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1   /*
2    * Copyright (C) 2015 Obeo.
3    * and other copyright owners as documented in the project's IP log.
4    *
5    * This program and the accompanying materials are made available
6    * under the terms of the Eclipse Distribution License v1.0 which
7    * accompanies this distribution, is reproduced below, and is
8    * available at http://www.eclipse.org/org/documents/edl-v10.php
9    *
10   * All rights reserved.
11   *
12   * Redistribution and use in source and binary forms, with or
13   * without modification, are permitted provided that the following
14   * conditions are met:
15   *
16   * - Redistributions of source code must retain the above copyright
17   *   notice, this list of conditions and the following disclaimer.
18   *
19   * - Redistributions in binary form must reproduce the above
20   *   copyright notice, this list of conditions and the following
21   *   disclaimer in the documentation and/or other materials provided
22   *   with the distribution.
23   *
24   * - Neither the name of the Eclipse Foundation, Inc. nor the
25   *   names of its contributors may be used to endorse or promote
26   *   products derived from this software without specific prior
27   *   written permission.
28   *
29   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
30   * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
31   * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
34   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
35   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
36   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
37   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
38   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
40   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
41   * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
42   */
43  package org.eclipse.jgit.hooks;
44  
45  import java.io.ByteArrayOutputStream;
46  import java.io.IOException;
47  import java.io.PrintStream;
48  import java.util.concurrent.Callable;
49  
50  import org.eclipse.jgit.api.errors.AbortedByHookException;
51  import org.eclipse.jgit.lib.Repository;
52  import org.eclipse.jgit.util.FS;
53  import org.eclipse.jgit.util.ProcessResult;
54  
55  /**
56   * Git can fire off custom scripts when certain important actions occur. These
57   * custom scripts are called "hooks". There are two groups of hooks: client-side
58   * (that run on local operations such as committing and merging), and
59   * server-side (that run on network operations such as receiving pushed
60   * commits). This is the abstract super-class of the different hook
61   * implementations in JGit.
62   *
63   * @param <T>
64   *            the return type which is expected from {@link #call()}
65   * @see <a href="http://git-scm.com/book/en/v2/Customizing-Git-Git-Hooks">Git
66   *      Hooks on the git-scm official site</a>
67   * @since 4.0
68   */
69  abstract class GitHook<T> implements Callable<T> {
70  
71  	private final Repository repo;
72  
73  	/**
74  	 * The output stream to be used by the hook.
75  	 */
76  	protected final PrintStream outputStream;
77  
78  	/**
79  	 * @param repo
80  	 * @param outputStream
81  	 *            The output stream the hook must use. {@code null} is allowed,
82  	 *            in which case the hook will use {@code System.out}.
83  	 */
84  	protected GitHook(Repository repo, PrintStream outputStream) {
85  		this.repo = repo;
86  		this.outputStream = outputStream;
87  	}
88  
89  	/**
90  	 * Run the hook.
91  	 *
92  	 * @throws IOException
93  	 *             if IO goes wrong.
94  	 * @throws AbortedByHookException
95  	 *             If the hook has been run and a returned an exit code
96  	 *             different from zero.
97  	 */
98  	public abstract T call() throws IOException, AbortedByHookException;
99  
100 	/**
101 	 * @return The name of the hook, which must not be {@code null}.
102 	 */
103 	public abstract String getHookName();
104 
105 	/**
106 	 * @return The repository.
107 	 */
108 	protected Repository getRepository() {
109 		return repo;
110 	}
111 
112 	/**
113 	 * Override this method when needed to provide relevant parameters to the
114 	 * underlying hook script. The default implementation returns an empty
115 	 * array.
116 	 *
117 	 * @return The parameters the hook receives.
118 	 */
119 	protected String[] getParameters() {
120 		return new String[0];
121 	}
122 
123 	/**
124 	 * Override to provide relevant arguments via stdin to the underlying hook
125 	 * script. The default implementation returns {@code null}.
126 	 *
127 	 * @return The parameters the hook receives.
128 	 */
129 	protected String getStdinArgs() {
130 		return null;
131 	}
132 
133 	/**
134 	 * @return The output stream the hook must use. Never {@code null},
135 	 *         {@code System.out} is returned by default.
136 	 */
137 	protected PrintStream getOutputStream() {
138 		return outputStream == null ? System.out : outputStream;
139 	}
140 
141 	/**
142 	 * Runs the hook, without performing any validity checks.
143 	 *
144 	 * @throws AbortedByHookException
145 	 *             If the underlying hook script exited with non-zero.
146 	 */
147 	protected void doRun() throws AbortedByHookException {
148 		final ByteArrayOutputStream errorByteArray = new ByteArrayOutputStream();
149 		final PrintStream hookErrRedirect = new PrintStream(errorByteArray);
150 		ProcessResult result = FS.DETECTED.runHookIfPresent(getRepository(),
151 				getHookName(), getParameters(), getOutputStream(),
152 				hookErrRedirect, getStdinArgs());
153 		if (result.isExecutedWithError()) {
154 			throw new AbortedByHookException(errorByteArray.toString(),
155 					getHookName(), result.getExitCode());
156 		}
157 	}
158 
159 }