feat: initialize Kurdistan SDK - independent fork of Polkadot SDK

pezkuwi/node/core/approval-voting/src/approval_db/common/migration_helpers.rs

@@ -0,0 +1,40 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// This file is part of Pezkuwi.
+
+// Pezkuwi 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.
+
+// Pezkuwi 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 Pezkuwi.  If not, see <http://www.gnu.org/licenses/>.
+
+use bitvec::{order::Lsb0 as BitOrderLsb0, vec::BitVec};
+
+use pezkuwi_node_primitives::approval::{
+	v1::{AssignmentCert, AssignmentCertKind, VrfProof, VrfSignature, RELAY_VRF_MODULO_CONTEXT},
+	v2::VrfPreOutput,
+};
+
+pub fn make_bitvec(len: usize) -> BitVec<u8, BitOrderLsb0> {
+	bitvec::bitvec![u8, BitOrderLsb0; 0; len]
+}
+
+pub fn dummy_assignment_cert(kind: AssignmentCertKind) -> AssignmentCert {
+	let ctx = schnorrkel::signing_context(RELAY_VRF_MODULO_CONTEXT);
+	let msg = b"test-garbage";
+	let mut prng = rand_core::OsRng;
+	let keypair = schnorrkel::Keypair::generate_with(&mut prng);
+	let (inout, proof, _) = keypair.vrf_sign(ctx.bytes(msg));
+	let preout = inout.to_preout();
+
+	AssignmentCert {
+		kind,
+		vrf: VrfSignature { pre_output: VrfPreOutput(preout), proof: VrfProof(proof) },
+	}
+}

pezkuwi/node/core/approval-voting/src/approval_db/common/mod.rs

@@ -0,0 +1,293 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// This file is part of Pezkuwi.
+
+// Pezkuwi 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.
+
+// Pezkuwi 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 Pezkuwi.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Common helper functions for all versions of approval-voting database.
+use std::sync::Arc;
+
+use codec::{Decode, Encode};
+use pezkuwi_node_subsystem::{SubsystemError, SubsystemResult};
+use pezkuwi_node_subsystem_util::database::{DBTransaction, Database};
+use pezkuwi_primitives::{BlockNumber, CandidateHash, CandidateIndex, Hash};
+
+use crate::{
+	backend::{Backend, BackendWriteOp, V1ReadBackend, V2ReadBackend},
+	persisted_entries,
+};
+
+use super::{
+	v2::{load_block_entry_v1, load_candidate_entry_v1},
+	v3::{load_block_entry_v2, load_candidate_entry_v2, BlockEntry, CandidateEntry},
+};
+
+pub mod migration_helpers;
+
+const STORED_BLOCKS_KEY: &[u8] = b"Approvals_StoredBlocks";
+
+/// A range from earliest..last block number stored within the DB.
+#[derive(Encode, Decode, Debug, Clone, PartialEq)]
+pub struct StoredBlockRange(pub BlockNumber, pub BlockNumber);
+/// The database config.
+#[derive(Debug, Clone, Copy)]
+pub struct Config {
+	/// The column family in the database where data is stored.
+	pub col_approval_data: u32,
+}
+
+/// `DbBackend` is a concrete implementation of the higher-level Backend trait
+pub struct DbBackend {
+	inner: Arc<dyn Database>,
+	config: Config,
+}
+
+impl DbBackend {
+	/// Create a new [`DbBackend`] with the supplied key-value store and
+	/// config.
+	pub fn new(db: Arc<dyn Database>, config: Config) -> Self {
+		DbBackend { inner: db, config }
+	}
+}
+
+/// Errors while accessing things from the DB.
+#[derive(Debug, derive_more::From, derive_more::Display)]
+pub enum Error {
+	Io(std::io::Error),
+	InvalidDecoding(codec::Error),
+	InternalError(SubsystemError),
+}
+
+impl std::error::Error for Error {}
+
+/// Result alias for DB errors.
+pub type Result<T> = std::result::Result<T, Error>;
+
+impl Backend for DbBackend {
+	fn load_block_entry(
+		&self,
+		block_hash: &Hash,
+	) -> SubsystemResult<Option<persisted_entries::BlockEntry>> {
+		load_block_entry(&*self.inner, &self.config, block_hash).map(|e| e.map(Into::into))
+	}
+
+	fn load_candidate_entry(
+		&self,
+		candidate_hash: &CandidateHash,
+	) -> SubsystemResult<Option<persisted_entries::CandidateEntry>> {
+		load_candidate_entry(&*self.inner, &self.config, candidate_hash).map(|e| e.map(Into::into))
+	}
+
+	fn load_blocks_at_height(&self, block_height: &BlockNumber) -> SubsystemResult<Vec<Hash>> {
+		load_blocks_at_height(&*self.inner, &self.config, block_height)
+	}
+
+	fn load_all_blocks(&self) -> SubsystemResult<Vec<Hash>> {
+		load_all_blocks(&*self.inner, &self.config)
+	}
+
+	fn load_stored_blocks(&self) -> SubsystemResult<Option<StoredBlockRange>> {
+		load_stored_blocks(&*self.inner, &self.config)
+	}
+
+	/// Atomically write the list of operations, with later operations taking precedence over prior.
+	fn write<I>(&mut self, ops: I) -> SubsystemResult<()>
+	where
+		I: IntoIterator<Item = BackendWriteOp>,
+	{
+		let mut tx = DBTransaction::new();
+		for op in ops {
+			match op {
+				BackendWriteOp::WriteStoredBlockRange(stored_block_range) => {
+					tx.put_vec(
+						self.config.col_approval_data,
+						&STORED_BLOCKS_KEY,
+						stored_block_range.encode(),
+					);
+				},
+				BackendWriteOp::DeleteStoredBlockRange => {
+					tx.delete(self.config.col_approval_data, &STORED_BLOCKS_KEY);
+				},
+				BackendWriteOp::WriteBlocksAtHeight(h, blocks) => {
+					tx.put_vec(
+						self.config.col_approval_data,
+						&blocks_at_height_key(h),
+						blocks.encode(),
+					);
+				},
+				BackendWriteOp::DeleteBlocksAtHeight(h) => {
+					tx.delete(self.config.col_approval_data, &blocks_at_height_key(h));
+				},
+				BackendWriteOp::WriteBlockEntry(block_entry) => {
+					let block_entry: BlockEntry = block_entry.into();
+					tx.put_vec(
+						self.config.col_approval_data,
+						&block_entry_key(&block_entry.block_hash),
+						block_entry.encode(),
+					);
+				},
+				BackendWriteOp::DeleteBlockEntry(hash) => {
+					tx.delete(self.config.col_approval_data, &block_entry_key(&hash));
+				},
+				BackendWriteOp::WriteCandidateEntry(candidate_entry) => {
+					let candidate_entry: CandidateEntry = candidate_entry.into();
+					tx.put_vec(
+						self.config.col_approval_data,
+						&candidate_entry_key(&candidate_entry.candidate.hash()),
+						candidate_entry.encode(),
+					);
+				},
+				BackendWriteOp::DeleteCandidateEntry(candidate_hash) => {
+					tx.delete(self.config.col_approval_data, &candidate_entry_key(&candidate_hash));
+				},
+			}
+		}
+
+		self.inner.write(tx).map_err(|e| e.into())
+	}
+}
+
+impl V1ReadBackend for DbBackend {
+	fn load_candidate_entry_v1(
+		&self,
+		candidate_hash: &CandidateHash,
+		candidate_index: CandidateIndex,
+	) -> SubsystemResult<Option<persisted_entries::CandidateEntry>> {
+		load_candidate_entry_v1(&*self.inner, &self.config, candidate_hash)
+			.map(|e| e.map(|e| persisted_entries::CandidateEntry::from_v1(e, candidate_index)))
+	}
+
+	fn load_block_entry_v1(
+		&self,
+		block_hash: &Hash,
+	) -> SubsystemResult<Option<persisted_entries::BlockEntry>> {
+		load_block_entry_v1(&*self.inner, &self.config, block_hash).map(|e| e.map(Into::into))
+	}
+}
+
+impl V2ReadBackend for DbBackend {
+	fn load_candidate_entry_v2(
+		&self,
+		candidate_hash: &CandidateHash,
+		candidate_index: CandidateIndex,
+	) -> SubsystemResult<Option<persisted_entries::CandidateEntry>> {
+		load_candidate_entry_v2(&*self.inner, &self.config, candidate_hash)
+			.map(|e| e.map(|e| persisted_entries::CandidateEntry::from_v2(e, candidate_index)))
+	}
+
+	fn load_block_entry_v2(
+		&self,
+		block_hash: &Hash,
+	) -> SubsystemResult<Option<persisted_entries::BlockEntry>> {
+		load_block_entry_v2(&*self.inner, &self.config, block_hash).map(|e| e.map(Into::into))
+	}
+}
+
+pub(crate) fn load_decode<D: Decode>(
+	store: &dyn Database,
+	col_approval_data: u32,
+	key: &[u8],
+) -> Result<Option<D>> {
+	match store.get(col_approval_data, key)? {
+		None => Ok(None),
+		Some(raw) => D::decode(&mut &raw[..]).map(Some).map_err(Into::into),
+	}
+}
+
+/// The key a given block entry is stored under.
+pub(crate) fn block_entry_key(block_hash: &Hash) -> [u8; 46] {
+	const BLOCK_ENTRY_PREFIX: [u8; 14] = *b"Approvals_blck";
+
+	let mut key = [0u8; 14 + 32];
+	key[0..14].copy_from_slice(&BLOCK_ENTRY_PREFIX);
+	key[14..][..32].copy_from_slice(block_hash.as_ref());
+
+	key
+}
+
+/// The key a given candidate entry is stored under.
+pub(crate) fn candidate_entry_key(candidate_hash: &CandidateHash) -> [u8; 46] {
+	const CANDIDATE_ENTRY_PREFIX: [u8; 14] = *b"Approvals_cand";
+
+	let mut key = [0u8; 14 + 32];
+	key[0..14].copy_from_slice(&CANDIDATE_ENTRY_PREFIX);
+	key[14..][..32].copy_from_slice(candidate_hash.0.as_ref());
+
+	key
+}
+
+/// The key a set of block hashes corresponding to a block number is stored under.
+pub(crate) fn blocks_at_height_key(block_number: BlockNumber) -> [u8; 16] {
+	const BLOCKS_AT_HEIGHT_PREFIX: [u8; 12] = *b"Approvals_at";
+
+	let mut key = [0u8; 12 + 4];
+	key[0..12].copy_from_slice(&BLOCKS_AT_HEIGHT_PREFIX);
+	block_number.using_encoded(|s| key[12..16].copy_from_slice(s));
+
+	key
+}
+
+/// Return all blocks which have entries in the DB, ascending, by height.
+pub fn load_all_blocks(store: &dyn Database, config: &Config) -> SubsystemResult<Vec<Hash>> {
+	let mut hashes = Vec::new();
+	if let Some(stored_blocks) = load_stored_blocks(store, config)? {
+		for height in stored_blocks.0..stored_blocks.1 {
+			let blocks = load_blocks_at_height(store, config, &height)?;
+			hashes.extend(blocks);
+		}
+	}
+
+	Ok(hashes)
+}
+
+/// Load the stored-blocks key from the state.
+pub fn load_stored_blocks(
+	store: &dyn Database,
+	config: &Config,
+) -> SubsystemResult<Option<StoredBlockRange>> {
+	load_decode(store, config.col_approval_data, STORED_BLOCKS_KEY)
+		.map_err(|e| SubsystemError::with_origin("approval-voting", e))
+}
+
+/// Load a blocks-at-height entry for a given block number.
+pub fn load_blocks_at_height(
+	store: &dyn Database,
+	config: &Config,
+	block_number: &BlockNumber,
+) -> SubsystemResult<Vec<Hash>> {
+	load_decode(store, config.col_approval_data, &blocks_at_height_key(*block_number))
+		.map(|x| x.unwrap_or_default())
+		.map_err(|e| SubsystemError::with_origin("approval-voting", e))
+}
+
+/// Load a block entry from the aux store.
+pub fn load_block_entry(
+	store: &dyn Database,
+	config: &Config,
+	block_hash: &Hash,
+) -> SubsystemResult<Option<BlockEntry>> {
+	load_decode(store, config.col_approval_data, &block_entry_key(block_hash))
+		.map(|u: Option<BlockEntry>| u.map(|v| v.into()))
+		.map_err(|e| SubsystemError::with_origin("approval-voting", e))
+}
+
+/// Load a candidate entry from the aux store in current version format.
+pub fn load_candidate_entry(
+	store: &dyn Database,
+	config: &Config,
+	candidate_hash: &CandidateHash,
+) -> SubsystemResult<Option<CandidateEntry>> {
+	load_decode(store, config.col_approval_data, &candidate_entry_key(candidate_hash))
+		.map(|u: Option<CandidateEntry>| u.map(|v| v.into()))
+		.map_err(|e| SubsystemError::with_origin("approval-voting", e))
+}

pezkuwi/node/core/approval-voting/src/approval_db/mod.rs

@@ -0,0 +1,36 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// This file is part of Pezkuwi.
+
+// Pezkuwi 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.
+
+// Pezkuwi 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 Pezkuwi.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Approval DB accessors and writers for on-disk persisted approval storage
+//! data.
+//!
+//! We persist data to disk although it is not intended to be used across runs of the
+//! program. This is because under medium to long periods of finality stalling, for whatever
+//! reason that may be, the amount of data we'd need to keep would be potentially too large
+//! for memory.
+//!
+//! With tens or hundreds of teyrchains, hundreds of validators, and parablocks
+//! in every relay chain block, there can be a humongous amount of information to reference
+//! at any given time.
+//!
+//! As such, we provide a function from this module to clear the database on start-up.
+//! In the future, we may use a temporary DB which doesn't need to be wiped, but for the
+//! time being we share the same DB with the rest of Substrate.
+
+pub mod common;
+pub mod v1;
+pub mod v2;
+pub mod v3;

