refactor: rpc build (#2244)

rewrite rpc build with quota crate

Cargo.lock

@@ -2264,7 +2264,6 @@ dependencies = [
  "derivative",
  "derive_builder",
  "derive_more 2.1.1",
- "easytier-rpc-build",
  "encoding",
  "flume 0.12.0",
  "forwarded-header-value",
@@ -2310,6 +2309,7 @@ dependencies = [
  "pin-project-lite",
  "pnet",
  "prefix-trie",
+ "proc-macro2",
  "prost",
  "prost-build",
  "prost-reflect",
@@ -2319,6 +2319,7 @@ dependencies = [
  "prost-wkt-types",
  "quinn",
  "quinn-plaintext",
+ "quote",
  "rand 0.8.5",
  "rcgen",
  "regex",
@@ -2358,7 +2359,6 @@ dependencies = [
  "tokio-util",
  "tokio-websockets",
  "toml 0.8.19",
- "tonic-build",
  "tracing",
  "tracing-subscriber",
  "tun-easytier",
@@ -2437,14 +2437,6 @@ dependencies = [
  "windows 0.52.0",
 ]
 
-[[package]]
-name = "easytier-rpc-build"
-version = "0.1.0"
-dependencies = [
- "heck 0.5.0",
- "prost-build",
-]
-
 [[package]]
 name = "easytier-uptime"
 version = "0.1.0"
@@ -10055,19 +10047,6 @@ dependencies = [
  "tracing",
 ]
 
-[[package]]
-name = "tonic-build"
-version = "0.12.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "568392c5a2bd0020723e3f387891176aabafe36fd9fcd074ad309dfa0c8eb964"
-dependencies = [
- "prettyplease",
- "proc-macro2",
- "prost-build",
- "quote",
- "syn 2.0.117",
-]
-
 [[package]]
 name = "tower"
 version = "0.4.13"

Cargo.toml

@@ -3,7 +3,6 @@ resolver = "2"
 members = [
     "easytier",
     "easytier-gui/src-tauri",
-    "easytier-rpc-build",
     "easytier-web",
     "easytier-contrib/easytier-ffi",
     "easytier-contrib/easytier-uptime",

easytier-rpc-build/Cargo.toml

@@ -1,20 +0,0 @@
-[package]
-name = "easytier-rpc-build"
-description = "Protobuf RPC Service Generator for EasyTier"
-version = "0.1.0"
-edition.workspace = true
-homepage = "https://github.com/EasyTier/EasyTier"
-repository = "https://github.com/EasyTier/EasyTier"
-authors = ["kkrainbow"]
-keywords = ["vpn", "p2p", "network", "easytier"]
-categories = ["network-programming", "command-line-utilities"]
-license-file = "LICENSE"
-readme = "README.md"
-
-[dependencies]
-heck = "0.5"
-prost-build = "0.13"
-
-[features]
-default = []
-internal-namespace = []

easytier-rpc-build/LICENSE

@@ -1 +0,0 @@
-../LICENSE

easytier-rpc-build/README.md

@@ -1,3 +0,0 @@
-# Introduction
-
-This is a protobuf rpc service stub generator for [EasyTier](https://github.com/EasyTier/EasyTier) project.

