// // write_at.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 BOOST_ASIO_WRITE_AT_HPP #define BOOST_ASIO_WRITE_AT_HPP #if defined(_MSC_VER) && (_MSC_VER >= 1200) # pragma once #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) #include #include #include #include #include #if !defined(BOOST_ASIO_NO_EXTENSIONS) # include #endif // !defined(BOOST_ASIO_NO_EXTENSIONS) #include namespace lslboost { namespace asio { /** * @defgroup write_at lslboost::asio::write_at * * @brief The @c write_at function is a composed operation that writes a * certain amount of data at a specified offset before returning. */ /*@{*/ /// Write all of the supplied data at the specified offset before returning. /** * This function is used to write a certain number of bytes of data to a random * access device at a specified offset. The call will block until one of the * following conditions is true: * * @li All of the data in the supplied buffers has been written. 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 device's * write_some_at function. * * @param d The device to which the data is to be written. The type must support * the SyncRandomAccessWriteDevice concept. * * @param offset The offset at which the data will be written. * * @param buffers One or more buffers containing the data to be written. The sum * of the buffer sizes indicates the maximum number of bytes to write to the * device. * * @returns The number of bytes transferred. * * @throws lslboost::system::system_error Thrown on failure. * * @par Example * To write a single data buffer use the @ref buffer function as follows: * @code lslboost::asio::write_at(d, 42, lslboost::asio::buffer(data, size)); @endcode * See the @ref buffer documentation for information on writing multiple * buffers in one go, and how to use it with arrays, lslboost::array or * std::vector. * * @note This overload is equivalent to calling: * @code lslboost::asio::write_at( * d, offset, buffers, * lslboost::asio::transfer_all()); @endcode */ template std::size_t write_at(SyncRandomAccessWriteDevice& d, uint64_t offset, const ConstBufferSequence& buffers); /// Write all of the supplied data at the specified offset before returning. /** * This function is used to write a certain number of bytes of data to a random * access device at a specified offset. The call will block until one of the * following conditions is true: * * @li All of the data in the supplied buffers has been written. 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 device's * write_some_at function. * * @param d The device to which the data is to be written. The type must support * the SyncRandomAccessWriteDevice concept. * * @param offset The offset at which the data will be written. * * @param buffers One or more buffers containing the data to be written. The sum * of the buffer sizes indicates the maximum number of bytes to write to the * device. * * @param ec Set to indicate what error occurred, if any. * * @returns The number of bytes transferred. * * @par Example * To write a single data buffer use the @ref buffer function as follows: * @code lslboost::asio::write_at(d, 42, * lslboost::asio::buffer(data, size), ec); @endcode * See the @ref buffer documentation for information on writing multiple * buffers in one go, and how to use it with arrays, lslboost::array or * std::vector. * * @note This overload is equivalent to calling: * @code lslboost::asio::write_at( * d, offset, buffers, * lslboost::asio::transfer_all(), ec); @endcode */ template std::size_t write_at(SyncRandomAccessWriteDevice& d, uint64_t offset, const ConstBufferSequence& buffers, lslboost::system::error_code& ec); /// Write a certain amount of data at a specified offset before returning. /** * This function is used to write a certain number of bytes of data to a random * access device at a specified offset. The call will block until one of the * following conditions is true: * * @li All of the data in the supplied buffers has been written. 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 device's * write_some_at function. * * @param d The device to which the data is to be written. The type must support * the SyncRandomAccessWriteDevice concept. * * @param offset The offset at which the data will be written. * * @param buffers One or more buffers containing the data to be written. The sum * of the buffer sizes indicates the maximum number of bytes to write to the * device. * * @param completion_condition The function object to be called to determine * whether the write operation is complete. The signature of the function object * must be: * @code std::size_t completion_condition( * // Result of latest write_some_at operation. * const lslboost::system::error_code& error, * * // Number of bytes transferred so far. * std::size_t bytes_transferred * ); @endcode * A return value of 0 indicates that the write operation is complete. A * non-zero return value indicates the maximum number of bytes to be written on * the next call to the device's write_some_at function. * * @returns The number of bytes transferred. * * @throws lslboost::system::system_error Thrown on failure. * * @par Example * To write a single data buffer use the @ref buffer function as follows: * @code lslboost::asio::write_at(d, 42, lslboost::asio::buffer(data, size), * lslboost::asio::transfer_at_least(32)); @endcode * See the @ref buffer documentation for information on writing multiple * buffers in one go, and how to use it with arrays, lslboost::array or * std::vector. */ template std::size_t write_at(SyncRandomAccessWriteDevice& d, uint64_t offset, const ConstBufferSequence& buffers, CompletionCondition completion_condition); /// Write a certain amount of data at a specified offset before returning. /** * This function is used to write a certain number of bytes of data to a random * access device at a specified offset. The call will block until one of the * following conditions is true: * * @li All of the data in the supplied buffers has been written. 