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Java > Open Source Codes > org > apache > coyote > http11 > filters > IdentityInputFilter


1 /*
2  * Licensed to the Apache Software Foundation (ASF) under one or more
3  * contributor license agreements. See the NOTICE file distributed with
4  * this work for additional information regarding copyright ownership.
5  * The ASF licenses this file to You under the Apache License, Version 2.0
6  * (the "License"); you may not use this file except in compliance with
7  * the License. You may obtain a copy of the License at
8  *
9  * http://www.apache.org/licenses/LICENSE-2.0
10  *
11  * Unless required by applicable law or agreed to in writing, software
12  * distributed under the License is distributed on an "AS IS" BASIS,
13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  * See the License for the specific language governing permissions and
15  * limitations under the License.
16  */
17
18 package org.apache.coyote.http11.filters;
19
20 import java.io.IOException JavaDoc;
21
22 import org.apache.tomcat.util.buf.ByteChunk;
23
24 import org.apache.coyote.InputBuffer;
25 import org.apache.coyote.Request;
26 import org.apache.coyote.http11.InputFilter;
27
28 /**
29  * Identity input filter.
30  *
31  * @author Remy Maucherat
32  */
33 public class IdentityInputFilter implements InputFilter {
34
35
36     // -------------------------------------------------------------- Constants
37
38
39     protected static final String JavaDoc ENCODING_NAME = "identity";
40     protected static final ByteChunk ENCODING = new ByteChunk();
41
42
43     // ----------------------------------------------------- Static Initializer
44
45
46     static {
47         ENCODING.setBytes(ENCODING_NAME.getBytes(), 0, ENCODING_NAME.length());
48     }
49
50
51     // ----------------------------------------------------- Instance Variables
52
53
54     /**
55      * Content length.
56      */
57     protected long contentLength = -1;
58
59
60     /**
61      * Remaining bytes.
62      */
63     protected long remaining = 0;
64
65
66     /**
67      * Next buffer in the pipeline.
68      */
69     protected InputBuffer buffer;
70
71
72     /**
73      * Chunk used to read leftover bytes.
74      */
75     protected ByteChunk endChunk = new ByteChunk();
76
77
78     // ------------------------------------------------------------- Properties
79
80
81     /**
82      * Get content length.
83      */
84     public long getContentLength() {
85         return contentLength;
86     }
87
88
89     /**
90      * Get remaining bytes.
91      */
92     public long getRemaining() {
93         return remaining;
94     }
95
96
97     // ---------------------------------------------------- InputBuffer Methods
98
99
100     /**
101      * Read bytes.
102      *
103      * @return If the filter does request length control, this value is
104      * significant; it should be the number of bytes consumed from the buffer,
105      * up until the end of the current request body, or the buffer length,
106      * whichever is greater. If the filter does not do request body length
107      * control, the returned value should be -1.
108      */
109     public int doRead(ByteChunk chunk, Request req)
110         throws IOException JavaDoc {
111
112         int result = -1;
113
114         if (contentLength >= 0) {
115             if (remaining > 0) {
116                 int nRead = buffer.doRead(chunk, req);
117                 if (nRead > remaining) {
118                     // The chunk is longer than the number of bytes remaining
119 // in the body; changing the chunk length to the number
120 // of bytes remaining
121 chunk.setBytes(chunk.getBytes(), chunk.getStart(),
122                                    (int) remaining);
123                     result = (int) remaining;
124                 } else {
125                     result = nRead;
126                 }
127                 remaining = remaining - nRead;
128             } else {
129                 // No more bytes left to be read : return -1 and clear the
130 // buffer
131 chunk.recycle();
132                 result = -1;
133             }
134         }
135
136         return result;
137
138     }
139
140
141     // ---------------------------------------------------- InputFilter Methods
142
143
144     /**
145      * Read the content length from the request.
146      */
147     public void setRequest(Request request) {
148         contentLength = request.getContentLengthLong();
149         remaining = contentLength;
150     }
151
152
153     /**
154      * End the current request.
155      */
156     public long end()
157         throws IOException JavaDoc {
158
159         // Consume extra bytes.
160 while (remaining > 0) {
161             int nread = buffer.doRead(endChunk, null);
162             if (nread > 0 ) {
163                 remaining = remaining - nread;
164             } else { // errors are handled higher up.
165 remaining = 0;
166             }
167         }
168
169         // If too many bytes were read, return the amount.
170 return -remaining;
171
172     }
173
174
175     /**
176      * Set the next buffer in the filter pipeline.
177      */
178     public void setBuffer(InputBuffer buffer) {
179         this.buffer = buffer;
180     }
181
182
183     /**
184      * Make the filter ready to process the next request.
185      */
186     public void recycle() {
187         contentLength = -1;
188         remaining = 0;
189         endChunk.recycle();
190     }
191
192
193     /**
194      * Return the name of the associated encoding; Here, the value is
195      * "identity".
196      */
197     public ByteChunk getEncodingName() {
198         return ENCODING;
199     }
200
201
202 }
203
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