easytier-rpc-build/src/lib.rs

@@ -1,449 +0,0 @@
-extern crate heck;
-extern crate prost_build;
-
-use std::fmt;
-
-#[cfg(feature = "internal-namespace")]
-const NAMESPACE: &str = "crate::proto::rpc_types";
-
-#[cfg(not(feature = "internal-namespace"))]
-const NAMESPACE: &str = "easytier::proto::rpc_types";
-
-/// The service generator to be used with `prost-build` to generate RPC implementations for
-/// `prost-simple-rpc`.
-///
-/// See the crate-level documentation for more info.
-#[allow(missing_copy_implementations)]
-#[derive(Clone, Debug, Default)]
-pub struct ServiceGenerator {
-    _private: (),
-}
-
-impl prost_build::ServiceGenerator for ServiceGenerator {
-    fn generate(&mut self, service: prost_build::Service, mut buf: &mut String) {
-        use std::fmt::Write;
-
-        let descriptor_name = format!("{}Descriptor", service.name);
-        let server_name = format!("{}Server", service.name);
-        let client_name = format!("{}Client", service.name);
-        let method_descriptor_name = format!("{}MethodDescriptor", service.name);
-
-        let mut trait_methods = String::new();
-        let mut weak_impl_methods = String::new();
-        let mut enum_methods = String::new();
-        let mut list_enum_methods = String::new();
-        let mut client_methods = String::new();
-        let mut client_own_methods = String::new();
-        let mut match_name_methods = String::new();
-        let mut match_proto_name_methods = String::new();
-        let mut match_input_type_methods = String::new();
-        let mut match_input_proto_type_methods = String::new();
-        let mut match_output_type_methods = String::new();
-        let mut match_output_proto_type_methods = String::new();
-        let mut match_handle_methods = String::new();
-        // generate trait default method Xxx::json_call_method match branch
-        let mut match_trait_json_methods = String::new();
-
-        let mut match_method_try_from = String::new();
-
-        for (idx, method) in service.methods.iter().enumerate() {
-            assert!(
-                !method.client_streaming,
-                "Client streaming not yet supported for method {}",
-                method.proto_name
-            );
-            assert!(
-                !method.server_streaming,
-                "Server streaming not yet supported for method {}",
-                method.proto_name
-            );
-
-            ServiceGenerator::write_comments(&mut trait_methods, 4, &method.comments).unwrap();
-            writeln!(
-                trait_methods,
-                r#"    async fn {name}(&self, ctrl: Self::Controller, input: {input_type}) -> {namespace}::error::Result<{output_type}>;"#,
-                name = method.name,
-                input_type = method.input_type,
-                output_type = method.output_type,
-                namespace = NAMESPACE,
-            )
-            .unwrap();
-
-            writeln!(
-                weak_impl_methods,
-                r#"    async fn {method_name}(&self, ctrl: Self::Controller, input: {input_type}) -> {namespace}::error::Result<{output_type}> {{
-        let Some(service) = self.upgrade() else {{
-            return Err({namespace}::error::Error::Shutdown);
-        }};
-        service.{method_name}(ctrl, input).await
-    }}"#,
-                method_name = method.name,
-                input_type = method.input_type,
-                output_type = method.output_type,
-                namespace = NAMESPACE,
-            )
-            .unwrap();
-
-            ServiceGenerator::write_comments(&mut enum_methods, 4, &method.comments).unwrap();
-            writeln!(
-                enum_methods,
-                "    {name} = {index},",
-                name = method.proto_name,
-                index = idx + 1
-            )
-            .unwrap();
-
-            writeln!(
-                match_method_try_from,
-                "            {index} => Ok({service_name}MethodDescriptor::{name}),",
-                service_name = service.name,
-                name = method.proto_name,
-                index = idx + 1,
-            )
-            .unwrap();
-
-            writeln!(
-                list_enum_methods,
-                "            {service_name}MethodDescriptor::{name},",
-                service_name = service.name,
-                name = method.proto_name
-            )
-            .unwrap();
-
-            writeln!(
-                client_methods,
-                r#"    async fn {name}(&self, ctrl: H::Controller, input: {input_type}) -> {namespace}::error::Result<{output_type}> {{
-        {client_name}Client::{name}_inner(self.0.clone(), ctrl, input).await
-    }}"#,
-                name = method.name,
-                input_type = method.input_type,
-                output_type = method.output_type,
-                client_name = service.name,
-                namespace = NAMESPACE,
-            )
-            .unwrap();
-
-            writeln!(
-                client_own_methods,
-                r#"    async fn {name}_inner(handler: H, ctrl: H::Controller, input: {input_type}) -> {namespace}::error::Result<{output_type}> {{
-            {namespace}::__rt::call_method(handler, ctrl, {method_descriptor_name}::{proto_name}, input).await
-    }}"#,
-                name = method.name,
