blob: cd07790447340f7fc5224f08500adcf2fd06dc5b (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
|
/*
* Copyright (c) OSGi Alliance (2011). All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.osgi.framework.hooks.resolver;
import java.util.Collection;
import org.osgi.framework.Bundle;
import org.osgi.framework.wiring.BundleRevision;
import org.osgi.framework.wiring.FrameworkWiring;
/**
* OSGi Framework Resolver Hook Factory Service.
*
* <p>
* Bundles registering this service will be called by the framework during
* a bundle resolver process to obtain a {@link ResolverHook resolver hook}
* instance which will be used for the duration of a resolve process.
*
* @ThreadSafe
* @see ResolverHook
* @version $Id: 08a6fba0f95499d08047282124b88256d33e1ce4 $
*/
public interface ResolverHookFactory {
/**
* This method is called by the framework each time a resolve process begins
* to obtain a {@link ResolverHook resolver hook} instance. This resolver hook
* instance will be used for the duration of the resolve process. At the end of
* the resolve process the method {@link ResolverHook#end()} must be called by
* the framework and the framework must not hold any references of the resolver
* hook instance.
* <p>
* The triggers represent the collection of bundles which triggered
* the resolve process. This collection may be empty if the triggers
* cannot be determined by the framework. In most cases the triggers
* can easily be determined. Calling certain methods on
* {@link Bundle bundle} when a bundle is in the {@link Bundle#INSTALLED INSTALLED}
* state will cause the framework to begin a resolve process in order to resolve the
* bundle. The following methods will start a resolve process in this case:
* <ul>
* <li>{@link Bundle#start() start}</li>
* <li>{@link Bundle#loadClass(String) loadClass}</li>
* <li>{@link Bundle#findEntries(String, String, boolean) findEntries}</li>
* <li>{@link Bundle#getResource(String) getResource}</li>
* <li>{@link Bundle#getResources(String) getResources}</li>
* </ul>
* In such cases the collection will contain the single bundle which the
* framework is trying to resolve. Other cases will cause multiple bundles to be
* included in the trigger bundles collection. When {@link FrameworkWiring#resolveBundles(Collection)
* resolveBundles} is called the collection of triggers must include all the current bundle
* revisions for bundles passed to resolveBundles which are in the {@link Bundle#INSTALLED INSTALLED}
* state.
* <p>
* When {@link FrameworkWiring#refreshBundles(Collection, org.osgi.framework.FrameworkListener...)}
* is called the collection of triggers is determined with the following steps:
* <ul>
* <li>If the collection of bundles passed is null then {@link FrameworkWiring#getRemovalPendingBundles()}
* is called to get the initial collection of bundles.</li>
* <li>The equivalent of calling {@link FrameworkWiring#getDependencyClosure(Collection)} is called with
* the initial collection of bundles to get the dependency closure collection of the bundles being refreshed.</li>
* <li>Remove any non-active bundles from the dependency closure collection.</li>
* <li>For each bundle remaining in the dependency closure collection get the current bundle revision
* and add it to the collection of triggers.</li>
* </ul>
* <p>
* As described above, a resolve process is typically initiated as a result of calling API that causes the
* framework to attempt to resolve one or more bundles.
* The framework is free to start a resolve process at any time for reasons other than calls to framework API.
* For example, a resolve process may be used by the framework for diagnostic purposes and result in no
* bundles actually becoming resolved at the end of the process.
* Resolver hook implementations must be prepared for resolve processes that are initiated for other reasons
* besides calls to framework API.
* @param triggers an unmodifiable collection of bundles which triggered the resolve process.
* This collection may be empty if the collection of trigger bundles cannot be
* determined.
* @return a resolver hook instance to be used for the duration of the resolve process.
* A {@code null} value may be returned which indicates this resolver hook factory abstains from
* the resolve process.
*/
ResolverHook begin(Collection<BundleRevision> triggers);
}
|
