ServerConnection


1   /* Copyright (c) 1995-2000, The Hypersonic SQL Group.
2    * All rights reserved.
3    *
4    * Redistribution and use in source and binary forms, with or without
5    * modification, are permitted provided that the following conditions are met:
6    *
7    * Redistributions of source code must retain the above copyright notice, this
8    * list of conditions and the following disclaimer.
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10   * Redistributions in binary form must reproduce the above copyright notice,
11   * this list of conditions and the following disclaimer in the documentation
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15   * contributors may be used to endorse or promote products derived from this
16   * software without specific prior written permission.
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26   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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33   *
34   * For work added by the HSQL Development Group:
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36   * Copyright (c) 2001-2005, The HSQL Development Group
37   * All rights reserved.
38   *
39   * Redistribution and use in source and binary forms, with or without
40   * modification, are permitted provided that the following conditions are met:
41   *
42   * Redistributions of source code must retain the above copyright notice, this
43   * list of conditions and the following disclaimer.
44   *
45   * Redistributions in binary form must reproduce the above copyright notice,
46   * this list of conditions and the following disclaimer in the documentation
47   * and/or other materials provided with the distribution.
48   *
49   * Neither the name of the HSQL Development Group nor the names of its
50   * contributors may be used to endorse or promote products derived from this
51   * software without specific prior written permission.
52   *
53   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
54   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
55   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
56   * ARE DISCLAIMED. IN NO EVENT SHALL HSQL DEVELOPMENT GROUP, HSQLDB.ORG,
57   * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
58   * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
59   * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
60   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
61   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
62   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
63   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
64   */
65  
66  
67  package org.hsqldb;
68  
69  import java.io.BufferedOutputStream  ;
70  import java.io.DataInputStream  ;
71  import java.io.IOException  ;
72  import java.net.Socket  ;
73  
74  import org.hsqldb.lib.ArrayUtil;
75  import org.hsqldb.rowio.RowInputBinary;
76  import org.hsqldb.rowio.RowOutputBinary;
77  
78  // fredt@users 20020215 - patch 461556 by paul-h@users - server factory
79  // fredt@users 20020424 - patch 1.7.0 by fredt - shutdown without exit
80  // fredt@users 20021002 - patch 1.7.1 by fredt - changed notification method
81  // fredt@users 20030618 - patch 1.7.2 by fredt - changed read/write methods
82  
83  /**
84   *  All ServerConnection objects are listed in a Set in server
85   *  and removed by this class when closed.<p>
86   *
87   *  When the database or server is shutdown, the signalClose() method is called
88   *  for all current ServerConnection instances. This will call the private
89   *  close() method unless the ServerConnection thread itself has caused the
90   *  shutdown. In this case, the keepAlive flag is set to false, allowing the
91   *  thread to terminate once it has returned the result of the operation to
92   *  the client.
93   *  (fredt@users)<p>
94   *
95   * Rewritten in version HSQLDB 1.7.2, based on original Hypersonic code.
96   *
97   * @author Thomas Mueller (Hypersonic SQL Group)
98   * @author fredt@users
99   * @version 1.8.0
100  * @since Hypersonic SQL
101  */
102 class ServerConnection implements Runnable   {
103 
104     boolean                      keepAlive;
105     private String                 user;
106     private String                 password;
107     int                          dbID;
108     private volatile Session     session;
109     private Socket                 socket;
110     private Server               server;
111     private DataInputStream        dataInput;
112     private BufferedOutputStream   dataOutput;
113     private static int           mCurrentThread = 0;
114     private int                  mThread;
115     static final int             BUFFER_SIZE = 0x1000;
116     final byte[]                 mainBuffer  = new byte[BUFFER_SIZE];
117     RowOutputBinary              rowOut = new RowOutputBinary(BUFFER_SIZE);
118     RowInputBinary               rowIn       = new RowInputBinary(rowOut);
119     Thread                         runnerThread;
120 
121     /**
122      * Creates a new ServerConnection to the specified Server on the
123      * specified socket.
124      *
125      * @param socket the network socket on which Server communication
126      *      takes place
127      * @param server the Server instance to which the object
128      *      represents a connection
129      */
130     ServerConnection(Socket   socket, Server server) {
131 
132         this.socket = socket;
133         this.server = server;
134 
135         synchronized (ServerConnection.class) {
136             mThread = mCurrentThread++;
137         }
138 
139         synchronized (server.serverConnSet) {
140             server.serverConnSet.add(this);
141         }
142     }
143 
144     /**
145      * Signals this object to close, including exiting the thread running
146      * the request handling loop
147      */
148     void signalClose() {
149 
150         keepAlive = false;
151 
152         if (!Thread.currentThread().equals(runnerThread)) {
153             close();
154         }
155     }
156 
157     /**
158      * Closes this connection.
