[ANN] dokeysto: a simple key-value store in ocaml

UnixJunkie · June 20, 2018, 1:43am

Hello,

Dokeysto provides a persistent hash table of string keys to string values.
Optionally, if you use the right module (like Dokeysto.Db.RWZ), values will be compressed
using LZ4 before being written to disk.

The interface is here:

github.com

UnixJunkie/dokeysto/blob/master/src/db.mli


type filename = string

(** {4 Read-only persistent string key to string value hash table} *)

module RO: sig

  type t

  (** [open_existing fn] open in read-only mode the persistent
      hashtbl whose data are stored in file [fn] and whose
      index is stored in [fn ^ ".idx"]. *)
  val open_existing: filename -> t

  (** [close db] close the previously opened [db]. *)
  val close: t -> unit

  (** [mem db k] check if [k] is bound in [db]. *)
  val mem: t -> string -> bool

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An example/test is here:

github.com

UnixJunkie/dokeysto/blob/master/src/test.ml

open Printf

module Rwdb = Dokeysto.Db.RW
module Rwdbz = Dokeysto.Db.RWZ
module Rodb = Dokeysto.Db.RO
module Rodbz = Dokeysto.Db.ROZ

let n = 1_000_000

(* RWDB *)
let test_rwdb () =
  let start = Unix.gettimeofday () in
  let rw = Rwdb.create "rwdb" in
  for i = 1 to n do
    let s = string_of_int i in
    Rwdb.add rw s s
  done;
  let stop = Unix.gettimeofday () in
  printf "RW records creation rate: %.2f/s\n%!" (float n /. (stop -. start));
  Rwdb.sync rw;

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Regards,
F.

UnixJunkie · June 20, 2018, 1:45am

To install it:

opam update && opam install dokeysto

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[ANN] dokeysto: a simple key-value store in ocaml

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