Extrinsic pool (#182)

* Use latest version of txpool.

* Initial version of the pool.

* Fix abstraction.

* Implement watchers and notifications.

* Return hash from RPC.

* Remove commented code.

* Remove client dep.

* Fix tests.

substrate/substrate/rpc/src/author/mod.rs

@@ -16,7 +16,9 @@
 
 //! Substrate block-author/full-node API.
 
-use primitives::block::Extrinsic;
+use std::sync::Arc;
+use primitives::block::{Extrinsic, ExtrinsicHash};
+use extrinsic_pool::api::{Error, ExtrinsicPool};
 
 pub mod error;
 
@@ -30,6 +32,20 @@ build_rpc_trait! {
 	pub trait AuthorApi {
 		/// Submit extrinsic for inclusion in block.
 		#[rpc(name = "author_submitExtrinsic")]
-		fn submit_extrinsic(&self, Extrinsic) -> Result<()>;
+		fn submit_extrinsic(&self, Extrinsic) -> Result<ExtrinsicHash>;
+	}
+}
+
+impl<T> AuthorApi for Arc<T> where
+	T: ExtrinsicPool,
+{
+	fn submit_extrinsic(&self, xt: Extrinsic) -> Result<ExtrinsicHash> {
+		self
+			.submit(vec![xt])
+			.map(|mut res| res.pop().expect("One extrinsic passed; one result back; qed"))
+			.map_err(|e| e.into_pool_error()
+				.map(Into::into)
+				.unwrap_or_else(|e| error::ErrorKind::Verification(Box::new(e)).into())
+			)
 	}
 }