-                method_descriptor_name = method_descriptor_name,
-                proto_name = method.proto_name,
-                input_type = method.input_type,
-                output_type = method.output_type,
-                namespace = NAMESPACE,
-            ).unwrap();
-
-            let case = format!(
-                "            {service_name}MethodDescriptor::{proto_name} => ",
-                service_name = service.name,
-                proto_name = method.proto_name
-            );
-
-            writeln!(match_name_methods, "{}{:?},", case, method.name).unwrap();
-            writeln!(match_proto_name_methods, "{}{:?},", case, method.proto_name).unwrap();
-            writeln!(
-                match_input_type_methods,
-                "{}::std::any::TypeId::of::<{}>(),",
-                case, method.input_type
-            )
-            .unwrap();
-            writeln!(
-                match_input_proto_type_methods,
-                "{}{:?},",
-                case, method.input_proto_type
-            )
-            .unwrap();
-            writeln!(
-                match_output_type_methods,
-                "{}::std::any::TypeId::of::<{}>(),",
-                case, method.output_type
-            )
-            .unwrap();
-            writeln!(
-                match_output_proto_type_methods,
-                "{}{:?},",
-                case, method.output_proto_type
-            )
-            .unwrap();
-            write!(
-                match_handle_methods,
-                r#"{} {{
-                    let decoded: {input_type} = {namespace}::__rt::decode(input)?;
-                    let ret = service.{name}(ctrl, decoded).await?;
-                    {namespace}::__rt::encode(ret)
-                }}
-"#,
-                case,
-                input_type = method.input_type,
-                name = method.name,
-                namespace = NAMESPACE,
-            )
-            .unwrap();
-
-            write!(
-                match_trait_json_methods,
-                r#"            "{name}" | "{proto_name}" => {{
-                let req: {input_type} = ::serde_json::from_value(json).map_err(|e| {namespace}::error::Error::MalformatRpcPacket(format!("json error: {{}}", e)))?;
-                let resp = self.{typed_method}(ctrl, req).await?;
-                Ok(::serde_json::to_value(resp).map_err(|e| {namespace}::error::Error::MalformatRpcPacket(format!("json error: {{}}", e)))?)
-            }}
-"#,
-                name = method.name,
-                proto_name = method.proto_name,
-                input_type = method.input_type,
-                typed_method = method.name,
-                namespace = NAMESPACE,
-            )
-            .unwrap();
-        }
-
-        ServiceGenerator::write_comments(&mut buf, 0, &service.comments).unwrap();
-        write!(
-            buf,
-            r#"
-#[async_trait::async_trait]
-#[auto_impl::auto_impl(&, Arc, Box)]
-pub trait {name} {{
-    type Controller: {namespace}::controller::Controller;
-
-    {trait_methods}
-
-    async fn json_call_method(
-        &self,
-        ctrl: Self::Controller,
-        method_name: &str,
-        json: ::serde_json::Value,
-    ) -> {namespace}::error::Result<::serde_json::Value> {{
-        match method_name {{
-{match_trait_json_methods}
-            _ => Err({namespace}::error::Error::InvalidMethodIndex(0, method_name.to_string())),
-        }}
-    }}
-}}
-
-#[async_trait::async_trait]
-impl<T> {name} for ::std::sync::Weak<T>
-where
-    T: Send + Sync + 'static,
-    ::std::sync::Arc<T>: {name},
-{{
-    type Controller = <::std::sync::Arc<T> as {name}>::Controller;
-
-    {weak_impl_methods}
-}}
-
-/// A service descriptor for a `{name}`.
-#[derive(Clone, Debug, Eq, Ord, PartialEq, PartialOrd, Default)]
-pub struct {descriptor_name};
-
-/// Methods available on a `{name}`.
-///
-/// This can be used as a key when routing requests for servers/clients of a `{name}`.
-#[derive(Clone, Copy, Debug, Eq, Ord, PartialEq, PartialOrd)]
-#[repr(u8)]
-pub enum {method_descriptor_name} {{
-    {enum_methods}
-}}
-
-impl std::convert::TryFrom<u8> for {method_descriptor_name} {{
-    type Error = {namespace}::error::Error;
-    fn try_from(value: u8) -> {namespace}::error::Result<Self> {{
-        match value {{
-            {match_method_try_from}
-            _ => Err({namespace}::error::Error::InvalidMethodIndex(value, "{name}".to_string())),
-        }}
-    }}
-}}
-
-/// A client for a `{name}`.
-///
-/// This implements the `{name}` trait by dispatching all method calls to the supplied `Handler`.
-#[derive(Clone, Debug)]
-pub struct {client_name}<H>(H) where H: {namespace}::handler::Handler;
-
-impl<H> {client_name}<H> where H: {namespace}::handler::Handler<Descriptor = {descriptor_name}> {{
-    /// Creates a new client instance that delegates all method calls to the supplied handler.
-    pub fn new(handler: H) -> {client_name}<H> {{
-        {client_name}(handler)
-    }}
-}}
-
-impl<H> {client_name}<H> where H: {namespace}::handler::Handler<Descriptor = {descriptor_name}> {{
-    {client_own_methods}
-}}
-
-#[async_trait::async_trait]
-impl<H> {name} for {client_name}<H> where H: {namespace}::handler::Handler<Descriptor = {descriptor_name}> {{
-    type Controller = H::Controller;
-
-    {client_methods}
-}}
-