pezkuwi/node/core/approval-voting/src/approval_db/v1/mod.rs

@@ -0,0 +1,91 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// This file is part of Pezkuwi.
+
+// Pezkuwi 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.
+
+// Pezkuwi 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 Pezkuwi.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Version 1 of the DB schema.
+//!
+//! Note that the version here differs from the actual version of the teyrchains
+//! database (check `CURRENT_VERSION` in `node/service/src/teyrchains_db/upgrade.rs`).
+//! The code in this module implements the way approval voting works with
+//! its data in the database. Any breaking changes here will still
+//! require a db migration (check `node/service/src/teyrchains_db/upgrade.rs`).
+
+use codec::{Decode, Encode};
+use pezkuwi_node_primitives::approval::v1::{AssignmentCert, DelayTranche};
+use pezkuwi_primitives::{
+	BlockNumber, CandidateHash, CandidateReceiptV2 as CandidateReceipt, CoreIndex, GroupIndex,
+	Hash, SessionIndex, ValidatorIndex, ValidatorSignature,
+};
+use sp_consensus_slots::Slot;
+use std::collections::BTreeMap;
+
+use super::v2::Bitfield;
+
+/// Details pertaining to our assignment on a block.
+#[derive(Encode, Decode, Debug, Clone, PartialEq)]
+pub struct OurAssignment {
+	pub cert: AssignmentCert,
+	pub tranche: DelayTranche,
+	pub validator_index: ValidatorIndex,
+	// Whether the assignment has been triggered already.
+	pub triggered: bool,
+}
+use super::v2::TrancheEntry;
+
+/// Metadata regarding approval of a particular candidate within the context of some
+/// particular block.
+#[derive(Encode, Decode, Debug, Clone, PartialEq)]
+pub struct ApprovalEntry {
+	pub tranches: Vec<TrancheEntry>,
+	pub backing_group: GroupIndex,
+	pub our_assignment: Option<OurAssignment>,
+	pub our_approval_sig: Option<ValidatorSignature>,
+	// `n_validators` bits.
+	pub assignments: Bitfield,
+	pub approved: bool,
+}
+
+/// Metadata regarding approval of a particular candidate.
+#[derive(Encode, Decode, Debug, Clone, PartialEq)]
+pub struct CandidateEntry {
+	pub candidate: CandidateReceipt,
+	pub session: SessionIndex,
+	// Assignments are based on blocks, so we need to track assignments separately
+	// based on the block we are looking at.
+	pub block_assignments: BTreeMap<Hash, ApprovalEntry>,
+	pub approvals: Bitfield,
+}
+
+/// Metadata regarding approval of a particular block, by way of approval of the
+/// candidates contained within it.
+#[derive(Encode, Decode, Debug, Clone, PartialEq)]
+pub struct BlockEntry {
+	pub block_hash: Hash,
+	pub block_number: BlockNumber,
+	pub parent_hash: Hash,
+	pub session: SessionIndex,
+	pub slot: Slot,
+	/// Random bytes derived from the VRF submitted within the block by the block
+	/// author as a credential and used as input to approval assignment criteria.
+	pub relay_vrf_story: [u8; 32],
+	// The candidates included as-of this block and the index of the core they are
+	// leaving. Sorted ascending by core index.
+	pub candidates: Vec<(CoreIndex, CandidateHash)>,
+	// A bitfield where the i'th bit corresponds to the i'th candidate in `candidates`.
+	// The i'th bit is `true` iff the candidate has been approved in the context of this
+	// block. The block can be considered approved if the bitfield has all bits set to `true`.
+	pub approved_bitfield: Bitfield,
+	pub children: Vec<Hash>,
+}

