ext-boost/boost/asio/impl/read_at.hpp

658 lines
25 KiB
C++

//
// impl/read_at.hpp
// ~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#ifndef BOOST_ASIO_IMPL_READ_AT_HPP
#define BOOST_ASIO_IMPL_READ_AT_HPP
#if defined(_MSC_VER) && (_MSC_VER >= 1200)
# pragma once
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
#include <algorithm>
#include <boost/asio/associated_allocator.hpp>
#include <boost/asio/associated_executor.hpp>
#include <boost/asio/buffer.hpp>
#include <boost/asio/completion_condition.hpp>
#include <boost/asio/detail/array_fwd.hpp>
#include <boost/asio/detail/base_from_completion_cond.hpp>
#include <boost/asio/detail/bind_handler.hpp>
#include <boost/asio/detail/consuming_buffers.hpp>
#include <boost/asio/detail/dependent_type.hpp>
#include <boost/asio/detail/handler_alloc_helpers.hpp>
#include <boost/asio/detail/handler_cont_helpers.hpp>
#include <boost/asio/detail/handler_invoke_helpers.hpp>
#include <boost/asio/detail/handler_type_requirements.hpp>
#include <boost/asio/detail/non_const_lvalue.hpp>
#include <boost/asio/detail/throw_error.hpp>
#include <boost/asio/error.hpp>
#include <boost/asio/detail/push_options.hpp>
namespace boost {
namespace asio {
namespace detail
{
template <typename SyncRandomAccessReadDevice, typename MutableBufferSequence,
typename MutableBufferIterator, typename CompletionCondition>
std::size_t read_at_buffer_sequence(SyncRandomAccessReadDevice& d,
uint64_t offset, const MutableBufferSequence& buffers,
const MutableBufferIterator&, CompletionCondition completion_condition,
boost::system::error_code& ec)
{
ec = boost::system::error_code();
boost::asio::detail::consuming_buffers<mutable_buffer,
MutableBufferSequence, MutableBufferIterator> tmp(buffers);
while (!tmp.empty())
{
if (std::size_t max_size = detail::adapt_completion_condition_result(
completion_condition(ec, tmp.total_consumed())))
{
tmp.consume(d.read_some_at(offset + tmp.total_consumed(),
tmp.prepare(max_size), ec));
}
else
break;
}
return tmp.total_consumed();;
}
} // namespace detail
template <typename SyncRandomAccessReadDevice, typename MutableBufferSequence,
typename CompletionCondition>
std::size_t read_at(SyncRandomAccessReadDevice& d,
uint64_t offset, const MutableBufferSequence& buffers,
CompletionCondition completion_condition, boost::system::error_code& ec)
{
return detail::read_at_buffer_sequence(d, offset, buffers,
boost::asio::buffer_sequence_begin(buffers),
BOOST_ASIO_MOVE_CAST(CompletionCondition)(completion_condition), ec);
}
template <typename SyncRandomAccessReadDevice, typename MutableBufferSequence>
inline std::size_t read_at(SyncRandomAccessReadDevice& d,
uint64_t offset, const MutableBufferSequence& buffers)
{
boost::system::error_code ec;
std::size_t bytes_transferred = read_at(
d, offset, buffers, transfer_all(), ec);
boost::asio::detail::throw_error(ec, "read_at");
return bytes_transferred;
}
template <typename SyncRandomAccessReadDevice, typename MutableBufferSequence>
inline std::size_t read_at(SyncRandomAccessReadDevice& d,
uint64_t offset, const MutableBufferSequence& buffers,
boost::system::error_code& ec)
{
return read_at(d, offset, buffers, transfer_all(), ec);
}
template <typename SyncRandomAccessReadDevice, typename MutableBufferSequence,
typename CompletionCondition>
inline std::size_t read_at(SyncRandomAccessReadDevice& d,
uint64_t offset, const MutableBufferSequence& buffers,
CompletionCondition completion_condition)
{
boost::system::error_code ec;
std::size_t bytes_transferred = read_at(d, offset, buffers,
BOOST_ASIO_MOVE_CAST(CompletionCondition)(completion_condition), ec);
boost::asio::detail::throw_error(ec, "read_at");
return bytes_transferred;
}
#if !defined(BOOST_ASIO_NO_EXTENSIONS)
