1 package org.eclipse.aether.internal.impl;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import java.util.Arrays;
23
24 import org.eclipse.aether.artifact.Artifact;
25 import org.eclipse.aether.graph.DependencyNode;
26
27 /**
28 * @see DefaultDependencyCollector
29 */
30 final class NodeStack
31 {
32
33 private DependencyNode[] nodes = new DependencyNode[96];
34
35 private int size;
36
37 public DependencyNode top()
38 {
39 if ( size <= 0 )
40 {
41 throw new IllegalStateException( "stack empty" );
42 }
43 return nodes[size - 1];
44 }
45
46 public void push( DependencyNode node )
47 {
48 if ( size >= nodes.length )
49 {
50 DependencyNode[] tmp = new DependencyNode[size + 64];
51 System.arraycopy( nodes, 0, tmp, 0, nodes.length );
52 nodes = tmp;
53 }
54 nodes[size++] = node;
55 }
56
57 public void pop()
58 {
59 if ( size <= 0 )
60 {
61 throw new IllegalStateException( "stack empty" );
62 }
63 size--;
64 }
65
66 public int find( Artifact artifact )
67 {
68 for ( int i = size - 1; i >= 0; i-- )
69 {
70 DependencyNode node = nodes[i];
71
72 Artifact a = node.getArtifact();
73 if ( a == null )
74 {
75 break;
76 }
77
78 if ( !a.getArtifactId().equals( artifact.getArtifactId() ) )
79 {
80 continue;
81 }
82 if ( !a.getGroupId().equals( artifact.getGroupId() ) )
83 {
84 continue;
85 }
86 if ( !a.getExtension().equals( artifact.getExtension() ) )
87 {
88 continue;
89 }
90 if ( !a.getClassifier().equals( artifact.getClassifier() ) )
91 {
92 continue;
93 }
94 /*
95 * NOTE: While a:1 and a:2 are technically different artifacts, we want to consider the path a:2 -> b:2 ->
96 * a:1 a cycle in the current context. The artifacts themselves might not form a cycle but their producing
97 * projects surely do. Furthermore, conflict resolution will always have to consider a:1 a loser (otherwise
98 * its ancestor a:2 would get pruned and so would a:1) so there is no point in building the sub graph of
99 * a:1.
100 */
101
102 return i;
103 }
104
105 return -1;
106 }
107
108 public int size()
109 {
110 return size;
111 }
112
113 public DependencyNode get( int index )
114 {
115 return nodes[index];
116 }
117
118 @Override
119 public String toString()
120 {
121 return Arrays.toString( nodes );
122 }
123
124 }