happy-eyeballs-lwt 1.0.0 · OCaml Package

type t

The type of the abstract state of happy eyeballs.

type getaddrinfo =
  [ `A | `AAAA ] ->
  [ `host ] Domain_name.t ->
  (Ipaddr.Set.t, [ `Msg of string ]) result Lwt.t

val create : 
  ?happy_eyeballs:Happy_eyeballs.t ->
  ?getaddrinfo:getaddrinfo ->
  ?timer_interval:int64 ->
  unit ->
  t

create ~happy_eyeballs ~getaddrinfo ~timer_interval () creates an initial state of happy eyeballs with the specified timeouts in nanoseconds - the default for timer_interval is Duration.of_ms 10.

val connect_host : 
  t ->
  [ `host ] Domain_name.t ->
  int list ->
  ((Ipaddr.t * int) * Lwt_unix.file_descr, [ `Msg of string ]) result Lwt.t

connect_host t host ports establishes a connection to host on ports (tried in sequence).

raises Failure
if ports is empty.

val connect_ip : 
  t ->
  (Ipaddr.t * int) list ->
  ((Ipaddr.t * int) * Lwt_unix.file_descr, [ `Msg of string ]) result Lwt.t

connect_ip t addresses establishes a connection to addresses.

raises Failure
if addresses is the empty list.

val connect : 
  t ->
  string ->
  int list ->
  ((Ipaddr.t * int) * Lwt_unix.file_descr, [ `Msg of string ]) result Lwt.t

connect t host ports establishes a connection to host on ports, which may be a host name, or an IP address.

raises Failure
if ports is the empty list.

val inject : t -> getaddrinfo -> unit

inject t getaddrinfo injects a new domain-name resolver into the given happy-eyeballs instance. By default, the happy-eyeballs instance use Lwt_unix.getaddrinfo to be able to resolve domain-name. However, the user can choose to use its own implementation of a DNS resolver (like ocaml-dns).

So, the ceremony for using happy-eyeballs with your own DNS resolver is to create a happy-eyeballs instance, obtain an instance that can resolve domain names (such as ocaml-dns) and inject the latter's implementation into our first happy-eyeballs instance:

let _ =
  let dns = Dns_client_lwt.create () in
  let happy_eyeballs = Dns_client_lwt.create_happy_eyeballs dns in
  Happy_eyeballs_lwt.connect happy_eyeballs "robur.coop" [ 443 ]
  >>= function
  | Ok (_, fd) -> ...
  | Error _ -> ...

package happy-eyeballs-lwt