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c6b9f33dcf
This change adds support for stream-oriented and random-access files.
For example, to write to a newly created stream-oriented file:
asio::stream_file file(
my_io_context, "/path/to/file",
asio::stream_file::write_only
| asio::stream_file::create
| asio::stream_file::truncate);
file.async_write_some(my_buffer,
[](error_code e, size_t n)
{
// ...
});
or to read from a random-access file:
asio::random_access_file file(
my_io_context, "/path/to/file",
asio::random_access_file::read_only);
file.async_read_some_at(1234, my_buffer,
[](error_code e, size_t n)
{
// ...
});
This feature currently supports I/O completion ports on Windows, and
io_uring on Linux (define BOOST_ASIO_HAS_IO_URING to enable).
66 lines
1.5 KiB
C++
66 lines
1.5 KiB
C++
//
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// blocking_file_copy.cpp
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// ~~~~~~~~~~~~~~~~~~~~~~
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//
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// Copyright (c) 2003-2021 Christopher M. Kohlhoff (chris at kohlhoff dot com)
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//
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// Distributed under the Boost Software License, Version 1.0. (See accompanying
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// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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//
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#include <iostream>
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#include <boost/asio.hpp>
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#if defined(BOOST_ASIO_HAS_FILE)
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int main(int argc, char* argv[])
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{
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try
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{
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if (argc != 3)
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{
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std::cerr << "Usage: blocking_file_copy <from> <to>\n";
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return 1;
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}
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boost::asio::io_context io_context;
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boost::asio::stream_file from_file(io_context, argv[1],
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boost::asio::stream_file::read_only);
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boost::asio::stream_file to_file(io_context, argv[2],
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boost::asio::stream_file::write_only
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| boost::asio::stream_file::create
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| boost::asio::stream_file::truncate);
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char data[4096];
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boost::system::error_code error;
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for (;;)
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{
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std::size_t n = from_file.read_some(boost::asio::buffer(data), error);
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if (error)
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break;
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boost::asio::write(to_file, boost::asio::buffer(data, n), error);
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if (error)
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break;
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}
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if (error && error != boost::asio::error::eof)
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{
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std::cerr << "Error copying file: " << error.message() << "\n";
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return 1;
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}
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}
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catch (std::exception& e)
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{
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std::cerr << "Exception: " << e.what() << "\n";
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return 1;
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}
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return 0;
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}
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#else // defined(BOOST_ASIO_HAS_FILE)
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int main() {}
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#endif // defined(BOOST_ASIO_HAS_FILE)
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