582 lines
22 KiB
C++
582 lines
22 KiB
C++
//
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// windows/basic_random_access_handle.hpp
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// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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//
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// Copyright (c) 2003-2022 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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#ifndef BOOST_ASIO_WINDOWS_BASIC_RANDOM_ACCESS_HANDLE_HPP
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#define BOOST_ASIO_WINDOWS_BASIC_RANDOM_ACCESS_HANDLE_HPP
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#if defined(_MSC_VER) && (_MSC_VER >= 1200)
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# pragma once
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#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
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#include <boost/asio/detail/config.hpp>
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#include <boost/asio/windows/basic_overlapped_handle.hpp>
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#if defined(BOOST_ASIO_HAS_WINDOWS_RANDOM_ACCESS_HANDLE) \
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|| defined(GENERATING_DOCUMENTATION)
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#include <boost/asio/detail/push_options.hpp>
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namespace boost {
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namespace asio {
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namespace windows {
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/// Provides random-access handle functionality.
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/**
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* The windows::basic_random_access_handle class provides asynchronous and
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* blocking random-access handle functionality.
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*
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* @par Thread Safety
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* @e Distinct @e objects: Safe.@n
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* @e Shared @e objects: Unsafe.
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*/
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template <typename Executor = any_io_executor>
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class basic_random_access_handle
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: public basic_overlapped_handle<Executor>
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{
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private:
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class initiate_async_write_some_at;
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class initiate_async_read_some_at;
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public:
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/// The type of the executor associated with the object.
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typedef Executor executor_type;
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/// Rebinds the handle type to another executor.
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template <typename Executor1>
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struct rebind_executor
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{
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/// The handle type when rebound to the specified executor.
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typedef basic_random_access_handle<Executor1> other;
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};
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/// The native representation of a handle.
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#if defined(GENERATING_DOCUMENTATION)
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typedef implementation_defined native_handle_type;
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#else
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typedef boost::asio::detail::win_iocp_handle_service::native_handle_type
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native_handle_type;
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#endif
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/// Construct a random-access handle without opening it.
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/**
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* This constructor creates a random-access handle without opening it.
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*
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* @param ex The I/O executor that the random-access handle will use, by
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* default, to dispatch handlers for any asynchronous operations performed on
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* the random-access handle.
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*/
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explicit basic_random_access_handle(const executor_type& ex)
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: basic_overlapped_handle<Executor>(ex)
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{
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}
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/// Construct a random-access handle without opening it.
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/**
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* This constructor creates a random-access handle without opening it. The
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* handle needs to be opened or assigned before data can be written to or read
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* from it.
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*
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* @param context An execution context which provides the I/O executor that
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* the random-access handle will use, by default, to dispatch handlers for any
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* asynchronous operations performed on the random-access handle.
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*/
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template <typename ExecutionContext>
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explicit basic_random_access_handle(ExecutionContext& context,
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typename constraint<
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is_convertible<ExecutionContext&, execution_context&>::value,
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defaulted_constraint
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>::type = defaulted_constraint())
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: basic_overlapped_handle<Executor>(context)
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{
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}
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/// Construct a random-access handle on an existing native handle.
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/**
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* This constructor creates a random-access handle object to hold an existing
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* native handle.
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*
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* @param ex The I/O executor that the random-access handle will use, by
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* default, to dispatch handlers for any asynchronous operations performed on
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* the random-access handle.
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*
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* @param handle The new underlying handle implementation.
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*
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* @throws boost::system::system_error Thrown on failure.
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*/
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basic_random_access_handle(const executor_type& ex,
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const native_handle_type& handle)
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: basic_overlapped_handle<Executor>(ex, handle)
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{
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}
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/// Construct a random-access handle on an existing native handle.
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/**
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* This constructor creates a random-access handle object to hold an existing
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* native handle.
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*
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* @param context An execution context which provides the I/O executor that
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* the random-access handle will use, by default, to dispatch handlers for any
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* asynchronous operations performed on the random-access handle.
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*
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* @param handle The new underlying handle implementation.
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*
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* @throws boost::system::system_error Thrown on failure.
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*/
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template <typename ExecutionContext>
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basic_random_access_handle(ExecutionContext& context,
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const native_handle_type& handle,
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typename constraint<
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is_convertible<ExecutionContext&, execution_context&>::value
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>::type = 0)
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: basic_overlapped_handle<Executor>(context, handle)
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{
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}
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#if defined(BOOST_ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
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/// Move-construct a random-access handle from another.
