| // |
| // impl/read_at.hpp |
| // ~~~~~~~~~~~~~~~~ |
| // |
| // Copyright (c) 2003-2010 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/buffer.hpp> |
| #include <boost/asio/completion_condition.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/handler_alloc_helpers.hpp> |
| #include <boost/asio/detail/handler_invoke_helpers.hpp> |
| #include <boost/asio/detail/throw_error.hpp> |
| #include <boost/asio/error.hpp> |
| |
| #include <boost/asio/detail/push_options.hpp> |
| |
| namespace boost { |
| namespace asio { |
| |
| template <typename SyncRandomAccessReadDevice, typename MutableBufferSequence, |
| typename CompletionCondition> |
| std::size_t read_at(SyncRandomAccessReadDevice& d, |
| boost::uint64_t offset, const MutableBufferSequence& buffers, |
| CompletionCondition completion_condition, boost::system::error_code& ec) |
| { |
| ec = boost::system::error_code(); |
| boost::asio::detail::consuming_buffers< |
| mutable_buffer, MutableBufferSequence> tmp(buffers); |
| std::size_t total_transferred = 0; |
| tmp.prepare(detail::adapt_completion_condition_result( |
| completion_condition(ec, total_transferred))); |
| while (tmp.begin() != tmp.end()) |
| { |
| std::size_t bytes_transferred = d.read_some_at( |
| offset + total_transferred, tmp, ec); |
| tmp.consume(bytes_transferred); |
| total_transferred += bytes_transferred; |
| tmp.prepare(detail::adapt_completion_condition_result( |
| completion_condition(ec, total_transferred))); |
| } |
| return total_transferred; |
| } |
| |
| template <typename SyncRandomAccessReadDevice, typename MutableBufferSequence> |
| inline std::size_t read_at(SyncRandomAccessReadDevice& d, |
| boost::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); |
| return bytes_transferred; |
| } |
| |
| template <typename SyncRandomAccessReadDevice, typename MutableBufferSequence, |
| typename CompletionCondition> |
| inline std::size_t read_at(SyncRandomAccessReadDevice& d, |
| boost::uint64_t offset, const MutableBufferSequence& buffers, |
| CompletionCondition completion_condition) |
| { |
| boost::system::error_code ec; |
| std::size_t bytes_transferred = read_at( |
| d, offset, buffers, completion_condition, ec); |
| boost::asio::detail::throw_error(ec); |
| return bytes_transferred; |
| } |
| |
| #if !defined(BOOST_NO_IOSTREAM) |
| |
| template <typename SyncRandomAccessReadDevice, typename Allocator, |
| typename CompletionCondition> |
| std::size_t read_at(SyncRandomAccessReadDevice& d, |
| boost::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, |
| boost::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); |
| return bytes_transferred; |
| } |
| |
| template <typename SyncRandomAccessReadDevice, typename Allocator, |
| typename CompletionCondition> |
| inline std::size_t read_at(SyncRandomAccessReadDevice& d, |
| boost::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, completion_condition, ec); |
| boost::asio::detail::throw_error(ec); |
| return bytes_transferred; |
| } |
| |
| #endif // !defined(BOOST_NO_IOSTREAM) |
| |
| namespace detail |
| { |
| template <typename AsyncRandomAccessReadDevice, |
| typename MutableBufferSequence, typename CompletionCondition, |
| typename ReadHandler> |
| class read_at_op |
| : detail::base_from_completion_cond<CompletionCondition> |
| { |
| public: |
| read_at_op(AsyncRandomAccessReadDevice& device, |
| boost::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), |
| total_transferred_(0), |
| handler_(handler) |
| { |
| } |
| |
| void operator()(const boost::system::error_code& ec, |
| std::size_t bytes_transferred, int start = 0) |
| { |
| switch (start) |
| { |
| case 1: |
| buffers_.prepare(this->check_for_completion(ec, total_transferred_)); |
| for (;;) |
| { |
| device_.async_read_some_at( |
| offset_ + total_transferred_, buffers_, *this); |
| return; default: |
| total_transferred_ += bytes_transferred; |
| buffers_.consume(bytes_transferred); |
| buffers_.prepare(this->check_for_completion(ec, total_transferred_)); |
| if ((!ec && bytes_transferred == 0) |
| || buffers_.begin() == buffers_.end()) |
| break; |
| } |
| |
| handler_(ec, static_cast<const std::size_t&>(total_transferred_)); |
| } |
| } |
| |
| //private: |
| AsyncRandomAccessReadDevice& device_; |
| boost::uint64_t offset_; |
| boost::asio::detail::consuming_buffers< |
| mutable_buffer, MutableBufferSequence> buffers_; |
| std::size_t total_transferred_; |
| ReadHandler handler_; |
| }; |
| |
| template <typename AsyncRandomAccessReadDevice, |
| typename CompletionCondition, typename ReadHandler> |
| class read_at_op<AsyncRandomAccessReadDevice, |
| boost::asio::mutable_buffers_1, CompletionCondition, ReadHandler> |
| : detail::base_from_completion_cond<CompletionCondition> |
| { |
| public: |
| read_at_op(AsyncRandomAccessReadDevice& device, |
| boost::uint64_t offset, const boost::asio::mutable_buffers_1& buffers, |
| CompletionCondition completion_condition, ReadHandler handler) |
| : detail::base_from_completion_cond< |
| CompletionCondition>(completion_condition), |
