RPC: Pending Extrinsics (#563)

* Expose extrinsics in pool.

* Add test.

* Use latest transaction pool.

* Fix compilation.

substrate/substrate/extrinsic-pool/src/api.rs

@@ -16,6 +16,9 @@
 
 //! External API for extrinsic pool.
 
+use std::fmt::Debug;
+
+use serde::{Serialize, de::DeserializeOwned};
 use txpool;
 use futures::sync::mpsc;
 
@@ -43,6 +46,9 @@ pub trait ExtrinsicPool<Ex, BlockId, Hash>: Send + Sync + 'static {
 	/// Error type
 	type Error: Error;
 
+	/// Pooled extrinsics
+	type InPool: Debug + Serialize + DeserializeOwned + Send + Sync + 'static;
+
 	/// Submit a collection of extrinsics to the pool.
 	fn submit(&self, block: BlockId, xt: Vec<Ex>) -> Result<Vec<Hash>, Self::Error>;
 
@@ -54,4 +60,7 @@ pub trait ExtrinsicPool<Ex, BlockId, Hash>: Send + Sync + 'static {
 
 	/// Return an event stream of transactions imported to the pool.
 	fn import_notification_stream(&self) -> EventStream;
+
+	/// Return all extrinsics in the pool aggregated by the sender.
+	fn all(&self) -> Self::InPool;
 }

substrate/substrate/extrinsic-pool/src/pool.rs

@@ -149,4 +149,19 @@ impl<Hash, VEx, S, E> Pool<Hash, VEx, S, E> where
 	{
 		f(self.pool.read().pending(ready))
 	}
+
+	/// Retrieve all transactions in the pool. The transactions might be unordered.
+	pub fn all<F, T>(&self, f: F) -> T where
+		F: FnOnce(txpool::UnorderedIterator<VEx, AlwaysReady, S>) -> T,
+	{
+		f(self.pool.read().unordered_pending(AlwaysReady))
+	}
+}
+
+/// A Readiness implementation that returns `Ready` for all transactions.
+pub struct AlwaysReady;
+impl<VEx> txpool::Ready<VEx> for AlwaysReady {
+	fn is_ready(&mut self, _tx: &VEx) -> txpool::Readiness {
+		txpool::Readiness::Ready
+	}
 }