From 61ea7c65a64bb977c2e54ed1833d8d2190bb4007 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tomasz=20Drwi=C4=99ga?= <tomusdrw@users.noreply.github.com>
Date: Wed, 9 Dec 2020 12:05:06 +0100
Subject: [PATCH] [forwardport] Update `local` client to support middleware
 (Kudos Seun) (#589) (#600)

* Update `local` client to support middleware (Kudos Seun) (#589)

* v15.0.1

* v15.0.1 => v15.1.0

* v15.0.1 => v15.1.0

* cargo fmt

* fix tests

* adds *_with_middleware methods

* remove Unpin bound, add documentation, cargo fmt

* 15.0.1

* bump to 15.1.0

Co-authored-by: Seun Lanlege <seunlanlege@gmail.com>
Co-authored-by: Niklas <niklasadolfsson1@gmail.com>

* cargo fmt --all

Co-authored-by: Seun Lanlege <seunlanlege@gmail.com>
Co-authored-by: Niklas <niklasadolfsson1@gmail.com>
---
 .../transports/src/transports/local.rs        | 77 +++++++++++++++----
 1 file changed, 60 insertions(+), 17 deletions(-)

diff --git a/core-client/transports/src/transports/local.rs b/core-client/transports/src/transports/local.rs
index e4d91eaef..da91a554b 100644
--- a/core-client/transports/src/transports/local.rs
+++ b/core-client/transports/src/transports/local.rs
@@ -6,7 +6,7 @@ use futures::{
 	task::{Context, Poll},
 	Future, Sink, SinkExt, Stream, StreamExt,
 };
-use jsonrpc_core::{BoxFuture, MetaIoHandler, Metadata};
+use jsonrpc_core::{BoxFuture, MetaIoHandler, Metadata, Middleware};
 use jsonrpc_pubsub::Session;
 use std::ops::Deref;
 use std::pin::Pin;
@@ -26,10 +26,11 @@ enum Buffered {
 	None,
 }
 
-impl<TMetadata, THandler> LocalRpc<THandler, TMetadata>
+impl<TMetadata, THandler, TMiddleware> LocalRpc<THandler, TMetadata>
 where
 	TMetadata: Metadata,
-	THandler: Deref<Target = MetaIoHandler<TMetadata>>,
+	TMiddleware: Middleware<TMetadata>,
+	THandler: Deref<Target = MetaIoHandler<TMetadata, TMiddleware>>,
 {
 	/// Creates a new `LocalRpc` with default metadata.
 	pub fn new(handler: THandler) -> Self
@@ -50,10 +51,11 @@ where
 	}
 }
 
-impl<TMetadata, THandler> Stream for LocalRpc<THandler, TMetadata>
+impl<TMetadata, THandler, TMiddleware> Stream for LocalRpc<THandler, TMetadata>
 where
 	TMetadata: Metadata + Unpin,
-	THandler: Deref<Target = MetaIoHandler<TMetadata>> + Unpin,
+	TMiddleware: Middleware<TMetadata> + Unpin,
+	THandler: Deref<Target = MetaIoHandler<TMetadata, TMiddleware>> + Unpin,
 {
 	type Item = String;
 
@@ -62,10 +64,11 @@ where
 	}
 }
 
-impl<TMetadata, THandler> LocalRpc<THandler, TMetadata>
+impl<TMetadata, THandler, TMiddleware> LocalRpc<THandler, TMetadata>
 where
 	TMetadata: Metadata + Unpin,
-	THandler: Deref<Target = MetaIoHandler<TMetadata>> + Unpin,
+	TMiddleware: Middleware<TMetadata> + Unpin,
+	THandler: Deref<Target = MetaIoHandler<TMetadata, TMiddleware>> + Unpin,
 {
 	fn poll_buffered(&mut self, cx: &mut Context) -> Poll<Result<(), RpcError>> {
 		let response = match self.buffered {
@@ -87,10 +90,11 @@ where
 	}
 }
 
-impl<TMetadata, THandler> Sink<String> for LocalRpc<THandler, TMetadata>
+impl<TMetadata, THandler, TMiddleware> Sink<String> for LocalRpc<THandler, TMetadata>
 where
 	TMetadata: Metadata + Unpin,
-	THandler: Deref<Target = MetaIoHandler<TMetadata>> + Unpin,
+	TMiddleware: Middleware<TMetadata> + Unpin,
+	THandler: Deref<Target = MetaIoHandler<TMetadata, TMiddleware>> + Unpin,
 {
 	type Error = RpcError;
 
