Associated type Hasher for QueryPreimage, StorePreimage and Bounded (#1720)

I hope it's enough to fix #1701 
the only solution I found to make it happen is to put an associated type
to the `Bounded` enum as well.
@liamaharon @kianenigma @bkchr 

Polkadot address: 12poSUQPtcF1HUPQGY3zZu2P8emuW9YnsPduA4XG3oCEfJVp

---------

Signed-off-by: muraca <mmuraca247@gmail.com>
Co-authored-by: Liam Aharon <liam.aharon@hotmail.com>
Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>

substrate/frame/support/src/traits.rs

@@ -107,7 +107,7 @@ mod voting;
 pub use voting::{ClassCountOf, PollStatus, Polling, VoteTally};
 
 mod preimages;
-pub use preimages::{Bounded, BoundedInline, FetchResult, Hash, QueryPreimage, StorePreimage};
+pub use preimages::{Bounded, BoundedInline, FetchResult, QueryPreimage, StorePreimage};
 
 mod messages;
 pub use messages::{

substrate/frame/support/src/traits/preimages.rs

@@ -15,16 +15,17 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-//! Stuff for dealing with 32-byte hashed preimages.
+//! Stuff for dealing with hashed preimages.
 
 use codec::{Decode, Encode, EncodeLike, MaxEncodedLen};
 use scale_info::TypeInfo;
-use sp_core::{RuntimeDebug, H256};
-use sp_io::hashing::blake2_256;
-use sp_runtime::{traits::ConstU32, DispatchError};
+use sp_core::RuntimeDebug;
+use sp_runtime::{
+	traits::{ConstU32, Hash},
+	DispatchError,
+};
 use sp_std::borrow::Cow;
 
-pub type Hash = H256;
 pub type BoundedInline = crate::BoundedVec<u8, ConstU32<128>>;
 
 /// The maximum we expect a single legacy hash lookup to be.
@@ -32,29 +33,29 @@ const MAX_LEGACY_LEN: u32 = 1_000_000;
 
 #[derive(Encode, Decode, MaxEncodedLen, Clone, Eq, PartialEq, TypeInfo, RuntimeDebug)]
 #[codec(mel_bound())]
-pub enum Bounded<T> {
-	/// A Blake2 256 hash with no preimage length. We
-	/// do not support creation of this except for transitioning from legacy state.
-	/// In the future we will make this a pure `Dummy` item storing only the final `dummy` field.
-	Legacy { hash: Hash, dummy: sp_std::marker::PhantomData<T> },
+pub enum Bounded<T, H: Hash> {
+	/// A hash with no preimage length. We do not support creation of this except
+	/// for transitioning from legacy state. In the future we will make this a pure
+	/// `Dummy` item storing only the final `dummy` field.
+	Legacy { hash: H::Output, dummy: sp_std::marker::PhantomData<T> },
 	/// A an bounded `Call`. Its encoding must be at most 128 bytes.
 	Inline(BoundedInline),
-	/// A Blake2-256 hash of the call together with an upper limit for its size.
-	Lookup { hash: Hash, len: u32 },
+	/// A hash of the call together with an upper limit for its size.`
+	Lookup { hash: H::Output, len: u32 },
 }
 
-impl<T> Bounded<T> {
+impl<T, H: Hash> Bounded<T, H> {
 	/// Casts the wrapped type into something that encodes alike.
 	///
 	/// # Examples
 	/// ```
-	/// use frame_support::traits::Bounded;
+	/// use frame_support::{traits::Bounded, sp_runtime::traits::BlakeTwo256};
 	///
 	/// // Transmute from `String` to `&str`.
-	/// let x: Bounded<String> = Bounded::Inline(Default::default());
-	/// let _: Bounded<&str> = x.transmute();
+	/// let x: Bounded<String, BlakeTwo256> = Bounded::Inline(Default::default());
+	/// let _: Bounded<&str, BlakeTwo256> = x.transmute();
 	/// ```
-	pub fn transmute<S: Encode>(self) -> Bounded<S>
+	pub fn transmute<S: Encode>(self) -> Bounded<S, H>
 	where
 		T: Encode + EncodeLike<S>,
 	{
@@ -69,18 +70,18 @@ impl<T> Bounded<T> {
 	/// Returns the hash of the preimage.
 	///
 	/// The hash is re-calculated every time if the preimage is inlined.
-	pub fn hash(&self) -> Hash {
+	pub fn hash(&self) -> H::Output {
 		use Bounded::*;
 		match self {
 			Lookup { hash, .. } | Legacy { hash, .. } => *hash,
-			Inline(x) => blake2_256(x.as_ref()).into(),
+			Inline(x) => <H as Hash>::hash(x.as_ref()),
 		}
 	}
 
