api_schema: allow generic api handler functions

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>

src/api2.rs

@@ -35,7 +35,7 @@ pub fn router() -> Router {
 
     let route = Router::new()
         .get(ApiMethod::new(
-            |_,_,_| Ok(json!([
+            || Ok(json!([
                 {"subdir": "access"},
                 {"subdir": "admin"},
                 {"subdir": "config"},

src/api2/access.rs

@@ -70,7 +70,7 @@ pub fn router() -> Router {
 
     let route = Router::new()
         .get(ApiMethod::new(
-            |_,_,_| Ok(json!([
+            || Ok(json!([
                 {"subdir": "ticket"}
             ])),
             ObjectSchema::new("Directory index.")))

src/api2/admin.rs

@@ -8,7 +8,7 @@ pub fn router() -> Router {
 
     let route = Router::new()
         .get(ApiMethod::new(
-            |_,_,_| Ok(json!([
+            || Ok(json!([
                 {"subdir": "datastore"}
             ])),
             ObjectSchema::new("Directory index.")))

src/api2/admin/datastore.rs

@@ -388,7 +388,7 @@ pub fn router() -> Router {
 
     let datastore_info = Router::new()
         .get(ApiMethod::new(
-            |_,_,_| Ok(json!([
+            || Ok(json!([
                 {"subdir": "backups" },
                 {"subdir": "pxar" },
                 {"subdir": "gc" },

src/api2/config.rs

@@ -11,7 +11,7 @@ pub fn router() -> Router {
 
     let route = Router::new()
         .get(ApiMethod::new(
-            |_,_,_| Ok(json!([
+            || Ok(json!([
                 {"subdir": "datastore"},
             ])),
             ObjectSchema::new("Directory index.")))

src/api2/node.rs

@@ -35,7 +35,7 @@ pub fn router() -> Router {
 
     let route = Router::new()
         .get(ApiMethod::new(
-            |_,_,_| Ok(json!([
+            || Ok(json!([
                 {"subdir": "dns"},
                 {"subdir": "network"},
                 {"subdir": "services"},

src/api2/node/services.rs

@@ -224,7 +224,7 @@ pub fn router() -> Router {
 
     let service_api = Router::new()
         .get(ApiMethod::new(
-            |_,_,_| {
+            || {
                 let mut result = vec![];
                 for cmd in &["state", "start", "stop", "restart", "reload"] {
                     result.push(json!({"subdir": cmd }));

src/api2/node/tasks.rs

@@ -175,7 +175,7 @@ pub fn router() -> Router {
 
     let upid_api = Router::new()
         .get(ApiMethod::new(
-            |_,_,_| {
+            || {
                 let mut result = vec![];
                 for cmd in &["log", "status"] {
                     result.push(json!({"subdir": cmd }));

src/api_schema.rs

@@ -12,6 +12,7 @@
 mod schema;
 pub use schema::*;
 
+pub mod api_handler;
 pub mod registry;
 #[macro_use]
 pub mod router;

