Convert to std futures (#58)

* WIP

* Begin converting rpc layer to use std futures and jsonrpsee

* Convert metadata to async/await

* Convert block_hash to async/await

* Convert more methods to async/await

* Remove sp_rpc

* Fix more compilation errors

* Remove connect

* Starting to convert subscription functions

* Use jsonrpsee branch from PR for public client types

* Implement subscribe events with jsonrpsee subscription

* Converting subscriptions and wait_for_block_events

* WIP converting lib methods to async

* Use shared client reference directly for rpc call

`rpc_api!` macro currently only supports RawClient (which cannot be shared).
Also supports named params only which is not currently compatible with substrate rpd which accepts only positional params.

* Use &self instead of &mut self for shared Client

* Convert submit_and_watch to async/await

* Convert more Client fns to async

* Pin some trait futures

* Add serde error

* Fix client creation

* Fix client request compiler errors

* Unify metadata errors

* Add WS handshake error variant

* Fix some more compiler errors

* Fix more compiler errors

* Convert submit_extrinsic to async

* Convert submit and submit_and_watch

* Add Send + Sync constraints

* Clone clients

* Fix EventArg conversion error

* Fix remaining warnings/errors

* Replace deny warnings with specific lints

* Infallable subscription loops

* Use jsonrpsee wss branch

* Fix example

* Start to fix up tests

* Make contracts tests compile

* Make some more tests pass

* Fix up remaining tests

* Fmt

* Use correct event storage key type

* Fix finding events

* Use master jsonrpsee

src/frame/system.rs

@@ -16,16 +16,13 @@
 
 //! Implements support for the frame_system module.
 
-use std::fmt::Debug;
-
 use codec::Codec;
+use frame_support::Parameter;
 use futures::future::{
     self,
     Future,
 };
 use serde::de::DeserializeOwned;
-
-use frame_support::Parameter;
 use sp_runtime::traits::{
     Bounded,
     CheckEqual,
@@ -39,6 +36,10 @@ use sp_runtime::traits::{
     SimpleArithmetic,
     SimpleBitOps,
 };
+use std::{
+    fmt::Debug,
+    pin::Pin,
+};
 
 use crate::{
     error::Error,
@@ -123,17 +124,22 @@ pub trait SystemStore {
     fn account_nonce(
         &self,
         account_id: <Self::System as System>::AccountId,
-    ) -> Box<dyn Future<Item = <Self::System as System>::Index, Error = Error> + Send>;
+    ) -> Pin<
+        Box<dyn Future<Output = Result<<Self::System as System>::Index, Error>> + Send>,
+    >;
 }
 
-impl<T: System + Balances + 'static, S: 'static> SystemStore for Client<T, S> {
+impl<T: System + Balances + Sync + Send + 'static, S: 'static> SystemStore
+    for Client<T, S>
+{
     type System = T;
 
     fn account_nonce(
         &self,
         account_id: <Self::System as System>::AccountId,
-    ) -> Box<dyn Future<Item = <Self::System as System>::Index, Error = Error> + Send>
-    {
+    ) -> Pin<
+        Box<dyn Future<Output = Result<<Self::System as System>::Index, Error>> + Send>,
+    > {
         let account_nonce_map = || {
             Ok(self
                 .metadata
@@ -143,9 +149,14 @@ impl<T: System + Balances + 'static, S: 'static> SystemStore for Client<T, S> {
         };
         let map = match account_nonce_map() {
             Ok(map) => map,
-            Err(err) => return Box::new(future::err(err)),
+            Err(err) => return Box::pin(future::err(err)),
         };
-        Box::new(self.fetch_or(map.key(account_id), None, map.default()))
+        let client = self.clone();
+        Box::pin(async move {
+            client
+                .fetch_or(map.key(account_id), None, map.default())
+                .await
+        })
     }
 }