Make (observe-fs.Observe

Parameters

module IO : IO.S

Signature

type error =

| Invalid_directory
| Invalid_capacity of int
| Io of IO.error
| Zero_progress
| Invalid_write_count of int
| Unexpected of exn

type t

type delivery_facts =

| No_problem
| Rejected
| Delivery_lost
| Rejected_and_lost

val create : 
  dir:string ->
  ?capacity:int ->
  unit ->
  (t, error) Stdlib.result IO.t

Prepare the directory and start one bounded background writer.

val drain : t -> Observe.Drain.t

The synchronous ownership-transfer boundary for application config. Full and closed writers reject before projection. Projections in progress reserve queue capacity until they commit or fail.

val delivery_facts : t -> delivery_facts

Return finite cumulative facts about rejected offers and accepted records later discarded by terminal delivery failure. This is observation of the writer's owned delivery state, not a persistence or durability claim.

val flush : t -> (unit, error) Stdlib.result IO.t

Flush every record accepted before the call.

val shutdown : t -> (unit, error) Stdlib.result IO.t

Stop acceptance, drain accepted records, flush, close, and stop.

val pp_error : Stdlib.Format.formatter -> error -> unit