TLA  Line data    Source code

       1                 : //
       2                 : // Copyright (c) 2025 Vinnie Falco (vinnie.falco@gmail.com)
       3                 : //
       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)
       6                 : //
       7                 : // Official repository: https://github.com/cppalliance/capy
       8                 : //
       9                 : 
      10                 : #ifndef BOOST_CAPY_WRITE_HPP
      11                 : #define BOOST_CAPY_WRITE_HPP
      12                 : 
      13                 : #include <boost/capy/detail/config.hpp>
      14                 : #include <boost/capy/io_task.hpp>
      15                 : #include <boost/capy/buffers.hpp>
      16                 : #include <boost/capy/buffers/consuming_buffers.hpp>
      17                 : #include <boost/capy/concept/write_stream.hpp>
      18                 : #include <system_error>
      19                 : 
      20                 : #include <cstddef>
      21                 : 
      22                 : namespace boost {
      23                 : namespace capy {
      24                 : 
      25                 : /** Asynchronously write the entire buffer sequence.
      26                 : 
      27                 :     Writes data to the stream by calling `write_some` repeatedly
      28                 :     until the entire buffer sequence is written or an error occurs.
      29                 : 
      30                 :     @li The operation completes when:
      31                 :     @li The entire buffer sequence has been written
      32                 :     @li An error occurs
      33                 :     @li The operation is cancelled
      34                 : 
      35                 :     @par Cancellation
      36                 :     Supports cancellation via `stop_token` propagated through the
      37                 :     IoAwaitable protocol. When cancelled, returns with `cond::canceled`.
      38                 : 
      39                 :     @param stream The stream to write to. The caller retains ownership.
      40                 :     @param buffers The buffer sequence to write. The caller retains
      41                 :         ownership and must ensure validity until the operation completes.
      42                 : 
      43                 :     @return An awaitable yielding `(error_code, std::size_t)`.
      44                 :         On success, `n` equals `buffer_size(buffers)`. On error,
      45                 :         `n` is the number of bytes written before the error. Compare
      46                 :         error codes to conditions:
      47                 :         @li `cond::canceled` - Operation was cancelled
      48                 :         @li `std::errc::broken_pipe` - Peer closed connection
      49                 : 
      50                 :     @par Example
      51                 : 
      52                 :     @code
      53                 :     task<> send_response( WriteStream auto& stream, std::string_view body )
      54                 :     {
      55                 :         auto [ec, n] = co_await write( stream, make_buffer( body ) );
      56                 :         if( ec )
      57                 :             detail::throw_system_error( ec );
      58                 :         // All bytes written successfully
      59                 :     }
      60                 :     @endcode
      61                 : 
      62                 :     @see write_some, WriteStream, ConstBufferSequence
      63                 : */
      64                 : auto
      65 HIT          44 : write(
      66                 :     WriteStream auto& stream,
      67                 :     ConstBufferSequence auto const& buffers) ->
      68                 :         io_task<std::size_t>
      69                 : {
      70                 :     consuming_buffers consuming(buffers);
      71                 :     std::size_t const total_size = buffer_size(buffers);
      72                 :     std::size_t total_written = 0;
      73                 : 
      74                 :     while(total_written < total_size)
      75                 :     {
      76                 :         auto [ec, n] = co_await stream.write_some(consuming);
      77                 :         if(ec)
      78                 :             co_return {ec, total_written};
      79                 :         consuming.consume(n);
      80                 :         total_written += n;
      81                 :     }
      82                 : 
      83                 :     co_return {{}, total_written};
      84              88 : }
      85                 : 
      86                 : } // namespace capy
      87                 : } // namespace boost
      88                 : 
      89                 : #endif