Add helper library for using typed-rpc with ocaml-protoc

dune-project

@@ -107,6 +107,21 @@
   (ocaml-protoc-plugin
    (>= 4.5))))
 
+(package
+ (name grpc-protoc)
+ (synopsis "An implementation of gRPC using ocaml-protoc")
+ (description
+  "Functionality for building gRPC services and rpcs with `ocaml-protoc`")
+ (depends
+  (grpc
+   (= :version))
+  (ocaml-protoc
+   (>= 3.0))
+  (pbrt
+   (>= 3.0))
+  (pbrt_services
+   (>= 3.0))))
+
 (package
  (name grpc-examples)
  (synopsis "Various gRPC examples")

grpc-protoc.opam

@@ -0,0 +1,42 @@
+# This file is generated by dune, edit dune-project instead
+opam-version: "2.0"
+synopsis: "An implementation of gRPC using ocaml-protoc"
+description:
+  "Functionality for building gRPC services and rpcs with `ocaml-protoc`"
+maintainer: ["Daniel Quernheim <[email protected]>"]
+authors: [
+  "Andrew Jeffery <[email protected]>"
+  "Daniel Quernheim <[email protected]>"
+  "Michael Bacarella <[email protected]>"
+  "Sven Anderson <[email protected]>"
+  "Tim McGilchrist <[email protected]>"
+  "Wojtek Czekalski <[email protected]>"
+  "dimitris.mostrous <[email protected]>"
+]
+license: "BSD-3-Clause"
+homepage: "https://github.com/dialohq/ocaml-grpc"
+doc: "https://dialohq.github.io/ocaml-grpc"
+bug-reports: "https://github.com/dialohq/ocaml-grpc/issues"
+depends: [
+  "dune" {>= "3.7"}
+  "grpc" {= version}
+  "ocaml-protoc" {>= "3.0"}
+  "pbrt" {>= "3.0"}
+  "pbrt_services" {>= "3.0"}
+  "odoc" {with-doc}
+]
+build: [
+  ["dune" "subst"] {dev}
+  [
+    "dune"
+    "build"
+    "-p"
+    name
+    "-j"
+    jobs
+    "@install"
+    "@runtest" {with-test}
+    "@doc" {with-doc}
+  ]
+]
+dev-repo: "git+https://github.com/dialohq/ocaml-grpc.git"

lib/grpc-protoc/dune

@@ -0,0 +1,4 @@
+(library
+ (name grpc_protoc)
+ (public_name grpc-protoc)
+ (libraries grpc ocaml-protoc pbrt pbrt_services))

lib/grpc-protoc/grpc_protoc.ml

@@ -0,0 +1,55 @@
+let encode (type a) (encode : a -> Pbrt.Encoder.t -> unit) (a : a) =
+  let encoder = Pbrt.Encoder.create () in
+  encode a encoder;
+  Pbrt.Encoder.to_string encoder
+
+let decode (type a) (decode : Pbrt.Decoder.t -> a) buffer =
+  let decoder = Pbrt.Decoder.of_string buffer in
+  decode decoder
+
+module Client_rpc = struct
+  let make (type request response)
+      (rpc : (request, _, response, _) Pbrt_services.Client.rpc) ~request_mode
+      ~response_mode =
+    {
+      Grpc.Rpc.Client_rpc.service_spec =
+        { package = rpc.package; service_name = rpc.service_name };
+      rpc_name = rpc.rpc_name;
+      encode_request = encode rpc.encode_pb_req;
+      decode_response = decode rpc.decode_pb_res;
+      request_mode;
+      response_mode;
+    }
+
+  let unary rpc = make rpc ~request_mode:Unary ~response_mode:Unary
+  let client_streaming rpc = make rpc ~request_mode:Stream ~response_mode:Unary
+  let server_streaming rpc = make rpc ~request_mode:Unary ~response_mode:Stream
+
+  let bidirectional_streaming rpc =
+    make rpc ~request_mode:Stream ~response_mode:Stream
+end
+
+module Server_rpc = struct
+  let make (type request response)
+      (rpc : (request, _, response, _) Pbrt_services.Server.rpc) ~request_mode
+      ~response_mode =
+    {
+      Grpc.Rpc.Server_rpc.service_spec = None;
+      rpc_name = rpc.name;
+      decode_request = decode rpc.decode_pb_req;
+      encode_response = encode rpc.encode_pb_res;
+      request_mode;
+      response_mode;
+    }
+
+  let unary rpc = make rpc ~request_mode:Unary ~response_mode:Unary
+  let client_streaming rpc = make rpc ~request_mode:Stream ~response_mode:Unary
+  let server_streaming rpc = make rpc ~request_mode:Unary ~response_mode:Stream
+
+  let bidirectional_streaming rpc =
+    make rpc ~request_mode:Stream ~response_mode:Stream
+end
+
+let handlers { Pbrt_services.Server.package; service_name; handlers } =
+  Grpc.Rpc.Handlers.With_service_spec
+    { service_spec = { package; service_name }; handlers }

