Expose storage_prefix logic, and remove duplicate code (#9621)

* expose storage prefix generation, remove duplicate code

* remove more duplicate code

* clean up import

* fix io test

* remove slicing

* Update frame/support/src/storage/mod.rs

Co-authored-by: Guillaume Thiolliere <gui.thiolliere@gmail.com>

Co-authored-by: Guillaume Thiolliere <gui.thiolliere@gmail.com>

substrate/frame/support/src/storage/generator/double_map.rs

@@ -16,8 +16,8 @@
 // limitations under the License.
 
 use crate::{
-	hash::{ReversibleStorageHasher, StorageHasher, Twox128},
-	storage::{self, unhashed, KeyPrefixIterator, PrefixIterator, StorageAppend},
+	hash::{ReversibleStorageHasher, StorageHasher},
+	storage::{self, storage_prefix, unhashed, KeyPrefixIterator, PrefixIterator, StorageAppend},
 	Never,
 };
 use codec::{Decode, Encode, EncodeLike, FullCodec, FullEncode};
@@ -62,16 +62,8 @@ pub trait StorageDoubleMap<K1: FullEncode, K2: FullEncode, V: FullCodec> {
 	/// The full prefix; just the hash of `module_prefix` concatenated to the hash of
 	/// `storage_prefix`.
 	fn prefix_hash() -> Vec<u8> {
-		let module_prefix_hashed = Twox128::hash(Self::module_prefix());
-		let storage_prefix_hashed = Twox128::hash(Self::storage_prefix());
-
-		let mut result =
-			Vec::with_capacity(module_prefix_hashed.len() + storage_prefix_hashed.len());
-
-		result.extend_from_slice(&module_prefix_hashed[..]);
-		result.extend_from_slice(&storage_prefix_hashed[..]);
-
-		result
+		let result = storage_prefix(Self::module_prefix(), Self::storage_prefix());
+		result.to_vec()
 	}
 
 	/// Convert an optional value retrieved from storage to the type queried.
@@ -85,16 +77,12 @@ pub trait StorageDoubleMap<K1: FullEncode, K2: FullEncode, V: FullCodec> {
 	where
 		KArg1: EncodeLike<K1>,
 	{
-		let module_prefix_hashed = Twox128::hash(Self::module_prefix());
-		let storage_prefix_hashed = Twox128::hash(Self::storage_prefix());
+		let storage_prefix = storage_prefix(Self::module_prefix(), Self::storage_prefix());
 		let key_hashed = k1.borrow().using_encoded(Self::Hasher1::hash);
 
-		let mut final_key = Vec::with_capacity(
-			module_prefix_hashed.len() + storage_prefix_hashed.len() + key_hashed.as_ref().len(),
-		);
+		let mut final_key = Vec::with_capacity(storage_prefix.len() + key_hashed.as_ref().len());
 
-		final_key.extend_from_slice(&module_prefix_hashed[..]);
-		final_key.extend_from_slice(&storage_prefix_hashed[..]);
+		final_key.extend_from_slice(&storage_prefix);
 		final_key.extend_from_slice(key_hashed.as_ref());
 
 		final_key
@@ -106,20 +94,15 @@ pub trait StorageDoubleMap<K1: FullEncode, K2: FullEncode, V: FullCodec> {
 		KArg1: EncodeLike<K1>,
 		KArg2: EncodeLike<K2>,
 	{
-		let module_prefix_hashed = Twox128::hash(Self::module_prefix());
-		let storage_prefix_hashed = Twox128::hash(Self::storage_prefix());
+		let storage_prefix = storage_prefix(Self::module_prefix(), Self::storage_prefix());
 		let key1_hashed = k1.borrow().using_encoded(Self::Hasher1::hash);
 		let key2_hashed = k2.borrow().using_encoded(Self::Hasher2::hash);
 
 		let mut final_key = Vec::with_capacity(
-			module_prefix_hashed.len() +
-				storage_prefix_hashed.len() +
-				key1_hashed.as_ref().len() +
-				key2_hashed.as_ref().len(),
+			storage_prefix.len() + key1_hashed.as_ref().len() + key2_hashed.as_ref().len(),
 		);
 
-		final_key.extend_from_slice(&module_prefix_hashed[..]);
-		final_key.extend_from_slice(&storage_prefix_hashed[..]);
+		final_key.extend_from_slice(&storage_prefix);
 		final_key.extend_from_slice(key1_hashed.as_ref());
 		final_key.extend_from_slice(key2_hashed.as_ref());
 
@@ -319,20 +302,16 @@ where
 		key2: KeyArg2,
 	) -> Option<V> {
 		let old_key = {
-			let module_prefix_hashed = Twox128::hash(Self::module_prefix());
-			let storage_prefix_hashed = Twox128::hash(Self::storage_prefix());
+			let storage_prefix = storage_prefix(Self::module_prefix(), Self::storage_prefix());
+
 			let key1_hashed = key1.borrow().using_encoded(OldHasher1::hash);
 			let key2_hashed = key2.borrow().using_encoded(OldHasher2::hash);
 
 			let mut final_key = Vec::with_capacity(
-				module_prefix_hashed.len() +
-					storage_prefix_hashed.len() +
-					key1_hashed.as_ref().len() +
-					key2_hashed.as_ref().len(),
+				storage_prefix.len() + key1_hashed.as_ref().len() + key2_hashed.as_ref().len(),
 			);
 
