1//
2// windows/basic_random_access_handle.hpp
3// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
4//
5// Copyright (c) 2003-2015 Christopher M. Kohlhoff (chris at kohlhoff dot com)
6//
7// Distributed under the Boost Software License, Version 1.0. (See accompanying
8// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
9//
10
11#ifndef BOOST_ASIO_WINDOWS_BASIC_RANDOM_ACCESS_HANDLE_HPP
12#define BOOST_ASIO_WINDOWS_BASIC_RANDOM_ACCESS_HANDLE_HPP
13
14#if defined(_MSC_VER) && (_MSC_VER >= 1200)
15# pragma once
16#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
17
18#include <boost/asio/detail/config.hpp>
19
20#if defined(BOOST_ASIO_HAS_WINDOWS_RANDOM_ACCESS_HANDLE) \
21 || defined(GENERATING_DOCUMENTATION)
22
23#include <cstddef>
24#include <boost/asio/detail/handler_type_requirements.hpp>
25#include <boost/asio/detail/throw_error.hpp>
26#include <boost/asio/error.hpp>
27#include <boost/asio/windows/basic_handle.hpp>
28#include <boost/asio/windows/random_access_handle_service.hpp>
29
30#include <boost/asio/detail/push_options.hpp>
31
32namespace boost {
33namespace asio {
34namespace windows {
35
36/// Provides random-access handle functionality.
37/**
38 * The windows::basic_random_access_handle class template provides asynchronous
39 * and blocking random-access handle functionality.
40 *
41 * @par Thread Safety
42 * @e Distinct @e objects: Safe.@n
43 * @e Shared @e objects: Unsafe.
44 */
45template <typename RandomAccessHandleService = random_access_handle_service>
46class basic_random_access_handle
47 : public basic_handle<RandomAccessHandleService>
48{
49public:
50 /// (Deprecated: Use native_handle_type.) The native representation of a
51 /// handle.
52 typedef typename RandomAccessHandleService::native_handle_type native_type;
53
54 /// The native representation of a handle.
55 typedef typename RandomAccessHandleService::native_handle_type
56 native_handle_type;
57
58 /// Construct a basic_random_access_handle without opening it.
59 /**
60 * This constructor creates a random-access handle without opening it. The
61 * handle needs to be opened before data can be written to or read from it.
62 *
63 * @param io_service The io_service object that the random-access handle will
64 * use to dispatch handlers for any asynchronous operations performed on the
65 * handle.
66 */
67 explicit basic_random_access_handle(boost::asio::io_service& io_service)
68 : basic_handle<RandomAccessHandleService>(io_service)
69 {
70 }
71
72 /// Construct a basic_random_access_handle on an existing native handle.
73 /**
74 * This constructor creates a random-access handle object to hold an existing
75 * native handle.
76 *
77 * @param io_service The io_service object that the random-access handle will
78 * use to dispatch handlers for any asynchronous operations performed on the
79 * handle.
80 *
81 * @param handle The new underlying handle implementation.
82 *
83 * @throws boost::system::system_error Thrown on failure.
84 */
85 basic_random_access_handle(boost::asio::io_service& io_service,
86 const native_handle_type& handle)
87 : basic_handle<RandomAccessHandleService>(io_service, handle)
88 {
89 }
90
91#if defined(BOOST_ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
92 /// Move-construct a basic_random_access_handle from another.
93 /**
94 * This constructor moves a random-access handle from one object to another.
95 *
96 * @param other The other basic_random_access_handle object from which the
97 * move will occur.
98 *
99 * @note Following the move, the moved-from object is in the same state as if
100 * constructed using the @c basic_random_access_handle(io_service&)
101 * constructor.
102 */
103 basic_random_access_handle(basic_random_access_handle&& other)
104 : basic_handle<RandomAccessHandleService>(
105 BOOST_ASIO_MOVE_CAST(basic_random_access_handle)(other))
106 {
107 }
108
109 /// Move-assign a basic_random_access_handle from another.
110 /**
111 * This assignment operator moves a random-access handle from one object to
112 * another.
113 *
114 * @param other The other basic_random_access_handle object from which the
115 * move will occur.
116 *
117 * @note Following the move, the moved-from object is in the same state as if
118 * constructed using the @c basic_random_access_handle(io_service&)
119 * constructor.
120 */
121 basic_random_access_handle& operator=(basic_random_access_handle&& other)
122 {
123 basic_handle<RandomAccessHandleService>::operator=(
124 BOOST_ASIO_MOVE_CAST(basic_random_access_handle)(other));
125 return *this;
126 }
127#endif // defined(BOOST_ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
128
129 /// Write some data to the handle at the specified offset.
130 /**
131 * This function is used to write data to the random-access handle. The
132 * function call will block until one or more bytes of the data has been
133 * written successfully, or until an error occurs.
134 *
135 * @param offset The offset at which the data will be written.
