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diff --git a/lib/asio/read.hpp b/lib/asio/read.hpp new file mode 100644 index 0000000..e77206a --- /dev/null +++ b/lib/asio/read.hpp @@ -0,0 +1,947 @@ +// +// read.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_READ_HPP +#define ASIO_READ_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/async_result.hpp" +#include "asio/buffer.hpp" +#include "asio/error.hpp" + +#if !defined(ASIO_NO_EXTENSIONS) +# include "asio/basic_streambuf_fwd.hpp" +#endif // !defined(ASIO_NO_EXTENSIONS) + +#include "asio/detail/push_options.hpp" + +namespace asio { + +/** + * @defgroup read asio::read + * + * @brief Attempt to read a certain amount of data from a stream before + * returning. + */ +/*@{*/ + +/// Attempt to read a certain amount of data from a stream before returning. +/** + * This function is used to read a certain number of bytes of data from a + * stream. The call will block until one of the following conditions is true: + * + * @li The supplied buffers are full. That is, the bytes transferred is equal to + * the sum of the buffer sizes. + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * read_some function. + * + * @param s The stream from which the data is to be read. The type must support + * the SyncReadStream concept. + * + * @param buffers One or more buffers into which the data will be read. The sum + * of the buffer sizes indicates the maximum number of bytes to read from the + * stream. + * + * @returns The number of bytes transferred. + * + * @throws asio::system_error Thrown on failure. + * + * @par Example + * To read into a single data buffer use the @ref buffer function as follows: + * @code asio::read(s, asio::buffer(data, size)); @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. + * + * @note This overload is equivalent to calling: + * @code asio::read( + * s, buffers, + * asio::transfer_all()); @endcode + */ +template <typename SyncReadStream, typename MutableBufferSequence> +std::size_t read(SyncReadStream& s, const MutableBufferSequence& buffers, + typename enable_if< + is_mutable_buffer_sequence<MutableBufferSequence>::value + >::type* = 0); + +/// Attempt to read a certain amount of data from a stream before returning. +/** + * This function is used to read a certain number of bytes of data from a + * stream. The call will block until one of the following conditions is true: + * + * @li The supplied buffers are full. That is, the bytes transferred is equal to + * the sum of the buffer sizes. + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * read_some function. + * + * @param s The stream from which the data is to be read. The type must support + * the SyncReadStream concept. + * + * @param buffers One or more buffers into which the data will be read. The sum + * of the buffer sizes indicates the maximum number of bytes to read from the + * stream. + * + * @param ec Set to indicate what error occurred, if any. + * + * @returns The number of bytes transferred. + * + * @par Example + * To read into a single data buffer use the @ref buffer function as follows: + * @code asio::read(s, asio::buffer(data, size), ec); @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. + * + * @note This overload is equivalent to calling: + * @code asio::read( + * s, buffers, + * asio::transfer_all(), ec); @endcode + */ +template <typename SyncReadStream, typename MutableBufferSequence> +std::size_t read(SyncReadStream& s, const MutableBufferSequence& buffers, + asio::error_code& ec, + typename enable_if< + is_mutable_buffer_sequence<MutableBufferSequence>::value + >::type* = 0); + +/// Attempt to read a certain amount of data from a stream before returning. +/** + * This function is used to read a certain number of bytes of data from a + * stream. The call will block until one of the following conditions is true: + * + * @li The supplied buffers are full. That is, the bytes transferred is equal to + * the sum of the buffer sizes. + * + * @li The completion_condition function object returns 0. + * + * This operation is implemented in terms of zero or more calls to the stream's + * read_some function. + * + * @param s The stream from which the data is to be read. The type must support + * the SyncReadStream concept. + * + * @param buffers One or more buffers into which the data will be read. The sum + * of the buffer sizes indicates the maximum number of bytes to read from the + * stream. + * + * @param completion_condition The function object to be called to determine + * whether the read operation is complete. The signature of the function object + * must be: + * @code std::size_t completion_condition( + * // Result of latest read_some operation. + * const asio::error_code& error, + * + * // Number of bytes transferred so far. + * std::size_t bytes_transferred + * ); @endcode + * A return value of 0 indicates that the read operation is complete. A non-zero + * return value indicates the maximum number of bytes to be read on the next + * call to the stream's read_some function. + * + * @returns The