| // |
| // read_at.ipp |
| // ~~~~~~~~~~~ |
| // |
| // Copyright (c) 2003-2008 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_READ_AT_IPP |
| #define BOOST_ASIO_READ_AT_IPP |
| |
| #if defined(_MSC_VER) && (_MSC_VER >= 1200) |
| # pragma once |
| #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) |
| |
| #include <boost/asio/detail/push_options.hpp> |
| |
| #include <boost/asio/detail/push_options.hpp> |
| #include <algorithm> |
| #include <boost/asio/detail/pop_options.hpp> |
| |
| #include <boost/asio/buffer.hpp> |
| #include <boost/asio/completion_condition.hpp> |
| #include <boost/asio/error.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> |
| |
| 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.set_max_size(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.set_max_size(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; |
| } |
| |
| 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) |
| { |
| std::size_t total_transferred = 0; |
| for (;;) |
| { |
| std::size_t bytes_available = |
| std::min<std::size_t>(512, b.max_size() - b.size()); |
| 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; |
| if (b.size() == b.max_size() |
| || completion_condition(ec, total_transferred)) |
| 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; |
| } |
| |
| namespace detail |
| { |
| template <typename AsyncRandomAccessReadDevice, |
| typename MutableBufferSequence, typename CompletionCondition, |
| typename ReadHandler> |
| class read_at_handler |
| { |
| public: |
| typedef boost::asio::detail::consuming_buffers< |
| mutable_buffer, MutableBufferSequence> buffers_type; |
| |
| read_at_handler(AsyncRandomAccessReadDevice& stream, |
| boost::uint64_t offset, const buffers_type& buffers, |
| CompletionCondition completion_condition, ReadHandler handler) |
| : stream_(stream), |
| offset_(offset), |
| buffers_(buffers), |
| total_transferred_(0), |
| completion_condition_(completion_condition), |
| handler_(handler) |
| { |
| } |
| |
| void operator()(const boost::system::error_code& ec, |
| std::size_t bytes_transferred) |
| { |
| total_transferred_ += bytes_transferred; |
| buffers_.consume(bytes_transferred); |
| buffers_.set_max_size(detail::adapt_completion_condition_result( |
| completion_condition_(ec, total_transferred_))); |
| if (buffers_.begin() == buffers_.end()) |
| { |
| handler_(ec, total_transferred_); |
| } |
| else |
| { |
| stream_.async_read_some_at( |
| offset_ + total_transferred_, buffers_, *this); |
| } |
| } |
| |
| //private: |
| AsyncRandomAccessReadDevice& stream_; |
| boost::uint64_t offset_; |
| buffers_type buffers_; |
| std::size_t total_transferred_; |
| CompletionCondition completion_condition_; |
| ReadHandler handler_; |
| }; |
| |
| template <typename AsyncRandomAccessReadDevice, |
| typename MutableBufferSequence, typename CompletionCondition, |
| typename ReadHandler> |
| inline void* asio_handler_allocate(std::size_t size, |
| read_at_handler<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_handler<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_handler<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) |
| { |
| boost::asio::detail::consuming_buffers< |
| mutable_buffer, MutableBufferSequence> tmp(buffers); |
| |
| boost::system::error_code ec; |
| std::size_t total_transferred = 0; |
| tmp.set_max_size(detail::adapt_completion_condition_result( |
| completion_condition(ec, total_transferred))); |
| if (tmp.begin() == tmp.end()) |
| { |
| d.get_io_service().post(detail::bind_handler( |
| handler, ec, total_transferred)); |
| return; |
| } |
| |
| d.async_read_some_at(offset, tmp, |
| detail::read_at_handler<AsyncRandomAccessReadDevice, |
| MutableBufferSequence, CompletionCondition, ReadHandler>( |
| d, offset, tmp, completion_condition, handler)); |
| } |
| |
| 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); |
| } |
| |
| namespace detail |
| { |
| template <typename AsyncRandomAccessReadDevice, typename Allocator, |
| typename CompletionCondition, typename ReadHandler> |
| class read_at_streambuf_handler |
| { |
| public: |
| read_at_streambuf_handler(AsyncRandomAccessReadDevice& stream, |
| boost::uint64_t offset, basic_streambuf<Allocator>& streambuf, |
| CompletionCondition completion_condition, ReadHandler handler) |
| : stream_(stream), |
| offset_(offset), |
| streambuf_(streambuf), |
| total_transferred_(0), |
| completion_condition_(completion_condition), |
| handler_(handler) |
| { |
| } |
| |
| void operator()(const boost::system::error_code& ec, |
| std::size_t bytes_transferred) |
| { |
| total_transferred_ += bytes_transferred; |
| streambuf_.commit(bytes_transferred); |
| std::size_t max_size = detail::adapt_completion_condition_result( |
| completion_condition_(ec, total_transferred_)); |
| std::size_t bytes_available = std::min<std::size_t>(512, |
| std::min<std::size_t>(max_size, |
| streambuf_.max_size() - streambuf_.size())); |
| if (bytes_available == 0) |
| { |
| handler_(ec, total_transferred_); |
| } |
| else |
| { |
| stream_.async_read_some_at(offset_ + total_transferred_, |
| streambuf_.prepare(bytes_available), *this); |
| } |
| } |
| |
| //private: |
| AsyncRandomAccessReadDevice& stream_; |
| boost::uint64_t offset_; |
| boost::asio::basic_streambuf<Allocator>& streambuf_; |
| std::size_t total_transferred_; |
| CompletionCondition completion_condition_; |
| ReadHandler handler_; |
| }; |
| |
| template <typename AsyncRandomAccessReadDevice, typename Allocator, |
| typename CompletionCondition, typename ReadHandler> |
| inline void* asio_handler_allocate(std::size_t size, |
| read_at_streambuf_handler<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_handler<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_handler<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) |
| { |
| boost::system::error_code ec; |
| 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 = std::min<std::size_t>(512, |
| std::min<std::size_t>(max_size, b.max_size() - b.size())); |
| if (bytes_available == 0) |
| { |
| d.get_io_service().post(detail::bind_handler( |
| handler, ec, total_transferred)); |
| return; |
| } |
| |
| d.async_read_some_at(offset, b.prepare(bytes_available), |
| detail::read_at_streambuf_handler<AsyncRandomAccessReadDevice, Allocator, |
| CompletionCondition, ReadHandler>( |
| d, offset, b, completion_condition, handler)); |
| } |
| |
| 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); |
| } |
| |
| } // namespace asio |
| } // namespace boost |
| |
| #include <boost/asio/detail/pop_options.hpp> |
| |
| #endif // BOOST_ASIO_READ_AT_IPP |