-pub struct {client_name}Factory<C: {namespace}::controller::Controller>(std::marker::PhantomData<C>);
-
-impl<C: {namespace}::controller::Controller> Clone for {client_name}Factory<C> {{
-    fn clone(&self) -> Self {{
-        Self(std::marker::PhantomData)
-    }}
-}}
-
-impl<C> {namespace}::__rt::RpcClientFactory for {client_name}Factory<C> where C: {namespace}::controller::Controller {{
-    type Descriptor = {descriptor_name};
-    type ClientImpl = Box<dyn {name}<Controller = C> + Send + Sync + 'static>;
-    type Controller = C;
-
-    fn new(handler: impl {namespace}::handler::Handler<Descriptor = Self::Descriptor, Controller = Self::Controller>) -> Self::ClientImpl {{
-        Box::new({client_name}::new(handler))
-    }}
-}}
-
-/// A server for a `{name}`.
-///
-/// This implements the `Server` trait by handling requests and dispatch them to methods on the
-/// supplied `{name}`.
-#[derive(Clone, Debug)]
-pub struct {server_name}<A>(A) where A: {name} + Clone + Send + 'static;
-
-impl<T> {server_name}<::std::sync::Weak<T>>
-where
-    T: Send + Sync + 'static,
-    ::std::sync::Arc<T>: {name},
-{{
-    pub fn new_arc(service: ::std::sync::Arc<T>) -> {server_name}<::std::sync::Weak<T>> {{
-        {server_name}(::std::sync::Arc::downgrade(&service))
-    }}
-}}
-
-impl<A> {server_name}<A> where A: {name} + Clone + Send + 'static {{
-    /// Creates a new server instance that dispatches all calls to the supplied service.
-    pub fn new(service: A) -> {server_name}<A> {{
-        {server_name}(service)
-    }}
-
-    async fn call_inner(
-        service: A,
-        method: {method_descriptor_name},
-        ctrl: A::Controller,
-        input: ::bytes::Bytes)
-        -> {namespace}::error::Result<::bytes::Bytes> {{
-        match method {{
-            {match_handle_methods}        
-        }}
-    }}
-}}
-
-impl {namespace}::descriptor::ServiceDescriptor for {descriptor_name} {{
-    type Method = {method_descriptor_name};
-    fn name(&self) -> &'static str {{ {name:?} }}
-    fn proto_name(&self) -> &'static str {{ {proto_name:?} }}
-    fn package(&self) -> &'static str {{ {package:?} }}
-    fn methods(&self) -> &'static [Self::Method] {{
-        &[ {list_enum_methods} ]
-    }}
-}}
-
-#[async_trait::async_trait]
-impl<A> {namespace}::handler::Handler for {server_name}<A>
-where
-    A: {name} + Clone + Send + Sync + 'static {{
-    type Descriptor = {descriptor_name};
-    type Controller = A::Controller;
-
-    async fn call(
-        &self,
-        ctrl: A::Controller,
-        method: {method_descriptor_name},
-        input: ::bytes::Bytes)
-        -> {namespace}::error::Result<::bytes::Bytes> {{
-        {server_name}::call_inner(self.0.clone(), method, ctrl, input).await
-    }}
-}}
-
-impl {namespace}::descriptor::MethodDescriptor for {method_descriptor_name} {{
-    fn name(&self) -> &'static str {{
-        match *self {{
-            {match_name_methods}        
-        }}
-    }}
-
-    fn proto_name(&self) -> &'static str {{
-        match *self {{
-            {match_proto_name_methods}
-        }}
-    }}
-
-    fn input_type(&self) -> ::std::any::TypeId {{
-        match *self {{
-            {match_input_type_methods}
-        }}
-    }}
-
-    fn input_proto_type(&self) -> &'static str {{
-        match *self {{
-            {match_input_proto_type_methods}
-        }}
-    }}
-
-    fn output_type(&self) -> ::std::any::TypeId {{
-        match *self {{
-            {match_output_type_methods}
-        }}
-    }}
-
-    fn output_proto_type(&self) -> &'static str {{
-        match *self {{
-            {match_output_proto_type_methods}
-        }}
-    }}
-
-    fn index(&self) -> u8 {{
-        *self as u8
-    }}
-}}
-"#,
-            name = service.name,
-            descriptor_name = descriptor_name,
-            server_name = server_name,
-            client_name = client_name,
-            method_descriptor_name = method_descriptor_name,
-            proto_name = service.proto_name,
-            package = service.package,
-            trait_methods = trait_methods,
-            weak_impl_methods = weak_impl_methods,
-            enum_methods = enum_methods,
-            list_enum_methods = list_enum_methods,
-            client_own_methods = client_own_methods,
-            client_methods = client_methods,
-            match_name_methods = match_name_methods,
-            match_proto_name_methods = match_proto_name_methods,
-            match_input_type_methods = match_input_type_methods,
-            match_input_proto_type_methods = match_input_proto_type_methods,
-            match_output_type_methods = match_output_type_methods,
-            match_output_proto_type_methods = match_output_proto_type_methods,
-            match_handle_methods = match_handle_methods,
-            match_trait_json_methods = match_trait_json_methods,
-            namespace = NAMESPACE,
-        ).unwrap();
-    }
-}
-
-impl ServiceGenerator {
-    fn write_comments<W>(
-        mut write: W,
-        indent: usize,
-        comments: &prost_build::Comments,
-    ) -> fmt::Result
-    where
-        W: fmt::Write,
-    {
-        for comment in &comments.leading {
-            for line in comment.lines().filter(|s| !s.is_empty()) {
-                writeln!(write, "{}///{}", " ".repeat(indent), line)?;
-            }
-        }
-        Ok(())
-    }
-}