 	/// Returns the hash to lookup the preimage.
 	///
 	/// If this is a `Bounded::Inline`, `None` is returned as no lookup is required.
-	pub fn lookup_hash(&self) -> Option<Hash> {
+	pub fn lookup_hash(&self) -> Option<H::Output> {
 		use Bounded::*;
 		match self {
 			Lookup { hash, .. } | Legacy { hash, .. } => Some(*hash),
@@ -115,13 +116,13 @@ impl<T> Bounded<T> {
 	}
 
 	/// Constructs a `Lookup` bounded item.
-	pub fn unrequested(hash: Hash, len: u32) -> Self {
+	pub fn unrequested(hash: H::Output, len: u32) -> Self {
 		Self::Lookup { hash, len }
 	}
 
 	/// Constructs a `Legacy` bounded item.
 	#[deprecated = "This API is only for transitioning to Scheduler v3 API"]
-	pub fn from_legacy_hash(hash: impl Into<Hash>) -> Self {
+	pub fn from_legacy_hash(hash: impl Into<H::Output>) -> Self {
 		Self::Legacy { hash: hash.into(), dummy: sp_std::marker::PhantomData }
 	}
 }
@@ -130,24 +131,27 @@ pub type FetchResult = Result<Cow<'static, [u8]>, DispatchError>;
 
 /// A interface for looking up preimages from their hash on chain.
 pub trait QueryPreimage {
+	/// The hasher used in the runtime.
+	type H: Hash;
+
 	/// Returns whether a preimage exists for a given hash and if so its length.
-	fn len(hash: &Hash) -> Option<u32>;
+	fn len(hash: &<Self::H as sp_core::Hasher>::Out) -> Option<u32>;
 
 	/// Returns the preimage for a given hash. If given, `len` must be the size of the preimage.
-	fn fetch(hash: &Hash, len: Option<u32>) -> FetchResult;
+	fn fetch(hash: &<Self::H as sp_core::Hasher>::Out, len: Option<u32>) -> FetchResult;
 
 	/// Returns whether a preimage request exists for a given hash.
-	fn is_requested(hash: &Hash) -> bool;
+	fn is_requested(hash: &<Self::H as sp_core::Hasher>::Out) -> bool;
 
 	/// Request that someone report a preimage. Providers use this to optimise the economics for
 	/// preimage reporting.
-	fn request(hash: &Hash);
+	fn request(hash: &<Self::H as sp_core::Hasher>::Out);
 
 	/// Cancel a previous preimage request.
-	fn unrequest(hash: &Hash);
+	fn unrequest(hash: &<Self::H as sp_core::Hasher>::Out);
 
 	/// Request that the data required for decoding the given `bounded` value is made available.
-	fn hold<T>(bounded: &Bounded<T>) {
+	fn hold<T>(bounded: &Bounded<T, Self::H>) {
 		use Bounded::*;
 		match bounded {
 			Inline(..) => {},
@@ -157,7 +161,7 @@ pub trait QueryPreimage {
 
 	/// No longer request that the data required for decoding the given `bounded` value is made
 	/// available.
-	fn drop<T>(bounded: &Bounded<T>) {
+	fn drop<T>(bounded: &Bounded<T, Self::H>) {
 		use Bounded::*;
 		match bounded {
 			Inline(..) => {},
@@ -167,7 +171,7 @@ pub trait QueryPreimage {
 