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/**
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* This constructor moves a random-access handle from one object to another.
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*
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* @param other The other random-access handle object from which the
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* move will occur.
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*
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* @note Following the move, the moved-from object is in the same state as if
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* constructed using the @c basic_random_access_handle(const executor_type&)
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* constructor.
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*/
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basic_random_access_handle(basic_random_access_handle&& other)
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: basic_overlapped_handle<Executor>(std::move(other))
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{
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}
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/// Move-assign a random-access handle from another.
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/**
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* This assignment operator moves a random-access handle from one object to
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* another.
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*
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* @param other The other random-access handle object from which the
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* move will occur.
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*
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* @note Following the move, the moved-from object is in the same state as if
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* constructed using the @c basic_random_access_handle(const executor_type&)
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* constructor.
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*/
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basic_random_access_handle& operator=(basic_random_access_handle&& other)
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{
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basic_overlapped_handle<Executor>::operator=(std::move(other));
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return *this;
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}
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/// Move-construct a random-access handle from a handle of another executor
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/// type.
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/**
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* This constructor moves a random-access handle from one object to another.
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*
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* @param other The other random-access handle object from which the
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* move will occur.
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*
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* @note Following the move, the moved-from object is in the same state as if
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* constructed using the @c basic_random_access_handle(const executor_type&)
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* constructor.
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*/
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template<typename Executor1>
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basic_random_access_handle(basic_random_access_handle<Executor1>&& other,
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typename constraint<
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is_convertible<Executor1, Executor>::value,
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defaulted_constraint
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>::type = defaulted_constraint())
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: basic_overlapped_handle<Executor>(std::move(other))
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{
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}
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/// Move-assign a random-access handle from a handle of another executor
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/// type.
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/**
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* This assignment operator moves a random-access handle from one object to
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* another.
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*
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* @param other The other random-access handle object from which the
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* move will occur.
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*
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* @note Following the move, the moved-from object is in the same state as if
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* constructed using the @c basic_random_access_handle(const executor_type&)
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* constructor.
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*/
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template<typename Executor1>
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typename constraint<
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is_convertible<Executor1, Executor>::value,
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basic_random_access_handle&
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>::type operator=(basic_random_access_handle<Executor1>&& other)
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{
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basic_overlapped_handle<Executor>::operator=(std::move(other));
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return *this;
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}
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#endif // defined(BOOST_ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
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/// Write some data to the handle at the specified offset.
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/**
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* This function is used to write data to the random-access handle. The
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* function call will block until one or more bytes of the data has been
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* written successfully, or until an error occurs.
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*
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* @param offset The offset at which the data will be written.
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*
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* @param buffers One or more data buffers to be written to the handle.
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*
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* @returns The number of bytes written.
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*
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* @throws boost::system::system_error Thrown on failure. An error code of
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* boost::asio::error::eof indicates that the connection was closed by the
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* peer.
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*
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* @note The write_some_at operation may not write all of the data. Consider
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* using the @ref write_at function if you need to ensure that all data is
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* written before the blocking operation completes.
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*
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* @par Example
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* To write a single data buffer use the @ref buffer function as follows:
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* @code
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* handle.write_some_at(42, boost::asio::buffer(data, size));
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* @endcode
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* See the @ref buffer documentation for information on writing multiple
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* buffers in one go, and how to use it with arrays, boost::array or
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* std::vector.
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*/
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template <typename ConstBufferSequence>
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std::size_t write_some_at(uint64_t offset,
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const ConstBufferSequence& buffers)
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{
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boost::system::error_code ec;
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std::size_t s = this->impl_.get_service().write_some_at(
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this->impl_.get_implementation(), offset, buffers, ec);
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boost::asio::detail::throw_error(ec, "write_some_at");
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return s;
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}
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/// Write some data to the handle at the specified offset.
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/**
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* This function is used to write data to the random-access handle. The
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* function call will block until one or more bytes of the data has been
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* written successfully, or until an error occurs.
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*
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* @param offset The offset at which the data will be written.
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*
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* @param buffers One or more data buffers to be written to the handle.
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*
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* @param ec Set to indicate what error occurred, if any.
