// Sanity check
tikhomirov@49: 			throw new IllegalStateException();
tikhomirov@49: 		}
tikhomirov@49: 		return true;
tikhomirov@39: 	}
tikhomirov@49: 
tikhomirov@37: 	/**
tikhomirov@37: 	 * Access to revision data as is (decompressed, but otherwise unprocessed, i.e. not parsed for e.g. changeset or manifest entries) 
tikhomirov@37: 	 * @param nodeid
tikhomirov@37: 	 */
tikhomirov@37: 	public byte[] content(Nodeid nodeid) {
tikhomirov@49: 		return content(getLocalRevisionNumber(nodeid));
tikhomirov@37: 	}
tikhomirov@29: 	
tikhomirov@37: 	/**
tikhomirov@37: 	 * @param revision - repo-local index of this file change (not a changelog revision number!)
tikhomirov@37: 	 */
tikhomirov@37: 	public byte[] content(int revision) {
tikhomirov@37: 		final byte[][] dataPtr = new byte[1][];
tikhomirov@37: 		Revlog.Inspector insp = new Revlog.Inspector() {
tikhomirov@37: 			public void next(int revisionNumber, int actualLen, int baseRevision, int linkRevision, int parent1Revision, int parent2Revision, byte[] nodeid, byte[] data) {
tikhomirov@37: 				dataPtr[0] = data;
tikhomirov@37: 			}
tikhomirov@37: 		};
tikhomirov@37: 		content.iterate(revision, revision, true, insp);
tikhomirov@37: 		return dataPtr[0];
tikhomirov@37: 	}
tikhomirov@37: 
tikhomirov@22: 	// FIXME byte[] data might be too expensive, for few usecases it may be better to have intermediate Access object (when we don't need full data 
tikhomirov@22: 	// instantly - e.g. calculate hash, or comparing two revisions
tikhomirov@29: 	// XXX seems that RevlogStream is better place for this class. 
tikhomirov@2: 	public interface Inspector {
tikhomirov@3: 		// XXX boolean retVal to indicate whether to continue?
tikhomirov@24: 		// TODO specify nodeid and data length, and reuse policy (i.e. if revlog stream doesn't reuse nodeid[] for each call) 
tikhomirov@24: 		void next(int revisionNumber, int actualLen, int baseRevision, int linkRevision, int parent1Revision, int parent2Revision, byte[/*20*/] nodeid, byte[] data);
tikhomirov@2: 	}
tikhomirov@29: 
tikhomirov@29: 	/*
tikhomirov@29: 	 * XXX think over if it's better to do either:
tikhomirov@29: 	 * pw = getChangelog().new ParentWalker(); pw.init() and pass pw instance around as needed
tikhomirov@29: 	 * or
tikhomirov@29: 	 * add Revlog#getParentWalker(), static class, make cons() and #init package-local, and keep SoftReference to allow walker reuse.
tikhomirov@29: 	 * 
tikhomirov@29: 	 *  and yes, walker is not a proper name
tikhomirov@29: 	 */
tikhomirov@29: 	public final class ParentWalker {
tikhomirov@29: 		private Map<Nodeid, Nodeid> firstParent;
tikhomirov@29: 		private Map<Nodeid, Nodeid> secondParent;
tikhomirov@29: 		private Set<Nodeid> allNodes;
tikhomirov@29: 
tikhomirov@29: 		public ParentWalker() {
tikhomirov@29: 			firstParent = secondParent = Collections.emptyMap();
tikhomirov@29: 			allNodes = Collections.emptySet();
tikhomirov@29: 		}
tikhomirov@29: 		
tikhomirov@29: 		public void init() {
tikhomirov@29: 			final RevlogStream stream = Revlog.this.content;
tikhomirov@29: 			final int revisionCount = stream.revisionCount();
tikhomirov@29: 			firstParent = new HashMap<Nodeid, Nodeid>(revisionCount);
