blob: c4b4d59dbc1890eefe2fc19c0061a59dcf16f75e (
plain)
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
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
|
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
<title>streambuf</title>
<link rel="stylesheet" href="../../../../doc/src/boostbook.css" type="text/css">
<meta name="generator" content="DocBook XSL Stylesheets V1.79.1">
<link rel="home" href="../../boost_asio.html" title="Boost.Asio">
<link rel="up" href="../reference.html" title="Reference">
<link rel="prev" href="stream_socket_service/stream_socket_service.html" title="stream_socket_service::stream_socket_service">
<link rel="next" href="system_timer.html" title="system_timer">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<table cellpadding="2" width="100%"><tr>
<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../boost.png"></td>
<td align="center"><a href="../../../../index.html">Home</a></td>
<td align="center"><a href="../../../../libs/libraries.htm">Libraries</a></td>
<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
<td align="center"><a href="../../../../more/index.htm">More</a></td>
</tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="stream_socket_service/stream_socket_service.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../reference.html"><img src="../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../boost_asio.html"><img src="../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="system_timer.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_asio.reference.streambuf"></a><a class="link" href="streambuf.html" title="streambuf">streambuf</a>
</h3></div></div></div>
<p>
<a class="indexterm" name="idp202121760"></a>
Typedef for the typical usage of <a class="link" href="basic_streambuf.html" title="basic_streambuf"><code class="computeroutput"><span class="identifier">basic_streambuf</span></code></a>.
</p>
<pre class="programlisting"><span class="keyword">typedef</span> <span class="identifier">basic_streambuf</span> <span class="identifier">streambuf</span><span class="special">;</span>
</pre>
<h5>
<a name="boost_asio.reference.streambuf.h0"></a>
<span class="phrase"><a name="boost_asio.reference.streambuf.types"></a></span><a class="link" href="streambuf.html#boost_asio.reference.streambuf.types">Types</a>
</h5>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead><tr>
<th>
<p>
Name
</p>
</th>
<th>
<p>
Description
</p>
</th>
</tr></thead>
<tbody>
<tr>
<td>
<p>
<a class="link" href="basic_streambuf/const_buffers_type.html" title="basic_streambuf::const_buffers_type"><span class="bold"><strong>const_buffers_type</strong></span></a>
</p>
</td>
<td>
<p>
The type used to represent the input sequence as a list of buffers.
</p>
</td>
</tr>
<tr>
<td>
<p>
<a class="link" href="basic_streambuf/mutable_buffers_type.html" title="basic_streambuf::mutable_buffers_type"><span class="bold"><strong>mutable_buffers_type</strong></span></a>
</p>
</td>
<td>
<p>
The type used to represent the output sequence as a list of buffers.
</p>
</td>
</tr>
</tbody>
</table></div>
<h5>
<a name="boost_asio.reference.streambuf.h1"></a>
<span class="phrase"><a name="boost_asio.reference.streambuf.member_functions"></a></span><a class="link" href="streambuf.html#boost_asio.reference.streambuf.member_functions">Member
Functions</a>
</h5>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead><tr>
<th>
<p>
Name
</p>
</th>
<th>
<p>
Description
</p>
</th>
</tr></thead>
<tbody>
<tr>
<td>
<p>
<a class="link" href="basic_streambuf/basic_streambuf.html" title="basic_streambuf::basic_streambuf"><span class="bold"><strong>basic_streambuf</strong></span></a>
</p>
</td>
<td>
<p>
Construct a basic_streambuf object.
</p>
</td>
</tr>
<tr>
<td>
<p>
<a class="link" href="basic_streambuf/commit.html" title="basic_streambuf::commit"><span class="bold"><strong>commit</strong></span></a>
</p>
</td>
<td>
<p>
Move characters from the output sequence to the input sequence.
</p>
</td>
</tr>
<tr>
<td>
<p>
<a class="link" href="basic_streambuf/consume.html" title="basic_streambuf::consume"><span class="bold"><strong>consume</strong></span></a>
</p>
</td>
<td>
<p>
Remove characters from the input sequence.