pezkuwi/node/core/approval-voting/src/approval_db/v1/tests.rs

@@ -0,0 +1,567 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// This file is part of Pezkuwi.
+
+// Pezkuwi 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.
+
+// Pezkuwi 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 Pezkuwi.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Tests for the aux-schema of approval voting.
+
+use super::{DbBackend, StoredBlockRange, *};
+use crate::{
+	backend::{Backend, OverlayedBackend},
+	ops::{add_block_entry, canonicalize, force_approve, NewCandidateInfo},
+};
+use pezkuwi_node_subsystem_util::database::Database;
+use pezkuwi_primitives::Id as ParaId;
+use std::{collections::HashMap, sync::Arc};
+
+use pezkuwi_primitives_test_helpers::{
+	dummy_candidate_receipt, dummy_candidate_receipt_bad_sig, dummy_hash,
+};
+
+const DATA_COL: u32 = 0;
+
+const NUM_COLUMNS: u32 = 1;
+
+const TEST_CONFIG: Config = Config { col_approval_data: DATA_COL };
+
+fn make_db() -> (DbBackend, Arc<dyn Database>) {
+	let db = kvdb_memorydb::create(NUM_COLUMNS);
+	let db = pezkuwi_node_subsystem_util::database::kvdb_impl::DbAdapter::new(db, &[]);
+	let db_writer: Arc<dyn Database> = Arc::new(db);
+	(DbBackend::new(db_writer.clone(), TEST_CONFIG), db_writer)
+}
+
+fn make_block_entry(
+	block_hash: Hash,
+	parent_hash: Hash,
+	block_number: BlockNumber,
+	candidates: Vec<(CoreIndex, CandidateHash)>,
+) -> BlockEntry {
+	BlockEntry {
+		block_hash,
+		parent_hash,
+		block_number,
+		session: 1,
+		slot: Slot::from(1),
+		relay_vrf_story: [0u8; 32],
+		approved_bitfield: make_bitvec(candidates.len()),
+		candidates,
+		children: Vec::new(),
+	}
+}
+
+fn make_candidate(para_id: ParaId, relay_parent: Hash) -> CandidateReceipt {
+	let mut c = dummy_candidate_receipt(dummy_hash());
+
+	c.descriptor.para_id = para_id;
+	c.descriptor.relay_parent = relay_parent;
+
+	c
+}
+
+#[test]
+fn read_write() {
+	let (mut db, store) = make_db();
+
+	let hash_a = Hash::repeat_byte(1);
+	let hash_b = Hash::repeat_byte(2);
+	let candidate_hash = dummy_candidate_receipt_bad_sig(dummy_hash(), None).hash();
+
+	let range = StoredBlockRange(10, 20);
+	let at_height = vec![hash_a, hash_b];
+
+	let block_entry =
+		make_block_entry(hash_a, Default::default(), 1, vec![(CoreIndex(0), candidate_hash)]);
+
+	let candidate_entry = CandidateEntry {
+		candidate: dummy_candidate_receipt_bad_sig(dummy_hash(), None),
+		session: 5,
+		block_assignments: vec![(
+			hash_a,
+			ApprovalEntry {
+				tranches: Vec::new(),
+				backing_group: GroupIndex(1),
+				our_assignment: None,
+				our_approval_sig: None,
+				assignments: Default::default(),
+				approved: false,
+			},
+		)]
+		.into_iter()
+		.collect(),
+		approvals: Default::default(),
+	};
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	overlay_db.write_stored_block_range(range.clone());
+	overlay_db.write_blocks_at_height(1, at_height.clone());
+	overlay_db.write_block_entry(block_entry.clone().into());
+	overlay_db.write_candidate_entry(candidate_entry.clone().into());
+
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	assert_eq!(load_stored_blocks(store.as_ref(), &TEST_CONFIG).unwrap(), Some(range));
+	assert_eq!(load_blocks_at_height(store.as_ref(), &TEST_CONFIG, &1).unwrap(), at_height);
+	assert_eq!(
+		load_block_entry(store.as_ref(), &TEST_CONFIG, &hash_a).unwrap(),
+		Some(block_entry.into())
+	);
+	assert_eq!(
+		load_candidate_entry(store.as_ref(), &TEST_CONFIG, &candidate_hash).unwrap(),
+		Some(candidate_entry.into()),
+	);
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	overlay_db.delete_blocks_at_height(1);
+	overlay_db.delete_block_entry(&hash_a);
+	overlay_db.delete_candidate_entry(&candidate_hash);
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	assert!(load_blocks_at_height(store.as_ref(), &TEST_CONFIG, &1).unwrap().is_empty());
+	assert!(load_block_entry(store.as_ref(), &TEST_CONFIG, &hash_a).unwrap().is_none());
+	assert!(load_candidate_entry(store.as_ref(), &TEST_CONFIG, &candidate_hash)
+		.unwrap()
+		.is_none());
+}
+
+#[test]
+fn add_block_entry_works() {
+	let (mut db, store) = make_db();
+
+	let parent_hash = Hash::repeat_byte(1);
+	let block_hash_a = Hash::repeat_byte(2);
+	let block_hash_b = Hash::repeat_byte(69);
+
+	let candidate_receipt_a = make_candidate(ParaId::from(1_u32), parent_hash);
+	let candidate_receipt_b = make_candidate(ParaId::from(2_u32), parent_hash);
+
+	let candidate_hash_a = candidate_receipt_a.hash();
+	let candidate_hash_b = candidate_receipt_b.hash();
+
+	let block_number = 10;
+
+	let block_entry_a = make_block_entry(
+		block_hash_a,
+		parent_hash,
+		block_number,
+		vec![(CoreIndex(0), candidate_hash_a)],
+	);
+
+	let block_entry_b = make_block_entry(
+		block_hash_b,
+		parent_hash,
+		block_number,
+		vec![(CoreIndex(0), candidate_hash_a), (CoreIndex(1), candidate_hash_b)],
+	);
+
+	let n_validators = 10;
+
+	let mut new_candidate_info = HashMap::new();
+	new_candidate_info
+		.insert(candidate_hash_a, NewCandidateInfo::new(candidate_receipt_a, GroupIndex(0), None));
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	add_block_entry(&mut overlay_db, block_entry_a.clone().into(), n_validators, |h| {
+		new_candidate_info.get(h).map(|x| x.clone())
+	})
+	.unwrap();
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	new_candidate_info
+		.insert(candidate_hash_b, NewCandidateInfo::new(candidate_receipt_b, GroupIndex(1), None));
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	add_block_entry(&mut overlay_db, block_entry_b.clone().into(), n_validators, |h| {
+		new_candidate_info.get(h).map(|x| x.clone())
+	})
+	.unwrap();
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	assert_eq!(
+		load_block_entry(store.as_ref(), &TEST_CONFIG, &block_hash_a).unwrap(),
+		Some(block_entry_a.into())
+	);
+	assert_eq!(
+		load_block_entry(store.as_ref(), &TEST_CONFIG, &block_hash_b).unwrap(),
+		Some(block_entry_b.into())
+	);
+
+	let candidate_entry_a = load_candidate_entry(store.as_ref(), &TEST_CONFIG, &candidate_hash_a)
+		.unwrap()
+		.unwrap();
+	assert_eq!(
+		candidate_entry_a.block_assignments.keys().collect::<Vec<_>>(),
+		vec![&block_hash_a, &block_hash_b]
+	);
+
+	let candidate_entry_b = load_candidate_entry(store.as_ref(), &TEST_CONFIG, &candidate_hash_b)
+		.unwrap()
+		.unwrap();
+	assert_eq!(candidate_entry_b.block_assignments.keys().collect::<Vec<_>>(), vec![&block_hash_b]);
+}
+
+#[test]
+fn add_block_entry_adds_child() {
+	let (mut db, store) = make_db();
+
+	let parent_hash = Hash::repeat_byte(1);
+	let block_hash_a = Hash::repeat_byte(2);
+	let block_hash_b = Hash::repeat_byte(69);
+
+	let mut block_entry_a = make_block_entry(block_hash_a, parent_hash, 1, Vec::new());
+
+	let block_entry_b = make_block_entry(block_hash_b, block_hash_a, 2, Vec::new());
+
+	let n_validators = 10;
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	add_block_entry(&mut overlay_db, block_entry_a.clone().into(), n_validators, |_| None).unwrap();
+
+	add_block_entry(&mut overlay_db, block_entry_b.clone().into(), n_validators, |_| None).unwrap();
+
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	block_entry_a.children.push(block_hash_b);
+
+	assert_eq!(
+		load_block_entry(store.as_ref(), &TEST_CONFIG, &block_hash_a).unwrap(),
+		Some(block_entry_a.into())
+	);
+	assert_eq!(
+		load_block_entry(store.as_ref(), &TEST_CONFIG, &block_hash_b).unwrap(),
+		Some(block_entry_b.into())
+	);
+}
+
+#[test]
+fn canonicalize_works() {
+	let (mut db, store) = make_db();
+
+	//   -> B1 -> C1 -> D1
+	// A -> B2 -> C2 -> D2
+	//
+	// We'll canonicalize C1. Everything except D1 should disappear.
+	//
+	// Candidates:
+	// Cand1 in B2
+	// Cand2 in C2
+	// Cand3 in C2 and D1
+	// Cand4 in D1
+	// Cand5 in D2
+	// Only Cand3 and Cand4 should remain after canonicalize.
+
+	let n_validators = 10;
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	overlay_db.write_stored_block_range(StoredBlockRange(1, 5));
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	let genesis = Hash::repeat_byte(0);
+
+	let block_hash_a = Hash::repeat_byte(1);
+	let block_hash_b1 = Hash::repeat_byte(2);
+	let block_hash_b2 = Hash::repeat_byte(3);
+	let block_hash_c1 = Hash::repeat_byte(4);
+	let block_hash_c2 = Hash::repeat_byte(5);
+	let block_hash_d1 = Hash::repeat_byte(6);
+	let block_hash_d2 = Hash::repeat_byte(7);
+
+	let candidate_receipt_genesis = make_candidate(ParaId::from(1_u32), genesis);
+	let candidate_receipt_a = make_candidate(ParaId::from(2_u32), block_hash_a);
+	let candidate_receipt_b = make_candidate(ParaId::from(3_u32), block_hash_a);
+	let candidate_receipt_b1 = make_candidate(ParaId::from(4_u32), block_hash_b1);
+	let candidate_receipt_c1 = make_candidate(ParaId::from(5_u32), block_hash_c1);
+
+	let cand_hash_1 = candidate_receipt_genesis.hash();
+	let cand_hash_2 = candidate_receipt_a.hash();
+	let cand_hash_3 = candidate_receipt_b.hash();
+	let cand_hash_4 = candidate_receipt_b1.hash();
+	let cand_hash_5 = candidate_receipt_c1.hash();
+
+	let block_entry_a = make_block_entry(block_hash_a, genesis, 1, Vec::new());
+	let block_entry_b1 = make_block_entry(block_hash_b1, block_hash_a, 2, Vec::new());
+	let block_entry_b2 =
+		make_block_entry(block_hash_b2, block_hash_a, 2, vec![(CoreIndex(0), cand_hash_1)]);
+	let block_entry_c1 = make_block_entry(block_hash_c1, block_hash_b1, 3, Vec::new());
+	let block_entry_c2 = make_block_entry(
+		block_hash_c2,
+		block_hash_b2,
+		3,
+		vec![(CoreIndex(0), cand_hash_2), (CoreIndex(1), cand_hash_3)],
+	);
+	let block_entry_d1 = make_block_entry(
+		block_hash_d1,
+		block_hash_c1,
+		4,
+		vec![(CoreIndex(0), cand_hash_3), (CoreIndex(1), cand_hash_4)],
+	);
+	let block_entry_d2 =
+		make_block_entry(block_hash_d2, block_hash_c2, 4, vec![(CoreIndex(0), cand_hash_5)]);
+
+	let candidate_info = {
+		let mut candidate_info = HashMap::new();
+		candidate_info.insert(
+			cand_hash_1,
+			NewCandidateInfo::new(candidate_receipt_genesis, GroupIndex(1), None),
+		);
+
+		candidate_info
+			.insert(cand_hash_2, NewCandidateInfo::new(candidate_receipt_a, GroupIndex(2), None));
+
+		candidate_info
+			.insert(cand_hash_3, NewCandidateInfo::new(candidate_receipt_b, GroupIndex(3), None));
+
+		candidate_info
+			.insert(cand_hash_4, NewCandidateInfo::new(candidate_receipt_b1, GroupIndex(4), None));
+
+		candidate_info
+			.insert(cand_hash_5, NewCandidateInfo::new(candidate_receipt_c1, GroupIndex(5), None));
+
+		candidate_info
+	};
+
+	// now insert all the blocks.
+	let blocks = vec![
+		block_entry_a.clone(),
+		block_entry_b1.clone(),
+		block_entry_b2.clone(),
+		block_entry_c1.clone(),
+		block_entry_c2.clone(),
+		block_entry_d1.clone(),
+		block_entry_d2.clone(),
+	];
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	for block_entry in blocks {
+		add_block_entry(&mut overlay_db, block_entry.into(), n_validators, |h| {
+			candidate_info.get(h).map(|x| x.clone())
+		})
+		.unwrap();
+	}
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	let check_candidates_in_store = |expected: Vec<(CandidateHash, Option<Vec<_>>)>| {
+		for (c_hash, in_blocks) in expected {
+			let (entry, in_blocks) = match in_blocks {
+				None => {
+					assert!(load_candidate_entry(store.as_ref(), &TEST_CONFIG, &c_hash)
+						.unwrap()
+						.is_none());
+					continue
+				},
+				Some(i) => (
+					load_candidate_entry(store.as_ref(), &TEST_CONFIG, &c_hash).unwrap().unwrap(),
+					i,
+				),
+			};
+
+			assert_eq!(entry.block_assignments.len(), in_blocks.len());
+
+			for x in in_blocks {
+				assert!(entry.block_assignments.contains_key(&x));
+			}
+		}
+	};
+
+	let check_blocks_in_store = |expected: Vec<(Hash, Option<Vec<_>>)>| {
+		for (hash, with_candidates) in expected {
+			let (entry, with_candidates) = match with_candidates {
+				None => {
+					assert!(load_block_entry(store.as_ref(), &TEST_CONFIG, &hash)
+						.unwrap()
+						.is_none());
+					continue
+				},
+				Some(i) =>
+					(load_block_entry(store.as_ref(), &TEST_CONFIG, &hash).unwrap().unwrap(), i),
+			};
+
+			assert_eq!(entry.candidates.len(), with_candidates.len());
+
+			for x in with_candidates {
+				assert!(entry.candidates.iter().any(|(_, c)| c == &x));
+			}
+		}
+	};
+
+	check_candidates_in_store(vec![
+		(cand_hash_1, Some(vec![block_hash_b2])),
+		(cand_hash_2, Some(vec![block_hash_c2])),
+		(cand_hash_3, Some(vec![block_hash_c2, block_hash_d1])),
+		(cand_hash_4, Some(vec![block_hash_d1])),
+		(cand_hash_5, Some(vec![block_hash_d2])),
+	]);
+
+	check_blocks_in_store(vec![
+		(block_hash_a, Some(vec![])),
+		(block_hash_b1, Some(vec![])),
+		(block_hash_b2, Some(vec![cand_hash_1])),
+		(block_hash_c1, Some(vec![])),
+		(block_hash_c2, Some(vec![cand_hash_2, cand_hash_3])),
+		(block_hash_d1, Some(vec![cand_hash_3, cand_hash_4])),
+		(block_hash_d2, Some(vec![cand_hash_5])),
+	]);
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	canonicalize(&mut overlay_db, 3, block_hash_c1).unwrap();
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	assert_eq!(
+		load_stored_blocks(store.as_ref(), &TEST_CONFIG).unwrap().unwrap(),
+		StoredBlockRange(4, 5)
+	);
+
+	check_candidates_in_store(vec![
+		(cand_hash_1, None),
+		(cand_hash_2, None),
+		(cand_hash_3, Some(vec![block_hash_d1])),
+		(cand_hash_4, Some(vec![block_hash_d1])),
+		(cand_hash_5, None),
+	]);
+
+	check_blocks_in_store(vec![
+		(block_hash_a, None),
+		(block_hash_b1, None),
+		(block_hash_b2, None),
+		(block_hash_c1, None),
+		(block_hash_c2, None),
+		(block_hash_d1, Some(vec![cand_hash_3, cand_hash_4])),
+		(block_hash_d2, None),
+	]);
+}
+
+#[test]
+fn force_approve_works() {
+	let (mut db, store) = make_db();
+	let n_validators = 10;
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	overlay_db.write_stored_block_range(StoredBlockRange(1, 4));
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	let candidate_hash = CandidateHash(Hash::repeat_byte(42));
+	let single_candidate_vec = vec![(CoreIndex(0), candidate_hash)];
+	let candidate_info = {
+		let mut candidate_info = HashMap::new();
+		candidate_info.insert(
+			candidate_hash,
+			NewCandidateInfo::new(
+				make_candidate(ParaId::from(1_u32), Default::default()),
+				GroupIndex(1),
+				None,
+			),
+		);
+
+		candidate_info
+	};
+
+	let block_hash_a = Hash::repeat_byte(1); // 1
+	let block_hash_b = Hash::repeat_byte(2);
+	let block_hash_c = Hash::repeat_byte(3);
+	let block_hash_d = Hash::repeat_byte(4); // 4
+
+	let block_entry_a =
+		make_block_entry(block_hash_a, Default::default(), 1, single_candidate_vec.clone());
+	let block_entry_b =
+		make_block_entry(block_hash_b, block_hash_a, 2, single_candidate_vec.clone());
+	let block_entry_c =
+		make_block_entry(block_hash_c, block_hash_b, 3, single_candidate_vec.clone());
+	let block_entry_d =
+		make_block_entry(block_hash_d, block_hash_c, 4, single_candidate_vec.clone());
+
+	let blocks = vec![
+		block_entry_a.clone(),
+		block_entry_b.clone(),
+		block_entry_c.clone(),
+		block_entry_d.clone(),
+	];
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	for block_entry in blocks {
+		add_block_entry(&mut overlay_db, block_entry.into(), n_validators, |h| {
+			candidate_info.get(h).map(|x| x.clone())
+		})
+		.unwrap();
+	}
+	let approved_hashes = force_approve(&mut overlay_db, block_hash_d, 2).unwrap();
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	assert!(load_block_entry(store.as_ref(), &TEST_CONFIG, &block_hash_a,)
+		.unwrap()
+		.unwrap()
+		.approved_bitfield
+		.all());
+	assert!(load_block_entry(store.as_ref(), &TEST_CONFIG, &block_hash_b,)
+		.unwrap()
+		.unwrap()
+		.approved_bitfield
+		.all());
+	assert!(load_block_entry(store.as_ref(), &TEST_CONFIG, &block_hash_c,)
+		.unwrap()
+		.unwrap()
+		.approved_bitfield
+		.not_any());
+	assert!(load_block_entry(store.as_ref(), &TEST_CONFIG, &block_hash_d,)
+		.unwrap()
+		.unwrap()
+		.approved_bitfield
+		.not_any());
+	assert_eq!(approved_hashes, vec![block_hash_b, block_hash_a]);
+}
+
+#[test]
+fn load_all_blocks_works() {
+	let (mut db, store) = make_db();
+
+	let parent_hash = Hash::repeat_byte(1);
+	let block_hash_a = Hash::repeat_byte(2);
+	let block_hash_b = Hash::repeat_byte(69);
+	let block_hash_c = Hash::repeat_byte(42);
+
+	let block_number = 10;
+
+	let block_entry_a = make_block_entry(block_hash_a, parent_hash, block_number, vec![]);
+
+	let block_entry_b = make_block_entry(block_hash_b, parent_hash, block_number, vec![]);
+
+	let block_entry_c = make_block_entry(block_hash_c, block_hash_a, block_number + 1, vec![]);
+
+	let n_validators = 10;
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	add_block_entry(&mut overlay_db, block_entry_a.clone().into(), n_validators, |_| None).unwrap();
+
+	// add C before B to test sorting.
+	add_block_entry(&mut overlay_db, block_entry_c.clone().into(), n_validators, |_| None).unwrap();
+
+	add_block_entry(&mut overlay_db, block_entry_b.clone().into(), n_validators, |_| None).unwrap();
+
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	assert_eq!(
+		load_all_blocks(store.as_ref(), &TEST_CONFIG).unwrap(),
+		vec![block_hash_a, block_hash_b, block_hash_c],
+	)
+}