number of bytes transferred. + * + * @throws asio::system_error Thrown on failure. + * + * @par Example + * To read into a single data buffer use the @ref buffer function as follows: + * @code asio::read(s, asio::buffer(data, size), + * asio::transfer_at_least(32)); @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. + */ +template <typename SyncReadStream, typename MutableBufferSequence, + typename CompletionCondition> +std::size_t read(SyncReadStream& s, const MutableBufferSequence& buffers, + CompletionCondition completion_condition, + typename enable_if< + is_mutable_buffer_sequence<MutableBufferSequence>::value + >::type* = 0); + +/// Attempt to read a certain amount of data from a stream before returning. +/** + * This function is used to read a certain number of bytes of data from a + * stream. The call will block until one of the following conditions is true: + * + * @li The supplied buffers are full. That is, the bytes transferred is equal to + * the sum of the buffer sizes. + * + * @li The completion_condition function object returns 0. + * + * This operation is implemented in terms of zero or more calls to the stream's + * read_some function. + * + * @param s The stream from which the data is to be read. The type must support + * the SyncReadStream concept. + * + * @param buffers One or more buffers into which the data will be read. The sum + * of the buffer sizes indicates the maximum number of bytes to read from the + * stream. + * + * @param completion_condition The function object to be called to determine + * whether the read operation is complete. The signature of the function object + * must be: + * @code std::size_t completion_condition( + * // Result of latest read_some operation. + * const asio::error_code& error, + * + * // Number of bytes transferred so far. + * std::size_t bytes_transferred + * ); @endcode + * A return value of 0 indicates that the read operation is complete. A non-zero + * return value indicates the maximum number of bytes to be read on the next + * call to the stream's read_some function. + * + * @param ec Set to indicate what error occurred, if any. + * + * @returns The number of bytes read. If an error occurs, returns the total + * number of bytes successfully transferred prior to the error. + */ +template <typename SyncReadStream, typename MutableBufferSequence, + typename CompletionCondition> +std::size_t read(SyncReadStream& s, const MutableBufferSequence& buffers, + CompletionCondition completion_condition, asio::error_code& ec, + typename enable_if< + is_mutable_buffer_sequence<MutableBufferSequence>::value + >::type* = 0); + +/// Attempt to read a certain amount of data from a stream before returning. +/** + * This function is used to read a certain number of bytes of data from a + * stream. The call will block until one of the following conditions is true: + * + * @li The specified dynamic buffer sequence is full (that is, it has reached + * maximum size). + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * read_some function. + * + * @param s The stream from which the data is to be read. The type must support + * the SyncReadStream concept. + * + * @param buffers The dynamic buffer sequence into which the data will be read. + * + * @returns The number of bytes transferred. + * + * @throws asio::system_error Thrown on failure. + * + * @note This overload is equivalent to calling: + * @code asio::read( + * s, buffers, + * asio::transfer_all()); @endcode + */ +template <typename SyncReadStream, typename DynamicBuffer> +std::size_t read(SyncReadStream& s, + ASIO_MOVE_ARG(DynamicBuffer) buffers, + typename enable_if< + is_dynamic_buffer<typename decay<DynamicBuffer>::type>::value + >::type* = 0); + +/// Attempt to read a certain amount of data from a stream before returning. +/** + * This function is used to read a certain number of bytes of data from a + * stream. The call will block until one of the following conditions is true: + * + * @li The supplied buffer is full (that is, it has reached maximum size). + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * read_some function. + * + * @param s The stream from which the data is to be read. The type must support + * the SyncReadStream concept. + * + * @param buffers The dynamic buffer sequence into which the data will be read. + * + * @param ec Set to indicate what error occurred, if any. + * + * @returns The number of bytes transferred. + * + * @note This overload is equivalent to calling: + * @code asio::read( + * s, buffers, + * asio::transfer_all(), ec); @endcode + */ +template <typename SyncReadStream, typename DynamicBuffer> +std::size_t read(SyncReadStream& s, + ASIO_MOVE_ARG(DynamicBuffer) buffers, + asio::error_code& ec, + typename enable_if< + is_dynamic_buffer<typename decay<DynamicBuffer>::type>::value + >::type* = 0); + +/// Attempt to read a certain amount of data from a stream before returning. +/** + * This function is used to read a certain number of bytes of data from a + * stream. The call will block until one of the following conditions is