. /include/boost/capy /write.hpp
100.00% Lines (2/2) 100.00% Functions (1/1)
[ ] prev/next file n p prev/next uncovered line
TLA Baseline Branch
Line Hits Code Line Hits Code
1   // 1   //
2   // Copyright (c) 2025 Vinnie Falco (vinnie.falco@gmail.com) 2   // Copyright (c) 2025 Vinnie Falco (vinnie.falco@gmail.com)
3   // 3   //
4   // Distributed under the Boost Software License, Version 1.0. (See accompanying 4   // Distributed under the Boost Software License, Version 1.0. (See accompanying
5   // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) 5   // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6   // 6   //
7   // Official repository: https://github.com/cppalliance/capy 7   // Official repository: https://github.com/cppalliance/capy
8   // 8   //
9   9  
10   #ifndef BOOST_CAPY_WRITE_HPP 10   #ifndef BOOST_CAPY_WRITE_HPP
11   #define BOOST_CAPY_WRITE_HPP 11   #define BOOST_CAPY_WRITE_HPP
12   12  
13   #include <boost/capy/detail/config.hpp> 13   #include <boost/capy/detail/config.hpp>
14   #include <boost/capy/io_task.hpp> 14   #include <boost/capy/io_task.hpp>
15   #include <boost/capy/buffers.hpp> 15   #include <boost/capy/buffers.hpp>
16   #include <boost/capy/buffers/buffer_slice.hpp> 16   #include <boost/capy/buffers/buffer_slice.hpp>
17   #include <boost/capy/concept/write_stream.hpp> 17   #include <boost/capy/concept/write_stream.hpp>
18   #include <system_error> 18   #include <system_error>
19   19  
20   #include <cstddef> 20   #include <cstddef>
21   21  
22   namespace boost { 22   namespace boost {
23   namespace capy { 23   namespace capy {
24   24  
25   /** Write an entire buffer sequence to a stream. 25   /** Write an entire buffer sequence to a stream.
26   26  
27   @par Await-effects 27   @par Await-effects
28   28  
29   Writes the contents of `buffers` to `stream` via awaiting on 29   Writes the contents of `buffers` to `stream` via awaiting on
30   `stream.write_some` with consecutive portions of data from `buffers` 30   `stream.write_some` with consecutive portions of data from `buffers`
31   until: 31   until:
32   32  
33   @li either the full content of @c buffers is processed, 33   @li either the full content of @c buffers is processed,
34   @li or a contingency occurs. 34   @li or a contingency occurs.
35   35  
36   If `buffer_size(buffers) == 0` then no awaiting on `stream.write_some` 36   If `buffer_size(buffers) == 0` then no awaiting on `stream.write_some`
37   is performed. This is not a contingency. 37   is performed. This is not a contingency.
38   38  
39   39  
40   @par Await-returns 40   @par Await-returns
41   41  
42   An object of type `io_result<std::size_t>` destructuring as `[ec, n]`. 42   An object of type `io_result<std::size_t>` destructuring as `[ec, n]`.
43   43  
44   Upon a contingency, `n` represents the number of bytes written 44   Upon a contingency, `n` represents the number of bytes written
45   so far. 45   so far.
46   46  
47   Otherwise `n` represents the number of bytes written. 47   Otherwise `n` represents the number of bytes written.
48   48  
49   Contingencies: 49   Contingencies:
50   50  
51   @li The first contingency reported from 51   @li The first contingency reported from
52   awaiting on @c stream.write_some . 52   awaiting on @c stream.write_some .
53   53  
54   Notable conditions: 54   Notable conditions:
55   55  
56   @li @c cond::canceled — Operation was cancelled, 56   @li @c cond::canceled — Operation was cancelled,
57   @li @c std::errc::broken_pipe — Peer closed connection. 57   @li @c std::errc::broken_pipe — Peer closed connection.
58   58  
59   59  
60   @par Await-postcondition 60   @par Await-postcondition
61   61  
62   `ec || n == buffer_size(buffers)`. 62   `ec || n == buffer_size(buffers)`.
63   63  
64   64  
65   @par Cancellation 65   @par Cancellation
66   Supports cancellation via `stop_token` propagated through the 66   Supports cancellation via `stop_token` propagated through the
67   `IoAwaitable` protocol. When cancelled, returns with `cond::canceled`. 67   `IoAwaitable` protocol. When cancelled, returns with `cond::canceled`.
68   68  
69   @param stream The stream to write to. If the lifetime of `stream` ends 69   @param stream The stream to write to. If the lifetime of `stream` ends
70   before the coroutine finishes, the behavior is undefined. 70   before the coroutine finishes, the behavior is undefined.
71   71  
72   @param buffers The buffer sequence to write. If the lifetime of the buffer 72   @param buffers The buffer sequence to write. If the lifetime of the buffer
73   sequence represented by `buffers` ends 73   sequence represented by `buffers` ends
74   before the coroutine finishes, the behavior is undefined. 74   before the coroutine finishes, the behavior is undefined.
75   75  
76   76  
77   @par Example 77   @par Example
78   78  
79   @code 79   @code
80   capy::task<> send_response(capy::WriteStream auto& stream, std::string_view body) 80   capy::task<> send_response(capy::WriteStream auto& stream, std::string_view body)
81   { 81   {
82   auto [ec, n] = co_await capy::write(stream, capy::make_buffer(body)); 82   auto [ec, n] = co_await capy::write(stream, capy::make_buffer(body));
83   if (ec) 83   if (ec)
84   throw std::system_error(ec); 84   throw std::system_error(ec);
85   85  
86   // All bytes written successfully 86   // All bytes written successfully
87   } 87   }
88   @endcode 88   @endcode
89   89  
90   @return 90   @return
91   91  
92   @see WriteStream, ConstBufferSequence, IoAwaitable, io_result, cond. 92   @see WriteStream, ConstBufferSequence, IoAwaitable, io_result, cond.
93   */ 93   */
94   template <WriteStream S, ConstBufferSequence CB> 94   template <WriteStream S, ConstBufferSequence CB>
HITCBC 95   50 auto write(S& stream, CB buffers) -> io_task<std::size_t> 95   50 auto write(S& stream, CB buffers) -> io_task<std::size_t>
96   { 96   {
97   auto consuming = buffer_slice(buffers); 97   auto consuming = buffer_slice(buffers);
98   std::size_t const total_size = buffer_size(buffers); 98   std::size_t const total_size = buffer_size(buffers);
99   std::size_t total_written = 0; 99   std::size_t total_written = 0;
100   100  
101   while(total_written < total_size) 101   while(total_written < total_size)
102   { 102   {
103   auto [ec, n] = co_await stream.write_some(consuming.data()); 103   auto [ec, n] = co_await stream.write_some(consuming.data());
104   consuming.remove_prefix(n); 104   consuming.remove_prefix(n);
105   total_written += n; 105   total_written += n;
106   if(ec) 106   if(ec)
107   co_return {ec, total_written}; 107   co_return {ec, total_written};
108   } 108   }
109   109  
110   co_return {{}, total_written}; 110   co_return {{}, total_written};
HITCBC 111   100 } 111   100 }
112   112  
113   } // namespace capy 113   } // namespace capy
114   } // namespace boost 114   } // namespace boost
115   115  
116   #endif 116   #endif