</p>
</td>
</tr>
<tr>
<td>
<p>
<a class="link" href="basic_streambuf/data.html" title="basic_streambuf::data"><span class="bold"><strong>data</strong></span></a>
</p>
</td>
<td>
<p>
Get a list of buffers that represents the input sequence.
</p>
</td>
</tr>
<tr>
<td>
<p>
<a class="link" href="basic_streambuf/max_size.html" title="basic_streambuf::max_size"><span class="bold"><strong>max_size</strong></span></a>
</p>
</td>
<td>
<p>
Get the maximum size of the basic_streambuf.
</p>
</td>
</tr>
<tr>
<td>
<p>
<a class="link" href="basic_streambuf/prepare.html" title="basic_streambuf::prepare"><span class="bold"><strong>prepare</strong></span></a>
</p>
</td>
<td>
<p>
Get a list of buffers that represents the output sequence, with
the given size.
</p>
</td>
</tr>
<tr>
<td>
<p>
<a class="link" href="basic_streambuf/size.html" title="basic_streambuf::size"><span class="bold"><strong>size</strong></span></a>
</p>
</td>
<td>
<p>
Get the size of the input sequence.
</p>
</td>
</tr>
</tbody>
</table></div>
<h5>
<a name="boost_asio.reference.streambuf.h2"></a>
<span class="phrase"><a name="boost_asio.reference.streambuf.protected_member_functions"></a></span><a class="link" href="streambuf.html#boost_asio.reference.streambuf.protected_member_functions">Protected
Member Functions</a>
</h5>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead><tr>
<th>
<p>
Name
</p>
</th>
<th>
<p>
Description
</p>
</th>
</tr></thead>
<tbody>
<tr>
<td>
<p>
<a class="link" href="basic_streambuf/overflow.html" title="basic_streambuf::overflow"><span class="bold"><strong>overflow</strong></span></a>
</p>
</td>
<td>
<p>
Override std::streambuf behaviour.
</p>
</td>
</tr>
<tr>
<td>
<p>
<a class="link" href="basic_streambuf/reserve.html" title="basic_streambuf::reserve"><span class="bold"><strong>reserve</strong></span></a>
</p>
</td>
<td>
</td>
</tr>
<tr>
<td>
<p>
<a class="link" href="basic_streambuf/underflow.html" title="basic_streambuf::underflow"><span class="bold"><strong>underflow</strong></span></a>
</p>
</td>
<td>
<p>
Override std::streambuf behaviour.
</p>
</td>
</tr>
</tbody>
</table></div>
<p>
The <code class="computeroutput"><span class="identifier">basic_streambuf</span></code> class
is derived from <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">streambuf</span></code> to associate the streambuf's
input and output sequences with one or more character arrays. These character
arrays are internal to the <code class="computeroutput"><span class="identifier">basic_streambuf</span></code>
object, but direct access to the array elements is provided to permit them
to be used efficiently with I/O operations. Characters written to the output
sequence of a <code class="computeroutput"><span class="identifier">basic_streambuf</span></code>
object are appended to the input sequence of the same object.
</p>
<p>
The <code class="computeroutput"><span class="identifier">basic_streambuf</span></code> class's
public interface is intended to permit the following implementation strategies:
</p>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
A single contiguous character array, which is reallocated as necessary
to accommodate changes in the size of the character sequence. This is
the implementation approach currently used in Asio.
</li>
<li class="listitem">
A sequence of one or more character arrays, where each array is of the
same size. Additional character array objects are appended to the sequence
to accommodate changes in the size of the character sequence.
</li>
<li class="listitem">
A sequence of one or more character arrays of varying sizes. Additional
character array objects are appended to the sequence to accommodate changes
in the size of the character sequence.
</li>
</ul></div>
<p>
The constructor for <a class="link" href="basic_streambuf.html" title="basic_streambuf"><code class="computeroutput"><span class="identifier">basic_streambuf</span></code></a> accepts a <code class="computeroutput"><span class="identifier">size_t</span></code> argument specifying the maximum
of the sum of the sizes of the input sequence and output sequence. During
the lifetime of the <code class="computeroutput"><span class="identifier">basic_streambuf</span></code>
object, the following invariant holds:
</p>
<pre class="programlisting"><span class="identifier">size</span><span class="special">()</span> <span class="special"><=</span> <span class="identifier">max_size</span><span class="special">()</span>
</pre>
<p>
Any member function that would, if successful, cause the invariant to be
violated shall throw an exception of class <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">length_error</span></code>.