pezkuwi/node/core/approval-voting/src/approval_db/v2/migration_helpers.rs

@@ -0,0 +1,202 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// This file is part of Pezkuwi.
+
+// Pezkuwi 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.
+
+// Pezkuwi 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 Pezkuwi.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Approval DB migration helpers.
+use super::*;
+use crate::{
+	approval_db::common::{
+		migration_helpers::{dummy_assignment_cert, make_bitvec},
+		Error, Result, StoredBlockRange,
+	},
+	backend::Backend,
+};
+
+use pezkuwi_node_primitives::approval::v1::AssignmentCertKind;
+use pezkuwi_node_subsystem_util::database::Database;
+use sp_application_crypto::sp_core::H256;
+use std::{collections::HashSet, sync::Arc};
+
+fn make_block_entry_v1(
+	block_hash: Hash,
+	parent_hash: Hash,
+	block_number: BlockNumber,
+	candidates: Vec<(CoreIndex, CandidateHash)>,
+) -> crate::approval_db::v1::BlockEntry {
+	crate::approval_db::v1::BlockEntry {
+		block_hash,
+		parent_hash,
+		block_number,
+		session: 1,
+		slot: Slot::from(1),
+		relay_vrf_story: [0u8; 32],
+		approved_bitfield: make_bitvec(candidates.len()),
+		candidates,
+		children: Vec::new(),
+	}
+}
+
+/// Migrates `OurAssignment`, `CandidateEntry` and `ApprovalEntry` to version 2.
+/// Returns on any error.
+/// Must only be used in teyrchains DB migration code - `pezkuwi-service` crate.
+pub fn v1_to_latest(db: Arc<dyn Database>, config: Config) -> Result<()> {
+	let mut backend = crate::DbBackend::new(db, config);
+	let all_blocks = backend
+		.load_all_blocks()
+		.map_err(|e| Error::InternalError(e))?
+		.iter()
+		.filter_map(|block_hash| {
+			backend
+				.load_block_entry_v1(block_hash)
+				.map_err(|e| Error::InternalError(e))
+				.ok()?
+		})
+		.collect::<Vec<_>>();
+
+	gum::info!(
+		target: crate::LOG_TARGET,
+		"Migrating candidate entries on top of {} blocks",
+		all_blocks.len()
+	);
+
+	let mut overlay = crate::OverlayedBackend::new(&backend);
+	let mut counter = 0;
+	// Get all candidate entries, approval entries and convert each of them.
+	for block in all_blocks {
+		for (candidate_index, (_core_index, candidate_hash)) in
+			block.candidates().iter().enumerate()
+		{
+			// Loading the candidate will also perform the conversion to the updated format and
+			// return that representation.
+			if let Some(candidate_entry) = backend
+				.load_candidate_entry_v1(&candidate_hash, candidate_index as CandidateIndex)
+				.map_err(|e| Error::InternalError(e))?
+			{
+				// Write the updated representation.
+				overlay.write_candidate_entry(candidate_entry);
+				counter += 1;
+			}
+		}
+		overlay.write_block_entry(block);
+	}
+
+	gum::info!(target: crate::LOG_TARGET, "Migrated {} entries", counter);
+
+	// Commit all changes to DB.
+	let write_ops = overlay.into_write_ops();
+	backend.write(write_ops).unwrap();
+
+	Ok(())
+}
+
+// Fills the db with dummy data in v1 scheme.
+pub fn v1_fill_test_data<F>(
+	db: Arc<dyn Database>,
+	config: Config,
+	dummy_candidate_create: F,
+) -> Result<HashSet<CandidateHash>>
+where
+	F: Fn(H256) -> CandidateReceipt<H256>,
+{
+	let mut backend = crate::DbBackend::new(db.clone(), config);
+	let mut overlay_db = crate::OverlayedBackend::new(&backend);
+	let mut expected_candidates = HashSet::new();
+
+	const RELAY_BLOCK_COUNT: u32 = 10;
+
+	let range = StoredBlockRange(1, 11);
+	overlay_db.write_stored_block_range(range.clone());
+
+	for relay_number in 1..=RELAY_BLOCK_COUNT {
+		let relay_hash = Hash::repeat_byte(relay_number as u8);
+		let assignment_core_index = CoreIndex(relay_number);
+		let candidate = dummy_candidate_create(relay_hash);
+		let candidate_hash = candidate.hash();
+
+		let at_height = vec![relay_hash];
+
+		let block_entry = make_block_entry_v1(
+			relay_hash,
+			Default::default(),
+			relay_number,
+			vec![(assignment_core_index, candidate_hash)],
+		);
+
+		let dummy_assignment = crate::approval_db::v1::OurAssignment {
+			cert: dummy_assignment_cert(AssignmentCertKind::RelayVRFModulo { sample: 0 }).into(),
+			tranche: 0,
+			validator_index: ValidatorIndex(0),
+			triggered: false,
+		};
+
+		let candidate_entry = crate::approval_db::v1::CandidateEntry {
+			candidate,
+			session: 123,
+			block_assignments: vec![(
+				relay_hash,
+				crate::approval_db::v1::ApprovalEntry {
+					tranches: Vec::new(),
+					backing_group: GroupIndex(1),
+					our_assignment: Some(dummy_assignment),
+					our_approval_sig: None,
+					assignments: Default::default(),
+					approved: false,
+				},
+			)]
+			.into_iter()
+			.collect(),
+			approvals: Default::default(),
+		};
+
+		overlay_db.write_blocks_at_height(relay_number, at_height.clone());
+		expected_candidates.insert(candidate_entry.candidate.hash());
+
+		db.write(write_candidate_entry_v1(candidate_entry, config)).unwrap();
+		db.write(write_block_entry_v1(block_entry, config)).unwrap();
+	}
+
+	let write_ops = overlay_db.into_write_ops();
+	backend.write(write_ops).unwrap();
+
+	Ok(expected_candidates)
+}
+
+// Low level DB helper to write a candidate entry in v1 scheme.
+fn write_candidate_entry_v1(
+	candidate_entry: crate::approval_db::v1::CandidateEntry,
+	config: Config,
+) -> DBTransaction {
+	let mut tx = DBTransaction::new();
+	tx.put_vec(
+		config.col_approval_data,
+		&candidate_entry_key(&candidate_entry.candidate.hash()),
+		candidate_entry.encode(),
+	);
+	tx
+}
+
+// Low level DB helper to write a block entry in v1 scheme.
+fn write_block_entry_v1(
+	block_entry: crate::approval_db::v1::BlockEntry,
+	config: Config,
+) -> DBTransaction {
+	let mut tx = DBTransaction::new();
+	tx.put_vec(
+		config.col_approval_data,
+		&block_entry_key(&block_entry.block_hash),
+		block_entry.encode(),
+	);
+	tx
+}

pezkuwi/node/core/approval-voting/src/approval_db/v2/mod.rs

@@ -0,0 +1,153 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// This file is part of Pezkuwi.
+
+// Pezkuwi 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.
+
+// Pezkuwi 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 Pezkuwi.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Version 2 of the DB schema.
+
+use codec::{Decode, Encode};
+use pezkuwi_node_primitives::approval::{v1::DelayTranche, v2::AssignmentCertV2};
+use pezkuwi_node_subsystem::{SubsystemError, SubsystemResult};
+use pezkuwi_node_subsystem_util::database::{DBTransaction, Database};
+use pezkuwi_primitives::{
+	BlockNumber, CandidateHash, CandidateIndex, CandidateReceiptV2 as CandidateReceipt, CoreIndex,
+	GroupIndex, Hash, SessionIndex, ValidatorIndex, ValidatorSignature,
+};
+
+use sp_consensus_slots::Slot;
+
+use bitvec::{order::Lsb0 as BitOrderLsb0, vec::BitVec};
+use std::collections::BTreeMap;
+
+use crate::backend::V1ReadBackend;
+
+use super::common::{block_entry_key, candidate_entry_key, load_decode, Config};
+
+pub mod migration_helpers;
+#[cfg(test)]
+pub mod tests;
+
+// slot_duration * 2 + DelayTranche gives the number of delay tranches since the
+// unix epoch.
+#[derive(Encode, Decode, Clone, Copy, Debug, PartialEq)]
+pub struct Tick(u64);
+
+/// Convenience type definition
+pub type Bitfield = BitVec<u8, BitOrderLsb0>;
+
+/// Details pertaining to our assignment on a block.
+#[derive(Encode, Decode, Debug, Clone, PartialEq)]
+pub struct OurAssignment {
+	/// Our assignment certificate.
+	pub cert: AssignmentCertV2,
+	/// The tranche for which the assignment refers to.
+	pub tranche: DelayTranche,
+	/// Our validator index for the session in which the candidates were included.
+	pub validator_index: ValidatorIndex,
+	/// Whether the assignment has been triggered already.
+	pub triggered: bool,
+}
+
+/// Metadata regarding a specific tranche of assignments for a specific candidate.
+#[derive(Encode, Decode, Debug, Clone, PartialEq)]
+pub struct TrancheEntry {
+	pub tranche: DelayTranche,
+	// Assigned validators, and the instant we received their assignment, rounded
+	// to the nearest tick.
+	pub assignments: Vec<(ValidatorIndex, Tick)>,
+}
+
+/// Metadata regarding approval of a particular candidate within the context of some
+/// particular block.
+#[derive(Encode, Decode, Debug, Clone, PartialEq)]
+pub struct ApprovalEntry {
+	pub tranches: Vec<TrancheEntry>,
+	pub backing_group: GroupIndex,
+	pub our_assignment: Option<OurAssignment>,
+	pub our_approval_sig: Option<ValidatorSignature>,
+	// `n_validators` bits.
+	pub assigned_validators: Bitfield,
+	pub approved: bool,
+}
+
+/// Metadata regarding approval of a particular candidate.
+#[derive(Encode, Decode, Debug, Clone, PartialEq)]
+pub struct CandidateEntry {
+	pub candidate: CandidateReceipt,
+	pub session: SessionIndex,
+	// Assignments are based on blocks, so we need to track assignments separately
+	// based on the block we are looking at.
+	pub block_assignments: BTreeMap<Hash, ApprovalEntry>,
+	pub approvals: Bitfield,
+}
+
+/// Metadata regarding approval of a particular block, by way of approval of the
+/// candidates contained within it.
+#[derive(Encode, Decode, Debug, Clone, PartialEq)]
+pub struct BlockEntry {
+	pub block_hash: Hash,
+	pub block_number: BlockNumber,
+	pub parent_hash: Hash,
+	pub session: SessionIndex,
+	pub slot: Slot,
+	/// Random bytes derived from the VRF submitted within the block by the block
+	/// author as a credential and used as input to approval assignment criteria.
+	pub relay_vrf_story: [u8; 32],
+	// The candidates included as-of this block and the index of the core they are
+	// leaving. Sorted ascending by core index.
+	pub candidates: Vec<(CoreIndex, CandidateHash)>,
+	// A bitfield where the i'th bit corresponds to the i'th candidate in `candidates`.
+	// The i'th bit is `true` iff the candidate has been approved in the context of this
+	// block. The block can be considered approved if the bitfield has all bits set to `true`.
+	pub approved_bitfield: Bitfield,
+	pub children: Vec<Hash>,
+	// Assignments we already distributed. A 1 bit means the candidate index for which
+	// we already have sent out an assignment. We need this to avoid distributing
+	// multiple core assignments more than once.
+	pub distributed_assignments: Bitfield,
+}
+
+impl From<crate::Tick> for Tick {
+	fn from(tick: crate::Tick) -> Tick {
+		Tick(tick)
+	}
+}
+
+impl From<Tick> for crate::Tick {
+	fn from(tick: Tick) -> crate::Tick {
+		tick.0
+	}
+}
+
+/// Load a candidate entry from the aux store in v1 format.
+pub fn load_candidate_entry_v1(
+	store: &dyn Database,
+	config: &Config,
+	candidate_hash: &CandidateHash,
+) -> SubsystemResult<Option<super::v1::CandidateEntry>> {
+	load_decode(store, config.col_approval_data, &candidate_entry_key(candidate_hash))
+		.map(|u: Option<super::v1::CandidateEntry>| u.map(|v| v.into()))
+		.map_err(|e| SubsystemError::with_origin("approval-voting", e))
+}
+
+/// Load a block entry from the aux store in v1 format.
+pub fn load_block_entry_v1(
+	store: &dyn Database,
+	config: &Config,
+	block_hash: &Hash,
+) -> SubsystemResult<Option<super::v1::BlockEntry>> {
+	load_decode(store, config.col_approval_data, &block_entry_key(block_hash))
+		.map(|u: Option<super::v1::BlockEntry>| u.map(|v| v.into()))
+		.map_err(|e| SubsystemError::with_origin("approval-voting", e))
+}

