irmin-pack 3.5.2 · OCaml Package

Abstraction for a chunked suffix. It is functionally equivalent to Append_only_file but with a chunked implementation that is parameterized by

start_idx for create_rw to know the starting file name, and
start_idx and chunk_num for the open functions to know the starting file name and how many files there are.

module Io = Io

module Errs : Io_errors.S

module Ao : Append_only_file.S

Abstraction for irmin-pack's append only files (i.e. suffix and dict).

type t

type create_error = Io.create_error

type open_error = [

| Io.open_error
| `Closed
| `Invalid_argument
| `Inconsistent_store
| `Read_out_of_bounds

]

type add_new_error = [

| open_error
| Io.close_error
| `Pending_flush
| `File_exists of string
| `Multiple_empty_chunks

]

val create_rw : 
  root:string ->
  start_idx:int ->
  overwrite:bool ->
  auto_flush_threshold:int ->
  auto_flush_procedure:Ao.auto_flush_procedure ->
  (t, [> create_error ]) Stdlib.result

val open_rw : 
  root:string ->
  appendable_chunk_poff:Optint.Int63.t ->
  start_idx:int ->
  chunk_num:int ->
  dead_header_size:int ->
  auto_flush_threshold:int ->
  auto_flush_procedure:Ao.auto_flush_procedure ->
  (t, [> open_error ]) Stdlib.result

val open_ro : 
  root:string ->
  appendable_chunk_poff:Optint.Int63.t ->
  dead_header_size:int ->
  start_idx:int ->
  chunk_num:int ->
  (t, [> open_error ]) Stdlib.result

val add_chunk : 
  auto_flush_threshold:int ->
  auto_flush_procedure:Ao.auto_flush_procedure ->
  t ->
  (unit, [> add_new_error ]) Stdlib.result

val start_idx : t -> int

val chunk_num : t -> int

val close : t -> (unit, [> Io.close_error | `Pending_flush ]) Stdlib.result

val empty_buffer : t -> bool

val flush : t -> (unit, [> Io.write_error ]) Stdlib.result

val fsync : t -> (unit, [> Io.write_error ]) Stdlib.result

val appendable_chunk_poff : t -> Optint.Int63.t

appendable_chunk_poff t is the number of bytes of the chunk file that is currently appendable. It does not perform IO.

RW mode

It also counts the bytes not flushed yet.

RO mode

This information originates from the latest reload of the control file. Calling refresh_appendable_chunk_poff t updates appendable_chunk_poff.

val refresh_appendable_chunk_poff : 
  t ->
  Optint.Int63.t ->
  (unit, [> `Rw_not_allowed ]) Stdlib.result

Ingest the new end offset of the appendable chunk file. Typically happens in RO mode when the control file has been re-read.

RW mode

Always returns Error `Rw_not_allowed.

val end_soff : t -> Optint.Int63.t

end_soff t is the end offset for the chunked suffix. The valid range of offsets is 0 <= off < end_soff. Therefore, end_soff also represents the length of the chunked suffix.

val read_exn : t -> off:Optint.Int63.t -> len:int -> bytes -> unit

val append_exn : t -> string -> unit

val readonly : t -> bool

val auto_flush_threshold : t -> int option

val fold_chunks : 
  (acc:'a ->
    idx:int ->
    start_suffix_off:Optint.Int63.t ->
    end_suffix_off:Optint.Int63.t ->
    is_appendable:bool ->
    'a) ->
  'a ->
  t ->
  'a

package irmin-pack