#if !defined(BOOST_ASIO_NO_IOSTREAM)
template <typename SyncRandomAccessReadDevice, typename Allocator,
typename CompletionCondition>
std::size_t read_at(SyncRandomAccessReadDevice& d,
uint64_t offset, boost::asio::basic_streambuf<Allocator>& b,
CompletionCondition completion_condition, boost::system::error_code& ec)
{
ec = boost::system::error_code();
std::size_t total_transferred = 0;
std::size_t max_size = detail::adapt_completion_condition_result(
completion_condition(ec, total_transferred));
std::size_t bytes_available = read_size_helper(b, max_size);
while (bytes_available > 0)
{
std::size_t bytes_transferred = d.read_some_at(
offset + total_transferred, b.prepare(bytes_available), ec);
b.commit(bytes_transferred);
total_transferred += bytes_transferred;
max_size = detail::adapt_completion_condition_result(
completion_condition(ec, total_transferred));
bytes_available = read_size_helper(b, max_size);
}
return total_transferred;
}
template <typename SyncRandomAccessReadDevice, typename Allocator>
inline std::size_t read_at(SyncRandomAccessReadDevice& d,
uint64_t offset, boost::asio::basic_streambuf<Allocator>& b)
{
boost::system::error_code ec;
std::size_t bytes_transferred = read_at(
d, offset, b, transfer_all(), ec);
boost::asio::detail::throw_error(ec, "read_at");
return bytes_transferred;
}
template <typename SyncRandomAccessReadDevice, typename Allocator>
inline std::size_t read_at(SyncRandomAccessReadDevice& d,
uint64_t offset, boost::asio::basic_streambuf<Allocator>& b,
boost::system::error_code& ec)
{
return read_at(d, offset, b, transfer_all(), ec);
}
template <typename SyncRandomAccessReadDevice, typename Allocator,
typename CompletionCondition>
inline std::size_t read_at(SyncRandomAccessReadDevice& d,
uint64_t offset, boost::asio::basic_streambuf<Allocator>& b,
CompletionCondition completion_condition)
{
boost::system::error_code ec;
std::size_t bytes_transferred = read_at(d, offset, b,
BOOST_ASIO_MOVE_CAST(CompletionCondition)(completion_condition), ec);
boost::asio::detail::throw_error(ec, "read_at");
return bytes_transferred;
}
#endif // !defined(BOOST_ASIO_NO_IOSTREAM)
#endif // !defined(BOOST_ASIO_NO_EXTENSIONS)
namespace detail
{
template <typename AsyncRandomAccessReadDevice,
typename MutableBufferSequence, typename MutableBufferIterator,
typename CompletionCondition, typename ReadHandler>
class read_at_op
: detail::base_from_completion_cond<CompletionCondition>
{
public:
read_at_op(AsyncRandomAccessReadDevice& device,
uint64_t offset, const MutableBufferSequence& buffers,
CompletionCondition& completion_condition, ReadHandler& handler)
: detail::base_from_completion_cond<
CompletionCondition>(completion_condition),
device_(device),
offset_(offset),
buffers_(buffers),
start_(0),
handler_(BOOST_ASIO_MOVE_CAST(ReadHandler)(handler))
{
}
#if defined(BOOST_ASIO_HAS_MOVE)
read_at_op(const read_at_op& other)
: detail::base_from_completion_cond<CompletionCondition>(other),
device_(other.device_),
offset_(other.offset_),
buffers_(other.buffers_),
start_(other.start_),
handler_(other.handler_)
{
}
read_at_op(read_at_op&& other)
: detail::base_from_completion_cond<CompletionCondition>(
BOOST_ASIO_MOVE_CAST(detail::base_from_completion_cond<
CompletionCondition>)(other)),
device_(other.device_),
offset_(other.offset_),
buffers_(BOOST_ASIO_MOVE_CAST(buffers_type)(other.buffers_)),
start_(other.start_),
handler_(BOOST_ASIO_MOVE_CAST(ReadHandler)(other.handler_))
{
}
#endif // defined(BOOST_ASIO_HAS_MOVE)
void operator()(const boost::system::error_code& ec,
std::size_t bytes_transferred, int start = 0)
{
std::size_t max_size;
switch (start_ = start)
{
case 1:
max_size = this->check_for_completion(ec, buffers_.total_consumed());