pezkuwi/node/core/approval-voting/src/approval_db/v2/tests.rs

@@ -0,0 +1,586 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// This file is part of Pezkuwi.
+
+// Pezkuwi 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.
+
+// Pezkuwi 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 Pezkuwi.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Tests for the aux-schema of approval voting.
+
+use crate::{
+	approval_db::{
+		common::{migration_helpers::make_bitvec, DbBackend, StoredBlockRange, *},
+		v2::*,
+		v3::{load_block_entry_v2, load_candidate_entry_v2},
+	},
+	backend::{Backend, OverlayedBackend},
+	ops::{add_block_entry, canonicalize, force_approve, NewCandidateInfo},
+};
+use pezkuwi_primitives::{
+	BlockNumber, CandidateHash, CandidateReceiptV2 as CandidateReceipt, CoreIndex, GroupIndex,
+	Hash, MutateDescriptorV2,
+};
+
+use pezkuwi_node_subsystem_util::database::Database;
+use pezkuwi_primitives::Id as ParaId;
+use sp_consensus_slots::Slot;
+use std::{collections::HashMap, sync::Arc};
+
+use pezkuwi_primitives_test_helpers::{
+	dummy_candidate_receipt_bad_sig, dummy_candidate_receipt_v2,
+	dummy_candidate_receipt_v2_bad_sig, dummy_hash,
+};
+
+const DATA_COL: u32 = 0;
+
+const NUM_COLUMNS: u32 = 1;
+
+const TEST_CONFIG: Config = Config { col_approval_data: DATA_COL };
+
+fn make_db() -> (DbBackend, Arc<dyn Database>) {
+	let db = kvdb_memorydb::create(NUM_COLUMNS);
+	let db = pezkuwi_node_subsystem_util::database::kvdb_impl::DbAdapter::new(db, &[]);
+	let db_writer: Arc<dyn Database> = Arc::new(db);
+	(DbBackend::new(db_writer.clone(), TEST_CONFIG), db_writer)
+}
+
+fn make_block_entry(
+	block_hash: Hash,
+	parent_hash: Hash,
+	block_number: BlockNumber,
+	candidates: Vec<(CoreIndex, CandidateHash)>,
+) -> BlockEntry {
+	BlockEntry {
+		block_hash,
+		parent_hash,
+		block_number,
+		session: 1,
+		slot: Slot::from(1),
+		relay_vrf_story: [0u8; 32],
+		approved_bitfield: make_bitvec(candidates.len()),
+		candidates,
+		children: Vec::new(),
+		distributed_assignments: Default::default(),
+	}
+}
+
+fn make_candidate(para_id: ParaId, relay_parent: Hash) -> CandidateReceipt {
+	let mut c = dummy_candidate_receipt_v2(dummy_hash());
+
+	c.descriptor.set_para_id(para_id);
+	c.descriptor.set_relay_parent(relay_parent);
+
+	c
+}
+
+#[test]
+fn read_write() {
+	let (mut db, store) = make_db();
+
+	let hash_a = Hash::repeat_byte(1);
+	let hash_b = Hash::repeat_byte(2);
+	let candidate_hash = dummy_candidate_receipt_bad_sig(dummy_hash(), None).hash();
+
+	let range = StoredBlockRange(10, 20);
+	let at_height = vec![hash_a, hash_b];
+
+	let block_entry =
+		make_block_entry(hash_a, Default::default(), 1, vec![(CoreIndex(0), candidate_hash)]);
+
+	let candidate_entry = CandidateEntry {
+		candidate: dummy_candidate_receipt_v2_bad_sig(dummy_hash(), None),
+		session: 5,
+		block_assignments: vec![(
+			hash_a,
+			ApprovalEntry {
+				tranches: Vec::new(),
+				backing_group: GroupIndex(1),
+				our_assignment: None,
+				our_approval_sig: None,
+				assigned_validators: Default::default(),
+				approved: false,
+			},
+		)]
+		.into_iter()
+		.collect(),
+		approvals: Default::default(),
+	};
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	overlay_db.write_stored_block_range(range.clone());
+	overlay_db.write_blocks_at_height(1, at_height.clone());
+	overlay_db.write_block_entry(block_entry.clone().into());
+	overlay_db.write_candidate_entry(crate::persisted_entries::CandidateEntry::from_v2(
+		candidate_entry.clone(),
+		0,
+	));
+
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	assert_eq!(load_stored_blocks(store.as_ref(), &TEST_CONFIG).unwrap(), Some(range));
+	assert_eq!(load_blocks_at_height(store.as_ref(), &TEST_CONFIG, &1).unwrap(), at_height);
+	assert_eq!(
+		load_block_entry_v2(store.as_ref(), &TEST_CONFIG, &hash_a).unwrap(),
+		Some(block_entry.into())
+	);
+	assert_eq!(
+		load_candidate_entry_v2(store.as_ref(), &TEST_CONFIG, &candidate_hash).unwrap(),
+		Some(candidate_entry.into()),
+	);
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	overlay_db.delete_blocks_at_height(1);
+	overlay_db.delete_block_entry(&hash_a);
+	overlay_db.delete_candidate_entry(&candidate_hash);
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	assert!(load_blocks_at_height(store.as_ref(), &TEST_CONFIG, &1).unwrap().is_empty());
+	assert!(load_block_entry_v2(store.as_ref(), &TEST_CONFIG, &hash_a).unwrap().is_none());
+	assert!(load_candidate_entry_v2(store.as_ref(), &TEST_CONFIG, &candidate_hash)
+		.unwrap()
+		.is_none());
+}
+
+#[test]
+fn add_block_entry_works() {
+	let (mut db, store) = make_db();
+
+	let parent_hash = Hash::repeat_byte(1);
+	let block_hash_a = Hash::repeat_byte(2);
+	let block_hash_b = Hash::repeat_byte(69);
+
+	let candidate_receipt_a = make_candidate(ParaId::from(1_u32), parent_hash);
+	let candidate_receipt_b = make_candidate(ParaId::from(2_u32), parent_hash);
+
+	let candidate_hash_a = candidate_receipt_a.hash();
+	let candidate_hash_b = candidate_receipt_b.hash();
+
+	let block_number = 10;
+
+	let block_entry_a = make_block_entry(
+		block_hash_a,
+		parent_hash,
+		block_number,
+		vec![(CoreIndex(0), candidate_hash_a)],
+	);
+
+	let block_entry_b = make_block_entry(
+		block_hash_b,
+		parent_hash,
+		block_number,
+		vec![(CoreIndex(0), candidate_hash_a), (CoreIndex(1), candidate_hash_b)],
+	);
+
+	let n_validators = 10;
+
+	let mut new_candidate_info = HashMap::new();
+	new_candidate_info
+		.insert(candidate_hash_a, NewCandidateInfo::new(candidate_receipt_a, GroupIndex(0), None));
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	add_block_entry(&mut overlay_db, block_entry_a.clone().into(), n_validators, |h| {
+		new_candidate_info.get(h).map(|x| x.clone())
+	})
+	.unwrap();
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	new_candidate_info
+		.insert(candidate_hash_b, NewCandidateInfo::new(candidate_receipt_b, GroupIndex(1), None));
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	add_block_entry(&mut overlay_db, block_entry_b.clone().into(), n_validators, |h| {
+		new_candidate_info.get(h).map(|x| x.clone())
+	})
+	.unwrap();
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	assert_eq!(
+		load_block_entry_v2(store.as_ref(), &TEST_CONFIG, &block_hash_a).unwrap(),
+		Some(block_entry_a.into())
+	);
+	assert_eq!(
+		load_block_entry_v2(store.as_ref(), &TEST_CONFIG, &block_hash_b).unwrap(),
+		Some(block_entry_b.into())
+	);
+
+	let candidate_entry_a =
+		load_candidate_entry_v2(store.as_ref(), &TEST_CONFIG, &candidate_hash_a)
+			.unwrap()
+			.unwrap();
+	assert_eq!(
+		candidate_entry_a.block_assignments.keys().collect::<Vec<_>>(),
+		vec![&block_hash_a, &block_hash_b]
+	);
+
+	let candidate_entry_b =
+		load_candidate_entry_v2(store.as_ref(), &TEST_CONFIG, &candidate_hash_b)
+			.unwrap()
+			.unwrap();
+	assert_eq!(candidate_entry_b.block_assignments.keys().collect::<Vec<_>>(), vec![&block_hash_b]);
+}
+
+#[test]
+fn add_block_entry_adds_child() {
+	let (mut db, store) = make_db();
+
+	let parent_hash = Hash::repeat_byte(1);
+	let block_hash_a = Hash::repeat_byte(2);
+	let block_hash_b = Hash::repeat_byte(69);
+
+	let mut block_entry_a = make_block_entry(block_hash_a, parent_hash, 1, Vec::new());
+
+	let block_entry_b = make_block_entry(block_hash_b, block_hash_a, 2, Vec::new());
+
+	let n_validators = 10;
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	add_block_entry(&mut overlay_db, block_entry_a.clone().into(), n_validators, |_| None).unwrap();
+
+	add_block_entry(&mut overlay_db, block_entry_b.clone().into(), n_validators, |_| None).unwrap();
+
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	block_entry_a.children.push(block_hash_b);
+
+	assert_eq!(
+		load_block_entry_v2(store.as_ref(), &TEST_CONFIG, &block_hash_a).unwrap(),
+		Some(block_entry_a.into())
+	);
+	assert_eq!(
+		load_block_entry_v2(store.as_ref(), &TEST_CONFIG, &block_hash_b).unwrap(),
+		Some(block_entry_b.into())
+	);
+}
+
+#[test]
+fn canonicalize_works() {
+	let (mut db, store) = make_db();
+
+	//   -> B1 -> C1 -> D1
+	// A -> B2 -> C2 -> D2
+	//
+	// We'll canonicalize C1. Everything except D1 should disappear.
+	//
+	// Candidates:
+	// Cand1 in B2
+	// Cand2 in C2
+	// Cand3 in C2 and D1
+	// Cand4 in D1
+	// Cand5 in D2
+	// Only Cand3 and Cand4 should remain after canonicalize.
+
+	let n_validators = 10;
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	overlay_db.write_stored_block_range(StoredBlockRange(1, 5));
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	let genesis = Hash::repeat_byte(0);
+
+	let block_hash_a = Hash::repeat_byte(1);
+	let block_hash_b1 = Hash::repeat_byte(2);
+	let block_hash_b2 = Hash::repeat_byte(3);
+	let block_hash_c1 = Hash::repeat_byte(4);
+	let block_hash_c2 = Hash::repeat_byte(5);
+	let block_hash_d1 = Hash::repeat_byte(6);
+	let block_hash_d2 = Hash::repeat_byte(7);
+
+	let candidate_receipt_genesis = make_candidate(ParaId::from(1_u32), genesis);
+	let candidate_receipt_a = make_candidate(ParaId::from(2_u32), block_hash_a);
+	let candidate_receipt_b = make_candidate(ParaId::from(3_u32), block_hash_a);
+	let candidate_receipt_b1 = make_candidate(ParaId::from(4_u32), block_hash_b1);
+	let candidate_receipt_c1 = make_candidate(ParaId::from(5_u32), block_hash_c1);
+
+	let cand_hash_1 = candidate_receipt_genesis.hash();
+	let cand_hash_2 = candidate_receipt_a.hash();
+	let cand_hash_3 = candidate_receipt_b.hash();
+	let cand_hash_4 = candidate_receipt_b1.hash();
+	let cand_hash_5 = candidate_receipt_c1.hash();
+
+	let block_entry_a = make_block_entry(block_hash_a, genesis, 1, Vec::new());
+	let block_entry_b1 = make_block_entry(block_hash_b1, block_hash_a, 2, Vec::new());
+	let block_entry_b2 =
+		make_block_entry(block_hash_b2, block_hash_a, 2, vec![(CoreIndex(0), cand_hash_1)]);
+	let block_entry_c1 = make_block_entry(block_hash_c1, block_hash_b1, 3, Vec::new());
+	let block_entry_c2 = make_block_entry(
+		block_hash_c2,
+		block_hash_b2,
+		3,
+		vec![(CoreIndex(0), cand_hash_2), (CoreIndex(1), cand_hash_3)],
+	);
+	let block_entry_d1 = make_block_entry(
+		block_hash_d1,
+		block_hash_c1,
+		4,
+		vec![(CoreIndex(0), cand_hash_3), (CoreIndex(1), cand_hash_4)],
+	);
+	let block_entry_d2 =
+		make_block_entry(block_hash_d2, block_hash_c2, 4, vec![(CoreIndex(0), cand_hash_5)]);
+
+	let candidate_info = {
+		let mut candidate_info = HashMap::new();
+		candidate_info.insert(
+			cand_hash_1,
+			NewCandidateInfo::new(candidate_receipt_genesis, GroupIndex(1), None),
+		);
+
+		candidate_info
+			.insert(cand_hash_2, NewCandidateInfo::new(candidate_receipt_a, GroupIndex(2), None));
+
+		candidate_info
+			.insert(cand_hash_3, NewCandidateInfo::new(candidate_receipt_b, GroupIndex(3), None));
+
+		candidate_info
+			.insert(cand_hash_4, NewCandidateInfo::new(candidate_receipt_b1, GroupIndex(4), None));
+
+		candidate_info
+			.insert(cand_hash_5, NewCandidateInfo::new(candidate_receipt_c1, GroupIndex(5), None));
+
+		candidate_info
+	};
+
+	// now insert all the blocks.
+	let blocks = vec![
+		block_entry_a.clone(),
+		block_entry_b1.clone(),
+		block_entry_b2.clone(),
+		block_entry_c1.clone(),
+		block_entry_c2.clone(),
+		block_entry_d1.clone(),
+		block_entry_d2.clone(),
+	];
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	for block_entry in blocks {
+		add_block_entry(&mut overlay_db, block_entry.into(), n_validators, |h| {
+			candidate_info.get(h).map(|x| x.clone())
+		})
+		.unwrap();
+	}
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	let check_candidates_in_store = |expected: Vec<(CandidateHash, Option<Vec<_>>)>| {
+		for (c_hash, in_blocks) in expected {
+			let (entry, in_blocks) = match in_blocks {
+				None => {
+					assert!(load_candidate_entry_v2(store.as_ref(), &TEST_CONFIG, &c_hash)
+						.unwrap()
+						.is_none());
+					continue;
+				},
+				Some(i) => (
+					load_candidate_entry_v2(store.as_ref(), &TEST_CONFIG, &c_hash)
+						.unwrap()
+						.unwrap(),
+					i,
+				),
+			};
+
+			assert_eq!(entry.block_assignments.len(), in_blocks.len());
+
+			for x in in_blocks {
+				assert!(entry.block_assignments.contains_key(&x));
+			}
+		}
+	};
+
+	let check_blocks_in_store = |expected: Vec<(Hash, Option<Vec<_>>)>| {
+		for (hash, with_candidates) in expected {
+			let (entry, with_candidates) = match with_candidates {
+				None => {
+					assert!(load_block_entry_v2(store.as_ref(), &TEST_CONFIG, &hash)
+						.unwrap()
+						.is_none());
+					continue;
+				},
+				Some(i) =>
+					(load_block_entry_v2(store.as_ref(), &TEST_CONFIG, &hash).unwrap().unwrap(), i),
+			};
+
+			assert_eq!(entry.candidates.len(), with_candidates.len());
+
+			for x in with_candidates {
+				assert!(entry.candidates.iter().any(|(_, c)| c == &x));
+			}
+		}
+	};
+
+	check_candidates_in_store(vec![
+		(cand_hash_1, Some(vec![block_hash_b2])),
+		(cand_hash_2, Some(vec![block_hash_c2])),
+		(cand_hash_3, Some(vec![block_hash_c2, block_hash_d1])),
+		(cand_hash_4, Some(vec![block_hash_d1])),
+		(cand_hash_5, Some(vec![block_hash_d2])),
+	]);
+
+	check_blocks_in_store(vec![
+		(block_hash_a, Some(vec![])),
+		(block_hash_b1, Some(vec![])),
+		(block_hash_b2, Some(vec![cand_hash_1])),
+		(block_hash_c1, Some(vec![])),
+		(block_hash_c2, Some(vec![cand_hash_2, cand_hash_3])),
+		(block_hash_d1, Some(vec![cand_hash_3, cand_hash_4])),
+		(block_hash_d2, Some(vec![cand_hash_5])),
+	]);
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	canonicalize(&mut overlay_db, 3, block_hash_c1).unwrap();
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	assert_eq!(
+		load_stored_blocks(store.as_ref(), &TEST_CONFIG).unwrap().unwrap(),
+		StoredBlockRange(4, 5)
+	);
+
+	check_candidates_in_store(vec![
+		(cand_hash_1, None),
+		(cand_hash_2, None),
+		(cand_hash_3, Some(vec![block_hash_d1])),
+		(cand_hash_4, Some(vec![block_hash_d1])),
+		(cand_hash_5, None),
+	]);
+
+	check_blocks_in_store(vec![
+		(block_hash_a, None),
+		(block_hash_b1, None),
+		(block_hash_b2, None),
+		(block_hash_c1, None),
+		(block_hash_c2, None),
+		(block_hash_d1, Some(vec![cand_hash_3, cand_hash_4])),
+		(block_hash_d2, None),
+	]);
+}
+
+#[test]
+fn force_approve_works() {
+	let (mut db, store) = make_db();
+	let n_validators = 10;
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	overlay_db.write_stored_block_range(StoredBlockRange(1, 4));
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	let candidate_hash = CandidateHash(Hash::repeat_byte(42));
+	let single_candidate_vec = vec![(CoreIndex(0), candidate_hash)];
+	let candidate_info = {
+		let mut candidate_info = HashMap::new();
+		candidate_info.insert(
+			candidate_hash,
+			NewCandidateInfo::new(
+				make_candidate(ParaId::from(1_u32), Default::default()),
+				GroupIndex(1),
+				None,
+			),
+		);
+
+		candidate_info
+	};
+
+	let block_hash_a = Hash::repeat_byte(1); // 1
+	let block_hash_b = Hash::repeat_byte(2);
+	let block_hash_c = Hash::repeat_byte(3);
+	let block_hash_d = Hash::repeat_byte(4); // 4
+
+	let block_entry_a =
+		make_block_entry(block_hash_a, Default::default(), 1, single_candidate_vec.clone());
+	let block_entry_b =
+		make_block_entry(block_hash_b, block_hash_a, 2, single_candidate_vec.clone());
+	let block_entry_c =
+		make_block_entry(block_hash_c, block_hash_b, 3, single_candidate_vec.clone());
+	let block_entry_d =
+		make_block_entry(block_hash_d, block_hash_c, 4, single_candidate_vec.clone());
+
+	let blocks = vec![
+		block_entry_a.clone(),
+		block_entry_b.clone(),
+		block_entry_c.clone(),
+		block_entry_d.clone(),
+	];
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	for block_entry in blocks {
+		add_block_entry(&mut overlay_db, block_entry.into(), n_validators, |h| {
+			candidate_info.get(h).map(|x| x.clone())
+		})
+		.unwrap();
+	}
+	let approved_hashes = force_approve(&mut overlay_db, block_hash_d, 2).unwrap();
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	assert!(load_block_entry_v2(store.as_ref(), &TEST_CONFIG, &block_hash_a,)
+		.unwrap()
+		.unwrap()
+		.approved_bitfield
+		.all());
+	assert!(load_block_entry_v2(store.as_ref(), &TEST_CONFIG, &block_hash_b,)
+		.unwrap()
+		.unwrap()
+		.approved_bitfield
+		.all());
+	assert!(load_block_entry_v2(store.as_ref(), &TEST_CONFIG, &block_hash_c,)
+		.unwrap()
+		.unwrap()
+		.approved_bitfield
+		.not_any());
+	assert!(load_block_entry_v2(store.as_ref(), &TEST_CONFIG, &block_hash_d,)
+		.unwrap()
+		.unwrap()
+		.approved_bitfield
+		.not_any());
+	assert_eq!(approved_hashes, vec![block_hash_b, block_hash_a]);
+}
+
+#[test]
+fn load_all_blocks_works() {
+	let (mut db, store) = make_db();
+
+	let parent_hash = Hash::repeat_byte(1);
+	let block_hash_a = Hash::repeat_byte(2);
+	let block_hash_b = Hash::repeat_byte(69);
+	let block_hash_c = Hash::repeat_byte(42);
+
+	let block_number = 10;
+
+	let block_entry_a = make_block_entry(block_hash_a, parent_hash, block_number, vec![]);
+
+	let block_entry_b = make_block_entry(block_hash_b, parent_hash, block_number, vec![]);
+
+	let block_entry_c = make_block_entry(block_hash_c, block_hash_a, block_number + 1, vec![]);
+
+	let n_validators = 10;
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	add_block_entry(&mut overlay_db, block_entry_a.clone().into(), n_validators, |_| None).unwrap();
+
+	// add C before B to test sorting.
+	add_block_entry(&mut overlay_db, block_entry_c.clone().into(), n_validators, |_| None).unwrap();
+
+	add_block_entry(&mut overlay_db, block_entry_b.clone().into(), n_validators, |_| None).unwrap();
+
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	assert_eq!(
+		load_all_blocks(store.as_ref(), &TEST_CONFIG).unwrap(),
+		vec![block_hash_a, block_hash_b, block_hash_c],
+	)
+}

