TLA Line data Source code
1 : //
2 : // Copyright (c) 2026 Steve Gerbino
3 : // Copyright (c) 2026 Michael Vandeberg
4 : //
5 : // Distributed under the Boost Software License, Version 1.0. (See accompanying
6 : // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
7 : //
8 : // Official repository: https://github.com/cppalliance/corosio
9 : //
10 :
11 : #ifndef BOOST_COROSIO_NATIVE_NATIVE_STREAM_FILE_HPP
12 : #define BOOST_COROSIO_NATIVE_NATIVE_STREAM_FILE_HPP
13 :
14 : #include <boost/corosio/stream_file.hpp>
15 : #include <boost/corosio/backend.hpp>
16 :
17 : #ifndef BOOST_COROSIO_MRDOCS
18 : #if BOOST_COROSIO_HAS_EPOLL || BOOST_COROSIO_HAS_SELECT || \
19 : BOOST_COROSIO_HAS_KQUEUE
20 : #include <boost/corosio/native/detail/posix/posix_stream_file_service.hpp>
21 : #endif
22 :
23 : #if BOOST_COROSIO_HAS_IO_URING
24 : #include <boost/corosio/native/detail/io_uring/io_uring_stream_file.hpp>
25 : #endif
26 :
27 : #if BOOST_COROSIO_HAS_IOCP
28 : #include <boost/corosio/native/detail/iocp/win_file_service.hpp>
29 : #endif
30 : #endif // !BOOST_COROSIO_MRDOCS
31 :
32 : namespace boost::corosio {
33 :
34 : /** A sequential file with devirtualized async I/O operations.
35 :
36 : This class template inherits from @ref stream_file and shadows
37 : `read_some` / `write_some` with versions that call the backend
38 : implementation directly, allowing the compiler to inline through
39 : the entire call chain.
40 :
41 : Non-async operations (`open`, `close`, `size`, `resize`, `seek`,
42 : `sync_data`, `sync_all`) remain unchanged and dispatch through
43 : the compiled library.
44 :
45 : A `native_stream_file` IS-A `stream_file` and can be passed to
46 : any function expecting `stream_file&` or `io_stream&`, in which
47 : case virtual dispatch is used transparently.
48 :
49 : @note On POSIX platforms, file I/O is dispatched to a thread
50 : pool regardless of the chosen reactor backend, so all three
51 : reactor tags (`epoll`, `select`, `kqueue`) resolve to the same
52 : underlying implementation. The `Backend` template parameter
53 : exists for API symmetry with @ref native_tcp_socket and friends.
54 : The vtable savings are smaller relative to the thread-pool /
55 : overlapped-I/O cost than they are for socket operations.
56 :
57 : @tparam Backend A backend tag value (e.g., `epoll`, `iocp`).
58 :
59 : @par Thread Safety
60 : Same as @ref stream_file.
61 :
62 : @par Example
63 : @par !example native_stream_file
64 :
65 : @see stream_file, epoll_t, iocp_t
66 : */
67 : template<auto Backend>
68 : class native_stream_file : public stream_file
69 : {
70 : using backend_type = decltype(Backend);
71 : using impl_type = typename backend_type::stream_file_type;
72 : using service_type = typename backend_type::stream_file_service_type;
73 :
74 HIT 12 : impl_type& get_impl() noexcept
75 : {
76 12 : return *static_cast<impl_type*>(h_.get());
77 : }
78 :
79 : template<class MutableBufferSequence>
80 : struct native_read_awaitable
81 : {
82 : native_stream_file& self_;
83 : MutableBufferSequence buffers_;
84 : std::stop_token token_;
85 : mutable std::error_code ec_;
86 : mutable std::size_t bytes_transferred_ = 0;
87 :
88 6 : native_read_awaitable(
89 : native_stream_file& self,
90 : MutableBufferSequence buffers) noexcept
91 6 : : self_(self)
92 6 : , buffers_(std::move(buffers))
93 : {
94 6 : }
95 :
96 6 : bool await_ready() const noexcept
97 : {
98 : // A pre-set ec_ means the initiator failed before
99 : // dispatch (e.g. a closed object).