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 device's * write_some_at function. * * @param d The device to which the data is to be written. The type must support * the SyncRandomAccessWriteDevice concept. * * @param offset The offset at which the data will be written. * * @param buffers One or more buffers containing the data to be written. The sum * of the buffer sizes indicates the maximum number of bytes to write to the * device. * * @param completion_condition The function object to be called to determine * whether the write operation is complete. The signature of the function object * must be: * @code std::size_t completion_condition( * // Result of latest write_some_at operation. * const lslboost::system::error_code& error, * * // Number of bytes transferred so far. * std::size_t bytes_transferred * ); @endcode * A return value of 0 indicates that the write operation is complete. A * non-zero return value indicates the maximum number of bytes to be written on * the next call to the device's write_some_at function. * * @param ec Set to indicate what error occurred, if any. * * @returns The number of bytes written. If an error occurs, returns the total * number of bytes successfully transferred prior to the error. */ template std::size_t write_at(SyncRandomAccessWriteDevice& d, uint64_t offset, const ConstBufferSequence& buffers, CompletionCondition completion_condition, lslboost::system::error_code& ec); #if !defined(BOOST_ASIO_NO_EXTENSIONS) #if !defined(BOOST_ASIO_NO_IOSTREAM) /// Write all of the supplied data at the specified offset before returning. /** * This function is used to write a certain number of bytes of data to a random * access device at a specified offset. The call will block until one of the * following conditions is true: * * @li All of the data in the supplied basic_streambuf has been written. * * @li An error occurred. * * This operation is implemented in terms of zero or more calls to the device's * write_some_at function. * * @param d The device to which the data is to be written. The type must support * the SyncRandomAccessWriteDevice concept. * * @param offset The offset at which the data will be written. * * @param b The basic_streambuf object from which data will be written. * * @returns The number of bytes transferred. * * @throws lslboost::system::system_error Thrown on failure. * * @note This overload is equivalent to calling: * @code lslboost::asio::write_at( * d, 42, b, * lslboost::asio::transfer_all()); @endcode */ template std::size_t write_at(SyncRandomAccessWriteDevice& d, uint64_t offset, basic_streambuf& b); /// Write all of the supplied data at the specified offset before returning. /** * This function is used to write a certain number of bytes of data to a random * access device at a specified offset. The call will block until one of the * following conditions is true: * * @li All of the data in the supplied basic_streambuf has been written. * * @li An error occurred. * * This operation is implemented in terms of zero or more calls to the device's * write_some_at function. * * @param d The device to which the data is to be written. The type must support * the SyncRandomAccessWriteDevice concept. * * @param offset The offset at which the data will be written. * * @param b The basic_streambuf object from which data will be written. * * @param ec Set to indicate what error occurred, if any. * * @returns The number of bytes transferred. * * @note This overload is equivalent to calling: * @code lslboost::asio::write_at( * d, 42, b, * lslboost::asio::transfer_all(), ec); @endcode */ template std::size_t write_at(SyncRandomAccessWriteDevice& d, uint64_t offset, basic_streambuf& b, lslboost::system::error_code& ec); /// Write a certain amount of data at a specified offset before returning. /** * This function is used to write a certain number of bytes of data to a random * access device at a specified offset. The call will block until one of the * following conditions is true: * * @li All of the data in the supplied basic_streambuf has been written. * * @li The completion_condition function object returns 0. * * This operation is implemented in terms of zero or more calls to the device's * write_some_at function. * * @param d The device to which the data is to be written. The type must support * the SyncRandomAccessWriteDevice concept. * * @param offset The offset at which the data will be written. * * @param b The basic_streambuf object from which data will be written. * * @param completion_condition The function object to be called to determine * whether the write operation is complete. The signature of the function object * must be: * @code std::size_t completion_condition( * // Result of latest write_some_at operation. * const lslboost::system::error_code& error, * * // Number of bytes transferred so far. * std::size_t bytes_transferred * ); @endcode * A return value of 0 indicates that the write operation is complete. A * non-zero return value indicates the maximum number of bytes to be written on * the next call to the device's write_some_at function. * * @returns The number of bytes transferred. * * @throws lslboost::system::system_error Thrown on failure. */ template std::size_t write_at(SyncRandomAccessWriteDevice& d, uint64_t offset, basic_streambuf& b, CompletionCondition completion_condition); /// Write a certain amount of data at a specified offset before returning. /** * This function is used to write a certain number of bytes of data to a random * access device at a specified offset. The call will block until one of the * following conditions is true: * * @li All of the data in the supplied basic_streambuf has been written. * * @li The completion_condition function object returns 0. * * This operation is implemented in terms of zero or more calls to the device's * write_some_at