136 *
137 * @param buffers One or more data buffers to be written to the handle.
138 *
139 * @returns The number of bytes written.
140 *
141 * @throws boost::system::system_error Thrown on failure. An error code of
142 * boost::asio::error::eof indicates that the connection was closed by the
143 * peer.
144 *
145 * @note The write_some_at operation may not write all of the data. Consider
146 * using the @ref write_at function if you need to ensure that all data is
147 * written before the blocking operation completes.
148 *
149 * @par Example
150 * To write a single data buffer use the @ref buffer function as follows:
151 * @code
152 * handle.write_some_at(42, boost::asio::buffer(data, size));
153 * @endcode
154 * See the @ref buffer documentation for information on writing multiple
155 * buffers in one go, and how to use it with arrays, boost::array or
156 * std::vector.
157 */
158 template <typename ConstBufferSequence>
159 std::size_t write_some_at(uint64_t offset,
160 const ConstBufferSequence& buffers)
161 {
162 boost::system::error_code ec;
163 std::size_t s = this->get_service().write_some_at(
164 this->get_implementation(), offset, buffers, ec);
165 boost::asio::detail::throw_error(ec, "write_some_at");
166 return s;
167 }
168
169 /// Write some data to the handle at the specified offset.
170 /**
171 * This function is used to write data to the random-access handle. The
172 * function call will block until one or more bytes of the data has been
173 * written successfully, or until an error occurs.
174 *
175 * @param offset The offset at which the data will be written.
176 *
177 * @param buffers One or more data buffers to be written to the handle.
178 *
179 * @param ec Set to indicate what error occurred, if any.
180 *
181 * @returns The number of bytes written. Returns 0 if an error occurred.
182 *
183 * @note The write_some operation may not transmit all of the data to the
184 * peer. Consider using the @ref write_at function if you need to ensure that
185 * all data is written before the blocking operation completes.
186 */
187 template <typename ConstBufferSequence>
188 std::size_t write_some_at(uint64_t offset,
189 const ConstBufferSequence& buffers, boost::system::error_code& ec)
190 {
191 return this->get_service().write_some_at(
192 this->get_implementation(), offset, buffers, ec);
193 }
194
195 /// Start an asynchronous write at the specified offset.
196 /**
197 * This function is used to asynchronously write data to the random-access
198 * handle. The function call always returns immediately.
199 *
200 * @param offset The offset at which the data will be written.
201 *
202 * @param buffers One or more data buffers to be written to the handle.
203 * Although the buffers object may be copied as necessary, ownership of the
204 * underlying memory blocks is retained by the caller, which must guarantee
205 * that they remain valid until the handler is called.
206 *
207 * @param handler The handler to be called when the write operation completes.
208 * Copies will be made of the handler as required. The function signature of
209 * the handler must be:
210 * @code void handler(
211 * const boost::system::error_code& error, // Result of operation.
212 * std::size_t bytes_transferred // Number of bytes written.
213 * ); @endcode
214 * Regardless of whether the asynchronous operation completes immediately or
215 * not, the handler will not be invoked from within this function. Invocation
216 * of the handler will be performed in a manner equivalent to using
217 * boost::asio::io_service::post().
218 *
219 * @note The write operation may not transmit all of the data to the peer.
220 * Consider using the @ref async_write_at function if you need to ensure that
221 * all data is written before the asynchronous operation completes.
222 *
223 * @par Example
224 * To write a single data buffer use the @ref buffer function as follows:
225 * @code
226 * handle.async_write_some_at(42, boost::asio::buffer(data, size), handler);
227 * @endcode
228 * See the @ref buffer documentation for information on writing multiple
229 * buffers in one go, and how to use it with arrays, boost::array or
230 * std::vector.
231 */
232 template <typename ConstBufferSequence, typename WriteHandler>
233 BOOST_ASIO_INITFN_RESULT_TYPE(WriteHandler,
234 void (boost::system::error_code, std::size_t))
235 async_write_some_at(uint64_t offset,
236 const ConstBufferSequence& buffers,
237 BOOST_ASIO_MOVE_ARG(WriteHandler) handler)
238 {
239 // If you get an error on the following line it means that your handler does
240 // not meet the documented type requirements for a WriteHandler.
241 BOOST_ASIO_WRITE_HANDLER_CHECK(WriteHandler, handler) type_check;
242
243 return this->get_service().async_write_some_at(this->get_implementation(),
244 offset, buffers, BOOST_ASIO_MOVE_CAST(WriteHandler)(handler));
245 }
246
247 /// Read some data from the handle at the specified offset.
248 /**
249 * This function is used to read data from the random-access handle. The
250 * function call will block until one or more bytes of data has been read
251 * successfully, or until an error occurs.
252 *
253 * @param offset The offset at which the data will be read.
254 *
255 * @param buffers One or more buffers into which the data will be read.
256 *
257 * @returns The number of bytes read.
