Module Lib_databox.Store_client.TS

A timeseries store implementation which fulfills TS_SIG

type t

val create : endpoint:string ‑> Utils.databox_ctx ‑> ?⁠logging:bool ‑> unit ‑> t

create store_uri ctx ?logging () creates a timeseries store instance. store_uri could be read from Utils.store_endpoint, ctx could be returned from Utils.databox_init, logging defaults to false.

val register_datasource : t ‑> meta:Store_datasource.meta ‑> unit Lwt.t

See KV_SIG.register_datasource.

val get_datasource_catalogue : t ‑> string Lwt.t

See KV_SIG.get_datasource_catalogue.

Store data functions

val write : t ‑> datasource_id:string ‑> payload:Ezjsonm.t ‑> unit Lwt.t

val write_at : t ‑> datasource_id:string ‑> ts:int64 ‑> payload:Ezjsonm.t ‑> unit Lwt.t

Load data functions

All data loaded will be attached with a timestamp, for example:

{ timestamp: 1516633601325,
  data: [
    {temperature: 10.7, long:-0.127758, lat:51.507351, loc: "London" },
    {temperature: -4.1, long:116.407396 lat:39.904200, loc: "Beijing"},
    {temperature: 5.6, long:-122.332071 lat:47.606209, loc: "Seattle"},
  ]
}

Data from data field above is whatever data written into the store by the write functions. For functions last_n, first_n, since, range, the returned result will be an array of elements of such format.

val latest : t ‑> datasource_id:string ‑> Ezjsonm.t Lwt.t

val earliest : t ‑> datasource_id:string ‑> Ezjsonm.t Lwt.t

val last_n : t ‑> datasource_id:string ‑> int ‑> Ezjsonm.t Lwt.t

val first_n : t ‑> datasource_id:string ‑> int ‑> Ezjsonm.t Lwt.t

val since : t ‑> datasource_id:string ‑> since_ts:int64 ‑> Ezjsonm.t Lwt.t

val range : t ‑> datasource_id:string ‑> from_ts:int64 ‑> to_ts:int64 ‑> Ezjsonm.t Lwt.t

range t ~datasource_id ~from_ts ~to_ts, the from_ts and to_ts are both inclusive when the store loads the data

val observe : t ‑> datasource_id:string ‑> ?⁠timeout:int ‑> unit ‑> Ezjsonm.t Lwt_stream.t Lwt.t

observe t ~datasource_id ?timeout () returns a stream from which each new value written to datasource_id could be feteched.

timeout defaults to 0, which means observing until TS_SIG.stop_observing is called, unit is seconds.

val stop_observing : t ‑> datasource_id:string ‑> unit Lwt.t