function. * * @param d The device to which the data is to be written. The type must support * the SyncRandomAccessWriteDevice concept. * * @param offset The offset at which the data will be written. * * @param b The basic_streambuf object from which data will be written. * * @param completion_condition The function object to be called to determine * whether the write operation is complete. The signature of the function object * must be: * @code std::size_t completion_condition( * // Result of latest write_some_at operation. * const lslboost::system::error_code& error, * * // Number of bytes transferred so far. * std::size_t bytes_transferred * ); @endcode * A return value of 0 indicates that the write operation is complete. A * non-zero return value indicates the maximum number of bytes to be written on * the next call to the device's write_some_at function. * * @param ec Set to indicate what error occurred, if any. * * @returns The number of bytes written. If an error occurs, returns the total * number of bytes successfully transferred prior to the error. */ template std::size_t write_at(SyncRandomAccessWriteDevice& d, uint64_t offset, basic_streambuf& b, CompletionCondition completion_condition, lslboost::system::error_code& ec); #endif // !defined(BOOST_ASIO_NO_IOSTREAM) #endif // !defined(BOOST_ASIO_NO_EXTENSIONS) /*@}*/ /** * @defgroup async_write_at lslboost::asio::async_write_at * * @brief The @c async_write_at function is a composed asynchronous operation * that writes a certain amount of data at the specified offset before * completion. */ /*@{*/ /// Start an asynchronous operation to write all of the supplied data at the /// specified offset. /** * This function is used to asynchronously write a certain number of bytes of * data to a random access device at a specified offset. The function call * always returns immediately. The asynchronous operation will continue until * one of the following conditions is true: * * @li All of the data in the supplied buffers has been written. 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 device's * async_write_some_at function, and is known as a composed operation. * The program must ensure that the device performs no overlapping * write operations (such as async_write_at, the device's async_write_some_at * function, or any other composed operations that perform writes) until this * operation completes. Operations are overlapping if the regions defined by * their offsets, and the numbers of bytes to write, intersect. * * @param d The device to which the data is to be written. The type must support * the AsyncRandomAccessWriteDevice concept. * * @param offset The offset at which the data will be written. * * @param buffers One or more buffers containing the data to be written. * 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 write operation completes. * Copies will be made of the handler as required. The function signature of * the handler must be: * @code void handler( * // Result of operation. * const lslboost::system::error_code& error, * * // Number of bytes written from the buffers. If an error * // occurred, this will be less than the sum of the buffer sizes. * std::size_t bytes_transferred * ); @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 * lslboost::asio::io_context::post(). * * @par Example * To write a single data buffer use the @ref buffer function as follows: * @code * lslboost::asio::async_write_at(d, 42, lslboost::asio::buffer(data, size), handler); * @endcode * See the @ref buffer documentation for information on writing multiple * buffers in one go, and how to use it with arrays, lslboost::array or * std::vector. */ template BOOST_ASIO_INITFN_RESULT_TYPE(WriteHandler, void (lslboost::system::error_code, std::size_t)) async_write_at(AsyncRandomAccessWriteDevice& d, uint64_t offset, const ConstBufferSequence& buffers, BOOST_ASIO_MOVE_ARG(WriteHandler) handler); /// Start an asynchronous operation to write a certain amount of data at the /// specified offset. /** * This function is used to asynchronously write a certain number of bytes of * data to a random access device at a specified offset. The function call * always returns immediately. The asynchronous operation will continue until * one of the following conditions is true: * * @li All of the data in the supplied buffers has been written. 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 device's * async_write_some_at function, and is known as a composed operation. * The program must ensure that the device performs no overlapping * write operations (such as async_write_at, the device's async_write_some_at * function, or any other composed operations that perform writes) until this * operation completes. Operations are overlapping if the regions defined by * their offsets, and the numbers of bytes to write, intersect. * * @param d The device to which the data is to be written. The type must support * the AsyncRandomAccessWriteDevice concept. * * @param offset The offset at which the data will be written. * * @param buffers One or more buffers containing the data to be written. * 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 write operation is complete. The signature of the function object * must be: * @code std::size_t completion_condition( * // Result of latest async_write_some_at operation. * const lslboost::system::error_code& error, * * // Number of bytes transferred so far. * std::size_t bytes_transferred * ); @endcode * A return value of 0 indicates that the write operation is complete. A * non-zero return value indicates the maximum number of bytes to be written on * the next call to the device's async_write_some_at function. * * @param handler The handler to be called when the write operation completes. * Copies will be made of the handler as required. The function signature of the * handler must be: * @code void handler( * // Result of operation. * const