package datakit-server
Library
Module
Module type
Parameter
Class
Class type
The type for flows. A flow represents the state of a single stream that is connected to an endpoint.
val error_message : error -> string
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.