twirp + tiny_httpd

dune-project

@@ -45,3 +45,20 @@
     (pbrt_yojson (= :version)))
   (tags (protobuf encode decode services rpc)))
 
+(package
+  (name twirp_ezcurl)
+  (synopsis "Twirp client implementation using ezcurl")
+  (depends
+    (pbrt (= :version))
+    (pbrt_services (= :version))
+    yojson
+    ezcurl))
+
+(package
+  (name twirp_tiny_httpd)
+  (synopsis "Twirp server implementation for tiny_httpd")
+  (depends
+    (pbrt (= :version))
+    (pbrt_services (= :version))
+    yojson
+    tiny_httpd))

examples/twirp_ezcurl/README.md

@@ -0,0 +1,8 @@
+
+While running the server on port 8084:
+
+```sh
+$ PORT=8084 dune exec examples/twirp_ezcurl/calculator_client.exe
+query on http://localhost:8084/
+add call: returned 131
+```

examples/twirp_ezcurl/calculator.proto

@@ -0,0 +1,29 @@
+syntax = "proto3";
+
+message DivByZero {}
+
+message I32 {
+  int32 value = 0;
+}
+
+message AddReq {
+  int32 a = 1;
+  int32 b = 2;
+}
+
+message AddAllReq {
+  repeated int32 ints = 1;
+}
+
+message Empty {}
+
+service Calculator {
+  rpc add(AddReq) returns (I32);
+
+  rpc add_all(AddAllReq) returns (I32);
+
+  rpc ping(Empty) returns (Empty);
+
+  rpc get_pings(Empty) returns (I32);
+}
+

examples/twirp_ezcurl/calculator_client.ml

@@ -0,0 +1,20 @@
+let spf = Printf.sprintf
+let aspf = Format.asprintf
+
+let () =
+  let port = try int_of_string (Sys.getenv "PORT") with _ -> 8080 in
+  Printf.printf "query on http://localhost:%d/\n%!" port;
+
+  let r =
+    match
+      Twirp_ezcurl.call ~use_tls:false ~host:"localhost" ~port
+        Calculator.Calculator.add
+      @@ Calculator.default_add_req ~a:31l ~b:100l ()
+    with
+    | Ok x -> x.value |> Int32.to_int
+    | Error err ->
+      failwith (aspf "call to add failed: %a" Twirp_ezcurl.pp_error err)
+  in
+
+  Printf.printf "add call: returned %d\n%!" r;
+  ()

examples/twirp_ezcurl/dune

@@ -0,0 +1,11 @@
+
+(executable
+  (name calculator_client)
+  (flags :standard -w -40)
+  (libraries ezcurl twirp_ezcurl))
+
+(rule
+ (targets calculator.ml calculator.mli)
+ (deps calculator.proto)
+ (action
+  (run ocaml-protoc --binary --pp --yojson --services --ml_out ./ %{deps})))

examples/twirp_tiny_httpd/README.md

@@ -0,0 +1,15 @@
+Basic service using Twirp.
+
+Example use:
+
+```sh
+$ PORT=8084 dune exec examples/twirp_tiny_httpd/calculator_server.exe
+listen on http://localhost:8084/
+
+$ curl -X POST http://localhost:8084/twirp/Calculator/add --json '{"a": 1, "b": 2}'
+{"value":3}⏎
+
+$ curl -X POST http://localhost:8084/twirp/Calculator/add_all --json '{"ints": [1,2,3,4]}'
+{"value":10}⏎
+```
+

examples/twirp_tiny_httpd/calculator.proto

@@ -0,0 +1,29 @@
+syntax = "proto3";
+
+message DivByZero {}
+
+message I32 {
+  int32 value = 0;
+}
+
+message AddReq {
+  int32 a = 1;
+  int32 b = 2;
+}
+
+message AddAllReq {
+  repeated int32 ints = 1;
+}
+
+message Empty {}
+
+service Calculator {
+  rpc add(AddReq) returns (I32);
+
+  rpc add_all(AddAllReq) returns (I32);
+
+  rpc ping(Empty) returns (Empty);
+
+  rpc get_pings(Empty) returns (I32);
+}
+

examples/twirp_tiny_httpd/calculator_server.ml

@@ -0,0 +1,33 @@
+module H = Tiny_httpd
+open Calculator
+
+module Service_impl = struct
+  let add (a : add_req) : i32 = default_i32 ~value:Int32.(add a.a a.b) ()
+
+  let add_all (a : add_all_req) : i32 =
+    let l = ref 0l in
+    List.iter (fun x -> l := Int32.add !l x) a.ints;
+    default_i32 ~value:!l ()
+
+  let n_pings = ref 0
+  let ping () = incr n_pings
+  let get_pings () : i32 = default_i32 ~value:(Int32.of_int !n_pings) ()
+end
+
+let calc_service : Twirp_tiny_httpd.handler Pbrt_services.Server.t =
+  Calculator.make_server
+    ~add:(fun rpc -> Twirp_tiny_httpd.mk_handler rpc Service_impl.add)
+    ~add_all:(fun rpc -> Twirp_tiny_httpd.mk_handler rpc Service_impl.add_all)
+    ~ping:(fun rpc -> Twirp_tiny_httpd.mk_handler rpc Service_impl.ping)
+    ~get_pings:(fun rpc ->
+      Twirp_tiny_httpd.mk_handler rpc Service_impl.get_pings)
+    ()
+
+let () =
+  let port = try int_of_string (Sys.getenv "PORT") with _ -> 8080 in
+  Printf.printf "listen on http://localhost:%d/\n%!" port;
+
+  let server = H.create ~port () in
+  Twirp_tiny_httpd.add_service ~prefix:(Some "twirp") server calc_service;
+
+  H.run_exn server

