package mirage-flow-lwt
Library
Module
Module type
Parameter
Class
Class type
include Mirage_flow.S with type 'a io = 'a Lwt.t with type buffer = Cstruct.t
type 'a io = 'a Lwt.t
The type for potentially blocking I/O operations.
The type for write errors.
val pp_write_error : write_error Fmt.t
pp_write_error
is the pretty-printer for write errors.
type buffer = Cstruct.t
The type for memory buffer.
The type for flows. A flow represents the state of a single reliable stream that is connected to an endpoint.
val read : flow -> (buffer Mirage_flow.or_eof, error) Pervasives.result io
read flow
blocks until some data is available and returns a fresh buffer containing it.
The returned buffer will be of a size convenient to the flow implementation, but will always have at least 1 byte.
If the remote endpoint calls close
then calls to read
will keep returning data until all the in-flight data has been read. read flow
will return `Eof
when the remote endpoint has called close
and when there is no more in-flight data.
val write : flow -> buffer -> (unit, write_error) Pervasives.result io
write flow buffer
writes a buffer to the flow. 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, Error `Closed
indicates that the connection is now closed and therefore the data could not be written. Other errors are possible.
val writev : flow -> buffer list -> (unit, write_error) Pervasives.result io
writev flow buffers
writes a sequence of buffers to the flow. There is no indication when the buffers have actually been read and, therefore, they must not be reused. The result Ok ()
indicates success, Error `Closed
indicates that the connection is now closed and therefore the data could not be written. Other errors are possible.
close flow
flushes all pending writes and signals 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 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)
.
close flow
waits until the remote endpoint has also called close
before returning. At this point no data can flow in either direction and resources associated with the flow can be freed.
Close the write
direction of the flow, flushing any buffered data and causing future calls to read
by the peer to return `Eof
.