true: + * + * @li The specified dynamic buffer sequence is full (that is, it has reached + * maximum size). + * + * @li The completion_condition function object returns 0. + * + * This operation is implemented in terms of zero or more calls to the stream's + * read_some function. + * + * @param s The stream from which the data is to be read. The type must support + * the SyncReadStream concept. + * + * @param buffers The dynamic buffer sequence into which the data will be read. + * + * @param completion_condition The function object to be called to determine + * whether the read operation is complete. The signature of the function object + * must be: + * @code std::size_t completion_condition( + * // Result of latest read_some operation. + * const asio::error_code& error, + * + * // Number of bytes transferred so far. + * std::size_t bytes_transferred + * ); @endcode + * A return value of 0 indicates that the read operation is complete. A non-zero + * return value indicates the maximum number of bytes to be read on the next + * call to the stream's read_some function. + * + * @returns The number of bytes transferred. + * + * @throws asio::system_error Thrown on failure. + */ +template <typename SyncReadStream, typename DynamicBuffer, + typename CompletionCondition> +std::size_t read(SyncReadStream& s, + ASIO_MOVE_ARG(DynamicBuffer) buffers, + CompletionCondition completion_condition, + typename enable_if< + is_dynamic_buffer<typename decay<DynamicBuffer>::type>::value + >::type* = 0); + +/// Attempt to read a certain amount of data from a stream before returning. +/** + * This function is used to read a certain number of bytes of data from a + * stream. The call will block until one of the following conditions is true: + * + * @li The specified dynamic buffer sequence is full (that is, it has reached + * maximum size). + * + * @li The completion_condition function object returns 0. + * + * This operation is implemented in terms of zero or more calls to the stream's + * read_some function. + * + * @param s The stream from which the data is to be read. The type must support + * the SyncReadStream concept. + * + * @param buffers The dynamic buffer sequence into which the data will be read. + * + * @param completion_condition The function object to be called to determine + * whether the read operation is complete. The signature of the function object + * must be: + * @code std::size_t completion_condition( + * // Result of latest read_some operation. + * const asio::error_code& error, + * + * // Number of bytes transferred so far. + * std::size_t bytes_transferred + * ); @endcode + * A return value of 0 indicates that the read operation is complete. A non-zero + * return value indicates the maximum number of bytes to be read on the next + * call to the stream's read_some function. + * + * @param ec Set to indicate what error occurred, if any. + * + * @returns The number of bytes read. If an error occurs, returns the total + * number of bytes successfully transferred prior to the error. + */ +template <typename SyncReadStream, typename DynamicBuffer, + typename CompletionCondition> +std::size_t read(SyncReadStream& s, + ASIO_MOVE_ARG(DynamicBuffer) buffers, + CompletionCondition completion_condition, asio::error_code& ec, + typename enable_if< + is_dynamic_buffer<typename decay<DynamicBuffer>::type>::value + >::type* = 0); + +#if !defined(ASIO_NO_EXTENSIONS) +#if !defined(ASIO_NO_IOSTREAM) + +/// Attempt to read a certain amount of data from a stream before returning. +/** + * This function is used to read a certain number of bytes of data from a + * stream. The call will block until one of the following conditions is true: + * + * @li The supplied buffer is full (that is, it has reached maximum size). + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * read_some function. + * + * @param s The stream from which the data is to be read. The type must support + * the SyncReadStream concept. + * + * @param b The basic_streambuf object into which the data will be read. + * + * @returns The number of bytes transferred. + * + * @throws asio::system_error Thrown on failure. + * + * @note This overload is equivalent to calling: + * @code asio::read( + * s, b, + * asio::transfer_all()); @endcode + */ +template <typename SyncReadStream, typename Allocator> +std::size_t read(SyncReadStream& s, basic_streambuf<Allocator>& b); + +/// Attempt to read a certain amount of data from a stream before returning. +/** + * This function is used to read a certain number of bytes of data from a + * stream. The call will block until one of the following conditions is true: + * + * @li The supplied buffer is full (that is, it has reached maximum size). + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * read_some function. + * + * @param s The stream from which the data is to be read. The type must support + * the SyncReadStream concept. + * + * @param b The basic_streambuf object into which the data will be read. + * + * @param ec Set to indicate what error occurred, if any. + * + * @returns