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.io;
29
30 import java.io.IOException;
31 import java.io.InputStream;
32
33 import org.apache.hc.core5.util.CharArrayBuffer;
34
35 /**
36 * Session input buffer for HTTP/1.1 blocking connections.
37 * <p>
38 * This interface facilitates intermediate buffering of input data streamed from
39 * an input stream and provides methods for reading lines of text.
40 *
41 * @since 4.0
42 */
43 public interface SessionInputBuffer {
44
45 /**
46 * Returns length data stored in the buffer
47 *
48 * @return data length
49 */
50 int length();
51
52 /**
53 * Returns total capacity of the buffer
54 *
55 * @return total capacity
56 */
57 int capacity();
58
59 /**
60 * Returns available space in the buffer.
61 *
62 * @return available space.
63 */
64 int available();
65
66 /**
67 * Reads up to {@code len} bytes of data from the session buffer into
68 * an array of bytes. An attempt is made to read as many as
69 * {@code len} bytes, but a smaller number may be read, possibly
70 * zero. The number of bytes actually read is returned as an integer.
71 *
72 * <p> This method blocks until input data is available, end of file is
73 * detected, or an exception is thrown.
74 *
75 * <p> If {@code off} is negative, or {@code len} is negative, or
76 * {@code off+len} is greater than the length of the array
77 * {@code b}, then an {@code IndexOutOfBoundsException} is
78 * thrown.
79 * <p> If {@code len} is zero, then no bytes are read and 0 is returned.
80 *
81 * @param b the buffer into which the data is read.
82 * @param off the start offset in array {@code b}
83 * at which the data is written.
84 * @param len the maximum number of bytes to read.
85 * @param inputStream Input stream
86 * @return the total number of bytes read into the buffer, or
87 * {@code -1} if there is no more data because the end of
88 * the stream has been reached.
89 * @throws IOException if an I/O error occurs.
90 */
91 int read(byte[] b, int off, int len, InputStream inputStream) throws IOException;
92
93 /**
94 * Reads some number of bytes from the session buffer and stores them into
95 * the buffer array {@code b}. The number of bytes actually read is
96 * returned as an integer. This method blocks until input data is
97 * available, end of file is detected, or an exception is thrown.
98 *
99 * @param b the buffer into which the data is read.
100 * @param inputStream Input stream
101 * @return the total number of bytes read into the buffer, or
102 * {@code -1} is there is no more data because the end of
103 * the stream has been reached.
104 * @throws IOException if an I/O error occurs.
105 */
106 int read(byte[] b, InputStream inputStream) throws IOException;
107
108 /**
109 * Reads the next byte of data from this session buffer. The value byte is
110 * returned as an {@code int} in the range {@code 0} to
111 * {@code 255}. If no byte is available because the end of the stream
112 * has been reached, the value {@code -1} is returned. This method
113 * blocks until input data is available, the end of the stream is detected,
114 * or an exception is thrown.
115 *
116 * @param inputStream Input stream
117 * @return the next byte of data, or {@code -1} if the end of the
118 * stream is reached.
119 * @throws IOException if an I/O error occurs.
120 */
121 int read(InputStream inputStream) throws IOException;
122
123 /**
124 * Reads a complete line of characters up to a line delimiter from this
125 * session buffer into the given line buffer. The number of chars actually
126 * read is returned as an integer. The line delimiter itself is discarded.
127 * If no char is available because the end of the stream has been reached,
128 * the value {@code -1} is returned. This method blocks until input
129 * data is available, end of file is detected, or an exception is thrown.
130 * <p>
131 * The choice of a char encoding and line delimiter sequence is up to the
132 * specific implementations of this interface.
133 *
134 * @param buffer the line buffer, one line of characters upon return
135 * @param inputStream Input stream
136 * @return the total number of bytes read into the buffer, or
137 * {@code -1} is there is no more data because the end of
138 * the stream has been reached.
139 * @throws IOException if an I/O error occurs.
140 */
141 int readLine(CharArrayBuffer buffer, InputStream inputStream) throws IOException;
142
143 /**
144 * Returns {@link HttpTransportMetrics} for this session buffer.
145 *
146 * @return transport metrics.
147 */
148 HttpTransportMetrics getMetrics();
149
150 }