Changes tries: support forks (#950)

* forks support in changes trie storage

* moved convert_hash to primitives

* optimize ChangesTrieRootsStorage::root when anchor is canonicalized

substrate/core/client/src/cht.rs

@@ -27,7 +27,7 @@ use hash_db;
 use heapsize::HeapSizeOf;
 use trie;
 
-use primitives::H256;
+use primitives::{H256, convert_hash};
 use runtime_primitives::traits::{As, Header as HeaderT, SimpleArithmetic, One};
 use state_machine::backend::InMemory as InMemoryState;
 use state_machine::{prove_read, read_proof_check};
@@ -113,8 +113,7 @@ pub fn check_proof<Header, Hasher>(
 		Hasher: hash_db::Hasher,
 		Hasher::Out: Ord + HeapSizeOf,
 {
-	let mut root: Hasher::Out = Default::default();
-	root.as_mut().copy_from_slice(local_root.as_ref());
+	let root: Hasher::Out = convert_hash(&local_root);
 	let local_cht_key = encode_cht_key(local_number);
 	let local_cht_value = read_proof_check::<Hasher>(root, remote_proof,
 		&local_cht_key).map_err(|e| ClientError::from(e))?;

substrate/core/client/src/client.rs

@@ -30,14 +30,14 @@ use consensus::{ImportBlock, ImportResult, BlockOrigin};
 use runtime_primitives::traits::{Block as BlockT, Header as HeaderT, Zero, As, NumberFor, CurrentHeight, BlockNumberToHash};
 use runtime_primitives::{ApplyResult, BuildStorage};
 use runtime_api as api;
-use primitives::{Blake2Hasher, H256, ChangesTrieConfiguration};
+use primitives::{Blake2Hasher, H256, ChangesTrieConfiguration, convert_hash};
 use primitives::storage::{StorageKey, StorageData};
 use primitives::storage::well_known_keys;
 use codec::{Encode, Decode};
 use state_machine::{
 	Backend as StateBackend, CodeExecutor,
-	ExecutionStrategy, ExecutionManager, prove_read,
-	key_changes, key_changes_proof, OverlayedChanges
+	ExecutionStrategy, ExecutionManager, ChangesTrieAnchorBlockId,
+	prove_read, key_changes, key_changes_proof, OverlayedChanges
 };
 
 use backend::{self, BlockImportOperation};
@@ -355,7 +355,10 @@ impl<B, E, Block> Client<B, E, Block> where
 			config,
 			storage,
 			self.require_block_number_from_id(&BlockId::Hash(first))?.as_(),
-			self.require_block_number_from_id(&BlockId::Hash(last))?.as_(),
+			&ChangesTrieAnchorBlockId {
+				hash: convert_hash(&last),
+				number: self.require_block_number_from_id(&BlockId::Hash(last))?.as_(),
+			},
 			self.backend.blockchain().info()?.best_number.as_(),
 			key)
 		.map_err(|err| error::ErrorKind::ChangesTrieAccessFailed(err).into())
@@ -388,7 +391,10 @@ impl<B, E, Block> Client<B, E, Block> where
 			config,
 			storage,
 			self.require_block_number_from_id(&BlockId::Hash(first))?.as_(),
-			self.require_block_number_from_id(&BlockId::Hash(last))?.as_(),
+			&ChangesTrieAnchorBlockId {
+				hash: convert_hash(&last),
+				number: self.require_block_number_from_id(&BlockId::Hash(last))?.as_(),
+			},
 			max_number.as_(),
 			key)
 		.map_err(|err| error::ErrorKind::ChangesTrieAccessFailed(err).into())

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

@@ -21,6 +21,7 @@ use std::marker::PhantomData;
 use std::sync::Arc;
 use futures::{IntoFuture, Future};
 
+use primitives::convert_hash;
 use runtime_primitives::generic::BlockId;
 use runtime_primitives::traits::{Block as BlockT, Header as HeaderT};
 use state_machine::{Backend as StateBackend, CodeExecutor, OverlayedChanges,
@@ -136,8 +137,7 @@ pub fn check_execution_proof<Header, E, H>(
 
 {
 	let local_state_root = request.header.state_root();
-	let mut root: H::Out = Default::default();
-	root.as_mut().copy_from_slice(local_state_root.as_ref());
+	let root: H::Out = convert_hash(&local_state_root);
 
 	let mut changes = OverlayedChanges::default();
 	let local_result = execution_proof_check::<H, _>(

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

@@ -21,10 +21,10 @@ use futures::IntoFuture;
 
 use hash_db::Hasher;
 use heapsize::HeapSizeOf;
-use primitives::ChangesTrieConfiguration;
+use primitives::{ChangesTrieConfiguration, convert_hash};
 use runtime_primitives::traits::{As, Block as BlockT, Header as HeaderT, NumberFor};
-use state_machine::{CodeExecutor, ChangesTrieRootsStorage, read_proof_check,
-	key_changes_proof_check};
+use state_machine::{CodeExecutor, ChangesTrieRootsStorage, ChangesTrieAnchorBlockId,
+	read_proof_check, key_changes_proof_check};
 
 use call_executor::CallResult;
 use cht;
@@ -192,9 +192,8 @@ impl<E, Block, H> FetchChecker<Block> for LightDataChecker<E, H>
 		request: &RemoteReadRequest<Block::Header>,
 		remote_proof: Vec<Vec<u8>>
 	) -> ClientResult<Option<Vec<u8>>> {
-		let mut root: H::Out = Default::default();
-		root.as_mut().copy_from_slice(request.header.state_root().as_ref());
-		read_proof_check::<H>(root, remote_proof, &request.key).map_err(Into::into)
+		read_proof_check::<H>(convert_hash(request.header.state_root()), remote_proof, &request.key)
+			.map_err(Into::into)
 	}
 
 	fn check_execution_proof(
@@ -229,7 +228,10 @@ impl<E, Block, H> FetchChecker<Block> for LightDataChecker<E, H>
 			},
 			remote_proof,
 			first_number,
-			request.last_block.0.as_(),
+			&ChangesTrieAnchorBlockId {
+				hash: convert_hash(&request.last_block.1),
+				number: request.last_block.0.as_(),
+			},
 			remote_max.as_(),
 			&request.key)
 		.map(|pairs| pairs.into_iter().map(|(b, x)| (As::sa(b), x)).collect())
@@ -248,15 +250,12 @@ impl<'a, H, Hash> ChangesTrieRootsStorage<H> for RootsStorage<'a, Hash>
 		H: Hasher,
 		Hash: 'a + Send + Sync + Clone + AsRef<[u8]>,
 {
-	fn root(&self, block: u64) -> Result<Option<H::Out>, String> {
+	fn root(&self, _anchor: &ChangesTrieAnchorBlockId<H::Out>, block: u64) -> Result<Option<H::Out>, String> {
+		// we can't ask for roots from parallel forks here => ignore anchor
 		Ok(block.checked_sub(self.first)
 			.and_then(|index| self.roots.get(index as usize))
 			.cloned()
-			.map(|root| {
-				let mut hasher_root: H::Out = Default::default();
-				hasher_root.as_mut().copy_from_slice(root.as_ref());
-				hasher_root
-			}))
+			.map(|root| convert_hash(&root)))
 	}
 }