pallet-mmr: RPC API and Runtime API work with block numbers (#12345)

* pallet-mmr: RPC API works with block_numbers * fixes * update rpc * fmt * final touches in the rpc * temporary fix * fix * fmt * docs * Update lib.rs * use NumberFor * validate input * update runtime * convert block_number to u64 * small edit * update runtime api * test fix * runtime fix * update test function * fmt * fix nits * remove block_num_to_leaf_index from runtime api * Update frame/merkle-mountain-range/src/lib.rs Co-authored-by: Robert Hambrock <roberthambrock@gmail.com> * fix tests * get the code to compile after merge * get the tests to compile * fix in tests? * fix test * Update frame/merkle-mountain-range/src/tests.rs Co-authored-by: Adrian Catangiu <adrian@parity.io> * Update frame/merkle-mountain-range/src/lib.rs Co-authored-by: Adrian Catangiu <adrian@parity.io> * Update primitives/merkle-mountain-range/src/lib.rs Co-authored-by: Adrian Catangiu <adrian@parity.io> * fix errors & nits * change block_num_to_leaf_index * don't make any assumptions * Update frame/merkle-mountain-range/src/tests.rs Co-authored-by: Adrian Catangiu <adrian@parity.io> * Update frame/merkle-mountain-range/src/tests.rs Co-authored-by: Adrian Catangiu <adrian@parity.io> * Update frame/merkle-mountain-range/src/tests.rs Co-authored-by: Adrian Catangiu <adrian@parity.io> * fix * small fix * use best_known_block_number * best_known_block_number instead of leaves_count * more readable? * remove warning * Update frame/merkle-mountain-range/src/lib.rs Co-authored-by: Robert Hambrock <roberthambrock@gmail.com> * simplify * update docs * nits * fmt & fix * merge fixes * fix * small fix * docs & nit fixes * Nit fixes * remove leaf_indices_to_block_numbers() * fmt Co-authored-by: Robert Hambrock <roberthambrock@gmail.com> Co-authored-by: Adrian Catangiu <adrian@parity.io>
2026-06-14 04:01:10 +00:00 · 2022-10-13 12:13:56 +02:00
parent 09164dbced
commit 9dd89e7fa3
10 changed files with 160 additions and 113 deletions
@@ -59,7 +59,7 @@
 use codec::Encode;
 use frame_support::weights::Weight;
 use sp_runtime::{
-	traits::{self, One, Saturating},
+	traits::{self, CheckedSub, One, Saturating},
 	SaturatedConversion,
 };

@@ -318,37 +318,73 @@ impl<T: Config<I>, I: 'static> Pallet<T, I> {
 			.saturating_add(leaf_index.saturated_into())
 	}

-	/// Generate a MMR proof for the given `leaf_indices`.
+	/// Convert a `block_num` into a leaf index.
+	fn block_num_to_leaf_index(block_num: T::BlockNumber) -> Result<LeafIndex, primitives::Error>
+	where
+		T: frame_system::Config,
+	{
+		// leaf_idx = (leaves_count - 1) - (current_block_num - block_num);
+		let best_block_num = <frame_system::Pallet<T>>::block_number();
+		let blocks_diff = best_block_num.checked_sub(&block_num).ok_or_else(|| {
+			primitives::Error::BlockNumToLeafIndex
+				.log_debug("The provided block_number is greater than the best block number.")
+		})?;
+		let blocks_diff_as_leaf_idx = blocks_diff.try_into().map_err(|_| {
+			primitives::Error::BlockNumToLeafIndex
+				.log_debug("The `blocks_diff` couldn't be converted to `LeafIndex`.")
+		})?;
+
+		let leaf_idx = Self::mmr_leaves()
+			.checked_sub(1)
+			.and_then(|last_leaf_idx| last_leaf_idx.checked_sub(blocks_diff_as_leaf_idx))
+			.ok_or_else(|| {
+				primitives::Error::BlockNumToLeafIndex
+					.log_debug("There aren't enough leaves in the chain.")
+			})?;
+		Ok(leaf_idx)
+	}
+
+	/// Generate a MMR proof for the given `block_numbers`.
 	///
 	/// Note this method can only be used from an off-chain context
 	/// (Offchain Worker or Runtime API call), since it requires
 	/// all the leaves to be present.
 	/// It may return an error or panic if used incorrectly.
 	pub fn generate_batch_proof(
-		leaf_indices: Vec<LeafIndex>,
+		block_numbers: Vec<T::BlockNumber>,
 	) -> Result<
 		(Vec<LeafOf<T, I>>, primitives::BatchProof<<T as Config<I>>::Hash>),
 		primitives::Error,
 	> {
-		Self::generate_historical_batch_proof(leaf_indices, Self::mmr_leaves())
+		Self::generate_historical_batch_proof(
+			block_numbers,
+			<frame_system::Pallet<T>>::block_number(),
+		)
 	}

-	/// Generate a MMR proof for the given `leaf_indices` for the MMR of `leaves_count` size.
+	/// Generate a MMR proof for the given `block_numbers` given the `best_known_block_number`.
 	///
 	/// Note this method can only be used from an off-chain context
 	/// (Offchain Worker or Runtime API call), since it requires
 	/// all the leaves to be present.
 	/// It may return an error or panic if used incorrectly.
 	pub fn generate_historical_batch_proof(
-		leaf_indices: Vec<LeafIndex>,
-		leaves_count: LeafIndex,
+		block_numbers: Vec<T::BlockNumber>,
+		best_known_block_number: T::BlockNumber,
 	) -> Result<
 		(Vec<LeafOf<T, I>>, primitives::BatchProof<<T as Config<I>>::Hash>),
 		primitives::Error,
 	> {
-		if leaves_count > Self::mmr_leaves() {
-			return Err(Error::InvalidLeavesCount)
-		}
+		let leaves_count =
+			Self::block_num_to_leaf_index(best_known_block_number)?.saturating_add(1);
+
+		// we need to translate the block_numbers into leaf indices.
+		let leaf_indices = block_numbers
+			.iter()
+			.map(|block_num| -> Result<LeafIndex, primitives::Error> {
+				Self::block_num_to_leaf_index(*block_num)
+			})
+			.collect::<Result<Vec<LeafIndex>, _>>()?;

 		let mmr: ModuleMmr<mmr::storage::OffchainStorage, T, I> = mmr::Mmr::new(leaves_count);
 		mmr.generate_batch_proof(leaf_indices)