pezkuwi/node/core/approval-voting/src/approval_db/v3/migration_helpers.rs

@@ -0,0 +1,237 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// This file is part of Pezkuwi.
+
+// Pezkuwi 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.
+
+// Pezkuwi 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 Pezkuwi.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Approval DB migration helpers.
+use super::*;
+use crate::{
+	approval_db::common::{
+		block_entry_key, candidate_entry_key,
+		migration_helpers::{dummy_assignment_cert, make_bitvec},
+		Config, Error, Result, StoredBlockRange,
+	},
+	backend::{Backend, V2ReadBackend},
+};
+use pezkuwi_node_primitives::approval::v1::AssignmentCertKind;
+use pezkuwi_node_subsystem_util::database::Database;
+use sp_application_crypto::sp_core::H256;
+use std::{collections::HashSet, sync::Arc};
+
+/// Migrates `BlockEntry`, `CandidateEntry`, `ApprovalEntry` and `OurApproval` to version 3.
+/// Returns on any error.
+/// Must only be used in teyrchains DB migration code - `pezkuwi-service` crate.
+pub fn v2_to_latest(db: Arc<dyn Database>, config: Config) -> Result<()> {
+	let mut backend = crate::DbBackend::new(db, config);
+	let all_blocks = backend
+		.load_all_blocks()
+		.map_err(|e| Error::InternalError(e))?
+		.iter()
+		.filter_map(|block_hash| {
+			backend
+				.load_block_entry_v2(block_hash)
+				.map_err(|e| Error::InternalError(e))
+				.ok()?
+		})
+		.collect::<Vec<_>>();
+
+	gum::info!(
+		target: crate::LOG_TARGET,
+		"Migrating candidate entries on top of {} blocks",
+		all_blocks.len()
+	);
+
+	let mut overlay = crate::OverlayedBackend::new(&backend);
+	let mut counter = 0;
+	// Get all candidate entries, approval entries and convert each of them.
+	for block in all_blocks {
+		for (candidate_index, (_core_index, candidate_hash)) in
+			block.candidates().iter().enumerate()
+		{
+			// Loading the candidate will also perform the conversion to the updated format and
+			// return that representation.
+			if let Some(candidate_entry) = backend
+				.load_candidate_entry_v2(&candidate_hash, candidate_index as CandidateIndex)
+				.map_err(|e| Error::InternalError(e))?
+			{
+				// Write the updated representation.
+				overlay.write_candidate_entry(candidate_entry);
+				counter += 1;
+			}
+		}
+		overlay.write_block_entry(block);
+	}
+
+	gum::info!(target: crate::LOG_TARGET, "Migrated {} entries", counter);
+
+	// Commit all changes to DB.
+	let write_ops = overlay.into_write_ops();
+	backend.write(write_ops).unwrap();
+
+	Ok(())
+}
+
+// Checks if the migration doesn't leave the DB in an unsane state.
+// This function is to be used in tests.
+pub fn v1_to_latest_sanity_check(
+	db: Arc<dyn Database>,
+	config: Config,
+	expected_candidates: HashSet<CandidateHash>,
+) -> Result<()> {
+	let backend = crate::DbBackend::new(db, config);
+
+	let all_blocks = backend
+		.load_all_blocks()
+		.unwrap()
+		.iter()
+		.map(|block_hash| backend.load_block_entry(block_hash).unwrap().unwrap())
+		.collect::<Vec<_>>();
+
+	let mut candidates = HashSet::new();
+
+	// Iterate all blocks and approval entries.
+	for block in all_blocks {
+		for (_core_index, candidate_hash) in block.candidates() {
+			// Loading the candidate will also perform the conversion to the updated format and
+			// return that representation.
+			if let Some(candidate_entry) = backend.load_candidate_entry(&candidate_hash).unwrap() {
+				candidates.insert(candidate_entry.candidate.hash());
+			}
+		}
+	}
+
+	assert_eq!(candidates, expected_candidates);
+
+	Ok(())
+}
+
+// Fills the db with dummy data in v2 scheme.
+pub fn v2_fill_test_data<F>(
+	db: Arc<dyn Database>,
+	config: Config,
+	dummy_candidate_create: F,
+) -> Result<HashSet<CandidateHash>>
+where
+	F: Fn(H256) -> CandidateReceipt<H256>,
+{
+	let mut backend = crate::DbBackend::new(db.clone(), config);
+	let mut overlay_db = crate::OverlayedBackend::new(&backend);
+	let mut expected_candidates = HashSet::new();
+
+	const RELAY_BLOCK_COUNT: u32 = 10;
+
+	let range = StoredBlockRange(1, 11);
+	overlay_db.write_stored_block_range(range.clone());
+
+	for relay_number in 1..=RELAY_BLOCK_COUNT {
+		let relay_hash = Hash::repeat_byte(relay_number as u8);
+		let assignment_core_index = CoreIndex(relay_number);
+		let candidate = dummy_candidate_create(relay_hash);
+		let candidate_hash = candidate.hash();
+
+		let at_height = vec![relay_hash];
+
+		let block_entry = make_block_entry_v2(
+			relay_hash,
+			Default::default(),
+			relay_number,
+			vec![(assignment_core_index, candidate_hash)],
+		);
+
+		let dummy_assignment = crate::approval_db::v2::OurAssignment {
+			cert: dummy_assignment_cert(AssignmentCertKind::RelayVRFModulo { sample: 0 }).into(),
+			tranche: 0,
+			validator_index: ValidatorIndex(0),
+			triggered: false,
+		};
+
+		let candidate_entry = crate::approval_db::v2::CandidateEntry {
+			candidate,
+			session: 123,
+			block_assignments: vec![(
+				relay_hash,
+				crate::approval_db::v2::ApprovalEntry {
+					tranches: Vec::new(),
+					backing_group: GroupIndex(1),
+					our_assignment: Some(dummy_assignment),
+					our_approval_sig: None,
+					approved: false,
+					assigned_validators: make_bitvec(1),
+				},
+			)]
+			.into_iter()
+			.collect(),
+			approvals: Default::default(),
+		};
+
+		overlay_db.write_blocks_at_height(relay_number, at_height.clone());
+		expected_candidates.insert(candidate_entry.candidate.hash());
+
+		db.write(write_candidate_entry_v2(candidate_entry, config)).unwrap();
+		db.write(write_block_entry_v2(block_entry, config)).unwrap();
+	}
+
+	let write_ops = overlay_db.into_write_ops();
+	backend.write(write_ops).unwrap();
+
+	Ok(expected_candidates)
+}
+
+fn make_block_entry_v2(
+	block_hash: Hash,
+	parent_hash: Hash,
+	block_number: BlockNumber,
+	candidates: Vec<(CoreIndex, CandidateHash)>,
+) -> crate::approval_db::v2::BlockEntry {
+	crate::approval_db::v2::BlockEntry {
+		block_hash,
+		parent_hash,
+		block_number,
+		session: 1,
+		slot: Slot::from(1),
+		relay_vrf_story: [0u8; 32],
+		approved_bitfield: make_bitvec(candidates.len()),
+		distributed_assignments: make_bitvec(candidates.len()),
+		candidates,
+		children: Vec::new(),
+	}
+}
+
+// Low level DB helper to write a candidate entry in v1 scheme.
+fn write_candidate_entry_v2(
+	candidate_entry: crate::approval_db::v2::CandidateEntry,
+	config: Config,
+) -> DBTransaction {
+	let mut tx = DBTransaction::new();
+	tx.put_vec(
+		config.col_approval_data,
+		&candidate_entry_key(&candidate_entry.candidate.hash()),
+		candidate_entry.encode(),
+	);
+	tx
+}
+
+// Low level DB helper to write a block entry in v1 scheme.
+fn write_block_entry_v2(
+	block_entry: crate::approval_db::v2::BlockEntry,
+	config: Config,
+) -> DBTransaction {
+	let mut tx = DBTransaction::new();
+	tx.put_vec(
+		config.col_approval_data,
+		&block_entry_key(&block_entry.block_hash),
+		block_entry.encode(),
+	);
+	tx
+}