 	/// Check to see if all data required for the given `bounded` value is available for its
 	/// decoding.
-	fn have<T>(bounded: &Bounded<T>) -> bool {
+	fn have<T>(bounded: &Bounded<T, Self::H>) -> bool {
 		use Bounded::*;
 		match bounded {
 			Inline(..) => true,
@@ -180,7 +184,7 @@ pub trait QueryPreimage {
 	/// It also directly requests the given `hash` using [`Self::request`].
 	///
 	/// This may not be `peek`-able or `realize`-able.
-	fn pick<T>(hash: Hash, len: u32) -> Bounded<T> {
+	fn pick<T>(hash: <Self::H as sp_core::Hasher>::Out, len: u32) -> Bounded<T, Self::H> {
 		Self::request(&hash);
 		Bounded::Lookup { hash, len }
 	}
@@ -190,7 +194,7 @@ pub trait QueryPreimage {
 	///
 	/// NOTE: This does not remove any data needed for realization. If you will no longer use the
 	/// `bounded`, call `realize` instead or call `drop` afterwards.
-	fn peek<T: Decode>(bounded: &Bounded<T>) -> Result<(T, Option<u32>), DispatchError> {
+	fn peek<T: Decode>(bounded: &Bounded<T, Self::H>) -> Result<(T, Option<u32>), DispatchError> {
 		use Bounded::*;
 		match bounded {
 			Inline(data) => T::decode(&mut &data[..]).ok().map(|x| (x, None)),
@@ -209,7 +213,9 @@ pub trait QueryPreimage {
 	/// Convert the given `bounded` value back into its original instance. If successful,
 	/// `drop` any data backing it. This will not break the realisability of independently
 	/// created instances of `Bounded` which happen to have identical data.
-	fn realize<T: Decode>(bounded: &Bounded<T>) -> Result<(T, Option<u32>), DispatchError> {
+	fn realize<T: Decode>(
+		bounded: &Bounded<T, Self::H>,
+	) -> Result<(T, Option<u32>), DispatchError> {
 		let r = Self::peek(bounded)?;
 		Self::drop(bounded);
 		Ok(r)
@@ -230,11 +236,11 @@ pub trait StorePreimage: QueryPreimage {
 	/// Request and attempt to store the bytes of a preimage on chain.
 	///
 	/// May return `DispatchError::Exhausted` if the preimage is just too big.
-	fn note(bytes: Cow<[u8]>) -> Result<Hash, DispatchError>;
+	fn note(bytes: Cow<[u8]>) -> Result<<Self::H as sp_core::Hasher>::Out, DispatchError>;
 
 	/// Attempt to clear a previously noted preimage. Exactly the same as `unrequest` but is
 	/// provided for symmetry.
-	fn unnote(hash: &Hash) {
+	fn unnote(hash: &<Self::H as sp_core::Hasher>::Out) {
 		Self::unrequest(hash)
 	}
 
@@ -244,7 +250,7 @@ pub trait StorePreimage: QueryPreimage {
 	///
 	/// NOTE: Once this API is used, you should use either `drop` or `realize`.
 	/// The value is also noted using [`Self::note`].
-	fn bound<T: Encode>(t: T) -> Result<Bounded<T>, DispatchError> {
+	fn bound<T: Encode>(t: T) -> Result<Bounded<T, Self::H>, DispatchError> {
 		let data = t.encode();
 		let len = data.len() as u32;
 		Ok(match BoundedInline::try_from(data) {
@@ -255,22 +261,24 @@ pub trait StorePreimage: QueryPreimage {
 }
 
 impl QueryPreimage for () {
-	fn len(_: &Hash) -> Option<u32> {
+	type H = sp_runtime::traits::BlakeTwo256;
+
+	fn len(_: &sp_core::H256) -> Option<u32> {
 		None
 	}
-	fn fetch(_: &Hash, _: Option<u32>) -> FetchResult {
+	fn fetch(_: &sp_core::H256, _: Option<u32>) -> FetchResult {
 		Err(DispatchError::Unavailable)
 	}
-	fn is_requested(_: &Hash) -> bool {
+	fn is_requested(_: &sp_core::H256) -> bool {
 		false
 	}
-	fn request(_: &Hash) {}
-	fn unrequest(_: &Hash) {}
+	fn request(_: &sp_core::H256) {}
+	fn unrequest(_: &sp_core::H256) {}
 }
 
 impl StorePreimage for () {
 	const MAX_LENGTH: usize = 0;
-	fn note(_: Cow<[u8]>) -> Result<Hash, DispatchError> {
+	fn note(_: Cow<[u8]>) -> Result<sp_core::H256, DispatchError> {
 		Err(DispatchError::Exhausted)
 	}
 }
@@ -279,22 +287,22 @@ impl StorePreimage for () {
 mod tests {
 	use super::*;
 	use crate::BoundedVec;
-	use sp_runtime::bounded_vec;
+	use sp_runtime::{bounded_vec, traits::BlakeTwo256};
 
