1 /*
2 * Copyright (C) 2016, Matthias Sohn <matthias.sohn@sap.com> and others
3 *
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Distribution License v. 1.0 which is available at
6 * https://www.eclipse.org/org/documents/edl-v10.php.
7 *
8 * SPDX-License-Identifier: BSD-3-Clause
9 */
10 package org.eclipse.jgit.attributes;
11
12 import java.io.IOException;
13 import java.io.InputStream;
14 import java.io.OutputStream;
15 import java.util.Set;
16 import java.util.concurrent.ConcurrentHashMap;
17
18 import org.eclipse.jgit.lib.Repository;
19
20 /**
21 * Registry for built-in filters
22 *
23 * @since 4.6
24 */
25 public class FilterCommandRegistry {
26 private static ConcurrentHashMap<String, FilterCommandFactory> filterCommandRegistry = new ConcurrentHashMap<>();
27
28 /**
29 * Register a {@link org.eclipse.jgit.attributes.FilterCommandFactory}
30 * responsible for creating
31 * {@link org.eclipse.jgit.attributes.FilterCommand}s for a certain command
32 * name. If the factory f1 is registered for the name "jgit://builtin/x"
33 * then a call to <code>getCommand("jgit://builtin/x", ...)</code> will call
34 * <code>f1(...)</code> to create a new instance of
35 * {@link org.eclipse.jgit.attributes.FilterCommand}
36 *
37 * @param filterCommandName
38 * the command name for which this factory is registered
39 * @param factory
40 * the factory responsible for creating
41 * {@link org.eclipse.jgit.attributes.FilterCommand}s for the
42 * specified name
43 * @return the previous factory associated with <tt>commandName</tt>, or
44 * <tt>null</tt> if there was no mapping for <tt>commandName</tt>
45 */
46 public static FilterCommandFactory register(String filterCommandName,
47 FilterCommandFactory factory) {
48 return filterCommandRegistry.put(filterCommandName, factory);
49 }
50
51 /**
52 * Unregister the {@link org.eclipse.jgit.attributes.FilterCommandFactory}
53 * registered for the given command name
54 *
55 * @param filterCommandName
56 * the FilterCommandFactory's filter command name
57 * @return the previous factory associated with <tt>filterCommandName</tt>,
58 * or <tt>null</tt> if there was no mapping for <tt>commandName</tt>
59 */
60 public static FilterCommandFactory unregister(String filterCommandName) {
61 return filterCommandRegistry.remove(filterCommandName);
62 }
63
64 /**
65 * Check whether any
66 * {@link org.eclipse.jgit.attributes.FilterCommandFactory} is registered
67 * for a given command name
68 *
69 * @param filterCommandName
70 * the name for which the registry should be checked
71 * @return <code>true</code> if any factory was registered for the name
72 */
73 public static boolean isRegistered(String filterCommandName) {
74 return filterCommandRegistry.containsKey(filterCommandName);
75 }
76
77 /**
78 * Get registered filter commands
79 *
80 * @return Set of commandNames for which a
81 * {@link org.eclipse.jgit.attributes.FilterCommandFactory} is
82 * registered
83 */
84 public static Set<String> getRegisteredFilterCommands() {
85 return filterCommandRegistry.keySet();
86 }
87
88 /**
89 * Create a new {@link org.eclipse.jgit.attributes.FilterCommand} for the
90 * given name. A factory must be registered for the name in advance.
91 *
92 * @param filterCommandName
93 * The name for which a new
94 * {@link org.eclipse.jgit.attributes.FilterCommand} should be
95 * created
96 * @param db
97 * the repository this command should work on
98 * @param in
99 * the {@link java.io.InputStream} this
100 * {@link org.eclipse.jgit.attributes.FilterCommand} should read
101 * from
102 * @param out
103 * the {@link java.io.OutputStream} this
104 * {@link org.eclipse.jgit.attributes.FilterCommand} should write
105 * to
106 * @return the command if a command could be created or <code>null</code> if
107 * there was no factory registered for that name
108 * @throws java.io.IOException
109 */
110 public static FilterCommand createFilterCommand(String filterCommandName,
111 Repository db, InputStream in, OutputStream out)
112 throws IOException {
113 FilterCommandFactory cf = filterCommandRegistry.get(filterCommandName);
114 return (cf == null) ? null : cf.create(db, in, out);
115 }
116
117 }