Storage chains: indexing, renewals and reference counting (#8265)

* Transaction indexing

* Tests and fixes

* Fixed a comment

* Style

* Build

* Style

* Apply suggestions from code review

Co-authored-by: cheme <emericchevalier.pro@gmail.com>

* Code review suggestions

* Add missing impl

* Apply suggestions from code review

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* impl JoinInput

* Don't store empty slices

* JoinInput operates on slices

Co-authored-by: cheme <emericchevalier.pro@gmail.com>
Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

substrate/client/api/src/backend.rs

@@ -26,7 +26,7 @@ use sp_runtime::{generic::BlockId, Justification, Justifications, Storage};
 use sp_runtime::traits::{Block as BlockT, NumberFor, HashFor};
 use sp_state_machine::{
 	ChangesTrieState, ChangesTrieStorage as StateChangesTrieStorage, ChangesTrieTransaction,
-	StorageCollection, ChildStorageCollection, OffchainChangesCollection,
+	StorageCollection, ChildStorageCollection, OffchainChangesCollection, IndexOperation,
 };
 use sp_storage::{StorageData, StorageKey, PrefixedStorageKey, ChildInfo};
 use crate::{
@@ -201,6 +201,9 @@ pub trait BlockImportOperation<Block: BlockT> {
 	/// Mark a block as new head. If both block import and set head are specified, set head
 	/// overrides block import's best block rule.
 	fn mark_head(&mut self, id: BlockId<Block>) -> sp_blockchain::Result<()>;
+
+	/// Add a transaction index operation.
+	fn update_transaction_index(&mut self, index: Vec<IndexOperation>) -> sp_blockchain::Result<()>;
 }
 
 /// Interface for performing operations on the backend.

substrate/client/api/src/client.rs

@@ -96,15 +96,18 @@ pub trait BlockBackend<Block: BlockT> {
 	/// Get block hash by number.
 	fn block_hash(&self, number: NumberFor<Block>) -> sp_blockchain::Result<Option<Block::Hash>>;
 
-	/// Get single extrinsic by hash.
-	fn extrinsic(
+	/// Get single indexed transaction by content hash. 
+	///
+	/// Note that this will only fetch transactions
+	/// that are indexed by the runtime with `storage_index_transaction`.
+	fn indexed_transaction(
 		&self,
 		hash: &Block::Hash,
-	) -> sp_blockchain::Result<Option<<Block as BlockT>::Extrinsic>>;
+	) -> sp_blockchain::Result<Option<Vec<u8>>>;
 
-	/// Check if extrinsic exists.
-	fn have_extrinsic(&self, hash: &Block::Hash) -> sp_blockchain::Result<bool> {
-		Ok(self.extrinsic(hash)?.is_some())
+	/// Check if transaction index exists.
+	fn has_indexed_transaction(&self, hash: &Block::Hash) -> sp_blockchain::Result<bool> {
+		Ok(self.indexed_transaction(hash)?.is_some())
 	}
 }
 

substrate/client/api/src/in_mem.rs

@@ -30,7 +30,7 @@ use sp_runtime::traits::{Block as BlockT, Header as HeaderT, Zero, NumberFor, Ha
 use sp_runtime::{Justification, Justifications, Storage};
 use sp_state_machine::{
 	ChangesTrieTransaction, InMemoryBackend, Backend as StateBackend, StorageCollection,
-	ChildStorageCollection,
+	ChildStorageCollection, IndexOperation,
 };
 use sp_blockchain::{CachedHeaderMetadata, HeaderMetadata};
 
@@ -415,10 +415,10 @@ impl<Block: BlockT> blockchain::Backend<Block> for Blockchain<Block> {
 		unimplemented!()
 	}
 
-	fn extrinsic(
+	fn indexed_transaction(
 		&self,
 		_hash: &Block::Hash,
-	) -> sp_blockchain::Result<Option<<Block as BlockT>::Extrinsic>> {
+	) -> sp_blockchain::Result<Option<Vec<u8>>> {
 		unimplemented!("Not supported by the in-mem backend.")
 	}
 }
@@ -613,6 +613,10 @@ impl<Block: BlockT> backend::BlockImportOperation<Block> for BlockImportOperatio
 		self.set_head = Some(block);
 		Ok(())
 	}
+
+	fn update_transaction_index(&mut self, _index: Vec<IndexOperation>) -> sp_blockchain::Result<()> {
+		Ok(())
+	}
 }
 
 /// In-memory backend. Keeps all states and blocks in memory.

substrate/client/api/src/leaves.rs

@@ -25,7 +25,7 @@ use sp_runtime::traits::AtLeast32Bit;
 use codec::{Encode, Decode};
 use sp_blockchain::{Error, Result};
 
-type DbHash = [u8; 32];
+type DbHash = sp_core::H256;
 
 #[derive(Debug, Clone, PartialEq, Eq)]
 struct LeafSetItem<H, N> {
@@ -55,6 +55,11 @@ impl<H, N: Ord> FinalizationDisplaced<H, N> {
 		// one transaction, then there will be no overlap in the keys.
 		self.leaves.append(&mut other.leaves);
 	}
+
+	/// Iterate over all displaced leaves.
+	pub fn leaves(&self) -> impl IntoIterator<Item=&H> {
+		self.leaves.values().flatten()
+	}
 }
 
 /// list of leaf hashes ordered by number (descending).