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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 static java.nio.charset.StandardCharsets.UTF_8;
46  
47  import java.io.ByteArrayOutputStream;
48  import java.io.IOException;
49  import java.io.PrintStream;
50  import java.io.UnsupportedEncodingException;
51  import java.util.concurrent.Callable;
52  
53  import org.eclipse.jgit.api.errors.AbortedByHookException;
54  import org.eclipse.jgit.lib.Repository;
55  import org.eclipse.jgit.util.FS;
56  import org.eclipse.jgit.util.ProcessResult;
57  
58  /**
59   * Git can fire off custom scripts when certain important actions occur. These
60   * custom scripts are called "hooks". There are two groups of hooks: client-side
61   * (that run on local operations such as committing and merging), and
62   * server-side (that run on network operations such as receiving pushed
63   * commits). This is the abstract super-class of the different hook
64   * implementations in JGit.
65   *
66   * @param <T>
67   *            the return type which is expected from {@link #call()}
68   * @see <a href="http://git-scm.com/book/en/v2/Customizing-Git-Git-Hooks">Git
69   *      Hooks on the git-scm official site</a>
70   * @since 4.0
71   */
72  abstract class GitHook<T> implements Callable<T> {
73  
74  	private final Repository repo;
75  
76  	/**
77  	 * The output stream to be used by the hook.
78  	 */
79  	protected final PrintStream outputStream;
80  
81  	/**
82  	 * Constructor for GitHook
83  	 *
84  	 * @param repo
85  	 *            a {@link org.eclipse.jgit.lib.Repository} object.
86  	 * @param outputStream
87  	 *            The output stream the hook must use. {@code null} is allowed,
88  	 *            in which case the hook will use {@code System.out}.
89  	 */
90  	protected GitHook(Repository repo, PrintStream outputStream) {
91  		this.repo = repo;
92  		this.outputStream = outputStream;
93  	}
94  
95  	/**
96  	 * {@inheritDoc}
97  	 * <p>
98  	 * Run the hook.
99  	 */
100 	@Override
101 	public abstract T call() throws IOException, AbortedByHookException;
102 
103 	/**
104 	 * Get name of the hook
105 	 *
106 	 * @return The name of the hook, which must not be {@code null}.
107 	 */
108 	public abstract String getHookName();
109 
110 	/**
111 	 * Get the repository
112 	 *
113 	 * @return The repository.
114 	 */
115 	protected Repository getRepository() {
116 		return repo;
117 	}
118 
119 	/**
120 	 * Override this method when needed to provide relevant parameters to the
121 	 * underlying hook script. The default implementation returns an empty
122 	 * array.
123 	 *
124 	 * @return The parameters the hook receives.
125 	 */
126 	protected String[] getParameters() {
127 		return new String[0];
128 	}
129 
130 	/**
131 	 * Override to provide relevant arguments via stdin to the underlying hook
132 	 * script. The default implementation returns {@code null}.
133 	 *
134 	 * @return The parameters the hook receives.
135 	 */
136 	protected String getStdinArgs() {
137 		return null;
138 	}
139 
140 	/**
141 	 * Get output stream
142 	 *
143 	 * @return The output stream the hook must use. Never {@code null},
144 	 *         {@code System.out} is returned by default.
145 	 */
146 	protected PrintStream getOutputStream() {
147 		return outputStream == null ? System.out : outputStream;
148 	}
149 
150 	/**
151 	 * Runs the hook, without performing any validity checks.
152 	 *
153 	 * @throws org.eclipse.jgit.api.errors.AbortedByHookException
154 	 *             If the underlying hook script exited with non-zero.
155 	 */
156 	protected void doRun() throws AbortedByHookException {
157 		final ByteArrayOutputStream errorByteArray = new ByteArrayOutputStream();
158 		PrintStream hookErrRedirect = null;
159 		try {
160 			hookErrRedirect = new PrintStream(errorByteArray, false,
161 					UTF_8.name());
162 		} catch (UnsupportedEncodingException e) {
163 			// UTF-8 is guaranteed to be available
164 		}
165 		ProcessResult result = FS.DETECTED.runHookIfPresent(getRepository(),
166 				getHookName(), getParameters(), getOutputStream(),
167 				hookErrRedirect, getStdinArgs());
168 		if (result.isExecutedWithError()) {
169 			throw new AbortedByHookException(
170 					new String(errorByteArray.toByteArray(), UTF_8),
171 					getHookName(), result.getExitCode());
172 		}
173 	}
174 
175 	/**
176 	 * Check whether a 'native' (i.e. script) hook is installed in the
177 	 * repository.
178 	 *
179 	 * @return whether a native hook script is installed in the repository.
180 	 * @since 4.11
181 	 */
182 	public boolean isNativeHookPresent() {
183 		return FS.DETECTED.findHook(getRepository(), getHookName()) != null;
184 	}
185 
186 }