The number of bytes transferred. + * + * @note This overload is equivalent to calling: + * @code asio::read( + * s, b, + * asio::transfer_all(), ec); @endcode + */ +template <typename SyncReadStream, typename Allocator> +std::size_t read(SyncReadStream& s, basic_streambuf<Allocator>& b, + asio::error_code& ec); + +/// Attempt to read a certain amount of data from a stream before returning. +/** + * This function is used to read a certain number of bytes of data from a + * stream. The call will block until one of the following conditions is true: + * + * @li The supplied buffer is full (that is, it has reached maximum size). + * + * @li The completion_condition function object returns 0. + * + * This operation is implemented in terms of zero or more calls to the stream's + * read_some function. + * + * @param s The stream from which the data is to be read. The type must support + * the SyncReadStream concept. + * + * @param b The basic_streambuf object into which the data will be read. + * + * @param completion_condition The function object to be called to determine + * whether the read operation is complete. The signature of the function object + * must be: + * @code std::size_t completion_condition( + * // Result of latest read_some operation. + * const asio::error_code& error, + * + * // Number of bytes transferred so far. + * std::size_t bytes_transferred + * ); @endcode + * A return value of 0 indicates that the read operation is complete. A non-zero + * return value indicates the maximum number of bytes to be read on the next + * call to the stream's read_some function. + * + * @returns The number of bytes transferred. + * + * @throws asio::system_error Thrown on failure. + */ +template <typename SyncReadStream, typename Allocator, + typename CompletionCondition> +std::size_t read(SyncReadStream& s, basic_streambuf<Allocator>& b, + CompletionCondition completion_condition); + +/// Attempt to read a certain amount of data from a stream before returning. +/** + * This function is used to read a certain number of bytes of data from a + * stream. The call will block until one of the following conditions is true: + * + * @li The supplied buffer is full (that is, it has reached maximum size). + * + * @li The completion_condition function object returns 0. + * + * This operation is implemented in terms of zero or more calls to the stream's + * read_some function. + * + * @param s The stream from which the data is to be read. The type must support + * the SyncReadStream concept. + * + * @param b The basic_streambuf object into which the data will be read. + * + * @param completion_condition The function object to be called to determine + * whether the read operation is complete. The signature of the function object + * must be: + * @code std::size_t completion_condition( + * // Result of latest read_some operation. + * const asio::error_code& error, + * + * // Number of bytes transferred so far. + * std::size_t bytes_transferred + * ); @endcode + * A return value of 0 indicates that the read operation is complete. A non-zero + * return value indicates the maximum number of bytes to be read on the next + * call to the stream's read_some function. + * + * @param ec Set to indicate what error occurred, if any. + * + * @returns The number of bytes read. If an error occurs, returns the total + * number of bytes successfully transferred prior to the error. + */ +template <typename SyncReadStream, typename Allocator, + typename CompletionCondition> +std::size_t read(SyncReadStream& s, basic_streambuf<Allocator>& b, + CompletionCondition completion_condition, asio::error_code& ec); + +#endif // !defined(ASIO_NO_IOSTREAM) +#endif // !defined(ASIO_NO_EXTENSIONS) + +/*@}*/ +/** + * @defgroup async_read asio::async_read + * + * @brief Start an asynchronous operation to read a certain amount of data from + * a stream. + */ +/*@{*/ + +/// Start an asynchronous operation to read a certain amount of data from a +/// stream. +/** + * This function is used to asynchronously read a certain number of bytes of + * data from a stream. The function call always returns immediately. The + * asynchronous operation will continue until one of the following conditions is + * true: + * + * @li The supplied buffers are full. That is, the bytes transferred is equal to + * the sum of the buffer sizes. + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * async_read_some function, and is known as a <em>composed operation</em>. The + * program must ensure that the stream performs no other read operations (such + * as async_read, the stream's async_read_some function, or any other composed + * operations that perform reads) until this operation completes. + * + * @param s The stream from which the data is to be read. The type must support + * the AsyncReadStream concept. + * + * @param buffers One or more buffers into which the data will be read. The sum + * of the buffer sizes indicates the maximum number of bytes to read from the + * stream. 