package irmin-pack

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Irmin backend which stores values in a pack file

Install 

dune-project
 Dependency

github.com Readme Changelog ISC License Edit opam file Versions (9)

Authors

  1. T
    Thomas Gazagnaire

Maintainers

  1. T
    thomas@gazagnaire.org

Sources

irmin-3.11.0.tbz
sha256=09996fbcc2c43e117a9bd8e9028c635e81cccb264d5e02d425ab8b06bbacdbdb
sha512=0391a6bf7b94a1edd50a3a8df9e58961739fa78d7d689d61f56bc87144483bad2ee539df595c33d9d52c29b3458da5dddf3a73b5eb85e49c4667c26d2cd46be1

doc/irmin-pack.unix/Irmin_pack_unix/Dispatcher/Make/argument-1-Fm/Suffix/index.html

Module Fm.Suffix

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

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

type t
type create_error = Io.create_error
type open_error = [
  1. | Io.open_error
  2. | `Closed
  3. | `Invalid_argument
  4. | `Inconsistent_store
  5. | `Read_out_of_bounds
]
type add_new_error = [
  1. | open_error
  2. | Io.close_error
  3. | `Pending_flush
  4. | `File_exists of string
  5. | `Multiple_empty_chunks
]
val create_rw : root:string -> start_idx:int -> overwrite:bool -> (t, [> create_error ]) result
val open_rw : root:string -> appendable_chunk_poff:Optint.Int63.t -> start_idx:int -> chunk_num:int -> dead_header_size:int -> (t, [> open_error ]) 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 ]) result
val add_chunk : t -> (unit, [> add_new_error ]) result
val start_idx : t -> int
val chunk_num : t -> int
val close : t -> (unit, [> Io.close_error | `Pending_flush ]) result
val empty_buffer : t -> bool
val flush : t -> (unit, [> Io.write_error ]) result
val fsync : t -> (unit, [> Io.write_error ]) 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 ]) 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 read_range_exn : t -> off:Optint.Int63.t -> min_len:int -> max_len:int -> bytes -> int
val append_exn : t -> string -> unit
val readonly : t -> bool
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