@@ -121,14 +125,15 @@ where
 	}
 }
 
-/// Connects to a `Deref<Target = MetaIoHandler<Metadata>`.
-pub fn connect_with_metadata<TClient, THandler, TMetadata>(
+/// Connects to a `Deref<Target = MetaIoHandler<Metadata>` specifying a custom middleware implementation.
+pub fn connect_with_metadata_and_middleware<TClient, THandler, TMetadata, TMiddleware>(
 	handler: THandler,
 	meta: TMetadata,
 ) -> (TClient, impl Future<Output = RpcResult<()>>)
 where
 	TClient: From<RpcChannel>,
-	THandler: Deref<Target = MetaIoHandler<TMetadata>> + Unpin,
+	TMiddleware: Middleware<TMetadata> + Unpin,
+	THandler: Deref<Target = MetaIoHandler<TMetadata, TMiddleware>> + Unpin,
 	TMetadata: Metadata + Unpin,
 {
 	let (sink, stream) = LocalRpc::with_metadata(handler, meta).split();
@@ -137,24 +142,53 @@ where
 	(client, rpc_client)
 }
 
+/// Connects to a `Deref<Target = MetaIoHandler<Metadata>`.
+pub fn connect_with_metadata<TClient, THandler, TMetadata>(
+	handler: THandler,
+	meta: TMetadata,
+) -> (TClient, impl Future<Output = RpcResult<()>>)
+where
+	TClient: From<RpcChannel>,
+	TMetadata: Metadata + Unpin,
+	THandler: Deref<Target = MetaIoHandler<TMetadata>> + Unpin,
+{
+	connect_with_metadata_and_middleware(handler, meta)
+}
+
+/// Connects to a `Deref<Target = MetaIoHandler<Metadata + Default>` specifying a custom middleware implementation.
+pub fn connect_with_middleware<TClient, THandler, TMetadata, TMiddleware>(
+	handler: THandler,
+) -> (TClient, impl Future<Output = RpcResult<()>>)
+where
+	TClient: From<RpcChannel>,
+	TMetadata: Metadata + Default + Unpin,
+	TMiddleware: Middleware<TMetadata> + Unpin,
+	THandler: Deref<Target = MetaIoHandler<TMetadata, TMiddleware>> + Unpin,
+{
+	connect_with_metadata_and_middleware(handler, Default::default())
+}
+
 /// Connects to a `Deref<Target = MetaIoHandler<Metadata + Default>`.
 pub fn connect<TClient, THandler, TMetadata>(handler: THandler) -> (TClient, impl Future<Output = RpcResult<()>>)
 where
 	TClient: From<RpcChannel>,
-	THandler: Deref<Target = MetaIoHandler<TMetadata>> + Unpin,
 	TMetadata: Metadata + Default + Unpin,
+	THandler: Deref<Target = MetaIoHandler<TMetadata>> + Unpin,
 {
-	connect_with_metadata(handler, Default::default())
+	connect_with_middleware(handler)
 }
 
 /// Metadata for LocalRpc.
 pub type LocalMeta = Arc<Session>;
 
-/// Connects with pubsub.
-pub fn connect_with_pubsub<TClient, THandler>(handler: THandler) -> (TClient, impl Future<Output = RpcResult<()>>)
+/// Connects with pubsub specifying a custom middleware implementation.
+pub fn connect_with_pubsub_and_middleware<TClient, THandler, TMiddleware>(
+	handler: THandler,
+) -> (TClient, impl Future<Output = RpcResult<()>>)
 where
 	TClient: From<RpcChannel>,
-	THandler: Deref<Target = MetaIoHandler<LocalMeta>> + Unpin,
+	TMiddleware: Middleware<LocalMeta> + Unpin,
+	THandler: Deref<Target = MetaIoHandler<LocalMeta, TMiddleware>> + Unpin,
 {
 	let (tx, rx) = mpsc::unbounded();
 	let meta = Arc::new(Session::new(tx));
@@ -164,3 +198,12 @@ where
 	let client = TClient::from(sender);
 	(client, rpc_client)
 }
+
+/// Connects with pubsub.
+pub fn connect_with_pubsub<TClient, THandler>(handler: THandler) -> (TClient, impl Future<Output = RpcResult<()>>)
+where
+	TClient: From<RpcChannel>,
+	THandler: Deref<Target = MetaIoHandler<LocalMeta>> + Unpin,
+{
+	connect_with_pubsub_and_middleware(handler)
+}