tikhomirov@29: 			secondParent = new HashMap<Nodeid, Nodeid>(firstParent.size() >> 1); // assume branches/merges are less frequent
tikhomirov@29: 			allNodes = new LinkedHashSet<Nodeid>();
tikhomirov@29: 			
tikhomirov@29: 			Inspector insp = new Inspector() {
tikhomirov@29: 				final Nodeid[] sequentialRevisionNodeids = new Nodeid[revisionCount];
tikhomirov@29: 				int ix = 0;
tikhomirov@29: 				public void next(int revisionNumber, int actualLen, int baseRevision, int linkRevision, int parent1Revision, int parent2Revision, byte[] nodeid, byte[] data) {
tikhomirov@29: 					if (ix != revisionNumber) {
tikhomirov@29: 						// XXX temp code, just to make sure I understand what's going on here
tikhomirov@29: 						throw new IllegalStateException();
tikhomirov@29: 					}
tikhomirov@29: 					if (parent1Revision >= revisionNumber || parent2Revision >= revisionNumber) {
tikhomirov@29: 						throw new IllegalStateException(); // sanity, revisions are sequential
tikhomirov@29: 					}
tikhomirov@29: 					final Nodeid nid = new Nodeid(nodeid, true);
tikhomirov@29: 					sequentialRevisionNodeids[ix++] = nid;
tikhomirov@29: 					allNodes.add(nid);
tikhomirov@29: 					if (parent1Revision != -1) {
tikhomirov@29: 						firstParent.put(nid, sequentialRevisionNodeids[parent1Revision]);
tikhomirov@29: 						if (parent2Revision != -1) {
tikhomirov@29: 							secondParent.put(nid, sequentialRevisionNodeids[parent2Revision]);
tikhomirov@29: 						}
tikhomirov@29: 					}
tikhomirov@29: 				}
tikhomirov@29: 			};
tikhomirov@29: 			stream.iterate(0, -1, false, insp);
tikhomirov@29: 		}
tikhomirov@29: 		
tikhomirov@29: 		public Set<Nodeid> allNodes() {
tikhomirov@29: 			return Collections.unmodifiableSet(allNodes);
tikhomirov@29: 		}
tikhomirov@31: 		
tikhomirov@31: 		// FIXME need to decide whether Nodeid(00 * 20) is always known or not
tikhomirov@31: 		public boolean knownNode(Nodeid nid) {
tikhomirov@31: 			return allNodes.contains(nid);
tikhomirov@31: 		}
tikhomirov@29: 
tikhomirov@29: 		// null if none
tikhomirov@29: 		public Nodeid firstParent(Nodeid nid) {
tikhomirov@29: 			return firstParent.get(nid);
tikhomirov@29: 		}
tikhomirov@49: 
tikhomirov@49: 		// never null, Nodeid.NULL if none known
tikhomirov@49: 		public Nodeid safeFirstParent(Nodeid nid) {
tikhomirov@49: 			Nodeid rv = firstParent(nid);
tikhomirov@49: 			return rv == null ? Nodeid.NULL : rv;
tikhomirov@49: 		}
tikhomirov@29: 		
tikhomirov@29: 		public Nodeid secondParent(Nodeid nid) {
tikhomirov@29: 			return secondParent.get(nid);
tikhomirov@29: 		}
tikhomirov@29: 
tikhomirov@49: 		public Nodeid safeSecondParent(Nodeid nid) {
tikhomirov@49: 			Nodeid rv = secondParent(nid);
tikhomirov@49: 			return rv == null ? Nodeid.NULL : rv;
tikhomirov@49: 		}
tikhomirov@49: 
tikhomirov@29: 		public boolean appendParentsOf(Nodeid nid, Collection<Nodeid> c) {
tikhomirov@29: 			Nodeid p1 = firstParent(nid);
tikhomirov@29: 			boolean modified = false;
tikhomirov@29: 			if (p1 != null) {
tikhomirov@29: 				modified = c.add(p1);
tikhomirov@29: 				Nodeid p2 = secondParent(nid);
tikhomirov@29: 				if (p2 != null) {
tikhomirov@29: 					modified = c.add(p2) || modified;
tikhomirov@29: 				}
tikhomirov@29: 			}
tikhomirov@29: 			return modified;
tikhomirov@29: 		}
tikhomirov@29: 	}
tikhomirov@2: }