do
{
device_.async_read_some_at(
offset_ + buffers_.total_consumed(), buffers_.prepare(max_size),
BOOST_ASIO_MOVE_CAST(read_at_op)(*this));
return; default:
buffers_.consume(bytes_transferred);
if ((!ec && bytes_transferred == 0) || buffers_.empty())
break;
max_size = this->check_for_completion(ec, buffers_.total_consumed());
} while (max_size > 0);
handler_(ec, buffers_.total_consumed());
}
}
//private:
typedef boost::asio::detail::consuming_buffers<mutable_buffer,
MutableBufferSequence, MutableBufferIterator> buffers_type;
AsyncRandomAccessReadDevice& device_;
uint64_t offset_;
buffers_type buffers_;
int start_;
ReadHandler handler_;
};
template <typename AsyncRandomAccessReadDevice,
typename MutableBufferSequence, typename MutableBufferIterator,
typename CompletionCondition, typename ReadHandler>
inline void* asio_handler_allocate(std::size_t size,
read_at_op<AsyncRandomAccessReadDevice, MutableBufferSequence,
MutableBufferIterator, CompletionCondition, ReadHandler>* this_handler)
{
return boost_asio_handler_alloc_helpers::allocate(
size, this_handler->handler_);
}
template <typename AsyncRandomAccessReadDevice,
typename MutableBufferSequence, typename MutableBufferIterator,
typename CompletionCondition, typename ReadHandler>
inline void asio_handler_deallocate(void* pointer, std::size_t size,
read_at_op<AsyncRandomAccessReadDevice, MutableBufferSequence,
MutableBufferIterator, CompletionCondition, ReadHandler>* this_handler)
{
boost_asio_handler_alloc_helpers::deallocate(
pointer, size, this_handler->handler_);
}
template <typename AsyncRandomAccessReadDevice,
typename MutableBufferSequence, typename MutableBufferIterator,
typename CompletionCondition, typename ReadHandler>
inline bool asio_handler_is_continuation(
read_at_op<AsyncRandomAccessReadDevice, MutableBufferSequence,
MutableBufferIterator, CompletionCondition, ReadHandler>* this_handler)
{
return this_handler->start_ == 0 ? true
: boost_asio_handler_cont_helpers::is_continuation(
this_handler->handler_);
}
template <typename Function, typename AsyncRandomAccessReadDevice,
typename MutableBufferSequence, typename MutableBufferIterator,
typename CompletionCondition, typename ReadHandler>
inline void asio_handler_invoke(Function& function,
read_at_op<AsyncRandomAccessReadDevice, MutableBufferSequence,
MutableBufferIterator, CompletionCondition, ReadHandler>* this_handler)
{
boost_asio_handler_invoke_helpers::invoke(
function, this_handler->handler_);
}
template <typename Function, typename AsyncRandomAccessReadDevice,
typename MutableBufferSequence, typename MutableBufferIterator,
typename CompletionCondition, typename ReadHandler>
inline void asio_handler_invoke(const Function& function,
read_at_op<AsyncRandomAccessReadDevice, MutableBufferSequence,
MutableBufferIterator, CompletionCondition, ReadHandler>* this_handler)
{
boost_asio_handler_invoke_helpers::invoke(
function, this_handler->handler_);
}
template <typename AsyncRandomAccessReadDevice,
typename MutableBufferSequence, typename MutableBufferIterator,
typename CompletionCondition, typename ReadHandler>
inline void start_read_at_buffer_sequence_op(AsyncRandomAccessReadDevice& d,
uint64_t offset, const MutableBufferSequence& buffers,
const MutableBufferIterator&, CompletionCondition& completion_condition,
ReadHandler& handler)
{
detail::read_at_op<AsyncRandomAccessReadDevice, MutableBufferSequence,
MutableBufferIterator, CompletionCondition, ReadHandler>(
d, offset, buffers, completion_condition, handler)(
boost::system::error_code(), 0, 1);
}
struct initiate_async_read_at_buffer_sequence
{
template <typename ReadHandler, typename AsyncRandomAccessReadDevice,
typename MutableBufferSequence, typename CompletionCondition>