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*
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* @returns The number of bytes written. Returns 0 if an error occurred.
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*
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* @note The write_some operation may not transmit all of the data to the
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* peer. Consider using the @ref write_at function if you need to ensure that
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* all data is written before the blocking operation completes.
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*/
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template <typename ConstBufferSequence>
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std::size_t write_some_at(uint64_t offset,
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const ConstBufferSequence& buffers, boost::system::error_code& ec)
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{
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return this->impl_.get_service().write_some_at(
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this->impl_.get_implementation(), offset, buffers, ec);
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}
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/// Start an asynchronous write at the specified offset.
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/**
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* This function is used to asynchronously write data to the random-access
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* handle. It is an initiating function for an @ref asynchronous_operation,
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* and always returns immediately.
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*
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* @param offset The offset at which the data will be written.
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*
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* @param buffers One or more data buffers to be written to the handle.
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* Although the buffers object may be copied as necessary, ownership of the
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* underlying memory blocks is retained by the caller, which must guarantee
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* that they remain valid until the completion handler is called.
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*
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* @param token The @ref completion_token that will be used to produce a
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* completion handler, which will be called when the write completes.
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* Potential completion tokens include @ref use_future, @ref use_awaitable,
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* @ref yield_context, or a function object with the correct completion
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* signature. The function signature of the completion handler must be:
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* @code void handler(
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* const boost::system::error_code& error, // Result of operation.
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* std::size_t bytes_transferred // Number of bytes written.
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* ); @endcode
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* Regardless of whether the asynchronous operation completes immediately or
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* not, the completion handler will not be invoked from within this function.
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* On immediate completion, invocation of the handler will be performed in a
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* manner equivalent to using boost::asio::post().
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*
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* @par Completion Signature
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* @code void(boost::system::error_code, std::size_t) @endcode
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*
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* @note The write operation may not transmit all of the data to the peer.
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* Consider using the @ref async_write_at function if you need to ensure that
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* all data is written before the asynchronous operation completes.
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*
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* @par Example
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* To write a single data buffer use the @ref buffer function as follows:
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* @code
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* handle.async_write_some_at(42, boost::asio::buffer(data, size), handler);
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* @endcode
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* See the @ref buffer documentation for information on writing multiple
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* buffers in one go, and how to use it with arrays, boost::array or
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* std::vector.
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*
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* @par Per-Operation Cancellation
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* This asynchronous operation supports cancellation for the following
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* boost::asio::cancellation_type values:
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*
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* @li @c cancellation_type::terminal
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*
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* @li @c cancellation_type::partial
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*
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* @li @c cancellation_type::total
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*/
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template <typename ConstBufferSequence,
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BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
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std::size_t)) WriteToken
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BOOST_ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
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BOOST_ASIO_INITFN_AUTO_RESULT_TYPE_PREFIX(WriteToken,
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void (boost::system::error_code, std::size_t))
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async_write_some_at(uint64_t offset,
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const ConstBufferSequence& buffers,
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BOOST_ASIO_MOVE_ARG(WriteToken) token
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BOOST_ASIO_DEFAULT_COMPLETION_TOKEN(executor_type))
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BOOST_ASIO_INITFN_AUTO_RESULT_TYPE_SUFFIX((
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async_initiate<WriteToken,
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void (boost::system::error_code, std::size_t)>(
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declval<initiate_async_write_some_at>(), token, offset, buffers)))
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{
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return async_initiate<WriteToken,
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void (boost::system::error_code, std::size_t)>(
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initiate_async_write_some_at(this), token, offset, buffers);
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}
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/// Read some data from the handle at the specified offset.
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/**
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* This function is used to read data from the random-access handle. The
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* function call will block until one or more bytes of data has been read
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* successfully, or until an error occurs.
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*
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* @param offset The offset at which the data will be read.
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*
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* @param buffers One or more buffers into which the data will be read.
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*
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* @returns The number of bytes read.
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*
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* @throws boost::system::system_error Thrown on failure. An error code of
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* boost::asio::error::eof indicates that the connection was closed by the
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* peer.
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|
*
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|
* @note The read_some operation may not read all of the requested number of
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|
* bytes. Consider using the @ref read_at function if you need to ensure that
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|
* the requested amount of data is read before the blocking operation
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|
* completes.
