Persistent, embedded key-value store in pure OCaml. Work in progress.
You can add a pin to the either the main branch or one of the releases. I plan to add Caliburn to the OPAM registry once the library is somewhat stable.
$ opam pin caliburn https://github.com/syedtaz/caliburn.git#main
Let's say we want to store a mapping between integers and strings. So we need a module that represents the type of the key-value pairs we will parameterize the database over which we will pass into the Make functor. This gives us a module for handling id -> name "databases".
open Caliburn
module Id_db = DB.Make (struct
type key = int [@@deriving bin_io, compare]
type value = string [@@deriving bin_io, compare]
end)This module can we used to interact with any int-string database. So let's create one! After that, you can insert, delete or get key-values at your discretion. You need to remember to close the DB connection once you're done -- otherwise the file handlers won't be cleaned up.
let%expect_test _ =
let db = Id_db.open_db "some/database" in
[%defer Id_db.close db];
let open Result.Let_syntax in
let _ =
let%bind _ = Int_DB.insert db ~key:1912 ~value:"Titanic sinks!" in
let%bind res = Int_DB.get db 1912 in
match res with
| Some v -> return (Format.printf "we found the value : %s" v)
| None -> return (Format.print_string "we couldn't find a value?")
in
();
[%expect {| we found the value : Titanic sinks! |}]