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.http.io;
29
30 import java.io.IOException;
31
32 import org.apache.http.util.CharArrayBuffer;
33
34 /**
35 * Session output buffer for blocking connections. This interface is similar to
36 * OutputStream class, but it also provides methods for writing lines of text.
37 * <p>
38 * Implementing classes are also expected to manage intermediate data buffering
39 * for optimal output performance.
40 *
41 * @since 4.0
42 */
43 public interface SessionOutputBuffer {
44
45 /**
46 * Writes {@code len} bytes from the specified byte array
47 * starting at offset {@code off} to this session buffer.
48 * <p>
49 * If {@code off} is negative, or {@code len} is negative, or
50 * {@code off+len} is greater than the length of the array
51 * {@code b}, then an {@code IndexOutOfBoundsException} is thrown.
52 *
53 * @param b the data.
54 * @param off the start offset in the data.
55 * @param len the number of bytes to write.
56 * @throws IOException if an I/O error occurs.
57 */
58 void write(byte[] b, int off, int len) throws IOException;
59
60 /**
61 * Writes {@code b.length} bytes from the specified byte array
62 * to this session buffer.
63 *
64 * @param b the data.
65 * @throws IOException if an I/O error occurs.
66 */
67 void write(byte[] b) throws IOException;
68
69 /**
70 * Writes the specified byte to this session buffer.
71 *
72 * @param b the {@code byte}.
73 * @throws IOException if an I/O error occurs.
74 */
75 void write(int b) throws IOException;
76
77 /**
78 * Writes characters from the specified string followed by a line delimiter
79 * to this session buffer.
80 * <p>
81 * The choice of a char encoding and line delimiter sequence is up to the
82 * specific implementations of this interface.
83 *
84 * @param s the line.
85 * @throws IOException if an I/O error occurs.
86 */
87 void writeLine(String s) throws IOException;
88
89 /**
90 * Writes characters from the specified char array followed by a line
91 * delimiter to this session buffer.
92 * <p>
93 * The choice of a char encoding and line delimiter sequence is up to the
94 * specific implementations of this interface.
95 *
96 * @param buffer the buffer containing chars of the line.
97 * @throws IOException if an I/O error occurs.
98 */
99 void writeLine(CharArrayBuffer buffer) throws IOException;
100
101 /**
102 * Flushes this session buffer and forces any buffered output bytes
103 * to be written out. The general contract of {@code flush} is
104 * that calling it is an indication that, if any bytes previously
105 * written have been buffered by the implementation of the output
106 * stream, such bytes should immediately be written to their
107 * intended destination.
108 *
109 * @throws IOException if an I/O error occurs.
110 */
111 void flush() throws IOException;
112
113 /**
114 * Returns {@link HttpTransportMetrics} for this session buffer.
115 *
116 * @return transport metrics.
117 */
118 HttpTransportMetrics getMetrics();
119
120 }