Kill the light client, CHTs and change tries. (#10080)

* Remove light client, change tries and CHTs

* Update tests

* fmt

* Restore changes_root

* Fixed benches

* Cargo fmt

* fmt

* fmt

substrate/primitives/runtime/src/generic/digest.rs

@@ -26,59 +26,49 @@ use crate::{
 	codec::{Decode, Encode, Error, Input},
 	scale_info::{
 		build::{Fields, Variants},
-		meta_type, Path, Type, TypeInfo, TypeParameter,
+		Path, Type, TypeInfo,
 	},
 	ConsensusEngineId,
 };
-use sp_core::{ChangesTrieConfiguration, RuntimeDebug};
+use sp_core::RuntimeDebug;
 
 /// Generic header digest.
 #[derive(PartialEq, Eq, Clone, Encode, Decode, RuntimeDebug, TypeInfo)]
 #[cfg_attr(feature = "std", derive(Serialize, Deserialize, parity_util_mem::MallocSizeOf))]
-pub struct Digest<Hash> {
+pub struct Digest {
 	/// A list of logs in the digest.
-	#[cfg_attr(
-		feature = "std",
-		serde(bound(serialize = "Hash: codec::Codec", deserialize = "Hash: codec::Codec"))
-	)]
-	pub logs: Vec<DigestItem<Hash>>,
+	pub logs: Vec<DigestItem>,
 }
 
-impl<Item> Default for Digest<Item> {
+impl Default for Digest {
 	fn default() -> Self {
 		Self { logs: Vec::new() }
 	}
 }
 
-impl<Hash> Digest<Hash> {
+impl Digest {
 	/// Get reference to all digest items.
-	pub fn logs(&self) -> &[DigestItem<Hash>] {
+	pub fn logs(&self) -> &[DigestItem] {
 		&self.logs
 	}
 
 	/// Push new digest item.
-	pub fn push(&mut self, item: DigestItem<Hash>) {
+	pub fn push(&mut self, item: DigestItem) {
 		self.logs.push(item);
 	}
 
 	/// Pop a digest item.
-	pub fn pop(&mut self) -> Option<DigestItem<Hash>> {
+	pub fn pop(&mut self) -> Option<DigestItem> {
 		self.logs.pop()
 	}
 
 	/// Get reference to the first digest item that matches the passed predicate.
-	pub fn log<T: ?Sized, F: Fn(&DigestItem<Hash>) -> Option<&T>>(
-		&self,
-		predicate: F,
-	) -> Option<&T> {
+	pub fn log<T: ?Sized, F: Fn(&DigestItem) -> Option<&T>>(&self, predicate: F) -> Option<&T> {
 		self.logs().iter().find_map(predicate)
 	}
 
 	/// Get a conversion of the first digest item that successfully converts using the function.
-	pub fn convert_first<T, F: Fn(&DigestItem<Hash>) -> Option<T>>(
-		&self,
-		predicate: F,
-	) -> Option<T> {
+	pub fn convert_first<T, F: Fn(&DigestItem) -> Option<T>>(&self, predicate: F) -> Option<T> {
 		self.logs().iter().find_map(predicate)
 	}
 }
@@ -87,12 +77,7 @@ impl<Hash> Digest<Hash> {
 /// provide opaque access to other items.
 #[derive(PartialEq, Eq, Clone, RuntimeDebug)]
 #[cfg_attr(feature = "std", derive(parity_util_mem::MallocSizeOf))]
-pub enum DigestItem<Hash> {
-	/// System digest item that contains the root of changes trie at given
-	/// block. It is created for every block iff runtime supports changes
-	/// trie creation.
-	ChangesTrieRoot(Hash),
-
+pub enum DigestItem {
 	/// A pre-runtime digest.
 	///
 	/// These are messages from the consensus engine to the runtime, although
@@ -116,10 +101,6 @@ pub enum DigestItem<Hash> {
 	/// by runtimes.
 	Seal(ConsensusEngineId, Vec<u8>),
 
-	/// Digest item that contains signal from changes tries manager to the
-	/// native code.
-	ChangesTrieSignal(ChangesTrieSignal),
-
 	/// Some other thing. Unsupported and experimental.
 	Other(Vec<u8>),
 