void operator()(BOOST_ASIO_MOVE_ARG(ReadHandler) handler,
AsyncRandomAccessReadDevice* d, uint64_t offset,
const MutableBufferSequence& buffers,
BOOST_ASIO_MOVE_ARG(CompletionCondition) completion_cond) 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;
non_const_lvalue<ReadHandler> handler2(handler);
non_const_lvalue<CompletionCondition> completion_cond2(completion_cond);
start_read_at_buffer_sequence_op(*d, offset, buffers,
boost::asio::buffer_sequence_begin(buffers),
completion_cond2.value, handler2.value);
}
};
} // namespace detail
#if !defined(GENERATING_DOCUMENTATION)
template <typename AsyncRandomAccessReadDevice,
typename MutableBufferSequence, typename MutableBufferIterator,
typename CompletionCondition, typename ReadHandler, typename Allocator>
struct associated_allocator<
detail::read_at_op<AsyncRandomAccessReadDevice, MutableBufferSequence,
MutableBufferIterator, CompletionCondition, ReadHandler>,
Allocator>
{
typedef typename associated_allocator<ReadHandler, Allocator>::type type;
static type get(
const detail::read_at_op<AsyncRandomAccessReadDevice,
MutableBufferSequence, MutableBufferIterator,
CompletionCondition, ReadHandler>& h,
const Allocator& a = Allocator()) BOOST_ASIO_NOEXCEPT
{
return associated_allocator<ReadHandler, Allocator>::get(h.handler_, a);
}
};
template <typename AsyncRandomAccessReadDevice,
typename MutableBufferSequence, typename MutableBufferIterator,
typename CompletionCondition, typename ReadHandler, typename Executor>
struct associated_executor<
detail::read_at_op<AsyncRandomAccessReadDevice, MutableBufferSequence,
MutableBufferIterator, CompletionCondition, ReadHandler>,
Executor>
{
typedef typename associated_executor<ReadHandler, Executor>::type type;
static type get(
const detail::read_at_op<AsyncRandomAccessReadDevice,
MutableBufferSequence, MutableBufferIterator,
CompletionCondition, ReadHandler>& h,
const Executor& ex = Executor()) BOOST_ASIO_NOEXCEPT
{
return associated_executor<ReadHandler, Executor>::get(h.handler_, ex);
}
};
#endif // !defined(GENERATING_DOCUMENTATION)
template <typename AsyncRandomAccessReadDevice, typename MutableBufferSequence,
typename CompletionCondition, typename ReadHandler>
inline BOOST_ASIO_INITFN_RESULT_TYPE(ReadHandler,
void (boost::system::error_code, std::size_t))
async_read_at(AsyncRandomAccessReadDevice& d,
uint64_t offset, const MutableBufferSequence& buffers,
CompletionCondition completion_condition,
BOOST_ASIO_MOVE_ARG(ReadHandler) handler)
{
return async_initiate<ReadHandler,
void (boost::system::error_code, std::size_t)>(
detail::initiate_async_read_at_buffer_sequence(), handler, &d, offset,
buffers, BOOST_ASIO_MOVE_CAST(CompletionCondition)(completion_condition));
}
template <typename AsyncRandomAccessReadDevice, typename MutableBufferSequence,
typename ReadHandler>
inline BOOST_ASIO_INITFN_RESULT_TYPE(ReadHandler,
void (boost::system::error_code, std::size_t))
async_read_at(AsyncRandomAccessReadDevice& d,
uint64_t offset, const MutableBufferSequence& buffers,
BOOST_ASIO_MOVE_ARG(ReadHandler) handler)
{
return async_initiate<ReadHandler,
void (boost::system::error_code, std::size_t)>(
detail::initiate_async_read_at_buffer_sequence(),
handler, &d, offset, buffers, transfer_all());
}
#if !defined(BOOST_ASIO_NO_EXTENSIONS)
#if !defined(BOOST_ASIO_NO_IOSTREAM)
namespace detail
{
template <typename AsyncRandomAccessReadDevice, typename Allocator,
typename CompletionCondition, typename ReadHandler>
class read_at_streambuf_op
: detail::base_from_completion_cond<CompletionCondition>
{
public:
read_at_streambuf_op(AsyncRandomAccessReadDevice& device,
uint64_t offset, basic_streambuf<Allocator>& streambuf,
CompletionCondition& completion_condition, ReadHandler& handler)
