Use ranged changes trie configuration in CT functions (#3404)

* CT config methods are accepting zero

* intrduce && use configuration range in CT

* Update core/client/db/src/lib.rs

Co-Authored-By: cheme <emericchevalier.pro@gmail.com>

* full PR URI

* updated next_max_level_digest_range comment

* added skewed digest description

* added comment for loop

* call next_max_level_digest_range from prev_max_level_digest_block

* more test cases

* Update core/state-machine/src/changes_trie/surface_iterator.rs

Co-Authored-By: cheme <emericchevalier.pro@gmail.com>

* updated comment

substrate/core/client/src/client.rs

@@ -43,7 +43,7 @@ use sr_primitives::{
 use state_machine::{
 	DBValue, Backend as StateBackend, CodeExecutor, ChangesTrieAnchorBlockId,
 	ExecutionStrategy, ExecutionManager, prove_read, prove_child_read,
-	ChangesTrieRootsStorage, ChangesTrieStorage,
+	ChangesTrieRootsStorage, ChangesTrieStorage, ChangesTrieConfigurationRange,
 	key_changes, key_changes_proof, OverlayedChanges, NeverOffchainExt,
 };
 use executor::{RuntimeVersion, RuntimeInfo};
@@ -554,8 +554,15 @@ impl<B, E, Block, RA> Client<B, E, Block, RA> where
 		let last_number = self.backend.blockchain().expect_block_number_from_id(&last)?;
 		let last_hash = self.backend.blockchain().expect_block_hash_from_id(&last)?;
 
-		key_changes::<_, Blake2Hasher, _>(
-			&config,
+		// FIXME: remove this in https://github.com/paritytech/substrate/pull/3201
+		let config_range = ChangesTrieConfigurationRange {
+			config: &config,
+			zero: Zero::zero(),
+			end: None,
+		};
+
+		key_changes::<Blake2Hasher, _>(
+			config_range,
 			&*storage,
 			first,
 			&ChangesTrieAnchorBlockId {
@@ -632,6 +639,10 @@ impl<B, E, Block, RA> Client<B, E, Block, RA> where
 		}
 
 		impl<'a, Block: BlockT> ChangesTrieStorage<Blake2Hasher, NumberFor<Block>> for AccessedRootsRecorder<'a, Block> {
+			fn as_roots_storage(&self) -> &dyn state_machine::ChangesTrieRootsStorage<Blake2Hasher, NumberFor<Block>> {
+				self
+			}
+
 			fn get(&self, key: &H256, prefix: Prefix) -> Result<Option<DBValue>, String> {
 				self.storage.get(key, prefix)
 			}
@@ -651,13 +662,20 @@ impl<B, E, Block, RA> Client<B, E, Block, RA> where
 			self.backend.blockchain().expect_block_number_from_id(&BlockId::Hash(max))?,
 		);
 
+		// FIXME: remove this in https://github.com/paritytech/substrate/pull/3201
+		let config_range = ChangesTrieConfigurationRange {
+			config: &config,
+			zero: Zero::zero(),
+			end: None,
+		};
+
 		// fetch key changes proof
 		let first_number = self.backend.blockchain()
 			.expect_block_number_from_id(&BlockId::Hash(first))?;
 		let last_number = self.backend.blockchain()
 			.expect_block_number_from_id(&BlockId::Hash(last))?;
-		let key_changes_proof = key_changes_proof::<_, Blake2Hasher, _>(
-			&config,
+		let key_changes_proof = key_changes_proof::<Blake2Hasher, _>(
+			config_range,
 			&recording_storage,
 			first_number,
 			&ChangesTrieAnchorBlockId {

substrate/core/client/src/in_mem.rs

@@ -758,6 +758,10 @@ impl<Block, H> state_machine::ChangesTrieStorage<H, NumberFor<Block>> for Change
 		Block: BlockT,
 		H: Hasher,
 {
+	fn as_roots_storage(&self) -> &dyn state_machine::ChangesTrieRootsStorage<H, NumberFor<Block>> {
+		self
+	}
+
 	fn get(&self, key: &H::Out, prefix: Prefix) -> Result<Option<state_machine::DBValue>, String> {
 		self.0.get(key, prefix)
 	}

substrate/core/client/src/light/fetcher.rs

@@ -26,11 +26,14 @@ use codec::{Decode, Encode};
 use primitives::{ChangesTrieConfiguration, convert_hash};
 use sr_primitives::traits::{
 	Block as BlockT, Header as HeaderT, Hash, HashFor, NumberFor,
-	SimpleArithmetic, CheckedConversion,
+	SimpleArithmetic, CheckedConversion, Zero,
 };
-use state_machine::{CodeExecutor, ChangesTrieRootsStorage, ChangesTrieAnchorBlockId,
+use state_machine::{
+	CodeExecutor, ChangesTrieRootsStorage,
+	ChangesTrieAnchorBlockId, ChangesTrieConfigurationRange,
 	TrieBackend, read_proof_check, key_changes_proof_check,
-	create_proof_check_backend_storage, read_child_proof_check};
+	create_proof_check_backend_storage, read_child_proof_check,
+};
 
 use crate::cht;
 use crate::error::{Error as ClientError, Result as ClientResult};
@@ -283,9 +286,16 @@ impl<E, H, B: BlockT, S: BlockchainStorage<B>, F> LightDataChecker<E, H, B, S, F
 			)?;
 		}
 
+		// FIXME: remove this in https://github.com/paritytech/substrate/pull/3201
+		let changes_trie_config_range = ChangesTrieConfigurationRange {
+			config: &request.changes_trie_config,
+			zero: Zero::zero(),
+			end: None,
+		};
+
 		// and now check the key changes proof + get the changes
-		key_changes_proof_check::<_, H, _>(
-			&request.changes_trie_config,
+		key_changes_proof_check::<H, _>(
+			changes_trie_config_range,
 			&RootsStorage {
 				roots: (request.tries_roots.0, &request.tries_roots.2),
 				prev_roots: remote_roots,