Add one Jaeger span per relay parent (#2196)

* Add one Jaeger span per relay parent

This adds one Jaeger span per relay parent, instead of always creating
new spans per relay parent. This should improve the UI view, because
subsystems are now grouped below one common span.

* Fix doc tests

* Replace `PerLeaveSpan` to `PerLeafSpan`

* More renaming

* Moare

* Update node/subsystem/src/lib.rs

Co-authored-by: Andronik Ordian <write@reusable.software>

* Skip the spans

* Increase `spec_version`

Co-authored-by: Andronik Ordian <write@reusable.software>

polkadot/node/network/protocol/src/lib.rs

@@ -21,10 +21,13 @@
 
 use polkadot_primitives::v1::{Hash, BlockNumber};
 use parity_scale_codec::{Encode, Decode};
-use std::convert::TryFrom;
-use std::fmt;
+use std::{convert::TryFrom, fmt, collections::HashMap};
 
 pub use sc_network::{ReputationChange, PeerId};
+#[doc(hidden)]
+pub use polkadot_node_jaeger::JaegerSpan;
+#[doc(hidden)]
+pub use std::sync::Arc;
 
 /// A unique identifier of a request.
 pub type RequestId = u64;
@@ -44,7 +47,6 @@ impl fmt::Display for WrongVariant {
 
 impl std::error::Error for WrongVariant {}
 
-
 /// The peer-sets that the network manages. Different subsystems will use different peer-sets.
 #[derive(Debug, Clone, Copy, PartialEq)]
 pub enum PeerSet {
@@ -103,8 +105,8 @@ pub enum NetworkBridgeEvent<M> {
 	/// Peer's `View` has changed.
 	PeerViewChange(PeerId, View),
 
-	/// Our `View` has changed.
-	OurViewChange(View),
+	/// Our view has changed.
+	OurViewChange(OurView),
 }
 
 macro_rules! impl_try_from {
@@ -159,6 +161,72 @@ impl<M> NetworkBridgeEvent<M> {
 	}
 }
 
+/// Specialized wrapper around [`View`].
+///
+/// Besides the access to the view itself, it also gives access to the [`JaegerSpan`] per leave/head.
+#[derive(Debug, Clone, Default)]
+pub struct OurView {
+	view: View,
+	span_per_head: HashMap<Hash, Arc<JaegerSpan>>,
+}
+
+impl OurView {
+	/// Creates a new instance.
+	pub fn new(heads: impl IntoIterator<Item = (Hash, Arc<JaegerSpan>)>, finalized_number: BlockNumber) -> Self {
+		let state_per_head = heads.into_iter().collect::<HashMap<_, _>>();
+
+		Self {
+			view: View {
+				heads: state_per_head.keys().cloned().collect(),
+				finalized_number,
+			},
+			span_per_head: state_per_head,
+		}
+	}
+
+	/// Returns the span per head map.
+	///
+	/// For each head there exists one span in this map.
+	pub fn span_per_head(&self) -> &HashMap<Hash, Arc<JaegerSpan>> {
+		&self.span_per_head
+	}
+}
+
+impl PartialEq for OurView {
+	fn eq(&self, other: &Self) -> bool {
+		self.view == other.view
+	}
+}
+
+impl std::ops::Deref for OurView {
+	type Target = View;
+
+	fn deref(&self) -> &View {
+		&self.view
+	}
+}
+
+/// Construct a new [`OurView`] with the given chain heads, finalized number 0 and disabled [`JaegerSpan`]'s.
+///
+/// NOTE: Use for tests only.
+///
+/// # Example
+///
+/// ```
+/// # use polkadot_node_network_protocol::our_view;
+/// # use polkadot_primitives::v1::Hash;
+/// let our_view = our_view![Hash::repeat_byte(1), Hash::repeat_byte(2)];
+/// ```
+#[macro_export]
+macro_rules! our_view {
+	( $( $hash:expr ),* $(,)? ) => {
+		$crate::OurView::new(
+			vec![ $( $hash.clone() ),* ].into_iter().map(|h| (h, $crate::Arc::new($crate::JaegerSpan::Disabled))),
+			0,
+		)
+	};
+}
+
 /// A succinct representation of a peer's view. This consists of a bounded amount of chain heads
 /// and the highest known finalized block number.
 ///
@@ -171,18 +239,21 @@ pub struct View {
 	pub finalized_number: BlockNumber,
 }
 
-
 /// Construct a new view with the given chain heads and finalized number 0.
+///
 /// NOTE: Use for tests only.
+///
 /// # Example
 ///
-/// ```ignore
-/// view![Hash::repeat_byte(1), Hash::repeat_byte(2)]
+/// ```
+/// # use polkadot_node_network_protocol::view;
+/// # use polkadot_primitives::v1::Hash;
+/// let view = view![Hash::repeat_byte(1), Hash::repeat_byte(2)];
 /// ```
 #[macro_export]
 macro_rules! view {
 	( $( $hash:expr ),* $(,)? ) => {
-		View { heads: vec![ $( $hash.clone() ),* ], finalized_number: 0 }
+		$crate::View { heads: vec![ $( $hash.clone() ),* ], finalized_number: 0 }
 	};
 }