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1
4 package com.tc.objectserver.managedobject;
5
6 import com.tc.object.ObjectID;
7
8 import java.util.HashMap  ;
9 import java.util.HashSet ;
10 import java.util.Iterator ;
11 import java.util.Map ;
12 import java.util.Set ;
13
14 public class BackReferences {
16
17 private final Map nodes;
18
19 private final Set parents;
20
21 public BackReferences() {
22 parents = new HashSet ();
23 nodes = new HashMap ();
24 }
25
26 public void addBackReference(ObjectID child, ObjectID parent) {
27 if (child.isNull()) return;
28 Node c = getOrCreateNode(child);
29 Node p = getOrCreateNode(parent);
30 p.addChild(c);
31 parents.add(parent);
32 }
33
34 private Node getOrCreateNode(ObjectID id) {
35 Node n = (Node) nodes.get(id);
36 if (n == null) {
37 n = new Node(id);
38 nodes.put(id, n);
39 }
40 return n;
41 }
42
43 public Set getAllParents() {
44 return new HashSet (parents);
45 }
46
47 public Set addReferencedChildrenTo(Set objectIDs, Set interestedParents) {
48 for (Iterator i = interestedParents.iterator(); i.hasNext();) {
49 ObjectID pid = (ObjectID) i.next();
50 Node p = getOrCreateNode(pid);
51 p.addAllReferencedChildrenTo(objectIDs);
52 }
53 return objectIDs;
54 }
55
56 private static class Node {
57
58 private final ObjectID id;
59 private final Set children;
60
61 public Node(ObjectID id) {
62 this.id = id;
63 this.children = new HashSet ();
64 }
65
66 public int hashCode() {
67 return id.hashCode();
68 }
69
70 public ObjectID getID() {
71 return id;
72 }
73
74 public boolean equals(Object o) {
75 if (o instanceof Node) {
76 Node other = (Node) o;
77 return this.id.equals(other.id);
78 }
79 return false;
80 }
81
82 public void addChild(Node c) {
83 children.add(c);
84 }
85
86 public Set addAllReferencedChildrenTo(Set objectIDs) {
87 for (Iterator i = children.iterator(); i.hasNext();) {
88 Node child = (Node) i.next();
89 if(!objectIDs.contains(child.getID())) {
90 objectIDs.add(child.getID());
91 child.addAllReferencedChildrenTo(objectIDs);
92 }
93 }
94 return objectIDs;
95 }
96
97 public String toString() {
98 return "Node(" + id + ") : children = " + children.size();
100 }
101 }
102
103 }
104 |
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