@@ -132,25 +113,8 @@ pub enum DigestItem<Hash> {
 	RuntimeEnvironmentUpdated,
 }
 
-/// Available changes trie signals.
-#[derive(PartialEq, Eq, Clone, Encode, Decode, TypeInfo)]
-#[cfg_attr(feature = "std", derive(Debug, parity_util_mem::MallocSizeOf))]
-pub enum ChangesTrieSignal {
-	/// New changes trie configuration is enacted, starting from **next block**.
-	///
-	/// The block that emits this signal will contain changes trie (CT) that covers
-	/// blocks range [BEGIN; current block], where BEGIN is (order matters):
-	/// - LAST_TOP_LEVEL_DIGEST_BLOCK+1 if top level digest CT has ever been created using current
-	///   configuration AND the last top level digest CT has been created at block
-	///   LAST_TOP_LEVEL_DIGEST_BLOCK;
-	/// - LAST_CONFIGURATION_CHANGE_BLOCK+1 if there has been CT configuration change before and
-	///   the last configuration change happened at block LAST_CONFIGURATION_CHANGE_BLOCK;
-	/// - 1 otherwise.
-	NewConfiguration(Option<ChangesTrieConfiguration>),
-}
-
 #[cfg(feature = "std")]
-impl<Hash: Encode> serde::Serialize for DigestItem<Hash> {
+impl serde::Serialize for DigestItem {
 	fn serialize<S>(&self, seq: S) -> Result<S::Ok, S::Error>
 	where
 		S: serde::Serializer,
@@ -160,7 +124,7 @@ impl<Hash: Encode> serde::Serialize for DigestItem<Hash> {
 }
 
 #[cfg(feature = "std")]
-impl<'a, Hash: Decode> serde::Deserialize<'a> for DigestItem<Hash> {
+impl<'a> serde::Deserialize<'a> for DigestItem {
 	fn deserialize<D>(de: D) -> Result<Self, D::Error>
 	where
 		D: serde::Deserializer<'a>,
@@ -171,75 +135,48 @@ impl<'a, Hash: Decode> serde::Deserialize<'a> for DigestItem<Hash> {
 	}
 }
 
-impl<Hash> TypeInfo for DigestItem<Hash>
-where
-	Hash: TypeInfo + 'static,
-{
+impl TypeInfo for DigestItem {
 	type Identity = Self;
 