easytier/Cargo.toml

@@ -11,6 +11,7 @@ keywords = ["vpn", "p2p", "network", "easytier"]
 categories = ["network-programming", "command-line-utilities"]
 license-file = "LICENSE"
 readme = "README.md"
+build = "build/main.rs"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
@@ -316,15 +317,14 @@ jemalloc-sys = { package = "tikv-jemalloc-sys", version = "0.6.0", features = [
 
 [build-dependencies]
 cfg_aliases = "0.2.1"
-tonic-build = "0.12"
+indoc = "2.0"
 globwalk = "0.8.1"
 regex = "1"
 prost-build = "0.13.5"
 prost-wkt-build = "0.6"
-easytier-rpc-build = { path = "../easytier-rpc-build", features = [
-    "internal-namespace",
-] }
 prost-reflect-build = { version = "0.14.0" }
+proc-macro2 = "1"
+quote = "1"
 thunk-rs = { git = "https://github.com/easytier/thunk.git", default-features = false, features = [
     "win7",
 ] }

easytier/build/main.rs

@@ -1,3 +1,6 @@
+mod rpc;
+
+use crate::rpc::ServiceGenerator;
 use cfg_aliases::cfg_aliases;
 use prost_wkt_build::{FileDescriptorSet, Message as _};
 #[cfg(target_os = "windows")]
@@ -197,7 +200,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
         .type_attribute("acl.Rule", "#[serde(default)]")
         .type_attribute("acl.GroupInfo", "#[serde(default)]")
         .field_attribute(".api.manage.NetworkConfig", "#[serde(default)]")
-        .service_generator(Box::new(easytier_rpc_build::ServiceGenerator::default()))
+        .service_generator(Box::new(ServiceGenerator::default()))
         .btree_map(["."])
         .skip_debug([".common.Ipv4Addr", ".common.Ipv6Addr", ".common.UUID"]);
 