src/api_schema/api_handler.rs

@@ -0,0 +1,135 @@
+use failure::Error;
+use serde_json::Value;
+
+use super::router::{ApiMethod, RpcEnvironment};
+
+pub type ApiHandlerFn = Box<
+    dyn Fn(Value, &ApiMethod, &mut dyn RpcEnvironment) -> Result<Value, Error>
+    + Send + Sync + 'static
+>;
+
+pub trait WrapApiHandler<Args, R, MetaArgs> {
+    fn wrap(self) -> ApiHandlerFn;
+}
+
+// fn()
+impl<F, R> WrapApiHandler<(), R, ()> for F
+where
+    F: Fn() -> Result<R, Error> + Send + Sync + 'static,
+    R: serde::Serialize,
+{
+    fn wrap(self) -> ApiHandlerFn {
+        Box::new(move |_value, _method, _rpc_env| {
+            Ok(serde_json::to_value((self)()?)?)
+        })
+    }
+}
+
+// fn(Arg)
+impl<F, A, R> WrapApiHandler<(A,), R, ()> for F
+where
+    F: Fn(A) -> Result<R, Error> + Send + Sync + 'static,
+    A: serde::de::DeserializeOwned,
+    R: serde::Serialize,
+{
+    fn wrap(self) -> ApiHandlerFn {
+        Box::new(move |value, _method, _rpc_env| {
+            Ok(serde_json::to_value((self)(serde_json::from_value(value)?)?)?)
+        })
+    }
+}
+
+// fn(&ApiMethod)
+impl<F, R> WrapApiHandler<(), R, (ApiMethod,)> for F
+where
+    F: Fn(&ApiMethod) -> Result<R, Error> + Send + Sync + 'static,
+    R: serde::Serialize,
+{
+    fn wrap(self) -> ApiHandlerFn {
+        Box::new(move |_value, method, _rpc_env| {
+            Ok(serde_json::to_value((self)(method)?)?)
+        })
+    }
+}
+
+// fn(Arg, &ApiMethod)
+impl<F, A, R> WrapApiHandler<(A,), R, (ApiMethod,)> for F
+where
+    F: Fn(A, &ApiMethod) -> Result<R, Error> + Send + Sync + 'static,
+    A: serde::de::DeserializeOwned,
+    R: serde::Serialize,
+{
+    fn wrap(self) -> ApiHandlerFn {
+        Box::new(move |value, method, _rpc_env| {
+            Ok(serde_json::to_value((self)(
+                serde_json::from_value(value)?,
+                method,
+            )?)?)
+        })
+    }
+}
+
+// RpcEnvironment is a trait, so use a "marker" type for it instead:
+pub struct RpcEnvArg();
+
+// fn(&mut dyn RpcEnvironment)
+impl<F, R> WrapApiHandler<(), R, (RpcEnvArg,)> for F
+where
+    F: Fn(&mut dyn RpcEnvironment) -> Result<R, Error> + Send + Sync + 'static,
+    R: serde::Serialize,
+{
+    fn wrap(self) -> ApiHandlerFn {
+        Box::new(move |_value, _method, rpc_env| {
+            Ok(serde_json::to_value((self)(rpc_env)?)?)
+        })
+    }
+}
+
+// fn(Arg, &mut dyn RpcEnvironment)
+impl<F, A, R> WrapApiHandler<(A,), R, (RpcEnvArg,)> for F
+where
+    F: Fn(A, &mut dyn RpcEnvironment) -> Result<R, Error> + Send + Sync + 'static,
+    A: serde::de::DeserializeOwned,
+    R: serde::Serialize,
+{
+    fn wrap(self) -> ApiHandlerFn {
+        Box::new(move |value, _method, rpc_env| {
+            Ok(serde_json::to_value((self)(
+                serde_json::from_value(value)?,
+                rpc_env,
+            )?)?)
+        })
+    }
+}
+
+// fn(&ApiMethod, &mut dyn RpcEnvironment)
+impl<F, R> WrapApiHandler<(), R, (ApiMethod, RpcEnvArg,)> for F
+where
+    F: Fn(&ApiMethod, &mut dyn RpcEnvironment) -> Result<R, Error> + Send + Sync + 'static,
+    R: serde::Serialize,
+{
+    fn wrap(self) -> ApiHandlerFn {
+        Box::new(move |_value, method, rpc_env| {
+            Ok(serde_json::to_value((self)(method, rpc_env)?)?)
+        })
+    }
+}
+
+// fn(Arg, &ApiMethod, &mut dyn RpcEnvironment)
+impl<F, A, R> WrapApiHandler<(A,), R, (ApiMethod, RpcEnvArg,)> for F
+where
+    F: Fn(A, &ApiMethod, &mut dyn RpcEnvironment) -> Result<R, Error> + Send + Sync + 'static,
+    A: serde::de::DeserializeOwned,
+    R: serde::Serialize,
+{
+    fn wrap(self) -> ApiHandlerFn {
+        Box::new(move |value, method, rpc_env| {
+            Ok(serde_json::to_value((self)(
+                serde_json::from_value(value)?,
+                method,
+                rpc_env,
+            )?)?)
+        })
+    }
+}
+

src/api_schema/router.rs

@@ -10,6 +10,8 @@ use hyper::{Body, Response, StatusCode};
 use hyper::rt::Future;
 use hyper::http::request::Parts;
 
+use super::api_handler::*;
+
 pub type BoxFut = Box<Future<Item = Response<Body>, Error = failure::Error> + Send>;
 
 /// Abstract Interface for API methods to interact with the environment
@@ -72,9 +74,10 @@ macro_rules! http_err {
     }}
 }
 
-type ApiHandlerFn = fn(Value, &ApiMethod, &mut dyn RpcEnvironment) -> Result<Value, Error>;
-
-type ApiAsyncHandlerFn = fn(Parts, Body, Value, &ApiAsyncMethod, &mut dyn RpcEnvironment) -> Result<BoxFut, Error>;
+type ApiAsyncHandlerFn = Box<
+    dyn Fn(Parts, Body, Value, &ApiAsyncMethod, &mut dyn RpcEnvironment) -> Result<BoxFut, Error>
+    + Send + Sync + 'static
+>;
 