 	fn type_info() -> Type {
-		Type::builder()
-			.path(Path::new("DigestItem", module_path!()))
-			.type_params(vec![TypeParameter::new("Hash", Some(meta_type::<Hash>()))])
-			.variant(
-				Variants::new()
-					.variant("ChangesTrieRoot", |v| {
-						v.index(DigestItemType::ChangesTrieRoot as u8)
-							.fields(Fields::unnamed().field(|f| f.ty::<Hash>().type_name("Hash")))
-					})
-					.variant("PreRuntime", |v| {
-						v.index(DigestItemType::PreRuntime as u8).fields(
-							Fields::unnamed()
-								.field(|f| {
-									f.ty::<ConsensusEngineId>().type_name("ConsensusEngineId")
-								})
-								.field(|f| f.ty::<Vec<u8>>().type_name("Vec<u8>")),
-						)
-					})
-					.variant("Consensus", |v| {
-						v.index(DigestItemType::Consensus as u8).fields(
-							Fields::unnamed()
-								.field(|f| {
-									f.ty::<ConsensusEngineId>().type_name("ConsensusEngineId")
-								})
-								.field(|f| f.ty::<Vec<u8>>().type_name("Vec<u8>")),
-						)
-					})
-					.variant("Seal", |v| {
-						v.index(DigestItemType::Seal as u8).fields(
-							Fields::unnamed()
-								.field(|f| {
-									f.ty::<ConsensusEngineId>().type_name("ConsensusEngineId")
-								})
-								.field(|f| f.ty::<Vec<u8>>().type_name("Vec<u8>")),
-						)
-					})
-					.variant("ChangesTrieSignal", |v| {
-						v.index(DigestItemType::ChangesTrieSignal as u8).fields(
-							Fields::unnamed().field(|f| {
-								f.ty::<ChangesTrieSignal>().type_name("ChangesTrieSignal")
-							}),
-						)
-					})
-					.variant("Other", |v| {
-						v.index(DigestItemType::Other as u8).fields(
-							Fields::unnamed().field(|f| f.ty::<Vec<u8>>().type_name("Vec<u8>")),
-						)
-					})
-					.variant("RuntimeEnvironmentUpdated", |v| {
-						v.index(DigestItemType::RuntimeEnvironmentUpdated as u8)
-							.fields(Fields::unit())
-					}),
-			)
+		Type::builder().path(Path::new("DigestItem", module_path!())).variant(
+			Variants::new()
+				.variant("PreRuntime", |v| {
+					v.index(DigestItemType::PreRuntime as u8).fields(
+						Fields::unnamed()
+							.field(|f| f.ty::<ConsensusEngineId>().type_name("ConsensusEngineId"))
+							.field(|f| f.ty::<Vec<u8>>().type_name("Vec<u8>")),
+					)
+				})
+				.variant("Consensus", |v| {
+					v.index(DigestItemType::Consensus as u8).fields(
+						Fields::unnamed()
+							.field(|f| f.ty::<ConsensusEngineId>().type_name("ConsensusEngineId"))
+							.field(|f| f.ty::<Vec<u8>>().type_name("Vec<u8>")),
+					)
+				})
+				.variant("Seal", |v| {
+					v.index(DigestItemType::Seal as u8).fields(
+						Fields::unnamed()
+							.field(|f| f.ty::<ConsensusEngineId>().type_name("ConsensusEngineId"))
+							.field(|f| f.ty::<Vec<u8>>().type_name("Vec<u8>")),
+					)
+				})
+				.variant("Other", |v| {
+					v.index(DigestItemType::Other as u8)
+						.fields(Fields::unnamed().field(|f| f.ty::<Vec<u8>>().type_name("Vec<u8>")))
+				})
+				.variant("RuntimeEnvironmentUpdated", |v| {
+					v.index(DigestItemType::RuntimeEnvironmentUpdated as u8).fields(Fields::unit())
+				}),
+		)
 	}
 }
 
 /// A 'referencing view' for digest item. Does not own its contents. Used by
 /// final runtime implementations for encoding/decoding its log items.
 #[derive(PartialEq, Eq, Clone, RuntimeDebug)]
-pub enum DigestItemRef<'a, Hash: 'a> {
-	/// Reference to `DigestItem::ChangesTrieRoot`.
-	ChangesTrieRoot(&'a Hash),
+pub enum DigestItemRef<'a> {
 	/// A pre-runtime digest.
 	///
 	/// These are messages from the consensus engine to the runtime, although
@@ -254,9 +191,6 @@ pub enum DigestItemRef<'a, Hash: 'a> {
 	/// Put a Seal on it. This is only used by native code, and is never seen
 	/// by runtimes.
 	Seal(&'a ConsensusEngineId, &'a Vec<u8>),
-	/// Digest item that contains signal from changes tries manager to the
-	/// native code.
-	ChangesTrieSignal(&'a ChangesTrieSignal),
 	/// Any 'non-system' digest item, opaque to the native code.
 	Other(&'a Vec<u8>),
 	/// Runtime code or heap pages updated.
@@ -271,11 +205,9 @@ pub enum DigestItemRef<'a, Hash: 'a> {
 #[derive(Encode, Decode)]
 pub enum DigestItemType {
 	Other = 0,
-	ChangesTrieRoot = 2,
 	Consensus = 4,
 	Seal = 5,
 	PreRuntime = 6,
-	ChangesTrieSignal = 7,
 	RuntimeEnvironmentUpdated = 8,
 }
 