</p>
<p>
The constructor for <code class="computeroutput"><span class="identifier">basic_streambuf</span></code>
takes an Allocator argument. A copy of this argument is used for any memory
allocation performed, by the constructor and by all member functions, during
the lifetime of each <code class="computeroutput"><span class="identifier">basic_streambuf</span></code>
object.
</p>
<h5>
<a name="boost_asio.reference.streambuf.h3"></a>
<span class="phrase"><a name="boost_asio.reference.streambuf.examples"></a></span><a class="link" href="streambuf.html#boost_asio.reference.streambuf.examples">Examples</a>
</h5>
<p>
Writing directly from an streambuf to a socket:
</p>
<pre class="programlisting"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">streambuf</span> <span class="identifier">b</span><span class="special">;</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">ostream</span> <span class="identifier">os</span><span class="special">(&</span><span class="identifier">b</span><span class="special">);</span>
<span class="identifier">os</span> <span class="special"><<</span> <span class="string">"Hello, World!\n"</span><span class="special">;</span>
<span class="comment">// try sending some data in input sequence</span>
<span class="identifier">size_t</span> <span class="identifier">n</span> <span class="special">=</span> <span class="identifier">sock</span><span class="special">.</span><span class="identifier">send</span><span class="special">(</span><span class="identifier">b</span><span class="special">.</span><span class="identifier">data</span><span class="special">());</span>
<span class="identifier">b</span><span class="special">.</span><span class="identifier">consume</span><span class="special">(</span><span class="identifier">n</span><span class="special">);</span> <span class="comment">// sent data is removed from input sequence</span>
</pre>
<p>
Reading from a socket directly into a streambuf:
</p>
<pre class="programlisting"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">streambuf</span> <span class="identifier">b</span><span class="special">;</span>
<span class="comment">// reserve 512 bytes in output sequence</span>
<span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">streambuf</span><span class="special">::</span><span class="identifier">mutable_buffers_type</span> <span class="identifier">bufs</span> <span class="special">=</span> <span class="identifier">b</span><span class="special">.</span><span class="identifier">prepare</span><span class="special">(</span><span class="number">512</span><span class="special">);</span>
<span class="identifier">size_t</span> <span class="identifier">n</span> <span class="special">=</span> <span class="identifier">sock</span><span class="special">.</span><span class="identifier">receive</span><span class="special">(</span><span class="identifier">bufs</span><span class="special">);</span>
<span class="comment">// received data is "committed" from output sequence to input sequence</span>
<span class="identifier">b</span><span class="special">.</span><span class="identifier">commit</span><span class="special">(</span><span class="identifier">n</span><span class="special">);</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">istream</span> <span class="identifier">is</span><span class="special">(&</span><span class="identifier">b</span><span class="special">);</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">s</span><span class="special">;</span>
<span class="identifier">is</span> <span class="special">>></span> <span class="identifier">s</span><span class="special">;</span>
</pre>
<h5>
<a name="boost_asio.reference.streambuf.h4"></a>
<span class="phrase"><a name="boost_asio.reference.streambuf.requirements"></a></span><a class="link" href="streambuf.html#boost_asio.reference.streambuf.requirements">Requirements</a>
</h5>
<p>
<span class="emphasis"><em>Header: </em></span><code class="literal">boost/asio/streambuf.hpp</code>
</p>
<p>
<span class="emphasis"><em>Convenience header: </em></span><code class="literal">boost/asio.hpp</code>
</p>
</div>
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
<td align="left"></td>
<td align="right"><div class="copyright-footer">Copyright © 2003-2017 Christopher M. Kohlhoff<p>
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
</p>
</div></td>
</tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="stream_socket_service/stream_socket_service.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../reference.html"><img src="../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../boost_asio.html"><img src="../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="system_timer.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a>
</div>
</body>
</html>
|