easytier/build/rpc.rs

@@ -0,0 +1,720 @@
+#![allow(non_snake_case)]
+
+use indoc::formatdoc;
+use proc_macro2::{Ident, TokenStream};
+use quote::{format_ident, quote};
+use std::str::FromStr;
+
+fn parse(value: &str) -> TokenStream {
+    TokenStream::from_str(value)
+        .unwrap_or_else(|err| panic!("Failed to parse tokens: {} ({})", value, err))
+}
+
+fn doc(comments: &prost_build::Comments) -> TokenStream {
+    let doc = comments
+        .leading
+        .iter()
+        .flat_map(|c| c.lines().filter(|s| !s.is_empty()));
+    quote! { #( #[doc = #doc] )* }
+}
+
+const NAMESPACE: &str = "crate::proto::rpc_types";
+
+struct Method {
+    index: u8,
+    doc: TokenStream,
+    method: Ident,
+    method_inner: Ident,
+    method_str: String,
+    method_proto: Ident,
+    method_proto_str: String,
+    Input: TokenStream,
+    Input_proto_str: String,
+    Output: TokenStream,
+    Output_proto_str: String,
+}
+
+impl Method {
+    fn new(index: u8, method: prost_build::Method) -> Self {
+        assert!(
+            !method.client_streaming,
+            "Client streaming not yet supported for method {}",
+            method.proto_name
+        );
+        assert!(
+            !method.server_streaming,
+            "Server streaming not yet supported for method {}",
+            method.proto_name
+        );
+        Self {
+            index,
+            doc: doc(&method.comments),
+            method: format_ident!("{}", method.name),
+            method_inner: format_ident!("{}_inner", method.name),
+            method_str: method.name,
+            method_proto: format_ident!("{}", method.proto_name),
+            method_proto_str: method.proto_name,
+            Input: parse(&method.input_type),
+            Input_proto_str: method.input_proto_type,
+            Output: parse(&method.output_type),
+            Output_proto_str: method.output_proto_type,
+        }
+    }
+}
+
+struct Service {
+    namespace: TokenStream,
+    doc: TokenStream,
+    Service: Ident,
+    ServiceDescriptor: Ident,
+    ServiceServer: Ident,
+    ServiceClient: Ident,
+    ServiceClientFactory: Ident,
+    ServiceMethodDescriptor: Ident,
+    Service_str: String,
+    Service_proto_str: String,
+    Service_package_str: String,
+    methods: Vec<Method>,
+}
+
+impl Service {
+    fn new(service: prost_build::Service) -> Self {
+        let methods = service
+            .methods
+            .into_iter()
+            .enumerate()
+            .map(|(i, method)| Method::new((i + 1) as u8, method))
+            .collect();
+
+        Self {
+            namespace: parse(NAMESPACE),
+            doc: doc(&service.comments),
+            Service: format_ident!("{}", service.name),
+            ServiceDescriptor: format_ident!("{}Descriptor", service.name),
+            ServiceServer: format_ident!("{}Server", service.name),
+            ServiceClient: format_ident!("{}Client", service.name),
+            ServiceClientFactory: format_ident!("{}ClientFactory", service.name),
+            ServiceMethodDescriptor: format_ident!("{}MethodDescriptor", service.name),
+            Service_str: service.name,
+            Service_proto_str: service.proto_name,
+            Service_package_str: service.package,
+            methods,
+        }
+    }
+
+    fn trait_Service(&self) -> TokenStream {
+        let Self {
+            namespace,
+            doc,
+            Service,
+            methods,
+            ..
+        } = self;
+
+        let match_json_call_method = methods.iter().map(
+            |Method {
+                 method,
+                 method_str,
+                 method_proto_str,
+                 Input,
+                 ..
+             }| {
+                quote! {
+                    #method_str | #method_proto_str => {
+                        let req: #Input = ::serde_json::from_value(json)
+                            .map_err(|e| #namespace::error::Error::MalformatRpcPacket(format!("json error: {}", e)))?;
+                        let resp = self.#method(ctrl, req).await?;
+                        Ok(::serde_json::to_value(resp)
+                            .map_err(|e| #namespace::error::Error::MalformatRpcPacket(format!("json error: {}", e)))?)
+                    }
+                }
+            },
+        );
+
+        let methods = methods.iter().map(
+            |Method {
+                 doc,
+                 method,
+                 Input,
+                 Output,
+                 ..
+             }| {
+                quote! {
+                    #doc
+                    async fn #method(&self, ctrl: Self::Controller, input: #Input) -> #namespace::error::Result<#Output>;
+                }
+            },
+        );
+
+        quote! {
+            #doc
+            #[async_trait::async_trait]
+            #[auto_impl::auto_impl(&, Arc, Box)]
+            pub trait #Service {
+                type Controller: #namespace::controller::Controller;
+
+                #(#methods)*
+
+                async fn json_call_method(
+                    &self,
+                    ctrl: Self::Controller,
+                    method: &str,
+                    json: ::serde_json::Value,
+                ) -> #namespace::error::Result<::serde_json::Value> {
+                    match method {
+                        #(#match_json_call_method)*
+                        _ => Err(#namespace::error::Error::InvalidMethodIndex(0, method.to_string())),
+                    }
+                }
+            }
+        }
+    }
+
+    fn impl_Service_for_Weak(&self) -> TokenStream {
+        let Self {
+            namespace,
+            Service,
+            methods,
+            ..
+        } = self;
+        let methods = methods.iter().map(
+            |Method {
+                 method,
+                 Input,
+                 Output,
+                 ..
+             }| {
+                quote! {
+                    async fn #method(&self, ctrl: Self::Controller, input: #Input) -> #namespace::error::Result<#Output> {
+                        let Some(service) = self.upgrade() else {
+                            return Err(#namespace::error::Error::Shutdown);
+                        };
+                        service.#method(ctrl, input).await
+                    }
+                }
+            },
+        );
+
+        quote! {
+            #[async_trait::async_trait]
+            impl<T> #Service for ::std::sync::Weak<T>
+            where
+                T: Send + Sync + 'static,
+                ::std::sync::Arc<T>: #Service,
+            {
+                type Controller = <::std::sync::Arc<T> as #Service>::Controller;
+
+                #(#methods)*
+            }
+        }
+    }
+
+    fn struct_ServiceDescriptor(&self) -> TokenStream {
+        let Self {
+            namespace,
+            ServiceDescriptor,
+            ServiceMethodDescriptor,
+            Service_str,
+            Service_proto_str,
+            Service_package_str,
+            methods,
+            ..
+        } = self;
+
+        let doc = format!("A service descriptor for a `{}`.", Service_str);
+
+        let methods = methods.iter().map(|Method { method_proto, .. }| {
+            quote! { #ServiceMethodDescriptor::#method_proto, }
+        });
+
+        quote! {
+            #[doc = #doc]
+            #[derive(Clone, Debug, Eq, Ord, PartialEq, PartialOrd, Default)]
+            pub struct #ServiceDescriptor;
+
+            impl #namespace::descriptor::ServiceDescriptor for #ServiceDescriptor {
+                type Method = #ServiceMethodDescriptor;