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 handler is called. + * + * @param handler The handler to be called when the read operation completes. + * Copies will be made of the handler as required. The function signature of the + * handler must be: + * @code void handler( + * const asio::error_code& error, // Result of operation. + * + * std::size_t bytes_transferred // Number of bytes copied into the + * // buffers. If an error occurred, + * // this will be the number of + * // bytes successfully transferred + * // prior to the error. + * ); @endcode + * Regardless of whether the asynchronous operation completes immediately or + * not, the handler will not be invoked from within this function. Invocation of + * the handler will be performed in a manner equivalent to using + * asio::io_context::post(). + * + * @par Example + * To read into a single data buffer use the @ref buffer function as follows: + * @code + * asio::async_read(s, 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. + * + * @note This overload is equivalent to calling: + * @code asio::async_read( + * s, buffers, + * asio::transfer_all(), + * handler); @endcode + */ +template <typename AsyncReadStream, typename MutableBufferSequence, + typename ReadHandler> +ASIO_INITFN_RESULT_TYPE(ReadHandler, + void (asio::error_code, std::size_t)) +async_read(AsyncReadStream& s, const MutableBufferSequence& buffers, + ASIO_MOVE_ARG(ReadHandler) handler, + typename enable_if< + is_mutable_buffer_sequence<MutableBufferSequence>::value + >::type* = 0); + +/// Start an asynchronous operation to read a certain amount of data from a +/// stream. +/** + * This function is used to asynchronously read a certain number of bytes of + * data from a stream. The function call always returns immediately. The + * asynchronous operation will continue until one of the following conditions is + * true: + * + * @li The supplied buffers are full. That is, the bytes transferred is equal to + * the sum of the buffer sizes. + * + * @li The completion_condition function object returns 0. + * + * @param s The stream from which the data is to be read. The type must support + * the AsyncReadStream concept. + * + * @param buffers One or more buffers into which the data will be read. The sum + * of the buffer sizes indicates the maximum number of bytes to read from the + * stream. 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 handler is called. + * + * @param completion_condition The function object to be called to determine + * whether the read operation is complete. The signature of the function object + * must be: + * @code std::size_t completion_condition( + * // Result of latest async_read_some operation. + * const asio::error_code& error, + * + * // Number of bytes transferred so far. + * std::size_t bytes_transferred + * ); @endcode + * A return value of 0 indicates that the read operation is complete. A non-zero + * return value indicates the maximum number of bytes to be read on the next + * call to the stream's async_read_some function. + * + * @param handler The handler to be called when the read operation completes. + * Copies will be made of the handler as required. The function signature of the + * handler must be: + * @code void handler( + * const asio::error_code& error, // Result of operation. + * + * std::size_t bytes_transferred // Number of bytes copied into the + * // buffers. If an error occurred, + * // this will be the number of + * // bytes successfully transferred + * // prior to the error. + * ); @endcode + * Regardless of whether the asynchronous operation completes immediately or + * not, the handler will not be invoked from within this function. Invocation of + * the handler will be performed in a manner equivalent to using + * asio::io_context::post(). + * + * @par Example + * To read into a single data buffer use the @ref buffer function as follows: + * @code asio::async_read(s, + * asio::buffer(data, size), + * asio::transfer_at_least(32), + * 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. + */ +template <typename AsyncReadStream, typename MutableBufferSequence, + typename CompletionCondition, typename ReadHandler> +ASIO_INITFN_RESULT_TYPE(ReadHandler, + void (asio::error_code, std::size_t)) +async_read(AsyncReadStream& s, const MutableBufferSequence& buffers, + CompletionCondition completion_condition, + ASIO_MOVE_ARG(ReadHandler) handler, + typename enable_if< + is_mutable_buffer_sequence<MutableBufferSequence>::value + >::type* = 0); + +/// Start an asynchronous operation to read a certain amount of data from a +/// stream. +/** + * This function is used to asynchronously read a certain number of bytes of + * data from a stream. The function call always returns immediately. The + * asynchronous operation will continue until one of the following conditions is + * true: + * + * @li The specified dynamic buffer sequence is full (that is, it has reached + * maximum size). + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * async_read_some function, and is known as a <em>composed operation</em>. The + * program must ensure that the stream