| CARVIEW |
GitHubIrmin is an OCaml library for building mergeable, branchable distributed data stores.
Built-In Snapshotting
Backup and restore your data at any point in time.
Storage Agnostic
You can use Irmin on top of your own storage layer.
Custom Datatypes
Automatic (de)serialisation for custom data types.
Highly Portable
Runs anywhere from Linux to web browsers and Xen unikernels.
Git Compatibility
Bidirectional compatibility with the Git on-disk format. Irmin state can be inspected and modified using the Git command-line tool.
Dynamic Behaviour
Allows users to define custom merge functions and create event-driven workflows using a notification mechanism.
Installation
To install Irmin, the command-line tool, and all optional dependencies using opam:
$ opam install irmin-cliA minimal installation, with only the in-memory storage backend can be installed by running:
$ opam install irminThe following packages have been made available on opam:
irmin- the base package, including an in-memory storage implementationirmin-chunk- chunked storageirmin-fs- filesystem-based storageirmin-git- Git compatible storageirmin-pack- pack-file based storageirmin-http- a simple REST interfaceirmin-graphql- a GraphQL serverirmin-mirage- MirageOS compatibilityirmin-cli- command-line toollibirmin- C bindings to the Irmin API
For more information about an individual package consult the online documentation.
Examples
Below is a simple example of setting a key and getting the value out of a Git-based, filesystem-backed store.
open Lwt.Syntax
(* Irmin store with string contents *)
module Store = Irmin_git_unix.FS.KV(Irmin.Contents.String)
(* Database configuration *)
let config = Irmin_git.config ~bare:true "/tmp/irmin/test"
(* Commit author *)
let author = "Example "
(* Commit information *)
let info fmt = Irmin_git_unix.info ~author fmt
let main =
(* Open the repo *)
let* repo = Store.Repo.v config in
(* Load the main branch *)
let* t = Store.main repo in
(* Set key "foo/bar" to "testing 123" *)
let* () = Store.set_exn t ~info:(info "Updating foo/bar") ["foo"; "bar"] "testing 123" in
(* Get key "foo/bar" and print it to stdout *)
let+ x = Store.get t ["foo"; "bar"] in
Printf.printf "foo/bar => '%s'\n" x
(* Run the program *)
let () = Lwt_main.run main
The example is contained in examples/readme.ml. It can be compiled and executed with Dune:
$ dune build examples/readme.exe
$ dune exec examples/readme.exe
foo/bar => 'testing 123'The examples directory contains more advanced examples, which can be executed in the same way.
Command-Line
The same thing can also be accomplished using Irmin, the command-line application installed with irmin-cli, by running:
$ echo "root: ." > irmin.yml
$ irmin init
$ irmin set foo/bar "testing 123"
$ irmin get foo/bartesting 123irmin.yml allows for Irmin flags to be set on a per-directory basis. You can also set flags globally using $HOME/.irmin/config.yml.
Run irmin help irmin.yml for further details.
Explore Further
Tutorial
Issues
LicenseIrmin is part of the MirageOS project and is supported by Tarides, Robur and OCaml Labs.