pezkuwi/node/core/approval-voting/src/approval_db/v3/mod.rs

@@ -0,0 +1,137 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// This file is part of Pezkuwi.
+
+// Pezkuwi 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.
+
+// Pezkuwi 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 Pezkuwi.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Version 3 of the DB schema.
+//!
+//! Version 3 modifies the `our_approval` format of `ApprovalEntry`
+//! and adds a new field `pending_signatures` for `BlockEntry`
+
+use codec::{Decode, Encode};
+use pezkuwi_node_primitives::approval::v2::CandidateBitfield;
+use pezkuwi_node_subsystem::SubsystemResult;
+use pezkuwi_node_subsystem_util::database::{DBTransaction, Database};
+use pezkuwi_overseer::SubsystemError;
+use pezkuwi_primitives::{
+	BlockNumber, CandidateHash, CandidateIndex, CandidateReceiptV2 as CandidateReceipt, CoreIndex,
+	GroupIndex, Hash, SessionIndex, ValidatorIndex, ValidatorSignature,
+};
+
+use sp_consensus_slots::Slot;
+
+use std::collections::BTreeMap;
+
+use super::common::{block_entry_key, candidate_entry_key, load_decode, Config};
+
+/// Re-export this structs as v3 since they did not change between v2 and v3.
+pub use super::v2::{Bitfield, OurAssignment, Tick, TrancheEntry};
+
+pub mod migration_helpers;
+
+#[cfg(test)]
+pub mod tests;
+
+/// Metadata about our approval signature
+#[derive(Encode, Decode, Debug, Clone, PartialEq)]
+pub struct OurApproval {
+	/// The signature for the candidates hashes pointed by indices.
+	pub signature: ValidatorSignature,
+	/// The indices of the candidates signed in this approval.
+	pub signed_candidates_indices: CandidateBitfield,
+}
+
+/// Metadata regarding approval of a particular candidate within the context of some
+/// particular block.
+#[derive(Encode, Decode, Debug, Clone, PartialEq)]
+pub struct ApprovalEntry {
+	pub tranches: Vec<TrancheEntry>,
+	pub backing_group: GroupIndex,
+	pub our_assignment: Option<OurAssignment>,
+	pub our_approval_sig: Option<OurApproval>,
+	// `n_validators` bits.
+	pub assigned_validators: Bitfield,
+	pub approved: bool,
+}
+
+/// Metadata regarding approval of a particular candidate.
+#[derive(Encode, Decode, Debug, Clone, PartialEq)]
+pub struct CandidateEntry {
+	pub candidate: CandidateReceipt,
+	pub session: SessionIndex,
+	// Assignments are based on blocks, so we need to track assignments separately
+	// based on the block we are looking at.
+	pub block_assignments: BTreeMap<Hash, ApprovalEntry>,
+	pub approvals: Bitfield,
+}
+
+/// Metadata regarding approval of a particular block, by way of approval of the
+/// candidates contained within it.
+#[derive(Encode, Decode, Debug, Clone, PartialEq)]
+pub struct BlockEntry {
+	pub block_hash: Hash,
+	pub block_number: BlockNumber,
+	pub parent_hash: Hash,
+	pub session: SessionIndex,
+	pub slot: Slot,
+	/// Random bytes derived from the VRF submitted within the block by the block
+	/// author as a credential and used as input to approval assignment criteria.
+	pub relay_vrf_story: [u8; 32],
+	// The candidates included as-of this block and the index of the core they are
+	// leaving. Sorted ascending by core index.
+	pub candidates: Vec<(CoreIndex, CandidateHash)>,
+	// A bitfield where the i'th bit corresponds to the i'th candidate in `candidates`.
+	// The i'th bit is `true` iff the candidate has been approved in the context of this
+	// block. The block can be considered approved if the bitfield has all bits set to `true`.
+	pub approved_bitfield: Bitfield,
+	pub children: Vec<Hash>,
+	// A list of candidates we have checked, but didn't not sign and
+	// advertise the vote yet.
+	pub candidates_pending_signature: BTreeMap<CandidateIndex, CandidateSigningContext>,
+	// Assignments we already distributed. A 1 bit means the candidate index for which
+	// we already have sent out an assignment. We need this to avoid distributing
+	// multiple core assignments more than once.
+	pub distributed_assignments: Bitfield,
+}
+
+#[derive(Encode, Decode, Debug, Clone, PartialEq)]
+/// Context needed for creating an approval signature for a given candidate.
+pub struct CandidateSigningContext {
+	/// The candidate hash, to be included in the signature.
+	pub candidate_hash: CandidateHash,
+	/// The latest tick we have to create and send the approval.
+	pub sign_no_later_than_tick: Tick,
+}
+
+/// Load a candidate entry from the aux store in v2 format.
+pub fn load_candidate_entry_v2(
+	store: &dyn Database,
+	config: &Config,
+	candidate_hash: &CandidateHash,
+) -> SubsystemResult<Option<super::v2::CandidateEntry>> {
+	load_decode(store, config.col_approval_data, &candidate_entry_key(candidate_hash))
+		.map(|u: Option<super::v2::CandidateEntry>| u.map(|v| v.into()))
+		.map_err(|e| SubsystemError::with_origin("approval-voting", e))
+}
+
+/// Load a block entry from the aux store in v2 format.
+pub fn load_block_entry_v2(
+	store: &dyn Database,
+	config: &Config,
+	block_hash: &Hash,
+) -> SubsystemResult<Option<super::v2::BlockEntry>> {
+	load_decode(store, config.col_approval_data, &block_entry_key(block_hash))
+		.map(|u: Option<super::v2::BlockEntry>| u.map(|v| v.into()))
+		.map_err(|e| SubsystemError::with_origin("approval-voting", e))
+}