@@ -293,25 +225,18 @@ pub enum OpaqueDigestItemId<'a> {
 	Other,
 }
 
-impl<Hash> DigestItem<Hash> {
+impl DigestItem {
 	/// Returns a 'referencing view' for this digest item.
-	pub fn dref(&self) -> DigestItemRef<Hash> {
+	pub fn dref(&self) -> DigestItemRef {
 		match *self {
-			Self::ChangesTrieRoot(ref v) => DigestItemRef::ChangesTrieRoot(v),
 			Self::PreRuntime(ref v, ref s) => DigestItemRef::PreRuntime(v, s),
 			Self::Consensus(ref v, ref s) => DigestItemRef::Consensus(v, s),
 			Self::Seal(ref v, ref s) => DigestItemRef::Seal(v, s),
-			Self::ChangesTrieSignal(ref s) => DigestItemRef::ChangesTrieSignal(s),
 			Self::Other(ref v) => DigestItemRef::Other(v),
 			Self::RuntimeEnvironmentUpdated => DigestItemRef::RuntimeEnvironmentUpdated,
 		}
 	}
 
-	/// Returns `Some` if the entry is the `ChangesTrieRoot` entry.
-	pub fn as_changes_trie_root(&self) -> Option<&Hash> {
-		self.dref().as_changes_trie_root()
-	}
-
 	/// Returns `Some` if this entry is the `PreRuntime` entry.
 	pub fn as_pre_runtime(&self) -> Option<(ConsensusEngineId, &[u8])> {
 		self.dref().as_pre_runtime()
@@ -327,11 +252,6 @@ impl<Hash> DigestItem<Hash> {
 		self.dref().as_seal()
 	}
 
-	/// Returns `Some` if the entry is the `ChangesTrieSignal` entry.
-	pub fn as_changes_trie_signal(&self) -> Option<&ChangesTrieSignal> {
-		self.dref().as_changes_trie_signal()
-	}
-
 	/// Returns Some if `self` is a `DigestItem::Other`.
 	pub fn as_other(&self) -> Option<&[u8]> {
 		self.dref().as_other()
@@ -372,20 +292,19 @@ impl<Hash> DigestItem<Hash> {
 	}
 }
 
-impl<Hash: Encode> Encode for DigestItem<Hash> {
+impl Encode for DigestItem {
 	fn encode(&self) -> Vec<u8> {
 		self.dref().encode()
 	}
 }
 
-impl<Hash: Encode> codec::EncodeLike for DigestItem<Hash> {}
+impl codec::EncodeLike for DigestItem {}
 
-impl<Hash: Decode> Decode for DigestItem<Hash> {
+impl Decode for DigestItem {
 	#[allow(deprecated)]
 	fn decode<I: Input>(input: &mut I) -> Result<Self, Error> {
 		let item_type: DigestItemType = Decode::decode(input)?;
 		match item_type {
-			DigestItemType::ChangesTrieRoot => Ok(Self::ChangesTrieRoot(Decode::decode(input)?)),
 			DigestItemType::PreRuntime => {
 				let vals: (ConsensusEngineId, Vec<u8>) = Decode::decode(input)?;
 				Ok(Self::PreRuntime(vals.0, vals.1))
@@ -398,23 +317,13 @@ impl<Hash: Decode> Decode for DigestItem<Hash> {
 				let vals: (ConsensusEngineId, Vec<u8>) = Decode::decode(input)?;
 				Ok(Self::Seal(vals.0, vals.1))
 			},
-			DigestItemType::ChangesTrieSignal =>
-				Ok(Self::ChangesTrieSignal(Decode::decode(input)?)),
 			DigestItemType::Other => Ok(Self::Other(Decode::decode(input)?)),
 			DigestItemType::RuntimeEnvironmentUpdated => Ok(Self::RuntimeEnvironmentUpdated),
 		}
 	}
 }
 
-impl<'a, Hash> DigestItemRef<'a, Hash> {
-	/// Cast this digest item into `ChangesTrieRoot`.
-	pub fn as_changes_trie_root(&self) -> Option<&'a Hash> {
-		match *self {
-			Self::ChangesTrieRoot(ref changes_trie_root) => Some(changes_trie_root),
-			_ => None,
-		}
-	}
-
+impl<'a> DigestItemRef<'a> {
 	/// Cast this digest item into `PreRuntime`
 	pub fn as_pre_runtime(&self) -> Option<(ConsensusEngineId, &'a [u8])> {
 		match *self {
@@ -439,14 +348,6 @@ impl<'a, Hash> DigestItemRef<'a, Hash> {
 		}
 	}
 