258 *
259 * @throws boost::system::system_error Thrown on failure. An error code of
260 * boost::asio::error::eof indicates that the connection was closed by the
261 * peer.
262 *
263 * @note The read_some operation may not read all of the requested number of
264 * bytes. Consider using the @ref read_at function if you need to ensure that
265 * the requested amount of data is read before the blocking operation
266 * completes.
267 *
268 * @par Example
269 * To read into a single data buffer use the @ref buffer function as follows:
270 * @code
271 * handle.read_some_at(42, boost::asio::buffer(data, size));
272 * @endcode
273 * See the @ref buffer documentation for information on reading into multiple
274 * buffers in one go, and how to use it with arrays, boost::array or
275 * std::vector.
276 */
277 template <typename MutableBufferSequence>
278 std::size_t read_some_at(uint64_t offset,
279 const MutableBufferSequence& buffers)
280 {
281 boost::system::error_code ec;
282 std::size_t s = this->get_service().read_some_at(
283 this->get_implementation(), offset, buffers, ec);
284 boost::asio::detail::throw_error(ec, "read_some_at");
285 return s;
286 }
287
288 /// Read some data from the handle at the specified offset.
289 /**
290 * This function is used to read data from the random-access handle. The
291 * function call will block until one or more bytes of data has been read
292 * successfully, or until an error occurs.
293 *
294 * @param offset The offset at which the data will be read.
295 *
296 * @param buffers One or more buffers into which the data will be read.
297 *
298 * @param ec Set to indicate what error occurred, if any.
299 *
300 * @returns The number of bytes read. Returns 0 if an error occurred.
301 *
302 * @note The read_some operation may not read all of the requested number of
303 * bytes. Consider using the @ref read_at function if you need to ensure that
304 * the requested amount of data is read before the blocking operation
305 * completes.
306 */
307 template <typename MutableBufferSequence>
308 std::size_t read_some_at(uint64_t offset,
309 const MutableBufferSequence& buffers, boost::system::error_code& ec)
310 {
311 return this->get_service().read_some_at(
312 this->get_implementation(), offset, buffers, ec);
313 }
314
315 /// Start an asynchronous read at the specified offset.
316 /**
317 * This function is used to asynchronously read data from the random-access
318 * handle. The function call always returns immediately.
319 *
320 * @param offset The offset at which the data will be read.
321 *
322 * @param buffers One or more buffers into which the data will be read.
323 * Although the buffers object may be copied as necessary, ownership of the
324 * underlying memory blocks is retained by the caller, which must guarantee
325 * that they remain valid until the handler is called.
326 *
327 * @param handler The handler to be called when the read operation completes.
328 * Copies will be made of the handler as required. The function signature of
329 * the handler must be:
330 * @code void handler(
331 * const boost::system::error_code& error, // Result of operation.
332 * std::size_t bytes_transferred // Number of bytes read.
333 * ); @endcode
334 * Regardless of whether the asynchronous operation completes immediately or
335 * not, the handler will not be invoked from within this function. Invocation
336 * of the handler will be performed in a manner equivalent to using
337 * boost::asio::io_service::post().
338 *
339 * @note The read operation may not read all of the requested number of bytes.
340 * Consider using the @ref async_read_at function if you need to ensure that
341 * the requested amount of data is read before the asynchronous operation
342 * completes.
343 *
344 * @par Example
345 * To read into a single data buffer use the @ref buffer function as follows:
346 * @code
347 * handle.async_read_some_at(42, boost::asio::buffer(data, size), handler);
348 * @endcode
349 * See the @ref buffer documentation for information on reading into multiple
350 * buffers in one go, and how to use it with arrays, boost::array or
351 * std::vector.
352 */
353 template <typename MutableBufferSequence, typename ReadHandler>
354 BOOST_ASIO_INITFN_RESULT_TYPE(ReadHandler,
355 void (boost::system::error_code, std::size_t))
356 async_read_some_at(uint64_t offset,
357 const MutableBufferSequence& buffers,
358 BOOST_ASIO_MOVE_ARG(ReadHandler) handler)
359 {
360 // If you get an error on the following line it means that your handler does
361 // not meet the documented type requirements for a ReadHandler.
362 BOOST_ASIO_READ_HANDLER_CHECK(ReadHandler, handler) type_check;
363
364 return this->get_service().async_read_some_at(this->get_implementation(),
365 offset, buffers, BOOST_ASIO_MOVE_CAST(ReadHandler)(handler));
366 }
367};
368
369} // namespace windows
370} // namespace asio
371} // namespace boost
372
373#include <boost/asio/detail/pop_options.hpp>
374
375#endif // defined(BOOST_ASIO_HAS_WINDOWS_RANDOM_ACCESS_HANDLE)
376 // || defined(GENERATING_DOCUMENTATION)
377
378#endif // BOOST_ASIO_WINDOWS_BASIC_RANDOM_ACCESS_HANDLE_HPP
379