lib/grpc-protoc/grpc_protoc.mli

@@ -0,0 +1,116 @@
+(** A utility library for constructing gRPC specifications using [Ocaml_protoc].
+
+    This module is designed to work alongside [Ocaml_protoc] to generate gRPC
+    stubs, as outlined in {!module:Grpc.Rpc}. It offers a collection of helper
+    functions that construct gRPC specifications from the code produced by
+    [Ocaml_protoc] based on the services defined in *.proto files. *)
+
+(** {1 Client side} *)
+
+module Client_rpc : sig
+  val unary :
+    ( 'request,
+      Pbrt_services.Value_mode.unary,
+      'response,
+      Pbrt_services.Value_mode.unary )
+    Pbrt_services.Client.rpc ->
+    ( 'request,
+      Grpc.Rpc.Value_mode.unary,
+      'response,
+      Grpc.Rpc.Value_mode.unary )
+    Grpc.Rpc.Client_rpc.t
+
+  val client_streaming :
+    ( 'request,
+      Pbrt_services.Value_mode.stream,
+      'response,
+      Pbrt_services.Value_mode.unary )
+    Pbrt_services.Client.rpc ->
+    ( 'request,
+      Grpc.Rpc.Value_mode.stream,
+      'response,
+      Grpc.Rpc.Value_mode.unary )
+    Grpc.Rpc.Client_rpc.t
+
+  val server_streaming :
+    ( 'request,
+      Pbrt_services.Value_mode.unary,
+      'response,
+      Pbrt_services.Value_mode.stream )
+    Pbrt_services.Client.rpc ->
+    ( 'request,
+      Grpc.Rpc.Value_mode.unary,
+      'response,
+      Grpc.Rpc.Value_mode.stream )
+    Grpc.Rpc.Client_rpc.t
+
+  val bidirectional_streaming :
+    ( 'request,
+      Pbrt_services.Value_mode.stream,
+      'response,
+      Pbrt_services.Value_mode.stream )
+    Pbrt_services.Client.rpc ->
+    ( 'request,
+      Grpc.Rpc.Value_mode.stream,
+      'response,
+      Grpc.Rpc.Value_mode.stream )
+    Grpc.Rpc.Client_rpc.t
+end
+
+(** {1 Server side} *)
+
+module Server_rpc : sig
+  val unary :
+    ( 'request,
+      Pbrt_services.Value_mode.unary,
+      'response,
+      Pbrt_services.Value_mode.unary )
+    Pbrt_services.Server.rpc ->
+    ( 'request,
+      Grpc.Rpc.Value_mode.unary,
+      'response,
+      Grpc.Rpc.Value_mode.unary,
+      unit )
+    Grpc.Rpc.Server_rpc.t
+
+  val client_streaming :
+    ( 'request,
+      Pbrt_services.Value_mode.stream,
+      'response,
+      Pbrt_services.Value_mode.unary )
+    Pbrt_services.Server.rpc ->
+    ( 'request,
+      Grpc.Rpc.Value_mode.stream,
+      'response,
+      Grpc.Rpc.Value_mode.unary,
+      unit )
+    Grpc.Rpc.Server_rpc.t
+
+  val server_streaming :
+    ( 'request,
+      Pbrt_services.Value_mode.unary,
+      'response,
+      Pbrt_services.Value_mode.stream )
+    Pbrt_services.Server.rpc ->
+    ( 'request,
+      Grpc.Rpc.Value_mode.unary,
+      'response,
+      Grpc.Rpc.Value_mode.stream,
+      unit )
+    Grpc.Rpc.Server_rpc.t
+
+  val bidirectional_streaming :
+    ( 'request,
+      Pbrt_services.Value_mode.stream,
+      'response,
+      Pbrt_services.Value_mode.stream )
+    Pbrt_services.Server.rpc ->
+    ( 'request,
+      Grpc.Rpc.Value_mode.stream,
+      'response,
+      Grpc.Rpc.Value_mode.stream,
+      unit )
+    Grpc.Rpc.Server_rpc.t
+end
+
+val handlers : 'a Pbrt_services.Server.t -> (_, 'a) Grpc.Rpc.Handlers.t