: detail::base_from_completion_cond<
CompletionCondition>(completion_condition),
device_(device),
offset_(offset),
streambuf_(streambuf),
start_(0),
total_transferred_(0),
handler_(BOOST_ASIO_MOVE_CAST(ReadHandler)(handler))
{
}
#if defined(BOOST_ASIO_HAS_MOVE)
read_at_streambuf_op(const read_at_streambuf_op& other)
: detail::base_from_completion_cond<CompletionCondition>(other),
device_(other.device_),
offset_(other.offset_),
streambuf_(other.streambuf_),
start_(other.start_),
total_transferred_(other.total_transferred_),
handler_(other.handler_)
{
}
read_at_streambuf_op(read_at_streambuf_op&& other)
: detail::base_from_completion_cond<CompletionCondition>(
BOOST_ASIO_MOVE_CAST(detail::base_from_completion_cond<
CompletionCondition>)(other)),
device_(other.device_),
offset_(other.offset_),
streambuf_(other.streambuf_),
start_(other.start_),
total_transferred_(other.total_transferred_),
handler_(BOOST_ASIO_MOVE_CAST(ReadHandler)(other.handler_))
{
}
#endif // defined(BOOST_ASIO_HAS_MOVE)
void operator()(const boost::system::error_code& ec,
std::size_t bytes_transferred, int start = 0)
{
std::size_t max_size, bytes_available;
switch (start_ = start)
{
case 1:
max_size = this->check_for_completion(ec, total_transferred_);
bytes_available = read_size_helper(streambuf_, max_size);
for (;;)
{
device_.async_read_some_at(offset_ + total_transferred_,
streambuf_.prepare(bytes_available),
BOOST_ASIO_MOVE_CAST(read_at_streambuf_op)(*this));
return; default:
total_transferred_ += bytes_transferred;
streambuf_.commit(bytes_transferred);
max_size = this->check_for_completion(ec, total_transferred_);
bytes_available = read_size_helper(streambuf_, max_size);
if ((!ec && bytes_transferred == 0) || bytes_available == 0)
break;
}
handler_(ec, static_cast<const std::size_t&>(total_transferred_));
}
}
//private:
AsyncRandomAccessReadDevice& device_;
uint64_t offset_;
boost::asio::basic_streambuf<Allocator>& streambuf_;
int start_;
std::size_t total_transferred_;
ReadHandler handler_;
};
template <typename AsyncRandomAccessReadDevice, typename Allocator,
typename CompletionCondition, typename ReadHandler>
inline void* asio_handler_allocate(std::size_t size,
read_at_streambuf_op<AsyncRandomAccessReadDevice, Allocator,
CompletionCondition, ReadHandler>* this_handler)
{
return boost_asio_handler_alloc_helpers::allocate(
size, this_handler->handler_);
}
template <typename AsyncRandomAccessReadDevice, typename Allocator,
typename CompletionCondition, typename ReadHandler>
inline void asio_handler_deallocate(void* pointer, std::size_t size,
read_at_streambuf_op<AsyncRandomAccessReadDevice, Allocator,
CompletionCondition, ReadHandler>* this_handler)
{
boost_asio_handler_alloc_helpers::deallocate(
pointer, size, this_handler->handler_);
}
template <typename AsyncRandomAccessReadDevice, typename Allocator,
typename CompletionCondition, typename ReadHandler>
inline bool asio_handler_is_continuation(
read_at_streambuf_op<AsyncRandomAccessReadDevice, Allocator,
CompletionCondition, ReadHandler>* this_handler)
{
return this_handler->start_ == 0 ? true
: boost_asio_handler_cont_helpers::is_continuation(
this_handler->handler_);
}
template <typename Function, typename AsyncRandomAccessReadDevice,
typename Allocator, typename CompletionCondition, typename ReadHandler>
inline void asio_handler_invoke(Function& function,
read_at_streambuf_op<AsyncRandomAccessReadDevice, Allocator,
CompletionCondition, ReadHandler>* this_handler)
{
boost_asio_handler_invoke_helpers::invoke(
function, this_handler->handler_);
}
template <typename Function, typename AsyncRandomAccessReadDevice,
typename Allocator, typename CompletionCondition, typename ReadHandler>
