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Diffstat (limited to 'lib/asio/completion_condition.hpp')
-rw-r--r-- | lib/asio/completion_condition.hpp | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/lib/asio/completion_condition.hpp b/lib/asio/completion_condition.hpp new file mode 100644 index 0000000..563f417 --- /dev/null +++ b/lib/asio/completion_condition.hpp @@ -0,0 +1,218 @@ +// +// completion_condition.hpp +// ~~~~~~~~~~~~~~~~~~~~~~~~ +// +// Copyright (c) 2003-2018 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 ASIO_COMPLETION_CONDITION_HPP +#define ASIO_COMPLETION_CONDITION_HPP + +#if defined(_MSC_VER) && (_MSC_VER >= 1200) +# pragma once +#endif // defined(_MSC_VER) && (_MSC_VER >= 1200) + +#include "asio/detail/config.hpp" +#include <cstddef> + +#include "asio/detail/push_options.hpp" + +namespace asio { + +namespace detail { + +// The default maximum number of bytes to transfer in a single operation. +enum default_max_transfer_size_t { default_max_transfer_size = 65536 }; + +// Adapt result of old-style completion conditions (which had a bool result +// where true indicated that the operation was complete). +inline std::size_t adapt_completion_condition_result(bool result) +{ + return result ? 0 : default_max_transfer_size; +} + +// Adapt result of current completion conditions (which have a size_t result +// where 0 means the operation is complete, and otherwise the result is the +// maximum number of bytes to transfer on the next underlying operation). +inline std::size_t adapt_completion_condition_result(std::size_t result) +{ + return result; +} + +class transfer_all_t +{ +public: + typedef std::size_t result_type; + + template <typename Error> + std::size_t operator()(const Error& err, std::size_t) + { + return !!err ? 0 : default_max_transfer_size; + } +}; + +class transfer_at_least_t +{ +public: + typedef std::size_t result_type; + + explicit transfer_at_least_t(std::size_t minimum) + : minimum_(minimum) + { + } + + template <typename Error> + std::size_t operator()(const Error& err, std::size_t bytes_transferred) + { + return (!!err || bytes_transferred >= minimum_) + ? 0 : default_max_transfer_size; + } + +private: + std::size_t minimum_; +}; + +class transfer_exactly_t +{ +public: + typedef std::size_t result_type; + + explicit transfer_exactly_t(std::size_t size) + : size_(size) + { + } + + template <typename Error> + std::size_t operator()(const Error& err, std::size_t bytes_transferred) + { + return (!!err || bytes_transferred >= size_) ? 0 : + (size_ - bytes_transferred < default_max_transfer_size + ? size_ - bytes_transferred : std::size_t(default_max_transfer_size)); + } + +private: + std::size_t size_; +}; + +} // namespace detail + +/** + * @defgroup completion_condition Completion Condition Function Objects + * + * Function objects used for determining when a read or write operation should + * complete. + */ +/*@{*/ + +/// Return a completion condition function object that indicates that a read or +/// write operation should continue until all of the data has been transferred, +/// or until an error occurs. +/** + * This function is used to create an object, of unspecified type, that meets + * CompletionCondition requirements. + * + * @par Example + * Reading until a buffer is full: + * @code + * boost::array<char, 128> buf; + * asio::error_code ec; + * std::size_t n = asio::read( + * sock, asio::buffer(buf), + * asio::transfer_all(), ec); + * if (ec) + * { + * // An error occurred. + * } + * else + * { + * // n == 128 + * } + * @endcode + */ +#if defined(GENERATING_DOCUMENTATION) +unspecified transfer_all(); +#else +inline detail::transfer_all_t transfer_all() +{ + return detail::transfer_all_t(); +} +#endif + +/// Return a completion condition function object that indicates that a read or +/// write operation should continue until a minimum number of bytes has been +/// transferred, or until an error occurs. +/** + * This function is used to create an object, of unspecified type, that meets + * CompletionCondition requirements. + * + * @par Example + * Reading until a buffer is full or contains at least 64 bytes: + * @code + * boost::array<char, 128> buf; + * asio::error_code ec; + * std::size_t n = asio::read( + * sock, asio::buffer(buf), + * asio::transfer_at_least(64), ec); + * if (ec) + * { + * // An error occurred. + * } + * else + * { + * // n >= 64 && n <= 128 + * } + * @endcode + */ +#if defined(GENERATING_DOCUMENTATION) +unspecified transfer_at_least(std::size_t minimum); +#else +inline detail::transfer_at_least_t transfer_at_least(std::size_t minimum) +{ + return detail::transfer_at_least_t(minimum); +} +#endif + +/// Return a completion condition function object that indicates that a read or +/// write operation should continue until an exact number of bytes has been +/// transferred, or until an error occurs. +/** + * This function is used to create an object, of unspecified type, that meets + * CompletionCondition requirements. + * + * @par Example + * Reading until a buffer is full or contains exactly 64 bytes: + * @code + * boost::array<char, 128> buf; + * asio::error_code ec; + * std::size_t n = asio::read( + * sock, asio::buffer(buf), + * asio::transfer_exactly(64), ec); + * if (ec) + * { + * // An error occurred. + * } + * else + * { + * // n == 64 + * } + * @endcode + */ +#if defined(GENERATING_DOCUMENTATION) +unspecified transfer_exactly(std::size_t size); +#else +inline detail::transfer_exactly_t transfer_exactly(std::size_t size) +{ + return detail::transfer_exactly_t(size); +} +#endif + +/*@}*/ + +} // namespace asio + +#include "asio/detail/pop_options.hpp" + +#endif // ASIO_COMPLETION_CONDITION_HPP |