-			final_key.extend_from_slice(&module_prefix_hashed[..]);
-			final_key.extend_from_slice(&storage_prefix_hashed[..]);
+			final_key.extend_from_slice(&storage_prefix);
 			final_key.extend_from_slice(key1_hashed.as_ref());
 			final_key.extend_from_slice(key2_hashed.as_ref());
 

substrate/frame/support/src/storage/generator/map.rs

@@ -16,8 +16,8 @@
 // limitations under the License.
 
 use crate::{
-	hash::{ReversibleStorageHasher, StorageHasher, Twox128},
-	storage::{self, unhashed, KeyPrefixIterator, PrefixIterator, StorageAppend},
+	hash::{ReversibleStorageHasher, StorageHasher},
+	storage::{self, storage_prefix, unhashed, KeyPrefixIterator, PrefixIterator, StorageAppend},
 	Never,
 };
 use codec::{Decode, Encode, EncodeLike, FullCodec, FullEncode};
@@ -52,16 +52,8 @@ pub trait StorageMap<K: FullEncode, V: FullCodec> {
 	/// The full prefix; just the hash of `module_prefix` concatenated to the hash of
 	/// `storage_prefix`.
 	fn prefix_hash() -> Vec<u8> {
-		let module_prefix_hashed = Twox128::hash(Self::module_prefix());
-		let storage_prefix_hashed = Twox128::hash(Self::storage_prefix());
-
-		let mut result =
-			Vec::with_capacity(module_prefix_hashed.len() + storage_prefix_hashed.len());
-
-		result.extend_from_slice(&module_prefix_hashed[..]);
-		result.extend_from_slice(&storage_prefix_hashed[..]);
-
-		result
+		let result = storage_prefix(Self::module_prefix(), Self::storage_prefix());
+		result.to_vec()
 	}
 
 	/// Convert an optional value retrieved from storage to the type queried.
@@ -75,16 +67,12 @@ pub trait StorageMap<K: FullEncode, V: FullCodec> {
 	where
 		KeyArg: EncodeLike<K>,
 	{
-		let module_prefix_hashed = Twox128::hash(Self::module_prefix());
-		let storage_prefix_hashed = Twox128::hash(Self::storage_prefix());
+		let storage_prefix = storage_prefix(Self::module_prefix(), Self::storage_prefix());
 		let key_hashed = key.borrow().using_encoded(Self::Hasher::hash);
 
-		let mut final_key = Vec::with_capacity(
-			module_prefix_hashed.len() + storage_prefix_hashed.len() + key_hashed.as_ref().len(),
-		);
+		let mut final_key = Vec::with_capacity(storage_prefix.len() + key_hashed.as_ref().len());
 
-		final_key.extend_from_slice(&module_prefix_hashed[..]);
-		final_key.extend_from_slice(&storage_prefix_hashed[..]);
+		final_key.extend_from_slice(&storage_prefix);
 		final_key.extend_from_slice(key_hashed.as_ref());
 
 		final_key
@@ -330,18 +318,13 @@ impl<K: FullEncode, V: FullCodec, G: StorageMap<K, V>> storage::StorageMap<K, V>
 
 	fn migrate_key<OldHasher: StorageHasher, KeyArg: EncodeLike<K>>(key: KeyArg) -> Option<V> {
 		let old_key = {
-			let module_prefix_hashed = Twox128::hash(Self::module_prefix());
-			let storage_prefix_hashed = Twox128::hash(Self::storage_prefix());
+			let storage_prefix = storage_prefix(Self::module_prefix(), Self::storage_prefix());
 			let key_hashed = key.borrow().using_encoded(OldHasher::hash);
 
-			let mut final_key = Vec::with_capacity(
-				module_prefix_hashed.len() +
-					storage_prefix_hashed.len() +
-					key_hashed.as_ref().len(),
-			);
+			let mut final_key =
+				Vec::with_capacity(storage_prefix.len() + key_hashed.as_ref().len());
 
-			final_key.extend_from_slice(&module_prefix_hashed[..]);
-			final_key.extend_from_slice(&storage_prefix_hashed[..]);
+			final_key.extend_from_slice(&storage_prefix);
 			final_key.extend_from_slice(key_hashed.as_ref());
 
 			final_key

substrate/frame/support/src/storage/generator/nmap.rs

@@ -30,9 +30,8 @@
 //! be compromised.
 