examples/twirp_tiny_httpd/dune

@@ -0,0 +1,11 @@
+
+(executable
+  (name calculator_server)
+  (flags :standard -w -44)
+  (libraries pbrt_services twirp_tiny_httpd tiny_httpd))
+
+(rule
+ (targets calculator.ml calculator.mli)
+ (deps calculator.proto)
+ (action
+  (run ocaml-protoc --binary --pp --yojson --services --ml_out ./ %{deps})))

src/runtime-services/pbrt_services.ml

@@ -74,10 +74,6 @@ module Server = struct
   (** A single RPC method, alongside encoders and decoders for
         input and output types. . *)
 
-  (** A RPC endpoint. *)
-  type any_rpc = RPC : ('req, 'req_mode, 'res, 'res_mode) rpc -> any_rpc
-  [@@unboxed]
-
   (** Helper to build a RPC *)
   let mk_rpc :
       name:string ->

src/twirp_ezcurl/dune

@@ -0,0 +1,14 @@
+
+(library
+ (name twirp_ezcurl)
+ (public_name twirp_ezcurl)
+ (synopsis "Twirp client")
+ (wrapped true)
+ (libraries pbrt pbrt_yojson yojson pbrt_services ezcurl))
+
+(rule
+  (targets twirp_error.ml twirp_error.mli)
+  (deps (:file twirp_error.proto))
+  (mode promote)
+  (action (run ../ocaml-protoc/ocaml_protoc.exe --pp --yojson --ml_out=. %{file})))
+

src/twirp_ezcurl/twirp_error.ml

@@ -0,0 +1,68 @@
+[@@@ocaml.warning "-27-30-39"]
+
+type error = {
+  code : string;
+  msg : string;
+}
+
+let rec default_error 
+  ?code:((code:string) = "")
+  ?msg:((msg:string) = "")
+  () : error  = {
+  code;
+  msg;
+}
+
+type error_mutable = {
+  mutable code : string;
+  mutable msg : string;
+}
+
+let default_error_mutable () : error_mutable = {
+  code = "";
+  msg = "";
+}
+
+[@@@ocaml.warning "-27-30-39"]
+
+(** {2 Formatters} *)
+
+let rec pp_error fmt (v:error) = 
+  let pp_i fmt () =
+    Pbrt.Pp.pp_record_field ~first:true "code" Pbrt.Pp.pp_string fmt v.code;
+    Pbrt.Pp.pp_record_field ~first:false "msg" Pbrt.Pp.pp_string fmt v.msg;
+  in
+  Pbrt.Pp.pp_brk pp_i fmt ()
+
+[@@@ocaml.warning "-27-30-39"]
+
+(** {2 Protobuf YoJson Encoding} *)
+
+let rec encode_json_error (v:error) = 
+  let assoc = [] in 
+  let assoc = ("code", Pbrt_yojson.make_string v.code) :: assoc in
+  let assoc = ("msg", Pbrt_yojson.make_string v.msg) :: assoc in
+  `Assoc assoc
+
+[@@@ocaml.warning "-27-30-39"]
+
+(** {2 JSON Decoding} *)
+
+let rec decode_json_error d =
+  let v = default_error_mutable () in
+  let assoc = match d with
+    | `Assoc assoc -> assoc
+    | _ -> assert(false)
+  in
+  List.iter (function 
+    | ("code", json_value) -> 
+      v.code <- Pbrt_yojson.string json_value "error" "code"
+    | ("msg", json_value) -> 
+      v.msg <- Pbrt_yojson.string json_value "error" "msg"
+
+    | (_, _) -> () (*Unknown fields are ignored*)
+  ) assoc;
+  ({
+    code = v.code;
+    msg = v.msg;
+  } : error)

src/twirp_ezcurl/twirp_error.mli

@@ -0,0 +1,44 @@
+
+(** Code for twirp_error.proto *)
+
+(* generated from "twirp_error.proto", do not edit *)
+
+
+
+(** {2 Types} *)
+
+type error = {
+  code : string;
+  msg : string;
+}
+
+
+(** {2 Basic values} *)
+
+val default_error : 
+  ?code:string ->
+  ?msg:string ->
+  unit ->
+  error
+(** [default_error ()] is the default value for type [error] *)
+
+
+(** {2 Formatters} *)
+
+val pp_error : Format.formatter -> error -> unit 
+(** [pp_error v] formats v *)
+
+
+(** {2 Protobuf YoJson Encoding} *)
+
+val encode_json_error : error -> Yojson.Basic.t
+(** [encode_json_error v encoder] encodes [v] to to json *)
+
+
+(** {2 JSON Decoding} *)
+
+val decode_json_error : Yojson.Basic.t -> error
+(** [decode_json_error decoder] decodes a [error] value from [decoder] *)
+
+
+(** {2 Services} *)

src/twirp_ezcurl/twirp_error.proto

@@ -0,0 +1,11 @@
+syntax = "proto3";
+
+message error {
+  // Error code
+  string code = 1;
+
+  // Human readable message
+  string msg = 2;
+}
+
+// TODO: meta?