1 /*
2 * Copyright (c) 2005 The University of Reading
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the University of Reading, nor the names of the
14 * authors or contributors may be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 package uk.ac.rdg.resc.jstyx.client.callbacks;
30
31 import uk.ac.rdg.resc.jstyx.client.StyxConnection;
32 import uk.ac.rdg.resc.jstyx.client.CStyxFile;
33 import uk.ac.rdg.resc.jstyx.client.MessageCallback;
34
35 import uk.ac.rdg.resc.jstyx.messages.StyxMessage;
36 import uk.ac.rdg.resc.jstyx.messages.TwalkMessage;
37 import uk.ac.rdg.resc.jstyx.messages.RwalkMessage;
38
39 /***
40 * A callback object used to get a fid for a CStyxFile.
41 *
42 * @author Jon Blower
43 * $Revision: 347 $
44 * $Date: 2005-08-05 14:46:40 +0100 (Fri, 05 Aug 2005) $
45 * $Log$
46 * Revision 1.1 2005/08/05 13:46:40 jonblower
47 * Factored out all callback objects from CStyxFile into separate classes
48 *
49 */
50
51 public class GetFidCallback extends MessageCallback
52 {
53 private MessageCallback callback;
54 private CStyxFile file;
55 private StyxConnection conn;
56
57 public GetFidCallback(CStyxFile file, MessageCallback callback)
58 {
59 this.file = file;
60 this.conn = this.file.getConnection();
61 this.callback = callback;
62 }
63
64 public void walkFid()
65 {
66 // Need to get a fid for this file
67 TwalkMessage tWalkMsg = new TwalkMessage(this.conn.getRootFid(),
68 this.conn.getFreeFid(), this.file.getPath());
69 this.conn.sendAsync(tWalkMsg, this);
70 }
71
72 public void replyArrived(StyxMessage rMessage, StyxMessage tMessage)
73 {
74 // Message can only be an RwalkMessage
75 RwalkMessage rWalkMsg = (RwalkMessage)rMessage;
76 TwalkMessage tWalkMsg = (TwalkMessage)tMessage;
77 // Check that the walk was successful
78 if (tWalkMsg.getNumPathElements() == rWalkMsg.getNumSuccessfulWalks())
79 {
80 this.file.setFid(tWalkMsg.getNewFid());
81 if (rWalkMsg.getNumSuccessfulWalks() > 0)
82 {
83 // We can't get the qid from the Rwalk if this was a zero-
84 // length walk
85 this.file.setQid(rWalkMsg.getQid(rWalkMsg.getNumSuccessfulWalks() - 1));
86 }
87 if (this.callback != null)
88 {
89 this.callback.replyArrived(rWalkMsg, tMessage);
90 }
91 }
92 else
93 {
94 // The walk failed at some point
95 String errMsg = "'" +
96 tWalkMsg.getPathElements()[rWalkMsg.getNumSuccessfulWalks()]
97 + "' does not exist.";
98 this.error(errMsg, tWalkMsg);
99 }
100 }
101
102 public void error(String message, StyxMessage tMessage)
103 {
104 // The walk was not successful. Return the fid to the pool
105 // and throw an error.
106 if (tMessage != null)
107 {
108 TwalkMessage tWalkMsg = (TwalkMessage)tMessage;
109 conn.returnFid(tWalkMsg.getNewFid());
110 }
111 String errMsg = "Error getting fid for " + this.file.getPath() + ": " + message;
112 if (this.callback != null)
113 {
114 this.callback.error(errMsg, tMessage);
115 }
116 else
117 {
118 this.file.fireError(errMsg);
119 }
120 }
121 }