 use crate::{
-	hash::{StorageHasher, Twox128},
 	storage::{
-		self,
+		self, storage_prefix,
 		types::{
 			EncodeLikeTuple, HasKeyPrefix, HasReversibleKeyPrefix, KeyGenerator,
 			ReversibleKeyGenerator, TupleToEncodedIter,
@@ -71,16 +70,8 @@ pub trait StorageNMap<K: KeyGenerator, V: FullCodec> {
 	/// The full prefix; just the hash of `module_prefix` concatenated to the hash of
 	/// `storage_prefix`.
 	fn prefix_hash() -> Vec<u8> {
-		let module_prefix_hashed = Twox128::hash(Self::module_prefix());
-		let storage_prefix_hashed = Twox128::hash(Self::storage_prefix());
-
-		let mut result =
-			Vec::with_capacity(module_prefix_hashed.len() + storage_prefix_hashed.len());
-
-		result.extend_from_slice(&module_prefix_hashed[..]);
-		result.extend_from_slice(&storage_prefix_hashed[..]);
-
-		result
+		let result = storage_prefix(Self::module_prefix(), Self::storage_prefix());
+		result.to_vec()
 	}
 
 	/// Convert an optional value retrieved from storage to the type queried.
@@ -94,16 +85,12 @@ pub trait StorageNMap<K: KeyGenerator, V: FullCodec> {
 	where
 		K: HasKeyPrefix<KP>,
 	{
-		let module_prefix_hashed = Twox128::hash(Self::module_prefix());
-		let storage_prefix_hashed = Twox128::hash(Self::storage_prefix());
+		let storage_prefix = storage_prefix(Self::module_prefix(), Self::storage_prefix());
 		let key_hashed = <K as HasKeyPrefix<KP>>::partial_key(key);
 
-		let mut final_key = Vec::with_capacity(
-			module_prefix_hashed.len() + storage_prefix_hashed.len() + key_hashed.len(),
-		);
+		let mut final_key = Vec::with_capacity(storage_prefix.len() + key_hashed.len());
 
-		final_key.extend_from_slice(&module_prefix_hashed[..]);
-		final_key.extend_from_slice(&storage_prefix_hashed[..]);
+		final_key.extend_from_slice(&storage_prefix);
 		final_key.extend_from_slice(key_hashed.as_ref());
 
 		final_key
@@ -115,16 +102,12 @@ pub trait StorageNMap<K: KeyGenerator, V: FullCodec> {
 		KG: KeyGenerator,
 		KArg: EncodeLikeTuple<KG::KArg> + TupleToEncodedIter,
 	{
-		let module_prefix_hashed = Twox128::hash(Self::module_prefix());
-		let storage_prefix_hashed = Twox128::hash(Self::storage_prefix());
+		let storage_prefix = storage_prefix(Self::module_prefix(), Self::storage_prefix());
 		let key_hashed = KG::final_key(key);
 
-		let mut final_key = Vec::with_capacity(
-			module_prefix_hashed.len() + storage_prefix_hashed.len() + key_hashed.len(),
-		);
+		let mut final_key = Vec::with_capacity(storage_prefix.len() + key_hashed.len());
 
-		final_key.extend_from_slice(&module_prefix_hashed[..]);
-		final_key.extend_from_slice(&storage_prefix_hashed[..]);
+		final_key.extend_from_slice(&storage_prefix);
 		final_key.extend_from_slice(key_hashed.as_ref());
 
 		final_key
@@ -286,16 +269,12 @@ where
 		KArg: EncodeLikeTuple<K::KArg> + TupleToEncodedIter,
 	{
 		let old_key = {
-			let module_prefix_hashed = Twox128::hash(Self::module_prefix());
-			let storage_prefix_hashed = Twox128::hash(Self::storage_prefix());
+			let storage_prefix = storage_prefix(Self::module_prefix(), Self::storage_prefix());
 			let key_hashed = K::migrate_key(&key, hash_fns);
 
-			let mut final_key = Vec::with_capacity(
-				module_prefix_hashed.len() + storage_prefix_hashed.len() + key_hashed.len(),
-			);
+			let mut final_key = Vec::with_capacity(storage_prefix.len() + key_hashed.len());
 
-			final_key.extend_from_slice(&module_prefix_hashed[..]);
-			final_key.extend_from_slice(&storage_prefix_hashed[..]);
+			final_key.extend_from_slice(&storage_prefix);
 			final_key.extend_from_slice(key_hashed.as_ref());
 
 			final_key

substrate/frame/support/src/storage/generator/value.rs

@@ -16,7 +16,6 @@
 // limitations under the License.
 
 use crate::{
-	hash::{StorageHasher, Twox128},
 	storage::{self, unhashed, StorageAppend},
 	Never,
 };
@@ -46,10 +45,7 @@ pub trait StorageValue<T: FullCodec> {
 
 	/// Generate the full key used in top storage.
 	fn storage_value_final_key() -> [u8; 32] {
-		let mut final_key = [0u8; 32];
-		final_key[0..16].copy_from_slice(&Twox128::hash(Self::module_prefix()));
-		final_key[16..32].copy_from_slice(&Twox128::hash(Self::storage_prefix()));
-		final_key
+		crate::storage::storage_prefix(Self::module_prefix(), Self::storage_prefix())
 	}
 }