performs no other read operations (such + * as async_read, the stream's async_read_some function, or any other composed + * operations that perform reads) until this operation completes. + * + * @param s The stream from which the data is to be read. The type must support + * the AsyncReadStream concept. + * + * @param buffers The dynamic buffer sequence 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 handler is called. + * + * @param handler The handler to be called when the read operation completes. + * Copies will be made of the handler as required. The function signature of the + * handler must be: + * @code void handler( + * const asio::error_code& error, // Result of operation. + * + * std::size_t bytes_transferred // Number of bytes copied into the + * // buffers. If an error occurred, + * // this will be the number of + * // bytes successfully transferred + * // prior to the error. + * ); @endcode + * Regardless of whether the asynchronous operation completes immediately or + * not, the handler will not be invoked from within this function. Invocation of + * the handler will be performed in a manner equivalent to using + * asio::io_context::post(). + * + * @note This overload is equivalent to calling: + * @code asio::async_read( + * s, buffers, + * asio::transfer_all(), + * handler); @endcode + */ +template <typename AsyncReadStream, + typename DynamicBuffer, typename ReadHandler> +ASIO_INITFN_RESULT_TYPE(ReadHandler, + void (asio::error_code, std::size_t)) +async_read(AsyncReadStream& s, + ASIO_MOVE_ARG(DynamicBuffer) buffers, + ASIO_MOVE_ARG(ReadHandler) handler, + typename enable_if< + is_dynamic_buffer<typename decay<DynamicBuffer>::type>::value + >::type* = 0); + +/// Start an asynchronous operation to read a certain amount of data from a +/// stream. +/** + * This function is used to asynchronously read a certain number of bytes of + * data from a stream. The function call always returns immediately. The + * asynchronous operation will continue until one of the following conditions is + * true: + * + * @li The specified dynamic buffer sequence is full (that is, it has reached + * maximum size). + * + * @li The completion_condition function object returns 0. + * + * This operation is implemented in terms of zero or more calls to the stream's + * async_read_some function, and is known as a <em>composed operation</em>. The + * program must ensure that the stream performs no other read operations (such + * as async_read, the stream's async_read_some function, or any other composed + * operations that perform reads) until this operation completes. + * + * @param s The stream from which the data is to be read. The type must support + * the AsyncReadStream concept. + * + * @param buffers The dynamic buffer sequence 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 handler is called. + * + * @param completion_condition The function object to be called to determine + * whether the read operation is complete. The signature of the function object + * must be: + * @code std::size_t completion_condition( + * // Result of latest async_read_some operation. + * const asio::error_code& error, + * + * // Number of bytes transferred so far. + * std::size_t bytes_transferred + * ); @endcode + * A return value of 0 indicates that the read operation is complete. A non-zero + * return value indicates the maximum number of bytes to be read on the next + * call to the stream's async_read_some function. + * + * @param handler The handler to be called when the read operation completes. + * Copies will be made of the handler as required. The function signature of the + * handler must be: + * @code void handler( + * const asio::error_code& error, // Result of operation. + * + * std::size_t bytes_transferred // Number of bytes copied into the + * // buffers. If an error occurred, + * // this will be the number of + * // bytes successfully transferred + * // prior to the error. + * ); @endcode + * Regardless of whether the asynchronous operation completes immediately or + * not, the handler will not be invoked from within this function. Invocation of + * the handler will be performed in a manner equivalent to using + * asio::io_context::post(). + */ +template <typename AsyncReadStream, typename DynamicBuffer, + typename CompletionCondition, typename ReadHandler> +ASIO_INITFN_RESULT_TYPE(ReadHandler, + void (asio::error_code, std::size_t)) +async_read(AsyncReadStream& s, + ASIO_MOVE_ARG(DynamicBuffer) buffers, + CompletionCondition completion_condition, + ASIO_MOVE_ARG(ReadHandler) handler, + typename enable_if< + is_dynamic_buffer<typename decay<DynamicBuffer>::type>::value + >::type* = 0); + +#if !defined(ASIO_NO_EXTENSIONS) +#if !defined(ASIO_NO_IOSTREAM) + +/// Start an asynchronous operation to read a certain amount of data from a +/// stream. +/** + * This function is used to asynchronously read a certain number of bytes of + * data from a stream. The function call always returns immediately. The + * asynchronous operation will continue until one of the following conditions