-	/// Cast this digest item into `ChangesTrieSignal`.
-	pub fn as_changes_trie_signal(&self) -> Option<&'a ChangesTrieSignal> {
-		match *self {
-			Self::ChangesTrieSignal(ref changes_trie_signal) => Some(changes_trie_signal),
-			_ => None,
-		}
-	}
-
 	/// Cast this digest item into `PreRuntime`
 	pub fn as_other(&self) -> Option<&'a [u8]> {
 		match *self {
@@ -508,15 +409,11 @@ impl<'a, Hash> DigestItemRef<'a, Hash> {
 	}
 }
 
-impl<'a, Hash: Encode> Encode for DigestItemRef<'a, Hash> {
+impl<'a> Encode for DigestItemRef<'a> {
 	fn encode(&self) -> Vec<u8> {
 		let mut v = Vec::new();
 
 		match *self {
-			Self::ChangesTrieRoot(changes_trie_root) => {
-				DigestItemType::ChangesTrieRoot.encode_to(&mut v);
-				changes_trie_root.encode_to(&mut v);
-			},
 			Self::Consensus(val, data) => {
 				DigestItemType::Consensus.encode_to(&mut v);
 				(val, data).encode_to(&mut v);
@@ -529,10 +426,6 @@ impl<'a, Hash: Encode> Encode for DigestItemRef<'a, Hash> {
 				DigestItemType::PreRuntime.encode_to(&mut v);
 				(val, data).encode_to(&mut v);
 			},
-			Self::ChangesTrieSignal(changes_trie_signal) => {
-				DigestItemType::ChangesTrieSignal.encode_to(&mut v);
-				changes_trie_signal.encode_to(&mut v);
-			},
 			Self::Other(val) => {
 				DigestItemType::Other.encode_to(&mut v);
 				val.encode_to(&mut v);
@@ -546,16 +439,7 @@ impl<'a, Hash: Encode> Encode for DigestItemRef<'a, Hash> {
 	}
 }
 
-impl ChangesTrieSignal {
-	/// Try to cast this signal to NewConfiguration.
-	pub fn as_new_configuration(&self) -> Option<&Option<ChangesTrieConfiguration>> {
-		match self {
-			Self::NewConfiguration(config) => Some(config),
-		}
-	}
-}
-
-impl<'a, Hash: Encode> codec::EncodeLike for DigestItemRef<'a, Hash> {}
+impl<'a> codec::EncodeLike for DigestItemRef<'a> {}
 
 #[cfg(test)]
 mod tests {
@@ -564,22 +448,18 @@ mod tests {
 	#[test]
 	fn should_serialize_digest() {
 		let digest = Digest {
-			logs: vec![
-				DigestItem::ChangesTrieRoot(4),
-				DigestItem::Other(vec![1, 2, 3]),
-				DigestItem::Seal(*b"test", vec![1, 2, 3]),
-			],
+			logs: vec![DigestItem::Other(vec![1, 2, 3]), DigestItem::Seal(*b"test", vec![1, 2, 3])],
 		};
 
 		assert_eq!(
 			serde_json::to_string(&digest).unwrap(),
-			r#"{"logs":["0x0204000000","0x000c010203","0x05746573740c010203"]}"#
+			r#"{"logs":["0x000c010203","0x05746573740c010203"]}"#
 		);
 	}
 
