View Javadoc
1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *   http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing,
13   * software distributed under the License is distributed on an
14   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   * KIND, either express or implied.  See the License for the
16   * specific language governing permissions and limitations
17   * under the License.
18   */
19  package org.eclipse.aether.collection;
20  
21  import java.util.Iterator;
22  import java.util.List;
23  
24  import org.eclipse.aether.RepositoryException;
25  import org.eclipse.aether.RepositorySystemSession;
26  import org.eclipse.aether.graph.Dependency;
27  import org.eclipse.aether.repository.ArtifactRepository;
28  import org.eclipse.aether.repository.RemoteRepository;
29  import org.eclipse.aether.version.Version;
30  import org.eclipse.aether.version.VersionConstraint;
31  
32  /**
33   * Decides which versions matching a version range should actually be considered for the dependency graph. The version
34   * filter is not invoked for dependencies that do not declare a version range but a single version.
35   * <p>
36   * <strong>Note:</strong> Implementations must be stateless.
37   * <p>
38   * <em>Warning:</em> This hook is called from a hot spot and therefore implementations should pay attention to
39   * performance. Among others, implementations should provide a semantic {@link Object#equals(Object) equals()} method.
40   *
41   * @see org.eclipse.aether.RepositorySystemSession#getVersionFilter()
42   * @see org.eclipse.aether.RepositorySystem#collectDependencies(org.eclipse.aether.RepositorySystemSession,
43   *      CollectRequest)
44   */
45  public interface VersionFilter {
46  
47      /**
48       * A context used during version filtering to hold relevant data.
49       *
50       * @noimplement This interface is not intended to be implemented by clients.
51       * @noextend This interface is not intended to be extended by clients.
52       */
53      interface VersionFilterContext extends Iterable<Version> {
54  
55          /**
56           * Gets the repository system session during which the version filtering happens.
57           *
58           * @return The repository system session, never {@code null}.
59           */
60          RepositorySystemSession getSession();
61  
62          /**
63           * Gets the dependency whose version range is being filtered.
64           *
65           * @return The dependency, never {@code null}.
66           */
67          Dependency getDependency();
68  
69          /**
70           * Gets the total number of available versions. This count reflects any removals made during version filtering.
71           *
72           * @return The total number of available versions.
73           */
74          int getCount();
75  
76          /**
77           * Gets an iterator over the available versions of the dependency. The iterator returns versions in ascending
78           * order. Use {@link Iterator#remove()} to exclude a version from further consideration in the dependency graph.
79           *
80           * @return The iterator of available versions, never {@code null}.
81           */
82          Iterator<Version> iterator();
83  
84          /**
85           * Gets the version constraint that was parsed from the dependency's version string.
86           *
87           * @return The parsed version constraint, never {@code null}.
88           */
89          VersionConstraint getVersionConstraint();
90  
91          /**
92           * Gets the repository from which the specified version was resolved.
93           *
94           * @param version The version whose source repository should be retrieved, must not be {@code null}.
95           * @return The repository from which the version was resolved or {@code null} if unknown.
96           */
97          ArtifactRepository getRepository(Version version);
98  
99          /**
100          * Gets the remote repositories from which the versions were resolved.
101          *
102          * @return The (read-only) list of repositories, never {@code null}.
103          */
104         List<RemoteRepository> getRepositories();
105     }
106 
107     /**
108      * Filters the available versions for a given dependency. Implementations will usually call
109      * {@link VersionFilterContext#iterator() context.iterator()} to inspect the available versions and use
110      * {@link java.util.Iterator#remove()} to delete unacceptable versions. If no versions remain after all filtering
111      * has been performed, the dependency collection process will automatically fail, i.e. implementations need not
112      * handle this situation on their own.
113      *
114      * @param context The version filter context, must not be {@code null}.
115      * @throws RepositoryException If the filtering could not be performed.
116      */
117     void filterVersions(VersionFilterContext context) throws RepositoryException;
118 
119     /**
120      * Derives a version filter for the specified collection context. The derived filter will be used to handle version
121      * ranges encountered in child dependencies of the current node. When calculating the child filter, implementors are
122      * strongly advised to simply return the current instance if nothing changed to help save memory.
123      *
124      * @param context The dependency collection context, must not be {@code null}.
125      * @return The version filter for the target node or {@code null} if versions should not be filtered any more.
126      */
127     VersionFilter deriveChildFilter(DependencyCollectionContext context);
128 }