Add a cache system

.gitmodules

@@ -0,0 +1,4 @@
+[submodule "scache"]
+	path = scache
+	url = https://github.com/moyodiallo/scache.git
+	branch = master

Dockerfile

@@ -1,9 +1,11 @@
 FROM ocaml/opam:debian-12-ocaml-5.1 AS build
 RUN sudo apt-get update && sudo apt-get install libev-dev capnproto m4 pkg-config libsqlite3-dev libgmp-dev libzstd-dev -y --no-install-recommends
-RUN cd ~/opam-repository && git fetch -q origin master && git reset --hard b61304c6db353e679a36720d8b914b029d6fbc0c && opam update
+RUN cd ~/opam-repository && git fetch -q origin master && git reset --hard bc52affc41b55ff00c0d3ac9a376538d79695aaf && opam update
 RUN sudo ln -sf /usr/bin/opam-2.1 /usr/bin/opam
+COPY --chown=opam scache/scache.opam /src/scache/
 COPY --chown=opam solver-service.opam solver-service-api.opam /src/
 WORKDIR /src
+RUN opam pin add -yn scache.dev "./scache"
 RUN opam install -y --deps-only .
 ADD --chown=opam . .
 RUN opam exec -- dune build @install

bin/main.ml

@@ -75,24 +75,25 @@ let start_server ~service vat_config =
   let+ vat = Capnp_rpc_unix.serve vat_config ~restore in
   Capnp_rpc_unix.Vat.sturdy_uri vat service_id
 
-let main_service () solver cap_file vat_config =
-  let uri = start_server ~service:(Solver_service.Service.v solver) vat_config in
+let main_service () solver cacheable cap_file vat_config =
+  let uri = start_server ~service:(Solver_service.Service.v ~cacheable solver) vat_config in
   Capnp_rpc_unix.Cap_file.save_uri uri cap_file |> or_die;
   Fmt.pr "Wrote solver service's address to %S@." cap_file;
   Fiber.await_cancel ()
 
-let main_service_pipe () solver =
+let main_service_pipe () solver cacheable =
   let socket = Lwt_unix.stdin in
   (* Run locally reading from socket *)
-  export (Solver_service.Service.v solver) ~on:socket
+  export (Solver_service.Service.v ~cacheable solver) ~on:socket
 
-let main_cluster () solver name capacity register_addr =
+let main_cluster () solver cacheable name capacity register_addr =
   let vat = Capnp_rpc_unix.client_only_vat () in
   let sr = Capnp_rpc_unix.Vat.import_exn vat register_addr in
   let `Cancelled =
     Solver_worker.run solver sr
       ~name
       ~capacity
+      ~cacheable
   in
   ()
 
@@ -128,6 +129,11 @@ let capacity =
   @@ Arg.info ~doc:"The number of cluster jobs that can run in parallel" ~docv:"N"
     [ "capacity" ]
 
+let cacheable =
+  Arg.value
+  @@ Arg.flag
+  @@ Arg.info ~doc:"Activate the cache system" [ "activate-cache"; "cache" ]
+
 let cap_file =
   Arg.required
   @@ Arg.opt Arg.(some string) None
@@ -168,6 +174,7 @@ let () =
         const main_service
         $ setup_log
         $ solver
+        $ cacheable
         $ cap_file
         $ Capnp_rpc_unix.Vat_config.cmd
       )
@@ -179,6 +186,7 @@ let () =
         const main_service_pipe
         $ setup_log
         $ solver
+        $ cacheable
       )
   in
   let run_agent =
@@ -188,6 +196,7 @@ let () =
         const main_cluster
         $ setup_log
         $ solver
+        $ cacheable
         $ worker_name
         $ capacity
         $ register_addr

dune

@@ -1 +1,3 @@
-(dirs :standard \ var cache)
+(dirs :standard \ var)
+
+(vendored_dirs scache)

dune-project

@@ -1,48 +1,97 @@
 (lang dune 3.7)
+
 (name solver-service)
 