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|
*
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|
* @par Example
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|
* To read into a single data buffer use the @ref buffer function as follows:
|
|
* @code
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|
* handle.read_some_at(42, boost::asio::buffer(data, size));
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|
* @endcode
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|
* See the @ref buffer documentation for information on reading into multiple
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* buffers in one go, and how to use it with arrays, boost::array or
|
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* std::vector.
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*/
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template <typename MutableBufferSequence>
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std::size_t read_some_at(uint64_t offset,
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const MutableBufferSequence& buffers)
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{
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boost::system::error_code ec;
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std::size_t s = this->impl_.get_service().read_some_at(
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this->impl_.get_implementation(), offset, buffers, ec);
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boost::asio::detail::throw_error(ec, "read_some_at");
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return s;
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}
|
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|
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/// Read some data from the handle at the specified offset.
|
|
/**
|
|
* This function is used to read data from the random-access handle. The
|
|
* function call will block until one or more bytes of data has been read
|
|
* successfully, or until an error occurs.
|
|
*
|
|
* @param offset The offset at which the data will be read.
|
|
*
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|
* @param buffers One or more buffers into which the data will be read.
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|
*
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|
* @param ec Set to indicate what error occurred, if any.
|
|
*
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|
* @returns The number of bytes read. Returns 0 if an error occurred.
|
|
*
|
|
* @note The read_some operation may not read all of the requested number of
|
|
* bytes. Consider using the @ref read_at function if you need to ensure that
|
|
* the requested amount of data is read before the blocking operation
|
|
* completes.
|
|
*/
|
|
template <typename MutableBufferSequence>
|
|
std::size_t read_some_at(uint64_t offset,
|
|
const MutableBufferSequence& buffers, boost::system::error_code& ec)
|
|
{
|
|
return this->impl_.get_service().read_some_at(
|
|
this->impl_.get_implementation(), offset, buffers, ec);
|
|
}
|
|
|
|
/// Start an asynchronous read at the specified offset.
|
|
/**
|
|
* This function is used to asynchronously read data from the random-access
|
|
* handle. It is an initiating function for an @ref asynchronous_operation,
|
|
* and always returns immediately.
|
|
*
|
|
* @param offset The offset at which the data will be read.
|
|
*
|
|
* @param buffers One or more buffers into which the data will be read.
|
|
* Although the buffers object may be copied as necessary, ownership of the
|
|
* underlying memory blocks is retained by the caller, which must guarantee
|
|
* that they remain valid until the completion handler is called.
|
|
*
|
|
* @param token The @ref completion_token that will be used to produce a
|
|
* completion handler, which will be called when the read completes.
|
|
* Potential completion tokens include @ref use_future, @ref use_awaitable,
|
|
* @ref yield_context, or a function object with the correct completion
|
|
* signature. The function signature of the completion handler must be:
|
|
* @code void handler(
|
|
* const boost::system::error_code& error, // Result of operation.
|
|
* std::size_t bytes_transferred // Number of bytes read.
|
|
* ); @endcode
|
|
* Regardless of whether the asynchronous operation completes immediately or
|
|
* not, the completion handler will not be invoked from within this function.
|
|
* On immediate completion, invocation of the handler will be performed in a
|
|
* manner equivalent to using boost::asio::post().
|
|
*
|
|
* @par Completion Signature
|
|
* @code void(boost::system::error_code, std::size_t) @endcode
|
|
*
|
|
* @note The read operation may not read all of the requested number of bytes.
|
|
* Consider using the @ref async_read_at function if you need to ensure that
|
|
* the requested amount of data is read before the asynchronous operation
|
|
* completes.
|
|
*
|
|
* @par Example
|
|
* To read into a single data buffer use the @ref buffer function as follows:
|
|
* @code
|
|
* handle.async_read_some_at(42, boost::asio::buffer(data, size), handler);
|
|
* @endcode
|
|
* See the @ref buffer documentation for information on reading into multiple
|
|
* buffers in one go, and how to use it with arrays, boost::array or
|
|
* std::vector.