 /// This struct defines synchronous API call which returns the restulkt as json `Value`
 pub struct ApiMethod {
@@ -89,15 +92,28 @@ pub struct ApiMethod {
     /// Return type Schema
     pub returns: Arc<Schema>,
     /// Handler function
-    pub handler: ApiHandlerFn,
+    pub handler: Option<ApiHandlerFn>,
 }
 
 impl ApiMethod {
 
-    pub fn new(handler: ApiHandlerFn, parameters: ObjectSchema) -> Self {
+    pub fn new<F, Args, R, MetaArgs>(func: F, parameters: ObjectSchema) -> Self
+    where
+        F: WrapApiHandler<Args, R, MetaArgs>,
+    {
         Self {
             parameters,
-            handler,
+            handler: Some(func.wrap()),
+            returns: Arc::new(Schema::Null),
+            protected: false,
+            reload_timezone: false,
+        }
+    }
+
+    pub fn new_dummy(parameters: ObjectSchema) -> Self {
+        Self {
+            parameters,
+            handler: None,
             returns: Arc::new(Schema::Null),
             protected: false,
             reload_timezone: false,
@@ -134,10 +150,14 @@ pub struct ApiAsyncMethod {
 
 impl ApiAsyncMethod {
 
-    pub fn new(handler: ApiAsyncHandlerFn, parameters: ObjectSchema) -> Self {
+    pub fn new<F>(handler: F, parameters: ObjectSchema) -> Self
+    where
+        F: Fn(Parts, Body, Value, &ApiAsyncMethod, &mut dyn RpcEnvironment) -> Result<BoxFut, Error>
+            + Send + Sync + 'static,
+    {
         Self {
             parameters,
-            handler,
+            handler: Box::new(handler),
             returns: Arc::new(Schema::Null),
         }
     }

src/cli/command.rs

@@ -1,7 +1,6 @@
 use failure::*;
 use std::collections::HashMap;
 use std::collections::HashSet;
-use serde_json::Value;
 
 use crate::api_schema::*;
 use crate::api_schema::router::*;
@@ -268,7 +267,7 @@ fn handle_simple_command(
         }
     };
 
-    if (cli_cmd.info.handler as *const fn()) == (dummy_help as *const fn()) {
+    if cli_cmd.info.handler.is_none() {
         let prefix = prefix.split(' ').next().unwrap().to_string();
         print_help(top_def, prefix, &rest, params["verbose"].as_bool());
         return;
@@ -282,7 +281,7 @@ fn handle_simple_command(
 
     let mut rpcenv = CliEnvironment::new();
 
-    match (cli_cmd.info.handler)(params, &cli_cmd.info, &mut rpcenv) {
+    match (cli_cmd.info.handler.as_ref().unwrap())(params, &cli_cmd.info, &mut rpcenv) {
         Ok(value) => {
             println!("Result: {}", serde_json::to_string_pretty(&value).unwrap());
         }
@@ -603,8 +602,7 @@ pub fn print_bash_completion(def: &CommandLineInterface) {
 
 fn help_command_def() ->  CliCommand {
     CliCommand::new(
-        ApiMethod::new(
-            dummy_help,
+        ApiMethod::new_dummy(
             ObjectSchema::new("Get help about specified command.")
                 .optional("verbose", BooleanSchema::new("Verbose help."))
         )
@@ -693,10 +691,6 @@ pub struct CliCommandMap {
     pub commands: HashMap<String, CommandLineInterface>,
 }
 
-fn dummy_help(_param: Value, _info: &ApiMethod, _rpcenv: &mut RpcEnvironment) -> Result<Value, Error> {
-    panic!("internal error"); // this is just a place holder - never call this
-}
-
 impl CliCommandMap {
 
     pub fn new() -> Self {

src/server/rest.rs

@@ -239,7 +239,7 @@ fn handle_sync_api_request(
     let resp = params
         .and_then(move |params| {
             let mut delay = false;
-            let resp = match (info.handler)(params, info, &mut rpcenv) {
+            let resp = match (info.handler.as_ref().unwrap())(params, info, &mut rpcenv) {
                 Ok(data) => (formatter.format_result)(data, &rpcenv),
                 Err(err) => {
                     if let Some(httperr) = err.downcast_ref::<HttpError>() {