1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
|
//
// ========================================================================
// Copyright (c) 1995-2013 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// and Apache License v2.0 which accompanies this distribution.
//
// The Eclipse Public License is available at
// http://www.eclipse.org/legal/epl-v10.html
//
// The Apache License v2.0 is available at
// http://www.opensource.org/licenses/apache2.0.php
//
// You may elect to redistribute this code under either of these licenses.
// ========================================================================
//
package org.eclipse.jetty.client;
import java.nio.ByteBuffer;
import java.util.Collections;
import java.util.Iterator;
import org.eclipse.jetty.client.api.ContentProvider;
import org.eclipse.jetty.client.util.DeferredContentProvider;
import org.eclipse.jetty.util.BufferUtil;
/**
* {@link HttpContent} is a stateful, linear representation of the request content provided
* by a {@link ContentProvider} that can be traversed one-way to obtain content buffers to
* send to a HTTP server.
* <p />
* {@link HttpContent} offers the notion of a one-way cursor to traverse the content.
* The cursor starts in a virtual "before" position and can be advanced using {@link #advance()}
* until it reaches a virtual "after" position where the content is fully consumed.
* <pre>
* +---+ +---+ +---+ +---+ +---+
* | | | | | | | | | |
* +---+ +---+ +---+ +---+ +---+
* ^ ^ ^ ^
* | | --> advance() | |
* | | last |
* | | |
* before | after
* |
* current
* </pre>
* At each valid (non-before and non-after) cursor position, {@link HttpContent} provides the following state:
* <ul>
* <li>the buffer containing the content to send, via {@link #getByteBuffer()}</li>
* <li>a copy of the content buffer that can be used for notifications, via {@link #getContent()}</li>
* <li>whether the buffer to write is the last one, via {@link #isLast()}</li>
* </ul>
* {@link HttpContent} may not have content, if the related {@link ContentProvider} is {@code null}, and this
* is reflected by {@link #hasContent()}.
* <p />
* {@link HttpContent} may have {@link DeferredContentProvider deferred content}, in which case {@link #advance()}
* moves the cursor to a position that provides {@code null} {@link #getByteBuffer() buffer} and
* {@link #getContent() content}. When the deferred content is available, a further call to {@link #advance()}
* will move the cursor to a position that provides non {@code null} buffer and content.
*/
public class HttpContent
{
private static final ByteBuffer AFTER = ByteBuffer.allocate(0);
private final ContentProvider provider;
private final Iterator<ByteBuffer> iterator;
private ByteBuffer buffer;
private volatile ByteBuffer content;
public HttpContent(ContentProvider provider)
{
this.provider = provider;
this.iterator = provider == null ? Collections.<ByteBuffer>emptyIterator() : provider.iterator();
}
/**
* @return whether there is any content at all
*/
public boolean hasContent()
{
return provider != null;
}
/**
* @return whether the cursor points to the last content
*/
public boolean isLast()
{
return !iterator.hasNext();
}
/**
* @return the {@link ByteBuffer} containing the content at the cursor's position
*/
public ByteBuffer getByteBuffer()
{
return buffer;
}
/**
* @return a {@link ByteBuffer#slice()} of {@link #getByteBuffer()} at the cursor's position
*/
public ByteBuffer getContent()
{
return content;
}
/**
* Advances the cursor to the next block of content.
* <p />
* The next block of content may be valid (which yields a non-null buffer
* returned by {@link #getByteBuffer()}), but may also be deferred
* (which yields a null buffer returned by {@link #getByteBuffer()}).
* <p />
* If the block of content pointed by the new cursor position is valid, this method returns true.
*
* @return true if there is content at the new cursor's position, false otherwise.
*/
public boolean advance()
{
if (isLast())
{
if (content != AFTER)
content = buffer = AFTER;
return false;
}
else
{
ByteBuffer buffer = this.buffer = iterator.next();
content = buffer == null ? null : buffer.slice();
return buffer != null;
}
}
/**
* @return whether the cursor has been advanced past the {@link #isLast() last} position.
*/
public boolean isConsumed()
{
return content == AFTER;
}
@Override
public String toString()
{
return String.format("%s@%x - has=%b,last=%b,consumed=%b,buffer=%s",
getClass().getSimpleName(),
hashCode(),
hasContent(),
isLast(),
isConsumed(),
BufferUtil.toDetailString(getContent()));
}
}
|