|
|
*
|
|
* @par Per-Operation Cancellation
|
|
* This asynchronous operation supports cancellation for the following
|
|
* boost::asio::cancellation_type values:
|
|
*
|
|
* @li @c cancellation_type::terminal
|
|
*
|
|
* @li @c cancellation_type::partial
|
|
*
|
|
* @li @c cancellation_type::total
|
|
*/
|
|
template <typename MutableBufferSequence,
|
|
BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
|
|
std::size_t)) ReadToken
|
|
BOOST_ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
|
|
BOOST_ASIO_INITFN_AUTO_RESULT_TYPE_PREFIX(ReadToken,
|
|
void (boost::system::error_code, std::size_t))
|
|
async_read_some_at(uint64_t offset,
|
|
const MutableBufferSequence& buffers,
|
|
BOOST_ASIO_MOVE_ARG(ReadToken) token
|
|
BOOST_ASIO_DEFAULT_COMPLETION_TOKEN(executor_type))
|
|
BOOST_ASIO_INITFN_AUTO_RESULT_TYPE_SUFFIX((
|
|
async_initiate<ReadToken,
|
|
void (boost::system::error_code, std::size_t)>(
|
|
declval<initiate_async_read_some_at>(), token, offset, buffers)))
|
|
{
|
|
return async_initiate<ReadToken,
|
|
void (boost::system::error_code, std::size_t)>(
|
|
initiate_async_read_some_at(this), token, offset, buffers);
|
|
}
|
|
|
|
private:
|
|
class initiate_async_write_some_at
|
|
{
|
|
public:
|
|
typedef Executor executor_type;
|
|
|
|
explicit initiate_async_write_some_at(basic_random_access_handle* self)
|
|
: self_(self)
|
|
{
|
|
}
|
|
|
|
executor_type get_executor() const BOOST_ASIO_NOEXCEPT
|
|
{
|
|
return self_->get_executor();
|
|
}
|
|
|
|
template <typename WriteHandler, typename ConstBufferSequence>
|
|
void operator()(BOOST_ASIO_MOVE_ARG(WriteHandler) handler,
|
|
uint64_t offset, const ConstBufferSequence& buffers) const
|
|
{
|
|
// If you get an error on the following line it means that your handler
|
|
// does not meet the documented type requirements for a WriteHandler.
|
|
BOOST_ASIO_WRITE_HANDLER_CHECK(WriteHandler, handler) type_check;
|
|
|
|
detail::non_const_lvalue<WriteHandler> handler2(handler);
|
|
self_->impl_.get_service().async_write_some_at(
|
|
self_->impl_.get_implementation(), offset, buffers,
|
|
handler2.value, self_->impl_.get_executor());
|
|
}
|
|
|
|
private:
|
|
basic_random_access_handle* self_;
|
|
};
|
|
|
|
class initiate_async_read_some_at
|
|
{
|
|
public:
|
|
typedef Executor executor_type;
|
|
|
|
explicit initiate_async_read_some_at(basic_random_access_handle* self)
|
|
: self_(self)
|
|
{
|
|
}
|
|
|
|
executor_type get_executor() const BOOST_ASIO_NOEXCEPT
|
|
{
|
|
return self_->get_executor();
|
|
}
|
|
|
|
template <typename ReadHandler, typename MutableBufferSequence>
|
|
void operator()(BOOST_ASIO_MOVE_ARG(ReadHandler) handler,
|
|
uint64_t offset, const MutableBufferSequence& buffers) const
|
|
{
|
|
// If you get an error on the following line it means that your handler
|
|
// does not meet the documented type requirements for a ReadHandler.
|
|
BOOST_ASIO_READ_HANDLER_CHECK(ReadHandler, handler) type_check;
|
|
|
|
detail::non_const_lvalue<ReadHandler> handler2(handler);
|
|
self_->impl_.get_service().async_read_some_at(
|
|
self_->impl_.get_implementation(), offset, buffers,
|
|
handler2.value, self_->impl_.get_executor());
|
|
}
|
|
|
|
private:
|
|
basic_random_access_handle* self_;
|
|
};
|
|
};
|
|
|
|
} // namespace windows
|
|
} // namespace asio
|
|
} // namespace boost
|
|
|
|
#include <boost/asio/detail/pop_options.hpp>
|
|
|
|
#endif // defined(BOOST_ASIO_HAS_WINDOWS_RANDOM_ACCESS_HANDLE)
|
|
// || defined(GENERATING_DOCUMENTATION)
|
|
|
|
#endif // BOOST_ASIO_WINDOWS_BASIC_RANDOM_ACCESS_HANDLE_HPP
|