 	#[test]
 	fn digest_item_type_info() {
-		let type_info = DigestItem::<u32>::type_info();
+		let type_info = DigestItem::type_info();
 		let variants = if let scale_info::TypeDef::Variant(variant) = type_info.type_def() {
 			variant.variants()
 		} else {
@@ -589,21 +469,13 @@ mod tests {
 		// ensure that all variants are covered by manual TypeInfo impl
 		let check = |digest_item_type: DigestItemType| {
 			let (variant_name, digest_item) = match digest_item_type {
-				DigestItemType::Other => ("Other", DigestItem::<u32>::Other(Default::default())),
-				DigestItemType::ChangesTrieRoot =>
-					("ChangesTrieRoot", DigestItem::ChangesTrieRoot(Default::default())),
+				DigestItemType::Other => ("Other", DigestItem::Other(Default::default())),
 				DigestItemType::Consensus =>
 					("Consensus", DigestItem::Consensus(Default::default(), Default::default())),
 				DigestItemType::Seal =>
 					("Seal", DigestItem::Seal(Default::default(), Default::default())),
 				DigestItemType::PreRuntime =>
 					("PreRuntime", DigestItem::PreRuntime(Default::default(), Default::default())),
-				DigestItemType::ChangesTrieSignal => (
-					"ChangesTrieSignal",
-					DigestItem::ChangesTrieSignal(ChangesTrieSignal::NewConfiguration(
-						Default::default(),
-					)),
-				),
 				DigestItemType::RuntimeEnvironmentUpdated =>
 					("RuntimeEnvironmentUpdated", DigestItem::RuntimeEnvironmentUpdated),
 			};
@@ -617,11 +489,9 @@ mod tests {
 		};
 
 		check(DigestItemType::Other);
-		check(DigestItemType::ChangesTrieRoot);
 		check(DigestItemType::Consensus);
 		check(DigestItemType::Seal);
 		check(DigestItemType::PreRuntime);
-		check(DigestItemType::ChangesTrieSignal);
 		check(DigestItemType::RuntimeEnvironmentUpdated);
 	}
 }

substrate/primitives/runtime/src/generic/header.rs

@@ -51,7 +51,7 @@ pub struct Header<Number: Copy + Into<U256> + TryFrom<U256>, Hash: HashT> {
 	/// The merkle root of the extrinsics.
 	pub extrinsics_root: Hash::Output,
 	/// A chain-specific digest of data useful for light clients or referencing auxiliary data.
-	pub digest: Digest<Hash::Output>,
+	pub digest: Digest,
 }
 
 #[cfg(feature = "std")]
@@ -150,11 +150,11 @@ where
 		self.parent_hash = hash
 	}
 
-	fn digest(&self) -> &Digest<Self::Hash> {
+	fn digest(&self) -> &Digest {
 		&self.digest
 	}
 
-	fn digest_mut(&mut self) -> &mut Digest<Self::Hash> {
+	fn digest_mut(&mut self) -> &mut Digest {
 		#[cfg(feature = "std")]
 		log::debug!(target: "header", "Retrieving mutable reference to digest");
 		&mut self.digest
@@ -165,7 +165,7 @@ where
 		extrinsics_root: Self::Hash,
 		state_root: Self::Hash,
 		parent_hash: Self::Hash,
-		digest: Digest<Self::Hash>,
+		digest: Digest,
 	) -> Self {
 		Self { number, extrinsics_root, state_root, parent_hash, digest }
 	}
@@ -235,10 +235,7 @@ mod tests {
 			state_root: BlakeTwo256::hash(b"3"),
 			extrinsics_root: BlakeTwo256::hash(b"4"),
 			digest: crate::generic::Digest {
-				logs: vec![
-					crate::generic::DigestItem::ChangesTrieRoot(BlakeTwo256::hash(b"5")),
-					crate::generic::DigestItem::Other(b"6".to_vec()),
-				],
+				logs: vec![crate::generic::DigestItem::Other(b"6".to_vec())],
 			},
 		};
 
@@ -251,9 +248,7 @@ mod tests {
 				72, 51, 123, 15, 62, 20, 134, 32, 23, 61, 170, 165, 249, 77, 0, 216, 129, 112, 93,
 				203, 240, 170, 131, 239, 218, 186, 97, 210, 237, 225, 235, 134, 73, 33, 73, 151,
 				87, 78, 32, 196, 100, 56, 138, 23, 36, 32, 210, 84, 3, 104, 43, 187, 184, 12, 73,
-				104, 49, 200, 204, 31, 143, 13, 8, 2, 112, 178, 1, 53, 47, 36, 191, 28, 151, 112,
-				185, 159, 143, 113, 32, 24, 33, 65, 28, 244, 20, 55, 124, 155, 140, 45, 188, 238,
-				97, 219, 135, 214, 0, 4, 54
+				104, 49, 200, 204, 31, 143, 13, 4, 0, 4, 54
 			],
 		);
 		assert_eq!(header, Header::<u32, BlakeTwo256>::decode(&mut &header_encoded[..]).unwrap());
@@ -264,10 +259,7 @@ mod tests {
 			state_root: BlakeTwo256::hash(b"3000"),
 			extrinsics_root: BlakeTwo256::hash(b"4000"),
 			digest: crate::generic::Digest {
-				logs: vec![
-					crate::generic::DigestItem::Other(b"5000".to_vec()),
-					crate::generic::DigestItem::ChangesTrieRoot(BlakeTwo256::hash(b"6000")),
-				],
+				logs: vec![crate::generic::DigestItem::Other(b"5000".to_vec())],
 			},
 		};
 
