comparison src/com/tmate/hgkit/ll/Revlog.java @ 29:6cce719bbb62

Collector for nodes and their parents
author Artem Tikhomirov <tikhomirov.artem@gmail.com>
date Tue, 11 Jan 2011 04:37:29 +0100
parents d4fdd1845b3f
children 346b66add79d
comparison
equal deleted inserted replaced
28:b2251b7a9823 29:6cce719bbb62
1 /* 1 /*
2 * Copyright (c) 2010, 2011 Artem Tikhomirov 2 * Copyright (c) 2010, 2011 Artem Tikhomirov
3 */ 3 */
4 package com.tmate.hgkit.ll; 4 package com.tmate.hgkit.ll;
5
6 import java.util.Collection;
7 import java.util.Collections;
8 import java.util.HashMap;
9 import java.util.LinkedHashSet;
10 import java.util.Map;
11 import java.util.Set;
5 12
6 /** 13 /**
7 * 14 *
8 * @author artem 15 * @author artem
9 */ 16 */
25 } 32 }
26 33
27 public int getRevisionCount() { 34 public int getRevisionCount() {
28 return content.revisionCount(); 35 return content.revisionCount();
29 } 36 }
30 37
31 // 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 38 // 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
32 // instantly - e.g. calculate hash, or comparing two revisions 39 // instantly - e.g. calculate hash, or comparing two revisions
40 // XXX seems that RevlogStream is better place for this class.
33 public interface Inspector { 41 public interface Inspector {
34 // XXX boolean retVal to indicate whether to continue? 42 // XXX boolean retVal to indicate whether to continue?
35 // TODO specify nodeid and data length, and reuse policy (i.e. if revlog stream doesn't reuse nodeid[] for each call) 43 // TODO specify nodeid and data length, and reuse policy (i.e. if revlog stream doesn't reuse nodeid[] for each call)
36 void next(int revisionNumber, int actualLen, int baseRevision, int linkRevision, int parent1Revision, int parent2Revision, byte[/*20*/] nodeid, byte[] data); 44 void next(int revisionNumber, int actualLen, int baseRevision, int linkRevision, int parent1Revision, int parent2Revision, byte[/*20*/] nodeid, byte[] data);
37 } 45 }
46
47 /*
48 * XXX think over if it's better to do either:
49 * pw = getChangelog().new ParentWalker(); pw.init() and pass pw instance around as needed
50 * or
51 * add Revlog#getParentWalker(), static class, make cons() and #init package-local, and keep SoftReference to allow walker reuse.
52 *
53 * and yes, walker is not a proper name
54 */
55 public final class ParentWalker {
56 private Map<Nodeid, Nodeid> firstParent;
57 private Map<Nodeid, Nodeid> secondParent;
58 private Set<Nodeid> allNodes;
59
60 public ParentWalker() {
61 firstParent = secondParent = Collections.emptyMap();
62 allNodes = Collections.emptySet();
63 }
64
65 public void init() {
66 final RevlogStream stream = Revlog.this.content;
67 final int revisionCount = stream.revisionCount();
68 firstParent = new HashMap<Nodeid, Nodeid>(revisionCount);
69 secondParent = new HashMap<Nodeid, Nodeid>(firstParent.size() >> 1); // assume branches/merges are less frequent
70 allNodes = new LinkedHashSet<Nodeid>();
71
72 Inspector insp = new Inspector() {
73 final Nodeid[] sequentialRevisionNodeids = new Nodeid[revisionCount];
74 int ix = 0;
75 public void next(int revisionNumber, int actualLen, int baseRevision, int linkRevision, int parent1Revision, int parent2Revision, byte[] nodeid, byte[] data) {
76 if (ix != revisionNumber) {
77 // XXX temp code, just to make sure I understand what's going on here
78 throw new IllegalStateException();
79 }
80 if (parent1Revision >= revisionNumber || parent2Revision >= revisionNumber) {
81 throw new IllegalStateException(); // sanity, revisions are sequential
82 }
83 final Nodeid nid = new Nodeid(nodeid, true);
84 sequentialRevisionNodeids[ix++] = nid;
85 allNodes.add(nid);
86 if (parent1Revision != -1) {
87 firstParent.put(nid, sequentialRevisionNodeids[parent1Revision]);
88 if (parent2Revision != -1) {
89 secondParent.put(nid, sequentialRevisionNodeids[parent2Revision]);
90 }
91 }
92 }
93 };
94 stream.iterate(0, -1, false, insp);
95 }
96
97 public Set<Nodeid> allNodes() {
98 return Collections.unmodifiableSet(allNodes);
99 }
100
101 // null if none
102 public Nodeid firstParent(Nodeid nid) {
103 return firstParent.get(nid);
104 }
105
106 public Nodeid secondParent(Nodeid nid) {
107 return secondParent.get(nid);
108 }
109
110 public boolean appendParentsOf(Nodeid nid, Collection<Nodeid> c) {
111 Nodeid p1 = firstParent(nid);
112 boolean modified = false;
113 if (p1 != null) {
114 modified = c.add(p1);
115 Nodeid p2 = secondParent(nid);
116 if (p2 != null) {
117 modified = c.add(p2) || modified;
118 }
119 }
120 return modified;
121 }
122 }
38 } 123 }