Remove enumerate_trie_root in favour of ordered_trie_root #2382 (#3360)

substrate/core/sr-io/src/lib.rs

@@ -153,15 +153,6 @@ export_api! {
 		/// "Commit" all existing operations and get the resultant storage change root.
 		fn storage_changes_root(parent_hash: [u8; 32]) -> Option<[u8; 32]>;
 
-		/// A trie root formed from the enumerated items.
-		/// TODO [#2382] remove (just use `ordered_trie_root` (NOTE currently not implemented for without_std))
-		fn enumerated_trie_root<H>(input: &[&[u8]]) -> H::Out
-		where
-			H: Hasher,
-			H: self::imp::HasherBounds,
-			H::Out: Ord
-		;
-
 		/// A trie root formed from the iterated items.
 		fn trie_root<H, I, A, B>(input: I) -> H::Out
 		where

substrate/core/sr-io/with_std.rs

@@ -167,14 +167,6 @@ impl StorageApi for () {
 		).unwrap_or(Ok(None)).expect("Invalid parent hash passed to storage_changes_root")
 	}
 
-	fn enumerated_trie_root<H>(input: &[&[u8]]) -> H::Out
-	where
-		H: Hasher,
-		H::Out: Ord,
-	{
-		Layout::<H>::ordered_trie_root(input)
-	}
-
 	fn trie_root<H, I, A, B>(input: I) -> H::Out
 	where
 		I: IntoIterator<Item = (A, B)>,

substrate/core/sr-io/without_std.rs

@@ -128,8 +128,11 @@ pub mod ext {
 
 	/// Ensures we use the right crypto when calling into native
 	pub trait ExternTrieCrypto: Hasher {
-		/// Calculate enumerated trie root.
-		fn enumerated_trie_root(values: &[&[u8]]) -> Self::Out;
+		/// A trie root formed from the enumerated items.
+		fn ordered_trie_root<
+			A: AsRef<[u8]>,
+			I: IntoIterator<Item = A>
+		>(values: I) -> Self::Out;
 	}
 
 	/// Additional bounds for Hasher trait for without_std.
@@ -138,9 +141,16 @@ pub mod ext {
 
 	// Ensures we use a Blake2_256-flavored Hasher when calling into native
 	impl ExternTrieCrypto for Blake2Hasher {
-		fn enumerated_trie_root(values: &[&[u8]]) -> Self::Out {
-			let lengths = values.iter().map(|v| (v.len() as u32).to_le()).collect::<Vec<_>>();
-			let values = values.iter().fold(Vec::new(), |mut acc, sl| { acc.extend_from_slice(sl); acc });
+		fn ordered_trie_root<
+			A: AsRef<[u8]>,
+			I: IntoIterator<Item = A>
+		>(items: I) -> Self::Out {
+			let mut values = Vec::new();
+			let mut lengths = Vec::new();
+			for v in items.into_iter() {
+				values.extend_from_slice(v.as_ref());
+				lengths.push((v.as_ref().len() as u32).to_le());
+			}
 			let mut result: [u8; 32] = Default::default();
 			unsafe {
 				ext_blake2_256_enumerated_trie_root.get()(
@@ -767,10 +777,6 @@ impl StorageApi for () {
 		}
 	}
 
-	fn enumerated_trie_root<H: Hasher + ExternTrieCrypto>(values: &[&[u8]]) -> H::Out {
-		H::enumerated_trie_root(values)
-	}
-
 	fn trie_root<
 		H: Hasher + ExternTrieCrypto,
 		I: IntoIterator<Item = (A, B)>,
@@ -784,8 +790,8 @@ impl StorageApi for () {
 		H: Hasher + ExternTrieCrypto,
 		I: IntoIterator<Item = A>,
 		A: AsRef<[u8]>
-	>(_input: I) -> H::Out {
-		unimplemented!()
+	>(values: I) -> H::Out {
+		H::ordered_trie_root(values)
 	}
 }