+                fn name(&self) -> &'static str { #Service_str }
+                fn proto_name(&self) -> &'static str { #Service_proto_str }
+                fn package(&self) -> &'static str { #Service_package_str }
+                fn methods(&self) -> &'static [Self::Method] {
+                    &[ #(#methods)* ]
+                }
+            }
+        }
+    }
+
+    fn enum_ServiceMethodDescriptor(&self) -> TokenStream {
+        let Self {
+            ServiceMethodDescriptor,
+            Service_str,
+            methods,
+            ..
+        } = self;
+
+        let doc = formatdoc! {"
+            Methods available on a `{Service_str}`.
+
+            This can be used as a key when routing requests for servers/clients of a `{Service_str}`.
+        "};
+
+        let variants = methods.iter().map(
+            |Method {
+                 method_proto,
+                 index,
+                 ..
+             }| {
+                quote! { #method_proto = #index, }
+            },
+        );
+
+        let impl_MethodDescriptor = self.impl_MethodDescriptor_for_ServiceMethodDescriptor();
+        let impl_TryFrom = self.impl_TryFrom_for_ServiceMethodDescriptor();
+        quote! {
+            #[doc = #doc]
+            #[derive(Clone, Copy, Debug, Eq, Ord, PartialEq, PartialOrd)]
+            #[repr(u8)]
+            pub enum #ServiceMethodDescriptor {
+                #(#variants)*
+            }
+
+            #impl_MethodDescriptor
+
+            #impl_TryFrom
+        }
+    }
+
+    fn impl_MethodDescriptor_for_ServiceMethodDescriptor(&self) -> TokenStream {
+        let Self {
+            namespace,
+            ServiceMethodDescriptor,
+            methods,
+            ..
+        } = self;
+
+        let name = {
+            let arms = methods.iter().map(
+                |Method {
+                     method_proto,
+                     method_str,
+                     ..
+                 }| {
+                    quote! { #ServiceMethodDescriptor::#method_proto => #method_str, }
+                },
+            );
+
+            quote! {
+                 fn name(&self) -> &'static str {
+                    match *self {
+                        #(#arms)*
+                    }
+                }
+            }
+        };
+
+        let proto_name = {
+            let arms = methods.iter().map(
+                |Method {
+                     method_proto,
+                     method_proto_str,
+                     ..
+                 }| {
+                    quote! { #ServiceMethodDescriptor::#method_proto => #method_proto_str, }
+                },
+            );
+
+            quote! {
+                fn proto_name(&self) -> &'static str {
+                    match *self {
+                        #(#arms)*
+                    }
+                }
+            }
+        };
+
+        let input_type = {
+            let arms = methods.iter().map(|Method { method_proto, Input, .. }| {
+                quote! { #ServiceMethodDescriptor::#method_proto => ::std::any::TypeId::of::<#Input>(), }
+            });
+
+            quote! {
+                fn input_type(&self) -> ::std::any::TypeId {
+                    match *self {
+                        #(#arms)*
+                    }
+                }
+            }
+        };
+
+        let input_proto_type = {
+            let arms = methods.iter().map(
+                |Method {
+                     method_proto,
+                     Input_proto_str,
+                     ..
+                 }| {
+                    quote! { #ServiceMethodDescriptor::#method_proto => #Input_proto_str, }
+                },
+            );
+
+            quote! {
+                fn input_proto_type(&self) -> &'static str {
+                    match *self {
+                        #(#arms)*
+                    }
+                }
+            }
+        };
+
+        let output_type = {
+            let arms = methods.iter().map(|Method { method_proto, Output, .. }| {
+                quote! { #ServiceMethodDescriptor::#method_proto => ::std::any::TypeId::of::<#Output>(), }
+            });
+
+            quote! {
+                fn output_type(&self) -> ::std::any::TypeId {
+                    match *self {
+                        #(#arms)*
+                    }
+                }
+            }
+        };
+
+        let output_proto_type = {
+            let arms = methods.iter().map(
+                |Method {
+                     method_proto,
+                     Output_proto_str,
+                     ..
+                 }| {
+                    quote! { #ServiceMethodDescriptor::#method_proto => #Output_proto_str, }
+                },
+            );
+
+            quote! {
+                fn output_proto_type(&self) -> &'static str {
+                    match *self {
+                        #(#arms)*
+                    }
+                }
+            }
+        };
+
+        quote! {
+            impl #namespace::descriptor::MethodDescriptor for #ServiceMethodDescriptor {
+                #name
+
+                #proto_name
+
+                #input_type
+
+                #input_proto_type
+
+                #output_type
+
+                #output_proto_type
+
+                fn index(&self) -> u8 {
+                    *self as u8
+                }
+            }
+        }
+    }
+
+    fn impl_TryFrom_for_ServiceMethodDescriptor(&self) -> TokenStream {
+        let Self {
+            namespace,
+            ServiceMethodDescriptor,
+            Service_str,
+            methods,
+            ..
+        } = self;
+
+        let arms = methods.iter().map(
+            |Method {
+                 method_proto,
+                 index,
+                 ..
+             }| {
+                quote! { #index => Ok(#ServiceMethodDescriptor::#method_proto), }
+            },
+        );
+
+        quote! {
+            impl std::convert::TryFrom<u8> for #ServiceMethodDescriptor {
+                type Error = #namespace::error::Error;
+                fn try_from(value: u8) -> #namespace::error::Result<Self> {
+                    match value {
+                        #(#arms)*
+                        _ => Err(#namespace::error::Error::InvalidMethodIndex(value, #Service_str.to_string())),
+                    }
+                }
+            }
+        }
+    }
+
+    fn struct_ServiceClient(&self) -> TokenStream {
+        let Self {
+            namespace,
+            ServiceDescriptor,
+            ServiceClient,
+            Service_str,
+            ..
+        } = self;
+
+        let doc = formatdoc! {"
+            A client for a `{Service_str}`.
+
+            This implements the `{Service_str}` trait by dispatching all method calls to the supplied `Handler`.
+        "};
+
+        let impl_service_client = self.impl_ServiceClient();
+        let impl_service_for_client = self.impl_Service_for_ServiceClient();
+        quote! {
+            #[doc = #doc]
+            #[derive(Clone, Debug)]
+            pub struct #ServiceClient<H>(H) where H: #namespace::handler::Handler;
+
+            impl<H> #ServiceClient<H> where H: #namespace::handler::Handler<Descriptor = #ServiceDescriptor> {
+                /// Creates a new client instance that delegates all method calls to the supplied handler.
+                pub fn new(handler: H) -> Self {
+                    Self(handler)
+                }
+            }
+
+            #impl_service_client
+
+            #impl_service_for_client
+        }
+    }
+
+    fn impl_ServiceClient(&self) -> TokenStream {
+        let Self {
+            namespace,
