asio::async_write_at

Start an asynchronous operation to write a certain amount of data at the specified offset. More...

Functions
template<typename AsyncRandomAccessWriteDevice , typename ConstBufferSequence , typename WriteHandler >
void	asio::async_write_at (AsyncRandomAccessWriteDevice &d, boost::uint64_t offset, const ConstBufferSequence &buffers, WriteHandler handler)
template<typename AsyncRandomAccessWriteDevice , typename ConstBufferSequence , typename CompletionCondition , typename WriteHandler >
void	asio::async_write_at (AsyncRandomAccessWriteDevice &d, boost::uint64_t offset, const ConstBufferSequence &buffers, CompletionCondition completion_condition, WriteHandler handler)
template<typename AsyncRandomAccessWriteDevice , typename Allocator , typename WriteHandler >
void	asio::async_write_at (AsyncRandomAccessWriteDevice &d, boost::uint64_t offset, basic_streambuf< Allocator > &b, WriteHandler handler)
template<typename AsyncRandomAccessWriteDevice , typename Allocator , typename CompletionCondition , typename WriteHandler >
void	asio::async_write_at (AsyncRandomAccessWriteDevice &d, boost::uint64_t offset, basic_streambuf< Allocator > &b, CompletionCondition completion_condition, WriteHandler handler)

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Detailed Description

Start an asynchronous operation to write a certain amount of data at the specified offset.

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Function Documentation

template<typename AsyncRandomAccessWriteDevice , typename ConstBufferSequence , typename WriteHandler >

void asio::async_write_at	(	AsyncRandomAccessWriteDevice &	d,
		boost::uint64_t	offset,
		const ConstBufferSequence &	buffers,
		WriteHandler	handler
	)

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:

• 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.

• An error occurred.

This operation is implemented in terms of one or more calls to the device's async_write_some_at function.

Parameters:

d	The device to which the data is to be written. The type must support the AsyncRandomAccessWriteDevice concept.
offset	The offset at which the data will be written.
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.
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: void handler( // Result of operation. const asio::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 ); 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_service::post().

Example

To write a single data buffer use the asio::buffer function as follows:

 asio::async_write_at(d, 42, asio::buffer(data, size), handler);

See the asio::buffer documentation for information on writing multiple buffers in one go, and how to use it with arrays, boost::array or std::vector.

template<typename AsyncRandomAccessWriteDevice , typename ConstBufferSequence , typename CompletionCondition , typename WriteHandler >

void asio::async_write_at	(	AsyncRandomAccessWriteDevice &	d,
		boost::uint64_t	offset,
		const ConstBufferSequence &	buffers,
		CompletionCondition	completion_condition,
		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:

• 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.

• The completion_condition function object returns true.

This operation is implemented in terms of one or more calls to the device's async_write_some_at function.

Parameters:

d	The device to which the data is to be written. The type must support the AsyncRandomAccessWriteDevice concept.
offset	The offset at which the data will be written.
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.
completion_condition	The function object to be called to determine whether the write operation is complete. The signature of the function object must be: bool completion_condition( // Result of latest write_some_at operation. const asio::error_code& error, // Number of bytes transferred so far. std::size_t bytes_transferred ); A return value of true indicates that the write operation is complete. False indicates that further calls to the device's async_write_some_at function are required.
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: void handler( // Result of operation. const asio::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 ); 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_service::post().

Example

To write a single data buffer use the asio::buffer function as follows:

 asio::async_write_at(d, 42,
     asio::buffer(data, size),
     asio::transfer_at_least(32),
     handler); 

See the asio::buffer documentation for information on writing multiple buffers in one go, and how to use it with arrays, boost::array or std::vector.

template<typename AsyncRandomAccessWriteDevice , typename Allocator , typename WriteHandler >

void asio::async_write_at	(	AsyncRandomAccessWriteDevice &	d,
		boost::uint64_t	offset,
		basic_streambuf< Allocator > &	b,
		WriteHandler	handler
	)

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:

• All of the data in the supplied basic_streambuf has been written.

• An error occurred.

This operation is implemented in terms of one or more calls to the device's async_write_some_at function.

Parameters:

d	The device to which the data is to be written. The type must support the AsyncRandomAccessWriteDevice concept.
offset	The offset at which the data will be written.
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.
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: void handler( // Result of operation. const asio::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 ); 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_service::post().

template<typename AsyncRandomAccessWriteDevice , typename Allocator , typename CompletionCondition , typename WriteHandler >

void asio::async_write_at	(	AsyncRandomAccessWriteDevice &	d,
		boost::uint64_t	offset,
		basic_streambuf< Allocator > &	b,
		CompletionCondition	completion_condition,
		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:

• All of the data in the supplied basic_streambuf has been written.

• The completion_condition function object returns true.

This operation is implemented in terms of one or more calls to the device's async_write_some_at function.

Parameters:

d	The device to which the data is to be written. The type must support the AsyncRandomAccessWriteDevice concept.
offset	The offset at which the data will be written.
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.
completion_condition	The function object to be called to determine whether the write operation is complete. The signature of the function object must be: bool completion_condition( // Result of latest async_write_some_at operation. const asio::error_code& error, // Number of bytes transferred so far. std::size_t bytes_transferred ); A return value of true indicates that the write operation is complete. False indicates that further calls to the device's async_write_some_at function are required.
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: void handler( // Result of operation. const asio::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 ); 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_service::post().