| device_(device), |
| offset_(offset), |
| buffer_(buffers), |
| total_transferred_(0), |
| handler_(handler) |
| { |
| } |
| |
| void operator()(const boost::system::error_code& ec, |
| std::size_t bytes_transferred, int start = 0) |
| { |
| std::size_t n = 0; |
| switch (start) |
| { |
| case 1: |
| n = this->check_for_completion(ec, total_transferred_); |
| for (;;) |
| { |
| device_.async_read_some_at(offset_ + total_transferred_, |
| boost::asio::buffer(buffer_ + total_transferred_, n), *this); |
| return; default: |
| total_transferred_ += bytes_transferred; |
| if ((!ec && bytes_transferred == 0) |
| || (n = this->check_for_completion(ec, total_transferred_)) == 0 |
| || total_transferred_ == boost::asio::buffer_size(buffer_)) |
| break; |
| } |
| |
| handler_(ec, static_cast<const std::size_t&>(total_transferred_)); |
| } |
| } |
| |
| //private: |
| AsyncRandomAccessReadDevice& device_; |
| boost::uint64_t offset_; |
| boost::asio::mutable_buffer buffer_; |
| std::size_t total_transferred_; |
| ReadHandler handler_; |
| }; |
| |
| template <typename AsyncRandomAccessReadDevice, |
| typename MutableBufferSequence, typename CompletionCondition, |
| typename ReadHandler> |
| inline void* asio_handler_allocate(std::size_t size, |
| read_at_op<AsyncRandomAccessReadDevice, MutableBufferSequence, |
| CompletionCondition, ReadHandler>* this_handler) |
| { |
| return boost_asio_handler_alloc_helpers::allocate( |
| size, this_handler->handler_); |
| } |
| |
| template <typename AsyncRandomAccessReadDevice, |
| typename MutableBufferSequence, typename CompletionCondition, |
| typename ReadHandler> |
| inline void asio_handler_deallocate(void* pointer, std::size_t size, |
| read_at_op<AsyncRandomAccessReadDevice, MutableBufferSequence, |
| CompletionCondition, ReadHandler>* this_handler) |
| { |
| boost_asio_handler_alloc_helpers::deallocate( |
| pointer, size, this_handler->handler_); |
| } |
| |
| template <typename Function, typename AsyncRandomAccessReadDevice, |
| typename MutableBufferSequence, typename CompletionCondition, |
| typename ReadHandler> |
| inline void asio_handler_invoke(const Function& function, |
| read_at_op<AsyncRandomAccessReadDevice, MutableBufferSequence, |
| CompletionCondition, ReadHandler>* this_handler) |
| { |
| boost_asio_handler_invoke_helpers::invoke( |
| function, this_handler->handler_); |
| } |
| } // namespace detail |
| |
| template <typename AsyncRandomAccessReadDevice, typename MutableBufferSequence, |
| typename CompletionCondition, typename ReadHandler> |
| inline void async_read_at(AsyncRandomAccessReadDevice& d, |
| boost::uint64_t offset, const MutableBufferSequence& buffers, |
| CompletionCondition completion_condition, ReadHandler handler) |
| { |
| detail::read_at_op<AsyncRandomAccessReadDevice, |
| MutableBufferSequence, CompletionCondition, ReadHandler>( |
| d, offset, buffers, completion_condition, handler)( |
| boost::system::error_code(), 0, 1); |
| } |
| |
| template <typename AsyncRandomAccessReadDevice, typename MutableBufferSequence, |
| typename ReadHandler> |
| inline void async_read_at(AsyncRandomAccessReadDevice& d, |
| boost::uint64_t offset, const MutableBufferSequence& buffers, |
| ReadHandler handler) |
| { |
| async_read_at(d, offset, buffers, transfer_all(), handler); |
| } |
| |
| #if !defined(BOOST_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, |
| boost::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), |
| total_transferred_(0), |
| handler_(handler) |
| { |
| } |
| |
| 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) |
| { |
| 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), *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_; |
| boost::uint64_t offset_; |
| boost::asio::basic_streambuf<Allocator>& streambuf_; |
| 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 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_); |
| } |
| } // namespace detail |
| |
| template <typename AsyncRandomAccessReadDevice, typename Allocator, |
| typename CompletionCondition, typename ReadHandler> |
| inline void async_read_at(AsyncRandomAccessReadDevice& d, |
| boost::uint64_t offset, boost::asio::basic_streambuf<Allocator>& b, |
| CompletionCondition completion_condition, ReadHandler handler) |
| { |
| detail::read_at_streambuf_op<AsyncRandomAccessReadDevice, |
| Allocator, CompletionCondition, ReadHandler>( |
| d, offset, b, completion_condition, handler)( |
| boost::system::error_code(), 0, 1); |
| } |
| |
| template <typename AsyncRandomAccessReadDevice, typename Allocator, |
| typename ReadHandler> |
| inline void async_read_at(AsyncRandomAccessReadDevice& d, |
| boost::uint64_t offset, boost::asio::basic_streambuf<Allocator>& b, |
| ReadHandler handler) |
| { |
| async_read_at(d, offset, b, transfer_all(), handler); |
| } |
| |
| #endif // !defined(BOOST_NO_IOSTREAM) |
| |
| } // namespace asio |
| } // namespace boost |
| |
| #include <boost/asio/detail/pop_options.hpp> |
| |
| #endif // BOOST_ASIO_IMPL_READ_AT_HPP |