Irmin, a distributed database that follows the same design principles as Git
Module type Irmin . Backend . Watch . S

Watch Helpers

type key

The type for store keys.

type value

The type for store values.

type watch

The type for watch handlers.

type t

The type for watch state.

val stats : t -> int * int

stats t is a tuple (k,a) represeting watch stats. k is the number of single key watchers for the store t and a the number of global watchers for t.

val notify : t -> key -> value option -> unit Lwt.t

Notify all listeners in the given watch state that a key has changed, with the new value associated to this key. None means the key has been removed.

val v : unit -> t

Create a watch state.

val clear : t -> unit Lwt.t

Clear all register listeners in the given watch state.

val watch_key : t -> key -> ?init:value -> ( value Diff.t -> unit Lwt.t ) -> watch Lwt.t

Watch a given key for changes. More efficient than watch.

val watch : t -> ?init:(key * value) list -> ( key -> value Diff.t -> unit Lwt.t ) -> watch Lwt.t

Add a watch handler. To watch a specific key, use watch_key which is more efficient.

val unwatch : t -> watch -> unit Lwt.t

Remove a watch handler.

val listen_dir : t -> string -> key:( string -> key option ) -> value:( key -> value option Lwt.t ) -> ( unit -> unit Lwt.t ) Lwt.t

Register a thread looking for changes in the given directory and return a function to stop watching and free up resources.