package dns-forward

The type for potentially blocking I/O operation

The type for memory buffer.

The type for flows. A flow represents the state of a single stream that is connected to an endpoint.

The type for errors.

Convert an error to a human-readable message, suitable for logging.

read flow will block until it either successfully reads a segment of data from the current flow, receives an Eof signifying that the connection is now closed, or an Error.

write flow buffer will block until buffer has been added to the send queue. There is no indication when the buffer has actually been read and, therefore, it must not be reused. The contents may be transmitted in separate packets, depending on the underlying transport. The result `Ok () indicates success, `Eof indicates that the connection is now closed and `Error indicates some other error.

writev flow buffers will block until the buffers have all been added to the send queue. There is no indication when the buffers have actually been read and, therefore, they must not be reused. The result `Ok () indicates success, `Eof indicates that the connection is now closed and `Error indicates some other error.

close flow will flush all pending writes and signal the remote endpoint that there will be no future writes. Once the remote endpoint has read all pending data, it is expected that calls to read on the remote will return `Eof.

Note it is still possible for the remote endpoint to write to the flow and for the local endpoint to call read. This state where the local endpoint has called close but the remote endpoint has not called close is similar to that of a half-closed TCP connection or a Unix socket after shutdown(SHUTDOWN_WRITE).

The result unit io will become determined when the remote endpoint finishes calling write and calls close. At this point no data can flow in either direction and resources associated with the flow can be freed.