is + * true: + * + * @li The supplied buffer is full (that is, it has reached maximum size). + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * async_read_some function, and is known as a <em>composed operation</em>. The + * program must ensure that the stream performs no other read operations (such + * as async_read, the stream's async_read_some function, or any other composed + * operations that perform reads) until this operation completes. + * + * @param s The stream from which the data is to be read. The type must support + * the AsyncReadStream concept. + * + * @param b A basic_streambuf object into which the data will be read. Ownership + * of the streambuf is retained by the caller, which must guarantee that it + * remains valid until the handler is called. + * + * @param handler The handler to be called when the read operation completes. + * Copies will be made of the handler as required. The function signature of the + * handler must be: + * @code void handler( + * const asio::error_code& error, // Result of operation. + * + * std::size_t bytes_transferred // Number of bytes copied into the + * // buffers. If an error occurred, + * // this will be the number of + * // bytes successfully transferred + * // prior to the error. + * ); @endcode + * Regardless of whether the asynchronous operation completes immediately or + * not, the handler will not be invoked from within this function. Invocation of + * the handler will be performed in a manner equivalent to using + * asio::io_context::post(). + * + * @note This overload is equivalent to calling: + * @code asio::async_read( + * s, b, + * asio::transfer_all(), + * handler); @endcode + */ +template <typename AsyncReadStream, typename Allocator, typename ReadHandler> +ASIO_INITFN_RESULT_TYPE(ReadHandler, + void (asio::error_code, std::size_t)) +async_read(AsyncReadStream& s, basic_streambuf<Allocator>& b, + ASIO_MOVE_ARG(ReadHandler) handler); + +/// Start an asynchronous operation to read a certain amount of data from a +/// stream. +/** + * This function is used to asynchronously read a certain number of bytes of + * data from a stream. The function call always returns immediately. The + * asynchronous operation will continue until one of the following conditions is + * true: + * + * @li The supplied buffer is full (that is, it has reached maximum size). + * + * @li The completion_condition function object returns 0. + * + * This operation is implemented in terms of zero or more calls to the stream's + * async_read_some function, and is known as a <em>composed operation</em>. The + * program must ensure that the stream performs no other read operations (such + * as async_read, the stream's async_read_some function, or any other composed + * operations that perform reads) until this operation completes. + * + * @param s The stream from which the data is to be read. The type must support + * the AsyncReadStream concept. + * + * @param b A basic_streambuf object into which the data will be read. Ownership + * of the streambuf is retained by the caller, which must guarantee that it + * remains valid until the handler is called. + * + * @param completion_condition The function object to be called to determine + * whether the read operation is complete. The signature of the function object + * must be: + * @code std::size_t completion_condition( + * // Result of latest async_read_some operation. + * const asio::error_code& error, + * + * // Number of bytes transferred so far. + * std::size_t bytes_transferred + * ); @endcode + * A return value of 0 indicates that the read operation is complete. A non-zero + * return value indicates the maximum number of bytes to be read on the next + * call to the stream's async_read_some function. + * + * @param handler The handler to be called when the read operation completes. + * Copies will be made of the handler as required. The function signature of the + * handler must be: + * @code void handler( + * const asio::error_code& error, // Result of operation. + * + * std::size_t bytes_transferred // Number of bytes copied into the + * // buffers. If an error occurred, + * // this will be the number of + * // bytes successfully transferred + * // prior to the error. + * ); @endcode + * Regardless of whether the asynchronous operation completes immediately or + * not, the handler will not be invoked from within this function. Invocation of + * the handler will be performed in a manner equivalent to using + * asio::io_context::post(). + */ +template <typename AsyncReadStream, typename Allocator, + typename CompletionCondition, typename ReadHandler> +ASIO_INITFN_RESULT_TYPE(ReadHandler, + void (asio::error_code, std::size_t)) +async_read(AsyncReadStream& s, basic_streambuf<Allocator>& b, + CompletionCondition completion_condition, + ASIO_MOVE_ARG(ReadHandler) handler); + +#endif // !defined(ASIO_NO_IOSTREAM) +#endif // !defined(ASIO_NO_EXTENSIONS) + +/*@}*/ + +} // namespace asio + +#include "asio/detail/pop_options.hpp" + +#include "asio/impl/read.hpp" + +#endif // ASIO_READ_HPP |