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.nio.reactor;
29
30 import java.io.IOException;
31 import java.nio.ByteBuffer;
32 import java.nio.channels.ReadableByteChannel;
33 import java.nio.channels.WritableByteChannel;
34 import java.nio.charset.CharacterCodingException;
35
36 import org.apache.http.util.CharArrayBuffer;
37
38 /**
39 * Session output buffer for non-blocking connections. This interface
40 * facilitates intermediate buffering of output data streamed out to
41 * a destination channel and writing data to the buffer from a source, usually
42 * {@link ByteBuffer} or {@link ReadableByteChannel}. This interface also
43 * provides methods for writing lines of text.
44 *
45 * @since 4.0
46 */
47 public interface SessionOutputBuffer {
48
49 /**
50 * Determines if the buffer contains data.
51 *
52 * @return {@code true} if there is data in the buffer,
53 * {@code false} otherwise.
54 */
55 boolean hasData();
56
57 /**
58 * Returns the length of this buffer.
59 *
60 * @return buffer length.
61 */
62 int length();
63
64 /**
65 * Makes an attempt to flush the content of this buffer to the given
66 * destination {@link WritableByteChannel}.
67 *
68 * @param channel the destination channel.
69 * @return The number of bytes written, possibly zero.
70 * @throws IOException in case of an I/O error.
71 */
72 int flush(WritableByteChannel channel)
73 throws IOException;
74
75 /**
76 * Copies content of the source buffer into this buffer. The capacity of
77 * the destination will be expanded in order to accommodate the entire
78 * content of the source buffer.
79 *
80 * @param src the source buffer.
81 */
82 void write(ByteBuffer src);
83
84 /**
85 * Reads a sequence of bytes from the source channel into this buffer.
86 *
87 * @param src the source channel.
88 */
89 void write(ReadableByteChannel src)
90 throws IOException;
91
92 /**
93 * Copies content of the source buffer into this buffer as one line of text
94 * including a line delimiter. The capacity of the destination will be
95 * expanded in order to accommodate the entire content of the source buffer.
96 * <p>
97 * The choice of a char encoding and line delimiter sequence is up to the
98 * specific implementations of this interface.
99 *
100 * @param src the source buffer.
101 */
102 void writeLine(CharArrayBuffer src)
103 throws CharacterCodingException;
104
105 /**
106 * Copies content of the given string into this buffer as one line of text
107 * including a line delimiter.
108 * The capacity of the destination will be expanded in order to accommodate
109 * the entire string.
110 * <p>
111 * The choice of a char encoding and line delimiter sequence is up to the
112 * specific implementations of this interface.
113 *
114 * @param s the string.
115 */
116 void writeLine(String s)
117 throws IOException;
118
119 }