1 /*
2 * ====================================================================
3 * Licensed to the Apache Software Foundation (ASF) under one
4 * or more contributor license agreements. See the NOTICE file
5 * distributed with this work for additional information
6 * regarding copyright ownership. The ASF licenses this file
7 * to you under the Apache License, Version 2.0 (the
8 * "License"); you may not use this file except in compliance
9 * with the License. You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing,
14 * software distributed under the License is distributed on an
15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16 * KIND, either express or implied. See the License for the
17 * specific language governing permissions and limitations
18 * under the License.
19 * ====================================================================
20 *
21 * This software consists of voluntary contributions made by many
22 * individuals on behalf of the Apache Software Foundation. For more
23 * information on the Apache Software Foundation, please see
24 * <http://www.apache.org/>.
25 *
26 */
27
28 package org.apache.hc.core5.http.nio.support.classic;
29
30 import java.io.IOException;
31
32 /**
33 * Generic content input buffer.
34 *
35 * @since 4.0
36 */
37 public interface ContentInputBuffer {
38
39 /**
40 * Return length data stored in the buffer
41 *
42 * @return data length
43 */
44 int length();
45
46 /**
47 * Resets the buffer by clearing its state and stored content.
48 */
49 void reset();
50
51 /**
52 * Reads up to {@code len} bytes of data from this buffer into
53 * an array of bytes. The exact number of bytes read depends how many bytes
54 * are stored in the buffer.
55 *
56 * <p> If {@code off} is negative, or {@code len} is negative, or
57 * {@code off+len} is greater than the length of the array
58 * {@code b}, this method can throw a runtime exception. The exact type
59 * of runtime exception thrown by this method depends on implementation.
60 * This method returns {@code -1} if the end of content stream has been
61 * reached.
62 *
63 * @param b the buffer into which the data is read.
64 * @param off the start offset in array {@code b}
65 * at which the data is written.
66 * @param len the maximum number of bytes to read.
67 * @return the total number of bytes read into the buffer, or
68 * {@code -1} if there is no more data because the end of
69 * the stream has been reached.
70 * @throws IOException if an I/O error occurs.
71 */
72 int read(byte[] b, int off, int len) throws IOException;
73
74 /**
75 * Reads one byte from this buffer. If the buffer is empty this method can
76 * throw a runtime exception. The exact type of runtime exception thrown
77 * by this method depends on implementation. This method returns
78 * {@code -1} if the end of content stream has been reached.
79 *
80 * @return one byte
81 */
82 int read() throws IOException;
83
84 }