websocket-lwt-unix 2.16 · OCaml Package

This module implements a websocket client and server library in the spirit of the otherwise similar TCP functions of the Lwt_io module. The websocket protocol add message framing in addition of simple TCP communication, and this library implement framing and unframing of messages.

include Websocket.S
  with type 'a IO.t := 'a Cohttp_lwt_unix.IO.t
   and type IO.ic := Cohttp_lwt_unix.IO.ic
   and type IO.oc := Cohttp_lwt_unix.IO.oc

module IO : 
  Cohttp.S.IO
    with type 'a t := 'a Cohttp_lwt_unix.IO.t
    with type ic := Cohttp_lwt_unix.IO.ic
    with type oc := Cohttp_lwt_unix.IO.oc

type mode =

| Client of int -> string
| Server

val make_read_frame : 
  ?buf:Buffer.t ->
  mode:mode ->
  Cohttp_lwt_unix.IO.ic ->
  Cohttp_lwt_unix.IO.oc ->
  unit ->
  'a Cohttp_lwt_unix.IO.t

val write_frame_to_buf : mode:mode -> Buffer.t -> Websocket.Frame.t -> unit

module Request : 
  Cohttp.S.Http_io
    with type t = Cohttp.Request.t
     and type 'a IO.t = 'a Cohttp_lwt_unix.IO.t
     and type IO.ic = Cohttp_lwt_unix.IO.ic
     and type IO.oc = Cohttp_lwt_unix.IO.oc

module Response : 
  Cohttp.S.Http_io
    with type t = Cohttp.Response.t
     and type 'a IO.t = 'a Cohttp_lwt_unix.IO.t
     and type IO.ic = Cohttp_lwt_unix.IO.ic
     and type IO.oc = Cohttp_lwt_unix.IO.oc

module Connected_client : sig ... end

type conn

val read : conn -> Websocket.Frame.t Lwt.t

val write : conn -> Websocket.Frame.t -> unit Lwt.t

val close_transport : conn -> unit Lwt.t

close_transport conn closes the underlying transport. You have to manage the connection state (ie. send close frames, etc.) yourself.

val connect : 
  ?extra_headers:Cohttp.Header.t ->
  ?random_string:(int -> string) ->
  ?ctx:Conduit_lwt_unix.ctx ->
  ?buf:Buffer.t ->
  Conduit_lwt_unix.client ->
  Uri.t ->
  conn Lwt.t

val establish_server : 
  ?read_buf:Buffer.t ->
  ?write_buf:Buffer.t ->
  ?timeout:int ->
  ?stop:unit Lwt.t ->
  ?on_exn:(exn -> unit) ->
  ?check_request:(Cohttp.Request.t -> bool) ->
  ?ctx:Conduit_lwt_unix.ctx ->
  mode:Conduit_lwt_unix.server ->
  (Connected_client.t -> unit Lwt.t) ->
  unit Lwt.t

exception_handler defaults to Lwt.async_exception_hook check_request is called before the http upgrade. If it returns false, the websocket connection is aborted with a "403 Forbidden" response. It defaults to check_origin_with_host

Convenience functions

val mk_frame_stream : 
  (unit -> Websocket.Frame.t Lwt.t) ->
  Websocket.Frame.t Lwt_stream.t

mk_frame_stream f is a stream build from f, which role is to receive the frames that will form the stream. When a Close frame is received, the stream will be closed.

val establish_standard_server : 
  ?read_buf:Buffer.t ->
  ?write_buf:Buffer.t ->
  ?timeout:int ->
  ?stop:unit Lwt.t ->
  ?on_exn:(exn -> unit) ->
  ?check_request:(Cohttp.Request.t -> bool) ->
  ?ctx:Conduit_lwt_unix.ctx ->
  mode:Conduit_lwt_unix.server ->
  (Connected_client.t -> unit Lwt.t) ->
  unit Lwt.t

establish_standard_server is like establish_server but with automatic handling of some frames:

A Pong frame is sent in response to a Ping frame,
a Close frame is sent in response to a Close frame.

All frames are then passed to the frame handling function.

package websocket-lwt-unix

Convenience functions