-(formatting (enabled_for dune))
+(formatting
+ (enabled_for dune))
+
 (generate_opam_files true)
-(source (github ocurrent/solver-service))
-(authors "Thomas Leonard <[email protected]>" "Patrick Ferris <[email protected]>")
-(maintainers "[email protected]" "Tim McGilchrist <[email protected]>")
+
+(source
+ (github ocurrent/solver-service))
+
+(authors
+ "Thomas Leonard <[email protected]>"
+ "Patrick Ferris <[email protected]>")
+
+(maintainers [email protected] "Tim McGilchrist <[email protected]>")
 
 (package
  (name solver-service)
  (synopsis "Choose package versions to test")
  (depends
-  (ocaml (>= 5.0.0))
-  ; Examples dependencies
-  (current_web (and (>= 0.6.4) :with-test))
-  (current_git (and (>= 0.6.4) :with-test))
-  (current_github (and (>= 0.6.4) :with-test))
-  (current_ocluster (and (>= 0.2.1) :with-test))
-  (ppx_deriving_yojson (>= 3.6.1))
-  (ppx_deriving (>= 5.1))
-  (yojson (>= 2.1.0))
-  (lwt (>= 5.6.1))
-  (eio (>= 0.12))
-  (eio_main (>= 0.12))
-  (lwt_eio (>= 0.5))
-  (logs (>= 0.7.0))
-  (fmt (>= 0.9.0))
-  (ocaml-version (>= 3.6.1))
-  (solver-service-api (= :version))
-  (dune-build-info (>= 3.8.0))
-  (opam-0install (>= 0.4.3))
-  (git-unix (>= 3.12.0))
-  (ocluster-api (>= 0.2.1))
-  (prometheus-app (>= 1.2))
-  (capnp-rpc-net (>= 1.2.3))
-  (capnp-rpc-unix (>= 1.2.3)))
- (conflicts (carton (< 0.4.2))))
+  (opam-file-format
+   (>= 2.1.6))
+  (ocaml
+   (>= 5.0.0))
+  (current_web
+   (and
+    (>= 0.6.4)
+    :with-test))
+  (current_git
+   (and
+    (>= 0.6.4)
+    :with-test))
+  (current_github
+   (and
+    (>= 0.6.4)
+    :with-test))
+  (current_ocluster
+   (and
+    (>= 0.2.1)
+    :with-test))
+  (ppx_deriving_yojson
+   (>= 3.6.1))
+  (ppx_deriving
+   (>= 5.1))
+  (yojson
+   (>= 2.1.0))
+  (lwt
+   (>= 5.6.1))
+  (eio
+   (>= 0.12))
+  (eio_main
+   (>= 0.12))
+  (lwt_eio
+   (>= 0.5))
+  (logs
+   (>= 0.7.0))
+  (fmt
+   (>= 0.9.0))
+  sqlite3
+  (ocaml-version
+   (>= 3.6.1))
+  (solver-service-api
+   (= :version))
+  (dune-build-info
+   (>= 3.8.0))
+  (opam-0install
+   (>= 0.4.3))
+  (git-unix
+   (>= 3.12.0))
+  (ocluster-api
+   (>= 0.2.1))
+  (prometheus-app
+   (>= 1.2))
+  (capnp-rpc-net
+   (>= 1.2.3))
+  (capnp-rpc-unix
+   (>= 1.2.3)))
+ (conflicts
+  (carton
+   (< 0.4.2))))
 
 (package
  (name solver-service-api)
  (synopsis "Cap'n Proto API for the solver service")
  (depends
-  (ocaml (>= 4.14.1))
-  (capnp (>= 3.5.0))
-  (capnp-rpc-lwt (>= 1.2.3))
-  (ppx_deriving_yojson (>= 3.6.1))
-  (ppx_deriving (>= 5.1))))
+  (ocaml
+   (>= 4.14.1))
+  (capnp
+   (>= 3.5.0))
+  (capnp-rpc-lwt
+   (>= 1.2.3))
+  (ppx_deriving_yojson
+   (>= 3.6.1))
+  (ppx_deriving
+   (>= 5.1))))

service/dune

@@ -7,5 +7,9 @@
   solver-service-api
   opam-0install
   capnp-rpc-net
+  opam-file-format
   git-unix
-  ocaml-version))
+  scache
+  ocaml-version)
+ (preprocess
+  (pps ppx_deriving_yojson)))