archive: Implement archive_unstable_storage (#1846)

This PR implements the `archive_unstable_storage` method that offers support for: - fetching values - fetching hashes - iterating over keys and values - iterating over keys and hashes - fetching merkle values from the trie-db A common component dedicated to RPC-V2 storage queries is created to bridge the gap between `chainHead/storage` and `archive/storage`. Query pagination is supported by `paginationStartKey`, similar to the old APIs. Similarly to the `chainHead/storage`, the `archive/storage` method accepts a maximum number of queried items. The design builds upon: https://github.com/paritytech/json-rpc-interface-spec/pull/94. Closes https://github.com/paritytech/polkadot-sdk/issues/1512. cc @paritytech/subxt-team --------- Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io> Co-authored-by: Niklas Adolfsson <niklasadolfsson1@gmail.com>
2026-06-19 06:31:03 +00:00 · 2024-01-15 16:03:32 +02:00
parent 46090ff114
commit 53bcbb15f1
15 changed files with 1278 additions and 363 deletions
@@ -0,0 +1,198 @@
+// This file is part of Substrate.
+
+// Copyright (C) Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+//! Storage queries for the RPC-V2 spec.
+
+use std::{marker::PhantomData, sync::Arc};
+
+use sc_client_api::{Backend, ChildInfo, StorageKey, StorageProvider};
+use sp_runtime::traits::Block as BlockT;
+
+use super::events::{StorageResult, StorageResultType};
+use crate::hex_string;
+
+/// Call into the storage of blocks.
+pub struct Storage<Client, Block, BE> {
+	/// Substrate client.
+	client: Arc<Client>,
+	_phandom: PhantomData<(BE, Block)>,
+}
+
+impl<Client, Block, BE> Storage<Client, Block, BE> {
+	/// Constructs a new [`Storage`].
+	pub fn new(client: Arc<Client>) -> Self {
+		Self { client, _phandom: PhantomData }
+	}
+}
+
+/// Query to iterate over storage.
+pub struct QueryIter {
+	/// The key from which the iteration was started.
+	pub query_key: StorageKey,
+	/// The key after which pagination should resume.
+	pub pagination_start_key: Option<StorageKey>,
+	/// The type of the query (either value or hash).
+	pub ty: IterQueryType,
+}
+
+/// The query type of an iteration.
+pub enum IterQueryType {
+	/// Iterating over (key, value) pairs.
+	Value,
+	/// Iterating over (key, hash) pairs.
+	Hash,
+}
+
+/// The result of making a query call.
+pub type QueryResult = Result<Option<StorageResult>, String>;
+
+/// The result of iterating over keys.
+pub type QueryIterResult = Result<(Vec<StorageResult>, Option<QueryIter>), String>;
+
+impl<Client, Block, BE> Storage<Client, Block, BE>
+where
+	Block: BlockT + 'static,
+	BE: Backend<Block> + 'static,
+	Client: StorageProvider<Block, BE> + 'static,
+{
+	/// Fetch the value from storage.
+	pub fn query_value(
+		&self,
+		hash: Block::Hash,
+		key: &StorageKey,
+		child_key: Option<&ChildInfo>,
+	) -> QueryResult {
+		let result = if let Some(child_key) = child_key {
+			self.client.child_storage(hash, child_key, key)
+		} else {
+			self.client.storage(hash, key)
+		};
+
+		result
+			.map(|opt| {
+				QueryResult::Ok(opt.map(|storage_data| StorageResult {
+					key: hex_string(&key.0),
+					result: StorageResultType::Value(hex_string(&storage_data.0)),
+				}))
+			})
+			.unwrap_or_else(|error| QueryResult::Err(error.to_string()))
+	}
+
+	/// Fetch the hash of a value from storage.
+	pub fn query_hash(
+		&self,
+		hash: Block::Hash,
+		key: &StorageKey,
+		child_key: Option<&ChildInfo>,
+	) -> QueryResult {
+		let result = if let Some(child_key) = child_key {
+			self.client.child_storage_hash(hash, child_key, key)
+		} else {
+			self.client.storage_hash(hash, key)
+		};
+
+		result
+			.map(|opt| {
+				QueryResult::Ok(opt.map(|storage_data| StorageResult {
+					key: hex_string(&key.0),
+					result: StorageResultType::Hash(hex_string(&storage_data.as_ref())),
+				}))
+			})
+			.unwrap_or_else(|error| QueryResult::Err(error.to_string()))
+	}
+
+	/// Fetch the closest merkle value.
+	pub fn query_merkle_value(
+		&self,
+		hash: Block::Hash,
+		key: &StorageKey,
+		child_key: Option<&ChildInfo>,
+	) -> QueryResult {
+		let result = if let Some(child_key) = child_key {
+			self.client.child_closest_merkle_value(hash, child_key, key)
+		} else {
+			self.client.closest_merkle_value(hash, key)
+		};
+
+		result
+			.map(|opt| {
+				QueryResult::Ok(opt.map(|storage_data| {
+					let result = match &storage_data {
+						sc_client_api::MerkleValue::Node(data) => hex_string(&data.as_slice()),
+						sc_client_api::MerkleValue::Hash(hash) => hex_string(&hash.as_ref()),
+					};
+
+					StorageResult {
+						key: hex_string(&key.0),
+						result: StorageResultType::ClosestDescendantMerkleValue(result),
+					}
+				}))
+			})
+			.unwrap_or_else(|error| QueryResult::Err(error.to_string()))
+	}
+
+	/// Iterate over at most the provided number of keys.
+	///
+	/// Returns the storage result with a potential next key to resume iteration.
+	pub fn query_iter_pagination(
+		&self,
+		query: QueryIter,
+		hash: Block::Hash,
+		child_key: Option<&ChildInfo>,
+		count: usize,
+	) -> QueryIterResult {
+		let QueryIter { ty, query_key, pagination_start_key } = query;
+
+		let mut keys_iter = if let Some(child_key) = child_key {
+			self.client.child_storage_keys(
+				hash,
+				child_key.to_owned(),
+				Some(&query_key),
+				pagination_start_key.as_ref(),
+			)
+		} else {
+			self.client.storage_keys(hash, Some(&query_key), pagination_start_key.as_ref())
+		}
+		.map_err(|err| err.to_string())?;
+
+		let mut ret = Vec::with_capacity(count);
+		let mut next_pagination_key = None;
+		for _ in 0..count {
+			let Some(key) = keys_iter.next() else { break };
+
+			next_pagination_key = Some(key.clone());
+
+			let result = match ty {
+				IterQueryType::Value => self.query_value(hash, &key, child_key),
+				IterQueryType::Hash => self.query_hash(hash, &key, child_key),
+			}?;
+
+			if let Some(value) = result {
+				ret.push(value);
+			}
+		}
+
+		// Save the next key if any to continue the iteration.
+		let maybe_next_query = keys_iter.next().map(|_| QueryIter {
+			ty,
+			query_key,
+			pagination_start_key: next_pagination_key,
+		});
+		Ok((ret, maybe_next_query))
+	}
+}