lslboost::system::error_code& error, * * // Number of bytes written from the buffers. If an error * // occurred, this will be less than the sum of the buffer sizes. * std::size_t bytes_transferred * ); @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 * lslboost::asio::io_context::post(). * * @par Example * To write a single data buffer use the @ref buffer function as follows: * @code lslboost::asio::async_write_at(d, 42, * lslboost::asio::buffer(data, size), * lslboost::asio::transfer_at_least(32), * handler); @endcode * See the @ref buffer documentation for information on writing multiple * buffers in one go, and how to use it with arrays, lslboost::array or * std::vector. */ template BOOST_ASIO_INITFN_RESULT_TYPE(WriteHandler, void (lslboost::system::error_code, std::size_t)) async_write_at(AsyncRandomAccessWriteDevice& d, uint64_t offset, const ConstBufferSequence& buffers, CompletionCondition completion_condition, BOOST_ASIO_MOVE_ARG(WriteHandler) handler); #if !defined(BOOST_ASIO_NO_EXTENSIONS) #if !defined(BOOST_ASIO_NO_IOSTREAM) /// Start an asynchronous operation to write all of the supplied data at the /// specified offset. /** * This function is used to asynchronously write a certain number of bytes of * data to a random access device at a specified offset. The function call * always returns immediately. The asynchronous operation will continue until * one of the following conditions is true: * * @li All of the data in the supplied basic_streambuf has been written. * * @li An error occurred. * * This operation is implemented in terms of zero or more calls to the device's * async_write_some_at function, and is known as a composed operation. * The program must ensure that the device performs no overlapping * write operations (such as async_write_at, the device's async_write_some_at * function, or any other composed operations that perform writes) until this * operation completes. Operations are overlapping if the regions defined by * their offsets, and the numbers of bytes to write, intersect. * * @param d The device to which the data is to be written. The type must support * the AsyncRandomAccessWriteDevice concept. * * @param offset The offset at which the data will be written. * * @param b A basic_streambuf object from which data will be written. 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 write operation completes. * Copies will be made of the handler as required. The function signature of the * handler must be: * @code void handler( * // Result of operation. * const lslboost::system::error_code& error, * * // Number of bytes written from the buffers. If an error * // occurred, this will be less than the sum of the buffer sizes. * std::size_t bytes_transferred * ); @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 * lslboost::asio::io_context::post(). */ template BOOST_ASIO_INITFN_RESULT_TYPE(WriteHandler, void (lslboost::system::error_code, std::size_t)) async_write_at(AsyncRandomAccessWriteDevice& d, uint64_t offset, basic_streambuf& b, BOOST_ASIO_MOVE_ARG(WriteHandler) handler); /// Start an asynchronous operation to write a certain amount of data at the /// specified offset. /** * This function is used to asynchronously write a certain number of bytes of * data to a random access device at a specified offset. The function call * always returns immediately. The asynchronous operation will continue until * one of the following conditions is true: * * @li All of the data in the supplied basic_streambuf has been written. * * @li The completion_condition function object returns 0. * * This operation is implemented in terms of zero or more calls to the device's * async_write_some_at function, and is known as a composed operation. * The program must ensure that the device performs no overlapping * write operations (such as async_write_at, the device's async_write_some_at * function, or any other composed operations that perform writes) until this * operation completes. Operations are overlapping if the regions defined by * their offsets, and the numbers of bytes to write, intersect. * * @param d The device to which the data is to be written. The type must support * the AsyncRandomAccessWriteDevice concept. * * @param offset The offset at which the data will be written. * * @param b A basic_streambuf object from which data will be written. 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 write operation is complete. The signature of the function object * must be: * @code std::size_t completion_condition( * // Result of latest async_write_some_at operation. * const lslboost::system::error_code& error, * * // Number of bytes transferred so far. * std::size_t bytes_transferred * ); @endcode * A return value of 0 indicates that the write operation is complete. A * non-zero return value indicates the maximum number of bytes to be written on * the next call to the device's async_write_some_at function. * * @param handler The handler to be called when the write operation completes. * Copies will be made of the handler as required. The function signature of the * handler must be: * @code void handler( * // Result of operation. * const lslboost::system::error_code& error, * * // Number of bytes written from the buffers. If an error * // occurred, this will be less than the sum of the buffer sizes. * std::size_t bytes_transferred * ); @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 * lslboost::asio::io_context::post(). */ template BOOST_ASIO_INITFN_RESULT_TYPE(WriteHandler, void (lslboost::system::error_code, std::size_t)) async_write_at(AsyncRandomAccessWriteDevice& d, uint64_t offset, basic_streambuf& b, CompletionCondition completion_condition, BOOST_ASIO_MOVE_ARG(WriteHandler) handler); #endif // !defined(BOOST_ASIO_NO_IOSTREAM) #endif // !defined(BOOST_ASIO_NO_EXTENSIONS) /*@}*/ } // namespace asio } // namespace lslboost #include #include #endif // BOOST_ASIO_WRITE_AT_HPP