100 6 : return static_cast<bool>(ec_) || token_.stop_requested();
101 : }
102 :
103 6 : [[nodiscard]] capy::io_result<std::size_t> await_resume() const noexcept
104 : {
105 6 : if (token_.stop_requested())
106 2 : return {make_error_code(std::errc::operation_canceled), 0};
107 4 : return {ec_, bytes_transferred_};
108 : }
109 :
110 6 : auto await_suspend(std::coroutine_handle<> h, capy::io_env const* env)
111 : -> std::coroutine_handle<>
112 : {
113 6 : token_ = env->stop_token;
114 18 : return self_.get_impl().read_some(
115 18 : h, env->executor, buffers_, token_, &ec_, &bytes_transferred_);
116 : }
117 : };
118 :
119 : template<class ConstBufferSequence>
120 : struct native_write_awaitable
121 : {
122 : native_stream_file& self_;
123 : ConstBufferSequence buffers_;
124 : std::stop_token token_;
125 : mutable std::error_code ec_;
126 : mutable std::size_t bytes_transferred_ = 0;
127 :
128 6 : native_write_awaitable(
129 : native_stream_file& self,
130 : ConstBufferSequence buffers) noexcept
131 6 : : self_(self)
132 6 : , buffers_(std::move(buffers))
133 : {
134 6 : }
135 :
136 6 : bool await_ready() const noexcept
137 : {
138 : // A pre-set ec_ means the initiator failed before
139 : // dispatch (e.g. a closed object).
140 6 : return static_cast<bool>(ec_) || token_.stop_requested();
141 : }
142 :
143 6 : [[nodiscard]] capy::io_result<std::size_t> await_resume() const noexcept
144 : {
145 6 : if (token_.stop_requested())
146 2 : return {make_error_code(std::errc::operation_canceled), 0};
147 4 : return {ec_, bytes_transferred_};
148 : }
149 :
150 6 : auto await_suspend(std::coroutine_handle<> h, capy::io_env const* env)
151 : -> std::coroutine_handle<>
152 : {
153 6 : token_ = env->stop_token;
154 18 : return self_.get_impl().write_some(
155 18 : h, env->executor, buffers_, token_, &ec_, &bytes_transferred_);
156 : }
157 : };
158 :
159 : public:
160 : /** Construct a native stream file from an execution context.
161 :
162 : @param ctx The execution context that will own this file.
163 : */
164 16 : explicit native_stream_file(capy::execution_context& ctx)
165 16 : : io_object(create_handle<service_type>(ctx))
166 : {
167 16 : }
168 :
169 : /** Construct a native stream file from an executor.
170 :
171 : @param ex The executor whose context will own this file.
172 : */
173 : template<class Ex>
174 : requires(!std::same_as<std::remove_cvref_t<Ex>, native_stream_file>) &&
175 : capy::Executor<Ex>
176 : explicit native_stream_file(Ex const& ex) : native_stream_file(ex.context())
177 : {
178 : }
179 :
180 : /// Move construct.
181 : native_stream_file(native_stream_file&&) noexcept = default;
182 :
183 : /// Move assign.
184 : native_stream_file& operator=(native_stream_file&&) noexcept = default;
185 :
186 : native_stream_file(native_stream_file const&) = delete;
187 : native_stream_file& operator=(native_stream_file const&) = delete;
188 :
189 : /** Asynchronously read data from the file.
190 :
191 : Calls the backend implementation directly, bypassing virtual
192 : dispatch. Otherwise identical to @ref io_stream::read_some.
193 : */
194 : template<capy::MutableBufferSequence MB>
195 6 : [[nodiscard]] auto read_some(MB const& buffers)
196 : {
197 6 : return native_read_awaitable<MB>(*this, buffers);
198 : }
199 :
200 : /** Asynchronously write data to the file.
201 :
202 : Calls the backend implementation directly, bypassing virtual
203 : dispatch. Otherwise identical to @ref io_stream::write_some.
204 : */
205 : template<capy::ConstBufferSequence CB>
206 6 : [[nodiscard]] auto write_some(CB const& buffers)
207 : {
208 6 : return native_write_awaitable<CB>(*this, buffers);
209 : }
210 : };
211 :
212 : } // namespace boost::corosio
213 :
214 : #endif // BOOST_COROSIO_NATIVE_NATIVE_STREAM_FILE_HPP
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