159      */
160     private void close() {
161 
162         if (session != null) {
163             session.close();
164         }
165 
166         session = null;
167 
168         // fredt@user - closing the socket is to stop this thread
169         try {
170             socket.close();
171         } catch (IOException   e) {}
172 
173         synchronized (server.serverConnSet) {
174             server.serverConnSet.remove(this);
175         }
176     }
177 
178     /**
179      * Initializes this connection.
180      */
181     private void init() {
182 
183         runnerThread = Thread.currentThread();
184         keepAlive    = true;
185 
186         try {
187             socket.setTcpNoDelay(true);
188 
189             dataInput  = new DataInputStream  (socket.getInputStream());
190             dataOutput = new BufferedOutputStream  (socket.getOutputStream());
191 
192             Result resultIn = Result.read(rowIn, dataInput);
193             Result resultOut;
194 
195             try {
196                 dbID     = server.getDBID(resultIn.subSubString);
197                 user     = resultIn.getMainString();
198                 password = resultIn.getSubString();
199 
200                 if (!server.isSilent()) {
201                     server.printWithThread(mThread
202                                            + ":trying to connect user "
203                                            + user);
204                 }
205 
206                 session = DatabaseManager.newSession(dbID,
207                                                      resultIn.getMainString(),
208                                                      resultIn.getSubString());
209                 resultOut = new Result(ResultConstants.UPDATECOUNT);
210                 resultOut.databaseID = session.getDatabase().databaseID;
211                 resultOut.sessionID  = session.getId();
212             } catch (HsqlException e) {
213                 session   = null;
214                 resultOut = new Result(e, null);
215             } catch (RuntimeException   e) {
216                 session   = null;
217                 resultOut = new Result(e, null);
218             }
219 
220             Result.write(resultOut, rowOut, dataOutput);
221 
222             return;
223         } catch (Exception   e) {
224             server.printWithThread(mThread + ":couldn't connect " + user);
225         }
226 
227         close();
228     }
229 
230     /**
231      * Initializes this connection and runs the request handling
232      * loop until closed.
233      */
234     public void run() {
235 
236         init();
237 
238         if (session != null) {
239             try {
240                 while (keepAlive) {
241                     Result resultIn = Result.read(rowIn, dataInput);
242 
243                     server.printRequest(mThread, resultIn);
244 
245                     Result resultOut;
246 
247                     if (resultIn.mode == ResultConstants.HSQLRESETSESSION) {
248                         resultOut = resetSession();
249                     } else {
250                         resultOut = session.execute(resultIn);
251                     }
252 
253                     Result.write(resultOut, rowOut, dataOutput);
254                     rowOut.setBuffer(mainBuffer);
255                     rowIn.resetRow(mainBuffer.length);
256                 }
257             } catch (IOException   e) {
258 
259                 // fredt - is thrown when connection drops
260                 server.printWithThread(mThread + ":disconnected " + user);
261             } catch (HsqlException e) {
262 
263                 // fredt - is thrown while constructing the result
264                 server.printStackTrace(e);
265             }
266 
267             close();
268         }
269     }
270 
271     /**
272      * Used by pooled connections to close the existing SQL session and open
273      * a new one.
274      */
275     private Result resetSession() {
276 
277         Result resultOut;
278 
279         if (!server.isSilent()) {
280             server.printWithThread(mThread + ":trying to connect user "
281                                    + user);
282         }
283 
284         try {
285             session.close();
286 
287             session = DatabaseManager.newSession(dbID, user, password);
288             resultOut            = new Result(ResultConstants.UPDATECOUNT);
289             resultOut.databaseID = session.getDatabase().databaseID;
290             resultOut.sessionID  = session.getId();
291         } catch (HsqlException e) {
292             session   = null;
293             resultOut = new Result(e, null);
294         }
295 
296         return resultOut;
297     }
298 
299     /**
300      * Retrieves the thread name to be used  when
301      * this object is the Runnable object of a Thread.
302      *
303      * @return the thread name to be used  when this object is the Runnable
304      * object of a Thread.
305      */
306     String   getConnectionThreadName() {
307         return "HSQLDB Connection @" + Integer.toString(hashCode(), 16);
308     }
309 }
310
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