 	#[test]
 	fn bounded_size_is_correct() {
-		assert_eq!(<Bounded<Vec<u8>> as MaxEncodedLen>::max_encoded_len(), 131);
+		assert_eq!(<Bounded<Vec<u8>, BlakeTwo256> as MaxEncodedLen>::max_encoded_len(), 131);
 	}
 
 	#[test]
 	fn bounded_basic_works() {
 		let data: BoundedVec<u8, _> = bounded_vec![b'a', b'b', b'c'];
 		let len = data.len() as u32;
-		let hash = blake2_256(&data).into();
+		let hash = BlakeTwo256::hash(&data).into();
 
 		// Inline works
 		{
-			let bound: Bounded<Vec<u8>> = Bounded::Inline(data.clone());
+			let bound: Bounded<Vec<u8>, BlakeTwo256> = Bounded::Inline(data.clone());
 			assert_eq!(bound.hash(), hash);
 			assert_eq!(bound.len(), Some(len));
 			assert!(!bound.lookup_needed());
@@ -302,7 +310,8 @@ mod tests {
 		}
 		// Legacy works
 		{
-			let bound: Bounded<Vec<u8>> = Bounded::Legacy { hash, dummy: Default::default() };
+			let bound: Bounded<Vec<u8>, BlakeTwo256> =
+				Bounded::Legacy { hash, dummy: Default::default() };
 			assert_eq!(bound.hash(), hash);
 			assert_eq!(bound.len(), None);
 			assert!(bound.lookup_needed());
@@ -310,7 +319,8 @@ mod tests {
 		}
 		// Lookup works
 		{
-			let bound: Bounded<Vec<u8>> = Bounded::Lookup { hash, len: data.len() as u32 };
+			let bound: Bounded<Vec<u8>, BlakeTwo256> =
+				Bounded::Lookup { hash, len: data.len() as u32 };
 			assert_eq!(bound.hash(), hash);
 			assert_eq!(bound.len(), Some(len));
 			assert!(bound.lookup_needed());
@@ -323,8 +333,8 @@ mod tests {
 		let data: BoundedVec<u8, _> = bounded_vec![b'a', b'b', b'c'];
 
 		// Transmute a `String` into a `&str`.
-		let x: Bounded<String> = Bounded::Inline(data.clone());
-		let y: Bounded<&str> = x.transmute();
+		let x: Bounded<String, BlakeTwo256> = Bounded::Inline(data.clone());
+		let y: Bounded<&str, BlakeTwo256> = x.transmute();
 		assert_eq!(y, Bounded::Inline(data));
 	}
 }

substrate/frame/support/src/traits/schedule.rs

@@ -387,6 +387,8 @@ pub mod v3 {
 	pub trait Anon<BlockNumber, Call, Origin> {
 		/// An address which can be used for removing a scheduled task.
 		type Address: Codec + MaxEncodedLen + Clone + Eq + EncodeLike + Debug + TypeInfo;
+		/// The hasher used in the runtime.
+		type Hasher: sp_runtime::traits::Hash;
 
 		/// Schedule a dispatch to happen at the beginning of some block in the future.
 		///
@@ -396,7 +398,7 @@ pub mod v3 {
 			maybe_periodic: Option<Period<BlockNumber>>,
 			priority: Priority,
 			origin: Origin,
-			call: Bounded<Call>,
+			call: Bounded<Call, Self::Hasher>,
 		) -> Result<Self::Address, DispatchError>;
 
 		/// Cancel a scheduled task. If periodic, then it will cancel all further instances of that,
@@ -434,6 +436,8 @@ pub mod v3 {
 	pub trait Named<BlockNumber, Call, Origin> {
 		/// An address which can be used for removing a scheduled task.
 		type Address: Codec + MaxEncodedLen + Clone + Eq + EncodeLike + sp_std::fmt::Debug;
+		/// The hasher used in the runtime.
+		type Hasher: sp_runtime::traits::Hash;
 
 		/// Schedule a dispatch to happen at the beginning of some block in the future.
 		///
@@ -446,7 +450,7 @@ pub mod v3 {
 			maybe_periodic: Option<Period<BlockNumber>>,
 			priority: Priority,
 			origin: Origin,
-			call: Bounded<Call>,
+			call: Bounded<Call, Self::Hasher>,
 		) -> Result<Self::Address, DispatchError>;
 
 		/// Cancel a scheduled, named task. If periodic, then it will cancel all further instances