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Java > Open Source Codes > net > nutch > ndfs > FSResults


1 /* Copyright (c) 2004 The Nutch Organization. All rights reserved. */
2 /* Use subject to the conditions in http://www.nutch.org/LICENSE.txt. */
3 package net.nutch.ndfs;
4
5 import net.nutch.io.*;
6 import net.nutch.ipc.*;
7 import net.nutch.util.*;
8
9 import java.io.*;
10 import java.net.*;
11 import java.util.*;
12
13 /*****************************************************
14  * The result of an NFS IPC call.
15  *
16  * @author Mike Cafarella
17  *****************************************************/
18 public class FSResults implements Writable, FSConstants {
19     public byte op;
20     public Writable first;
21     public Writable second;
22     boolean success = false;
23     boolean tryagain = false;
24
25     /**
26      */
27     public FSResults() {
28         this((byte) 0, NullWritable.get(), NullWritable.get());
29     }
30     public FSResults(byte op) {
31         this(op, NullWritable.get(), NullWritable.get());
32     }
33     public FSResults(byte op, Writable first) {
34         this(op, first, NullWritable.get());
35     }
36
37     /**
38      */
39     public FSResults(byte op, Writable first, Writable second) {
40         this.op = op;
41         this.first = first;
42         this.second = second;
43     }
44
45     /**
46      * Whether the call worked.
47      */
48     public boolean success() {
49         return success;
50     }
51
52     /**
53      * Whether the client should give it another shot
54      */
55     public boolean tryagain() {
56         return tryagain;
57     }
58
59     /**
60      */
61     public void write(DataOutput out) throws IOException {
62         out.writeByte(op);
63         first.write(out);
64         second.write(out);
65     }
66
67     /**
68      */
69     public void readFields(DataInput in) throws IOException {
70         op = in.readByte();
71
72         switch (op) {
73             //
74 // Issued to DataNodes
75 //
76 case OP_INVALIDATE_BLOCKS: {
77             success = true;
78             first = new ArrayWritable(Block.class);
79             break;
80         }
81         case OP_TRANSFERBLOCKS: {
82             success = true;
83             first = new ArrayWritable(Block.class);
84             second = new TwoDArrayWritable(DatanodeInfo.class);
85             break;
86         }
87         case OP_ACK: {
88             success = true;
89             break;
90         }
91
92             //
93 // Client operations
94 //
95 case OP_CLIENT_OPEN_ACK: {
96             success = true;
97             first = new ArrayWritable(Block.class);
98             second = new TwoDArrayWritable(DatanodeInfo.class);
99             break;
100         }
101         case OP_CLIENT_STARTFILE_ACK:
102         case OP_CLIENT_ADDBLOCK_ACK: {
103             success = true;
104             first = new Block();
105             second = new ArrayWritable(DatanodeInfo.class);
106             break;
107         }
108         case OP_CLIENT_COMPLETEFILE_ACK: {
109             success = true;
110             break;
111         }
112         case OP_CLIENT_RENAMETO_ACK:
113         case OP_CLIENT_DELETE_ACK: {
114             success = true;
115             break;
116         }
117         case OP_CLIENT_LISTING_ACK: {
118             success = true;
119             first = new ArrayWritable(NDFSFileInfo.class);
120             break;
121         }
122         case OP_CLIENT_OBTAINLOCK_ACK: {
123             success = true;
124             break;
125         }
126         case OP_CLIENT_RELEASELOCK_ACK: {
127             success = true;
128             break;
129         }
130         case OP_CLIENT_EXISTS_ACK:
131         case OP_CLIENT_ISDIR_ACK:
132         case OP_CLIENT_MKDIRS_ACK: {
133             success = true;
134             break;
135         }
136         case OP_CLIENT_RENEW_LEASE_ACK: {
137             success = true;
138             break;
139         }
140         case OP_CLIENT_ABANDONBLOCK_ACK: {
141             success = true;
142             break;
143         }
144         case OP_CLIENT_RAWSTATS_ACK: {
145             success = true;
146             first = new ArrayWritable(LongWritable.class);
147             break;
148         }
149         case OP_CLIENT_DATANODEREPORT_ACK: {
150             success = true;
151             first = new ArrayWritable(DatanodeInfo.class);
152             break;
153         }
154         case OP_CLIENT_TRYAGAIN: {
155             success = true;
156             tryagain = true;
157             break;
158         }
159         case OP_FAILURE: {
160             success = false;
161             break;
162         }
163         default: {
164             throw new IOException("Unknown opcode: " + op);
165         }
166         }
167
168         first.readFields(in);
169         second.readFields(in);
170     }
171 }
172
173
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