@@ -280,9 +272,7 @@ mod tests {
 				47, 12, 107, 88, 153, 146, 55, 21, 226, 186, 110, 48, 167, 187, 67, 183, 228, 232,
 				118, 136, 30, 254, 11, 87, 48, 112, 7, 97, 31, 82, 146, 110, 96, 87, 152, 68, 98,
 				162, 227, 222, 78, 14, 244, 194, 120, 154, 112, 97, 222, 144, 174, 101, 220, 44,
-				111, 126, 54, 34, 155, 220, 253, 124, 8, 0, 16, 53, 48, 48, 48, 2, 42, 105, 109,
-				150, 206, 223, 24, 44, 164, 77, 27, 137, 177, 220, 25, 170, 140, 35, 156, 246, 233,
-				112, 26, 23, 192, 61, 226, 14, 84, 219, 144, 252
+				111, 126, 54, 34, 155, 220, 253, 124, 4, 0, 16, 53, 48, 48, 48
 			],
 		);
 		assert_eq!(header, Header::<u32, BlakeTwo256>::decode(&mut &header_encoded[..]).unwrap());

substrate/primitives/runtime/src/generic/mod.rs

@@ -31,7 +31,7 @@ mod unchecked_extrinsic;
 pub use self::{
 	block::{Block, BlockId, SignedBlock},
 	checked_extrinsic::CheckedExtrinsic,
-	digest::{ChangesTrieSignal, Digest, DigestItem, DigestItemRef, OpaqueDigestItemId},
+	digest::{Digest, DigestItem, DigestItemRef, OpaqueDigestItemId},
 	era::{Era, Phase},
 	header::Header,
 	unchecked_extrinsic::{SignedPayload, UncheckedExtrinsic},

substrate/primitives/runtime/src/generic/tests.rs

@@ -19,29 +19,26 @@
 
 use super::DigestItem;
 use crate::codec::{Decode, Encode};
-use sp_core::H256;
 
 #[test]
 fn system_digest_item_encoding() {
-	let item = DigestItem::ChangesTrieRoot::<H256>(H256::default());
+	let item = DigestItem::Consensus([1, 2, 3, 4], vec![5, 6, 7, 8]);
 	let encoded = item.encode();
 	assert_eq!(
 		encoded,
 		vec![
-			// type = DigestItemType::ChangesTrieRoot
-			2, // trie root
-			0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-			0, 0, 0,
+			4, // type = DigestItemType::Consensus
+			1, 2, 3, 4, 16, 5, 6, 7, 8,
 		]
 	);
 
-	let decoded: DigestItem<H256> = Decode::decode(&mut &encoded[..]).unwrap();
+	let decoded: DigestItem = Decode::decode(&mut &encoded[..]).unwrap();
 	assert_eq!(item, decoded);
 }
 
 #[test]
 fn non_system_digest_item_encoding() {
-	let item = DigestItem::Other::<H256>(vec![10, 20, 30]);
+	let item = DigestItem::Other(vec![10, 20, 30]);
 	let encoded = item.encode();
 	assert_eq!(
 		encoded,
@@ -53,6 +50,6 @@ fn non_system_digest_item_encoding() {
 		]
 	);
 
-	let decoded: DigestItem<H256> = Decode::decode(&mut &encoded[..]).unwrap();
+	let decoded: DigestItem = Decode::decode(&mut &encoded[..]).unwrap();
 	assert_eq!(item, decoded);
 }