inline void asio_handler_invoke(const Function& function,
read_at_streambuf_op<AsyncRandomAccessReadDevice, Allocator,
CompletionCondition, ReadHandler>* this_handler)
{
boost_asio_handler_invoke_helpers::invoke(
function, this_handler->handler_);
}
struct initiate_async_read_at_streambuf
{
template <typename ReadHandler, typename AsyncRandomAccessReadDevice,
typename Allocator, typename CompletionCondition>
void operator()(BOOST_ASIO_MOVE_ARG(ReadHandler) handler,
AsyncRandomAccessReadDevice* d, uint64_t offset,
basic_streambuf<Allocator>* b,
BOOST_ASIO_MOVE_ARG(CompletionCondition) completion_cond) 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;
non_const_lvalue<ReadHandler> handler2(handler);
non_const_lvalue<CompletionCondition> completion_cond2(completion_cond);
read_at_streambuf_op<AsyncRandomAccessReadDevice, Allocator,
CompletionCondition, typename decay<ReadHandler>::type>(
*d, offset, *b, completion_cond2.value, handler2.value)(
boost::system::error_code(), 0, 1);
}
};
} // namespace detail
#if !defined(GENERATING_DOCUMENTATION)
template <typename AsyncRandomAccessReadDevice, typename Allocator,
typename CompletionCondition, typename ReadHandler, typename Allocator1>
struct associated_allocator<
detail::read_at_streambuf_op<AsyncRandomAccessReadDevice,
Allocator, CompletionCondition, ReadHandler>,
Allocator1>
{
typedef typename associated_allocator<ReadHandler, Allocator1>::type type;
static type get(
const detail::read_at_streambuf_op<AsyncRandomAccessReadDevice,
Allocator, CompletionCondition, ReadHandler>& h,
const Allocator1& a = Allocator1()) BOOST_ASIO_NOEXCEPT
{
return associated_allocator<ReadHandler, Allocator1>::get(h.handler_, a);
}
};
template <typename AsyncRandomAccessReadDevice, typename Executor,
typename CompletionCondition, typename ReadHandler, typename Executor1>
struct associated_executor<
detail::read_at_streambuf_op<AsyncRandomAccessReadDevice,
Executor, CompletionCondition, ReadHandler>,
Executor1>
{
typedef typename associated_executor<ReadHandler, Executor1>::type type;
static type get(
const detail::read_at_streambuf_op<AsyncRandomAccessReadDevice,
Executor, CompletionCondition, ReadHandler>& h,
const Executor1& ex = Executor1()) BOOST_ASIO_NOEXCEPT
{
return associated_executor<ReadHandler, Executor1>::get(h.handler_, ex);
}
};
#endif // !defined(GENERATING_DOCUMENTATION)
template <typename AsyncRandomAccessReadDevice, typename Allocator,
typename CompletionCondition, typename ReadHandler>
inline BOOST_ASIO_INITFN_RESULT_TYPE(ReadHandler,
void (boost::system::error_code, std::size_t))
async_read_at(AsyncRandomAccessReadDevice& d,
uint64_t offset, boost::asio::basic_streambuf<Allocator>& b,
CompletionCondition completion_condition,
BOOST_ASIO_MOVE_ARG(ReadHandler) handler)
{
return async_initiate<ReadHandler,
void (boost::system::error_code, std::size_t)>(
detail::initiate_async_read_at_streambuf(), handler, &d, offset,
&b, BOOST_ASIO_MOVE_CAST(CompletionCondition)(completion_condition));
}
template <typename AsyncRandomAccessReadDevice, typename Allocator,
typename ReadHandler>
inline BOOST_ASIO_INITFN_RESULT_TYPE(ReadHandler,
void (boost::system::error_code, std::size_t))
async_read_at(AsyncRandomAccessReadDevice& d,
uint64_t offset, boost::asio::basic_streambuf<Allocator>& b,
BOOST_ASIO_MOVE_ARG(ReadHandler) handler)
{
return async_initiate<ReadHandler,
void (boost::system::error_code, std::size_t)>(
detail::initiate_async_read_at_streambuf(),
handler, &d, offset, &b, transfer_all());
}
#endif // !defined(BOOST_ASIO_NO_IOSTREAM)
#endif // !defined(BOOST_ASIO_NO_EXTENSIONS)
} // namespace asio
} // namespace boost
#include <boost/asio/detail/pop_options.hpp>
#endif // BOOST_ASIO_IMPL_READ_AT_HPP