Optimize tree route to sync faster

Cargo.toml

@@ -26,6 +26,7 @@ members = [
 	"core/cli",
 	"core/client",
 	"core/client/db",
+	"core/client/header-metadata",
 	"core/consensus/aura",
 	"core/consensus/babe",
 	"core/consensus/common",

core/cli/Cargo.toml

@@ -24,6 +24,7 @@ exit-future = "0.1"
 serde_json = "1.0"
 panic-handler = { package = "substrate-panic-handler", path = "../../core/panic-handler" }
 client = { package = "substrate-client", path = "../../core/client" }
+header-metadata = { package = "substrate-header-metadata", path = "../../core/client/header-metadata" }
 network = { package = "substrate-network", path = "../../core/network" }
 sr-primitives = { path = "../../core/sr-primitives" }
 primitives = { package = "substrate-primitives", path = "../../core/primitives" }

core/cli/src/informant.rs

@@ -20,7 +20,7 @@ use client::BlockchainEvents;
 use futures::{Future, Stream};
 use futures03::{StreamExt as _, TryStreamExt as _};
 use log::{info, warn};
-use sr_primitives::{generic::BlockId, traits::Header};
+use sr_primitives::traits::Header;
 use service::AbstractService;
 
 mod display;
@@ -47,19 +47,18 @@ pub fn build(service: &impl AbstractService) -> impl Future<Item = (), Error = (
 		// detect and log reorganizations.
 		if let Some((ref last_num, ref last_hash)) = last_best {
 			if n.header.parent_hash() != last_hash && n.is_new_best  {
-				let tree_route = ::client::blockchain::tree_route(
-					|id| client.header(&id)?.ok_or_else(
-						|| client::error::Error::UnknownBlock(format!("{:?}", id))),
-					BlockId::Hash(last_hash.clone()),
-					BlockId::Hash(n.hash),
+				let maybe_ancestor = header_metadata::lowest_common_ancestor(
+					&*client,
+					last_hash.clone(),
+					n.hash,
 				);
 
-				match tree_route {
-					Ok(ref t) if !t.retracted().is_empty() => info!(
+				match maybe_ancestor {
+					Ok(ref ancestor) if ancestor.hash != *last_hash => info!(
 						"Reorg from #{},{} to #{},{}, common ancestor #{},{}",
 						last_num, last_hash,
 						n.header.number(), n.hash,
-						t.common_block().number, t.common_block().hash,
+						ancestor.number, ancestor.hash,
 					),
 					Ok(_) => {},
 					Err(e) => warn!("Error computing tree route: {}", e),

core/client/Cargo.toml

@@ -27,6 +27,7 @@ runtime-version = { package = "sr-version", path = "../sr-version", default-feat
 rstd = { package = "sr-std", path = "../sr-std", default-features = false }
 inherents = { package = "substrate-inherents", path = "../inherents", default-features = false }
 sr-api-macros = { path = "../sr-api-macros" }
+header-metadata = { package = "substrate-header-metadata", path = "header-metadata", optional = true }
 
 [dev-dependencies]
 env_logger = "0.6"
@@ -45,6 +46,7 @@ std = [
 	"sr-primitives/std",
 	"runtime-version/std",
 	"hash-db/std",
+	"header-metadata",
 	"consensus",
 	"parking_lot",
 	"derive_more",

core/client/db/Cargo.toml

@@ -22,6 +22,7 @@ executor = { package = "substrate-executor", path = "../../executor" }
 state_db = { package = "substrate-state-db", path = "../../state-db" }
 trie = { package = "substrate-trie", path = "../../trie" }
 consensus_common = { package = "substrate-consensus-common", path = "../../consensus/common" }
+header_metadata = { package = "substrate-header-metadata", path = "../header-metadata" }
 
 [dev-dependencies]
 substrate-keyring = { path = "../../keyring" }