+            ServiceClient,
+            ServiceDescriptor,
+            ServiceMethodDescriptor,
+            methods,
+            ..
+        } = self;
+
+        let methods = methods.iter().map(
+            |Method {
+                 method_inner,
+                 method_proto,
+                 Input,
+                 Output,
+                 ..
+             }| {
+                quote! {
+                    async fn #method_inner(handler: H, ctrl: H::Controller, input: #Input) -> #namespace::error::Result<#Output> {
+                        #namespace::__rt::call_method(handler, ctrl, #ServiceMethodDescriptor::#method_proto, input).await
+                    }
+                }
+            },
+        );
+
+        quote! {
+            impl<H> #ServiceClient<H> where H: #namespace::handler::Handler<Descriptor = #ServiceDescriptor> {
+                #(#methods)*
+            }
+        }
+    }
+
+    fn impl_Service_for_ServiceClient(&self) -> TokenStream {
+        let Self {
+            namespace,
+            Service,
+            ServiceClient,
+            ServiceDescriptor,
+            methods,
+            ..
+        } = self;
+
+        let methods = methods.iter().map(
+            |Method {
+                 method,
+                 method_inner,
+                 Input,
+                 Output,
+                 ..
+             }| {
+                quote! {
+                    async fn #method(&self, ctrl: H::Controller, input: #Input) -> #namespace::error::Result<#Output> {
+                        #ServiceClient::#method_inner(self.0.clone(), ctrl, input).await
+                    }
+                }
+            },
+        );
+
+        quote! {
+            #[async_trait::async_trait]
+            impl<H> #Service for #ServiceClient<H> where H: #namespace::handler::Handler<Descriptor = #ServiceDescriptor> {
+                type Controller = H::Controller;
+
+                #(#methods)*
+            }
+        }
+    }
+
+    fn struct_ServiceClientFactory(&self) -> TokenStream {
+        let Self {
+            namespace,
+            Service,
+            ServiceClient,
+            ServiceClientFactory,
+            ServiceDescriptor,
+            ..
+        } = self;
+
+        quote! {
+            pub struct #ServiceClientFactory<C: #namespace::controller::Controller>(std::marker::PhantomData<C>);
+
+            impl<C: #namespace::controller::Controller> Clone for #ServiceClientFactory<C> {
+                fn clone(&self) -> Self {
+                    Self(std::marker::PhantomData)
+                }
+            }
+
+            impl<C> #namespace::__rt::RpcClientFactory for #ServiceClientFactory<C> where C: #namespace::controller::Controller {
+                type Descriptor = #ServiceDescriptor;
+                type ClientImpl = Box<dyn #Service<Controller = C> + Send + Sync + 'static>;
+                type Controller = C;
+
+                fn new(handler: impl #namespace::handler::Handler<Descriptor = Self::Descriptor, Controller = Self::Controller>) -> Self::ClientImpl {
+                    Box::new(#ServiceClient::new(handler))
+                }
+            }
+        }
+    }
+
+    fn struct_ServiceServer(&self) -> TokenStream {
+        let Self {
+            namespace,
+            Service,
+            ServiceDescriptor,
+            ServiceServer,
+            ServiceMethodDescriptor,
+            Service_str,
+            methods,
+            ..
+        } = self;
+
+        let doc = formatdoc! {"
+            A server for a `{Service_str}`.
+
+            This implements the `Server` trait by handling requests and dispatch them to methods on the
+            supplied `{Service_str}`.
+        "};
+
+        let arms = methods.iter().map(
+            |Method {
+                 method_proto,
+                 method,
+                 Input,
+                 ..
+             }| {
+                quote! {
+                    #ServiceMethodDescriptor::#method_proto => {
+                        let decoded: #Input = #namespace::__rt::decode(input)?;
+                        let ret = service.#method(ctrl, decoded).await?;
+                        #namespace::__rt::encode(ret)
+                    }
+                }
+            },
+        );
+
+        quote! {
+            #[doc = #doc]
+            #[derive(Clone, Debug)]
+            pub struct #ServiceServer<A>(A) where A: #Service + Clone + Send + 'static;
+
+            impl<T> #ServiceServer<::std::sync::Weak<T>>
+            where
+                T: Send + Sync + 'static,
+                ::std::sync::Arc<T>: #Service,
+            {
+                pub fn new_arc(service: ::std::sync::Arc<T>) -> #ServiceServer<::std::sync::Weak<T>> {
+                    #ServiceServer(::std::sync::Arc::downgrade(&service))
+                }
+            }
+
+            impl<A> #ServiceServer<A> where A: #Service + Clone + Send + 'static {
+                /// Creates a new server instance that dispatches all calls to the supplied service.
+                pub fn new(service: A) -> #ServiceServer<A> {
+                    #ServiceServer(service)
+                }
+
+                async fn call_inner(
+                    service: A,
+                    method: #ServiceMethodDescriptor,
+                    ctrl: A::Controller,
+                    input: ::bytes::Bytes)
+                    -> #namespace::error::Result<::bytes::Bytes> {
+                    match method {
+                        #(#arms)*
+                    }
+                }
+            }
+
+            #[async_trait::async_trait]
+            impl<A> #namespace::handler::Handler for #ServiceServer<A>
+            where
+                A: #Service + Clone + Send + Sync + 'static {
+                type Descriptor = #ServiceDescriptor;
+                type Controller = A::Controller;
+
+                async fn call(
+                    &self,
+                    ctrl: A::Controller,
+                    method: #ServiceMethodDescriptor,
+                    input: ::bytes::Bytes)
+                    -> #namespace::error::Result<::bytes::Bytes> {
+                    #ServiceServer::call_inner(self.0.clone(), method, ctrl, input).await
+                }
+            }
+        }
+    }
+}
+
+/// The service generator to be used with `prost-build` to generate RPC implementations for
+/// `prost-simple-rpc`.
+///
+/// See the crate-level documentation for more info.
+#[non_exhaustive]
+#[derive(Debug, Default)]
+pub struct ServiceGenerator;
+
+impl prost_build::ServiceGenerator for ServiceGenerator {
+    fn generate(&mut self, service: prost_build::Service, buf: &mut String) {
+        let info = Service::new(service);
+
+        let trait_Service = info.trait_Service();
+        let impl_Service_for_Weak = info.impl_Service_for_Weak();
+        let struct_ServiceDescriptor = info.struct_ServiceDescriptor();
+        let enum_ServiceMethodDescriptor = info.enum_ServiceMethodDescriptor();
+        let struct_ServiceClient = info.struct_ServiceClient();
+        let struct_ServiceClientFactory = info.struct_ServiceClientFactory();
+        let struct_ServiceServer = info.struct_ServiceServer();
+
+        let tokens = quote! {
+            #trait_Service
+
+            #impl_Service_for_Weak
+
+            #struct_ServiceDescriptor
+
+            #enum_ServiceMethodDescriptor
+
+            #struct_ServiceClient
+
+            #struct_ServiceClientFactory
+
+            #struct_ServiceServer
+        };
+
+        buf.push('\n');
+        buf.push_str(&tokens.to_string());
+        buf.push('\n');
+    }
+}