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1   /*
2    * Copyright (C) 2015, Matthias Sohn <matthias.sohn@sap.com>
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.lfs.server.fs;
44  
45  import java.io.IOException;
46  import java.io.PrintWriter;
47  import java.text.MessageFormat;
48  
49  import javax.servlet.AsyncContext;
50  import javax.servlet.ServletException;
51  import javax.servlet.annotation.WebServlet;
52  import javax.servlet.http.HttpServlet;
53  import javax.servlet.http.HttpServletRequest;
54  import javax.servlet.http.HttpServletResponse;
55  
56  import org.apache.http.HttpStatus;
57  import org.eclipse.jgit.lfs.errors.InvalidLongObjectIdException;
58  import org.eclipse.jgit.lfs.lib.AnyLongObjectId;
59  import org.eclipse.jgit.lfs.lib.Constants;
60  import org.eclipse.jgit.lfs.lib.LongObjectId;
61  import org.eclipse.jgit.lfs.server.internal.LfsGson;
62  import org.eclipse.jgit.lfs.server.internal.LfsServerText;
63  
64  /**
65   * Servlet supporting upload and download of large objects as defined by the
66   * GitHub Large File Storage extension API extending git to allow separate
67   * storage of large files
68   * (https://github.com/github/git-lfs/tree/master/docs/api).
69   *
70   * @since 4.3
71   */
72  @WebServlet(asyncSupported = true)
73  public class FileLfsServlet extends HttpServlet {
74  
75  	private static final long serialVersionUID = 1L;
76  
77  	private final FileLfsRepository repository;
78  
79  	private final long timeout;
80  
81  	/**
82  	 * <p>Constructor for FileLfsServlet.</p>
83  	 *
84  	 * @param repository
85  	 *            the repository storing the large objects
86  	 * @param timeout
87  	 *            timeout for object upload / download in milliseconds
88  	 */
89  	public FileLfsServlet(FileLfsRepository repository, long timeout) {
90  		this.repository = repository;
91  		this.timeout = timeout;
92  	}
93  
94  	/**
95  	 * {@inheritDoc}
96  	 *
97  	 * Handle object downloads
98  	 */
99  	@Override
100 	protected void doGet(HttpServletRequest req,
101 			HttpServletResponse rsp) throws ServletException, IOException {
102 		AnyLongObjectId obj = getObjectToTransfer(req, rsp);
103 		if (obj != null) {
104 			if (repository.getSize(obj) == -1) {
105 				sendError(rsp, HttpStatus.SC_NOT_FOUND, MessageFormat
106 						.format(LfsServerText.get().objectNotFound,
107 								obj.getName()));
108 				return;
109 			}
110 			AsyncContext context = req.startAsync();
111 			context.setTimeout(timeout);
112 			rsp.getOutputStream()
113 					.setWriteListener(new ObjectDownloadListener(repository,
114 							context, rsp, obj));
115 		}
116 	}
117 
118 	/**
119 	 * Retrieve object id from request
120 	 *
121 	 * @param req
122 	 *            servlet request
123 	 * @param rsp
124 	 *            servlet response
125 	 * @return object id, or <code>null</code> if the object id could not be
126 	 *         retrieved
127 	 * @throws java.io.IOException
128 	 *             if an I/O error occurs
129 	 * @since 4.6
130 	 */
131 	protected AnyLongObjectId getObjectToTransfer(HttpServletRequest req,
132 			HttpServletResponse rsp) throws IOException {
133 		String info = req.getPathInfo();
134 		int length = 1 + Constants.LONG_OBJECT_ID_STRING_LENGTH;
135 		if (info.length() != length) {
136 			sendError(rsp, HttpStatus.SC_UNPROCESSABLE_ENTITY, MessageFormat
137 					.format(LfsServerText.get().invalidPathInfo, info));
138 			return null;
139 		}
140 		try {
141 			return LongObjectId.fromString(info.substring(1, length));
142 		} catch (InvalidLongObjectIdException e) {
143 			sendError(rsp, HttpStatus.SC_UNPROCESSABLE_ENTITY, e.getMessage());
144 			return null;
145 		}
146 	}
147 
148 	/**
149 	 * {@inheritDoc}
150 	 *
151 	 * Handle object uploads
152 	 */
153 	@Override
154 	protected void doPut(HttpServletRequest req,
155 			HttpServletResponse rsp) throws ServletException, IOException {
156 		AnyLongObjectId id = getObjectToTransfer(req, rsp);
157 		if (id != null) {
158 			AsyncContext context = req.startAsync();
159 			context.setTimeout(timeout);
160 			req.getInputStream().setReadListener(new ObjectUploadListener(
161 					repository, context, req, rsp, id));
162 		}
163 	}
164 
165 	/**
166 	 * Send an error response.
167 	 *
168 	 * @param rsp
169 	 *            the servlet response
170 	 * @param status
171 	 *            HTTP status code
172 	 * @param message
173 	 *            error message
174 	 * @throws java.io.IOException
175 	 *             on failure to send the response
176 	 * @since 4.6
177 	 */
178 	protected static void sendError(HttpServletResponse rsp, int status, String message)
179 			throws IOException {
180 		if (rsp.isCommitted()) {
181 			rsp.getOutputStream().close();
182 			return;
183 		}
184 		rsp.reset();
185 		rsp.setStatus(status);
186 		try (PrintWriter writer = rsp.getWriter()) {
187 			LfsGson.toJson(message, writer);
188 			writer.flush();
189 		}
190 		rsp.flushBuffer();
191 	}
192 }