pezkuwi/node/core/approval-voting/src/approval_db/v3/tests.rs

@@ -0,0 +1,624 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// This file is part of Pezkuwi.
+
+// Pezkuwi 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.
+
+// Pezkuwi 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 Pezkuwi.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Tests for the aux-schema of approval voting.
+
+use crate::{
+	approval_db::{
+		common::{migration_helpers::make_bitvec, DbBackend, StoredBlockRange, *},
+		v3::*,
+	},
+	backend::{Backend, OverlayedBackend},
+	ops::{add_block_entry, canonicalize, force_approve, NewCandidateInfo},
+};
+use pezkuwi_primitives::{
+	BlockNumber, CandidateHash, CandidateReceiptV2 as CandidateReceipt, CoreIndex, GroupIndex,
+	Hash, MutateDescriptorV2,
+};
+
+use pezkuwi_node_subsystem_util::database::Database;
+use pezkuwi_primitives::Id as ParaId;
+use sp_consensus_slots::Slot;
+use std::{collections::HashMap, sync::Arc};
+
+use pezkuwi_primitives_test_helpers::{
+	dummy_candidate_receipt_v2, dummy_candidate_receipt_v2_bad_sig, dummy_hash,
+};
+
+const DATA_COL: u32 = 0;
+
+const NUM_COLUMNS: u32 = 1;
+
+const TEST_CONFIG: Config = Config { col_approval_data: DATA_COL };
+
+fn make_db() -> (DbBackend, Arc<dyn Database>) {
+	let db = kvdb_memorydb::create(NUM_COLUMNS);
+	let db = pezkuwi_node_subsystem_util::database::kvdb_impl::DbAdapter::new(db, &[]);
+	let db_writer: Arc<dyn Database> = Arc::new(db);
+	(DbBackend::new(db_writer.clone(), TEST_CONFIG), db_writer)
+}
+
+fn make_block_entry(
+	block_hash: Hash,
+	parent_hash: Hash,
+	block_number: BlockNumber,
+	candidates: Vec<(CoreIndex, CandidateHash)>,
+) -> BlockEntry {
+	BlockEntry {
+		block_hash,
+		parent_hash,
+		block_number,
+		session: 1,
+		slot: Slot::from(1),
+		relay_vrf_story: [0u8; 32],
+		approved_bitfield: make_bitvec(candidates.len()),
+		candidates,
+		children: Vec::new(),
+		candidates_pending_signature: Default::default(),
+		distributed_assignments: Default::default(),
+	}
+}
+
+fn make_candidate(para_id: ParaId, relay_parent: Hash) -> CandidateReceipt {
+	let mut c = dummy_candidate_receipt_v2(dummy_hash());
+
+	c.descriptor.set_para_id(para_id);
+	c.descriptor.set_relay_parent(relay_parent);
+
+	c.into()
+}
+
+#[test]
+fn read_write() {
+	let (mut db, store) = make_db();
+
+	let hash_a = Hash::repeat_byte(1);
+	let hash_b = Hash::repeat_byte(2);
+	let candidate_hash = dummy_candidate_receipt_v2_bad_sig(dummy_hash(), None).hash();
+
+	let range = StoredBlockRange(10, 20);
+	let at_height = vec![hash_a, hash_b];
+
+	let block_entry =
+		make_block_entry(hash_a, Default::default(), 1, vec![(CoreIndex(0), candidate_hash)]);
+
+	let candidate_entry = CandidateEntry {
+		candidate: dummy_candidate_receipt_v2_bad_sig(dummy_hash(), None),
+		session: 5,
+		block_assignments: vec![(
+			hash_a,
+			ApprovalEntry {
+				tranches: Vec::new(),
+				backing_group: GroupIndex(1),
+				our_assignment: None,
+				our_approval_sig: None,
+				assigned_validators: Default::default(),
+				approved: false,
+			},
+		)]
+		.into_iter()
+		.collect(),
+		approvals: Default::default(),
+	};
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	overlay_db.write_stored_block_range(range.clone());
+	overlay_db.write_blocks_at_height(1, at_height.clone());
+	overlay_db.write_block_entry(block_entry.clone().into());
+	overlay_db.write_candidate_entry(candidate_entry.clone().into());
+
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	assert_eq!(load_stored_blocks(store.as_ref(), &TEST_CONFIG).unwrap(), Some(range));
+	assert_eq!(load_blocks_at_height(store.as_ref(), &TEST_CONFIG, &1).unwrap(), at_height);
+	assert_eq!(
+		load_block_entry(store.as_ref(), &TEST_CONFIG, &hash_a).unwrap(),
+		Some(block_entry.into())
+	);
+	assert_eq!(
+		load_candidate_entry(store.as_ref(), &TEST_CONFIG, &candidate_hash).unwrap(),
+		Some(candidate_entry.into()),
+	);
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	overlay_db.delete_blocks_at_height(1);
+	overlay_db.delete_block_entry(&hash_a);
+	overlay_db.delete_candidate_entry(&candidate_hash);
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	assert!(load_blocks_at_height(store.as_ref(), &TEST_CONFIG, &1).unwrap().is_empty());
+	assert!(load_block_entry(store.as_ref(), &TEST_CONFIG, &hash_a).unwrap().is_none());
+	assert!(load_candidate_entry(store.as_ref(), &TEST_CONFIG, &candidate_hash)
+		.unwrap()
+		.is_none());
+}
+
+#[test]
+fn add_block_entry_works() {
+	let (mut db, store) = make_db();
+
+	let parent_hash = Hash::repeat_byte(1);
+	let block_hash_a = Hash::repeat_byte(2);
+	let block_hash_b = Hash::repeat_byte(69);
+
+	let candidate_receipt_a = make_candidate(ParaId::from(1_u32), parent_hash);
+	let candidate_receipt_b = make_candidate(ParaId::from(2_u32), parent_hash);
+
+	let candidate_hash_a = candidate_receipt_a.hash();
+	let candidate_hash_b = candidate_receipt_b.hash();
+
+	let block_number = 10;
+
+	let block_entry_a = make_block_entry(
+		block_hash_a,
+		parent_hash,
+		block_number,
+		vec![(CoreIndex(0), candidate_hash_a)],
+	);
+
+	let block_entry_b = make_block_entry(
+		block_hash_b,
+		parent_hash,
+		block_number,
+		vec![(CoreIndex(0), candidate_hash_a), (CoreIndex(1), candidate_hash_b)],
+	);
+
+	let n_validators = 10;
+
+	let mut new_candidate_info = HashMap::new();
+	new_candidate_info
+		.insert(candidate_hash_a, NewCandidateInfo::new(candidate_receipt_a, GroupIndex(0), None));
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	add_block_entry(&mut overlay_db, block_entry_a.clone().into(), n_validators, |h| {
+		new_candidate_info.get(h).map(|x| x.clone())
+	})
+	.unwrap();
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	new_candidate_info
+		.insert(candidate_hash_b, NewCandidateInfo::new(candidate_receipt_b, GroupIndex(1), None));
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	add_block_entry(&mut overlay_db, block_entry_b.clone().into(), n_validators, |h| {
+		new_candidate_info.get(h).map(|x| x.clone())
+	})
+	.unwrap();
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	assert_eq!(
+		load_block_entry(store.as_ref(), &TEST_CONFIG, &block_hash_a).unwrap(),
+		Some(block_entry_a.into())
+	);
+	assert_eq!(
+		load_block_entry(store.as_ref(), &TEST_CONFIG, &block_hash_b).unwrap(),
+		Some(block_entry_b.into())
+	);
+
+	let candidate_entry_a = load_candidate_entry(store.as_ref(), &TEST_CONFIG, &candidate_hash_a)
+		.unwrap()
+		.unwrap();
+	assert_eq!(
+		candidate_entry_a.block_assignments.keys().collect::<Vec<_>>(),
+		vec![&block_hash_a, &block_hash_b]
+	);
+
+	let candidate_entry_b = load_candidate_entry(store.as_ref(), &TEST_CONFIG, &candidate_hash_b)
+		.unwrap()
+		.unwrap();
+	assert_eq!(candidate_entry_b.block_assignments.keys().collect::<Vec<_>>(), vec![&block_hash_b]);
+}
+
+#[test]
+fn add_block_entry_adds_child() {
+	let (mut db, store) = make_db();
+
+	let parent_hash = Hash::repeat_byte(1);
+	let block_hash_a = Hash::repeat_byte(2);
+	let block_hash_b = Hash::repeat_byte(69);
+
+	let mut block_entry_a = make_block_entry(block_hash_a, parent_hash, 1, Vec::new());
+
+	let block_entry_b = make_block_entry(block_hash_b, block_hash_a, 2, Vec::new());
+
+	let n_validators = 10;
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	add_block_entry(&mut overlay_db, block_entry_a.clone().into(), n_validators, |_| None).unwrap();
+
+	add_block_entry(&mut overlay_db, block_entry_b.clone().into(), n_validators, |_| None).unwrap();
+
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	block_entry_a.children.push(block_hash_b);
+
+	assert_eq!(
+		load_block_entry(store.as_ref(), &TEST_CONFIG, &block_hash_a).unwrap(),
+		Some(block_entry_a.into())
+	);
+	assert_eq!(
+		load_block_entry(store.as_ref(), &TEST_CONFIG, &block_hash_b).unwrap(),
+		Some(block_entry_b.into())
+	);
+}
+
+#[test]
+fn canonicalize_works() {
+	let (mut db, store) = make_db();
+
+	//   -> B1 -> C1 -> D1 -> E1
+	// A -> B2 -> C2 -> D2 -> E2
+	//
+	// We'll canonicalize C1. Everything except D1 should disappear.
+	//
+	// Candidates:
+	// Cand1 in B2
+	// Cand2 in C2
+	// Cand3 in C2 and D1
+	// Cand4 in D1
+	// Cand5 in D2
+	// Only Cand3 and Cand4 should remain after canonicalize.
+
+	let n_validators = 10;
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	overlay_db.write_stored_block_range(StoredBlockRange(1, 5));
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	let genesis = Hash::repeat_byte(0);
+
+	let block_hash_a = Hash::repeat_byte(1);
+	let block_hash_b1 = Hash::repeat_byte(2);
+	let block_hash_b2 = Hash::repeat_byte(3);
+	let block_hash_c1 = Hash::repeat_byte(4);
+	let block_hash_c2 = Hash::repeat_byte(5);
+	let block_hash_d1 = Hash::repeat_byte(6);
+	let block_hash_d2 = Hash::repeat_byte(7);
+	let block_hash_e1 = Hash::repeat_byte(8);
+	let block_hash_e2 = Hash::repeat_byte(9);
+
+	let candidate_receipt_genesis = make_candidate(ParaId::from(1_u32), genesis);
+	let candidate_receipt_a = make_candidate(ParaId::from(2_u32), block_hash_a);
+	let candidate_receipt_b = make_candidate(ParaId::from(3_u32), block_hash_a);
+	let candidate_receipt_b1 = make_candidate(ParaId::from(4_u32), block_hash_b1);
+	let candidate_receipt_c1 = make_candidate(ParaId::from(5_u32), block_hash_c1);
+	let candidate_receipt_e1 = make_candidate(ParaId::from(6_u32), block_hash_e1);
+
+	let cand_hash_1 = candidate_receipt_genesis.hash();
+	let cand_hash_2 = candidate_receipt_a.hash();
+	let cand_hash_3 = candidate_receipt_b.hash();
+	let cand_hash_4 = candidate_receipt_b1.hash();
+	let cand_hash_5 = candidate_receipt_c1.hash();
+	let cand_hash_6 = candidate_receipt_e1.hash();
+
+	let block_entry_a = make_block_entry(block_hash_a, genesis, 1, Vec::new());
+	let block_entry_b1 = make_block_entry(block_hash_b1, block_hash_a, 2, Vec::new());
+	let block_entry_b2 =
+		make_block_entry(block_hash_b2, block_hash_a, 2, vec![(CoreIndex(0), cand_hash_1)]);
+	let block_entry_c1 = make_block_entry(block_hash_c1, block_hash_b1, 3, Vec::new());
+	let block_entry_c2 = make_block_entry(
+		block_hash_c2,
+		block_hash_b2,
+		3,
+		vec![(CoreIndex(0), cand_hash_2), (CoreIndex(1), cand_hash_3)],
+	);
+	let block_entry_d1 = make_block_entry(
+		block_hash_d1,
+		block_hash_c1,
+		4,
+		vec![(CoreIndex(0), cand_hash_3), (CoreIndex(1), cand_hash_4)],
+	);
+	let block_entry_d2 =
+		make_block_entry(block_hash_d2, block_hash_c2, 4, vec![(CoreIndex(0), cand_hash_5)]);
+
+	let block_entry_e1 =
+		make_block_entry(block_hash_e1, block_hash_d1, 5, vec![(CoreIndex(0), cand_hash_6)]);
+
+	let block_entry_e2 =
+		make_block_entry(block_hash_e2, block_hash_d2, 5, vec![(CoreIndex(0), cand_hash_6)]);
+
+	let candidate_info = {
+		let mut candidate_info = HashMap::new();
+		candidate_info.insert(
+			cand_hash_1,
+			NewCandidateInfo::new(candidate_receipt_genesis, GroupIndex(1), None),
+		);
+
+		candidate_info
+			.insert(cand_hash_2, NewCandidateInfo::new(candidate_receipt_a, GroupIndex(2), None));
+
+		candidate_info
+			.insert(cand_hash_3, NewCandidateInfo::new(candidate_receipt_b, GroupIndex(3), None));
+
+		candidate_info
+			.insert(cand_hash_4, NewCandidateInfo::new(candidate_receipt_b1, GroupIndex(4), None));
+
+		candidate_info
+			.insert(cand_hash_5, NewCandidateInfo::new(candidate_receipt_c1, GroupIndex(5), None));
+
+		candidate_info
+			.insert(cand_hash_6, NewCandidateInfo::new(candidate_receipt_e1, GroupIndex(6), None));
+		candidate_info
+	};
+
+	// now insert all the blocks.
+	let blocks = vec![
+		block_entry_a.clone(),
+		block_entry_b1.clone(),
+		block_entry_b2.clone(),
+		block_entry_c1.clone(),
+		block_entry_c2.clone(),
+		block_entry_d1.clone(),
+		block_entry_d2.clone(),
+		block_entry_e1.clone(),
+		block_entry_e2.clone(),
+	];
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	for block_entry in blocks {
+		add_block_entry(&mut overlay_db, block_entry.into(), n_validators, |h| {
+			candidate_info.get(h).map(|x| x.clone())
+		})
+		.unwrap();
+	}
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	let check_candidates_in_store = |expected: Vec<(CandidateHash, Option<Vec<_>>)>| {
+		for (c_hash, in_blocks) in expected {
+			let (entry, in_blocks) = match in_blocks {
+				None => {
+					assert!(load_candidate_entry(store.as_ref(), &TEST_CONFIG, &c_hash)
+						.unwrap()
+						.is_none());
+					continue;
+				},
+				Some(i) => (
+					load_candidate_entry(store.as_ref(), &TEST_CONFIG, &c_hash).unwrap().unwrap(),
+					i,
+				),
+			};
+
+			assert_eq!(entry.block_assignments.len(), in_blocks.len());
+
+			for x in in_blocks {
+				assert!(entry.block_assignments.contains_key(&x));
+			}
+		}
+	};
+
+	let check_blocks_in_store = |expected: Vec<(Hash, Option<Vec<_>>)>| {
+		for (hash, with_candidates) in expected {
+			let (entry, with_candidates) = match with_candidates {
+				None => {
+					assert!(load_block_entry(store.as_ref(), &TEST_CONFIG, &hash)
+						.unwrap()
+						.is_none());
+					continue;
+				},
+				Some(i) =>
+					(load_block_entry(store.as_ref(), &TEST_CONFIG, &hash).unwrap().unwrap(), i),
+			};
+
+			assert_eq!(entry.candidates.len(), with_candidates.len());
+
+			for x in with_candidates {
+				assert!(entry.candidates.iter().any(|(_, c)| c == &x));
+			}
+		}
+	};
+
+	check_candidates_in_store(vec![
+		(cand_hash_1, Some(vec![block_hash_b2])),
+		(cand_hash_2, Some(vec![block_hash_c2])),
+		(cand_hash_3, Some(vec![block_hash_c2, block_hash_d1])),
+		(cand_hash_4, Some(vec![block_hash_d1])),
+		(cand_hash_5, Some(vec![block_hash_d2])),
+	]);
+
+	check_blocks_in_store(vec![
+		(block_hash_a, Some(vec![])),
+		(block_hash_b1, Some(vec![])),
+		(block_hash_b2, Some(vec![cand_hash_1])),
+		(block_hash_c1, Some(vec![])),
+		(block_hash_c2, Some(vec![cand_hash_2, cand_hash_3])),
+		(block_hash_d1, Some(vec![cand_hash_3, cand_hash_4])),
+		(block_hash_d2, Some(vec![cand_hash_5])),
+	]);
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	canonicalize(&mut overlay_db, 3, block_hash_c1).unwrap();
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	assert_eq!(
+		load_stored_blocks(store.as_ref(), &TEST_CONFIG).unwrap().unwrap(),
+		StoredBlockRange(4, 6)
+	);
+
+	check_candidates_in_store(vec![
+		(cand_hash_1, None),
+		(cand_hash_2, None),
+		(cand_hash_3, Some(vec![block_hash_d1])),
+		(cand_hash_4, Some(vec![block_hash_d1])),
+		(cand_hash_5, None),
+		(cand_hash_6, Some(vec![block_hash_e1])),
+	]);
+
+	check_blocks_in_store(vec![
+		(block_hash_a, None),
+		(block_hash_b1, None),
+		(block_hash_b2, None),
+		(block_hash_c1, None),
+		(block_hash_c2, None),
+		(block_hash_d1, Some(vec![cand_hash_3, cand_hash_4])),
+		(block_hash_e1, Some(vec![cand_hash_6])),
+		(block_hash_d2, None),
+	]);
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	canonicalize(&mut overlay_db, 4, block_hash_d1).unwrap();
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	assert_eq!(
+		load_stored_blocks(store.as_ref(), &TEST_CONFIG).unwrap().unwrap(),
+		StoredBlockRange(5, 6)
+	);
+
+	check_candidates_in_store(vec![
+		(cand_hash_1, None),
+		(cand_hash_2, None),
+		(cand_hash_3, None),
+		(cand_hash_4, None),
+		(cand_hash_5, None),
+		(cand_hash_6, Some(vec![block_hash_e1])),
+	]);
+
+	check_blocks_in_store(vec![
+		(block_hash_a, None),
+		(block_hash_b1, None),
+		(block_hash_b2, None),
+		(block_hash_c1, None),
+		(block_hash_c2, None),
+		(block_hash_d1, None),
+		(block_hash_e1, Some(vec![cand_hash_6])),
+		(block_hash_d2, None),
+	]);
+}
+
+#[test]
+fn force_approve_works() {
+	let (mut db, store) = make_db();
+	let n_validators = 10;
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	overlay_db.write_stored_block_range(StoredBlockRange(1, 4));
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	let candidate_hash = CandidateHash(Hash::repeat_byte(42));
+	let single_candidate_vec = vec![(CoreIndex(0), candidate_hash)];
+	let candidate_info = {
+		let mut candidate_info = HashMap::new();
+		candidate_info.insert(
+			candidate_hash,
+			NewCandidateInfo::new(
+				make_candidate(ParaId::from(1_u32), Default::default()),
+				GroupIndex(1),
+				None,
+			),
+		);
+
+		candidate_info
+	};
+
+	let block_hash_a = Hash::repeat_byte(1); // 1
+	let block_hash_b = Hash::repeat_byte(2);
+	let block_hash_c = Hash::repeat_byte(3);
+	let block_hash_d = Hash::repeat_byte(4); // 4
+
+	let block_entry_a =
+		make_block_entry(block_hash_a, Default::default(), 1, single_candidate_vec.clone());
+	let block_entry_b =
+		make_block_entry(block_hash_b, block_hash_a, 2, single_candidate_vec.clone());
+	let block_entry_c =
+		make_block_entry(block_hash_c, block_hash_b, 3, single_candidate_vec.clone());
+	let block_entry_d =
+		make_block_entry(block_hash_d, block_hash_c, 4, single_candidate_vec.clone());
+
+	let blocks = vec![
+		block_entry_a.clone(),
+		block_entry_b.clone(),
+		block_entry_c.clone(),
+		block_entry_d.clone(),
+	];
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	for block_entry in blocks {
+		add_block_entry(&mut overlay_db, block_entry.into(), n_validators, |h| {
+			candidate_info.get(h).map(|x| x.clone())
+		})
+		.unwrap();
+	}
+	let approved_hashes = force_approve(&mut overlay_db, block_hash_d, 2).unwrap();
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	assert!(load_block_entry(store.as_ref(), &TEST_CONFIG, &block_hash_a,)
+		.unwrap()
+		.unwrap()
+		.approved_bitfield
+		.all());
+	assert!(load_block_entry(store.as_ref(), &TEST_CONFIG, &block_hash_b,)
+		.unwrap()
+		.unwrap()
+		.approved_bitfield
+		.all());
+	assert!(load_block_entry(store.as_ref(), &TEST_CONFIG, &block_hash_c,)
+		.unwrap()
+		.unwrap()
+		.approved_bitfield
+		.not_any());
+	assert!(load_block_entry(store.as_ref(), &TEST_CONFIG, &block_hash_d,)
+		.unwrap()
+		.unwrap()
+		.approved_bitfield
+		.not_any());
+	assert_eq!(approved_hashes, vec![block_hash_b, block_hash_a]);
+}
+
+#[test]
+fn load_all_blocks_works() {
+	let (mut db, store) = make_db();
+
+	let parent_hash = Hash::repeat_byte(1);
+	let block_hash_a = Hash::repeat_byte(2);
+	let block_hash_b = Hash::repeat_byte(69);
+	let block_hash_c = Hash::repeat_byte(42);
+
+	let block_number = 10;
+
+	let block_entry_a = make_block_entry(block_hash_a, parent_hash, block_number, vec![]);
+
+	let block_entry_b = make_block_entry(block_hash_b, parent_hash, block_number, vec![]);
+
+	let block_entry_c = make_block_entry(block_hash_c, block_hash_a, block_number + 1, vec![]);
+
+	let n_validators = 10;
+
+	let mut overlay_db = OverlayedBackend::new(&db);
+	add_block_entry(&mut overlay_db, block_entry_a.clone().into(), n_validators, |_| None).unwrap();
+
+	// add C before B to test sorting.
+	add_block_entry(&mut overlay_db, block_entry_c.clone().into(), n_validators, |_| None).unwrap();
+
+	add_block_entry(&mut overlay_db, block_entry_b.clone().into(), n_validators, |_| None).unwrap();
+
+	let write_ops = overlay_db.into_write_ops();
+	db.write(write_ops).unwrap();
+
+	assert_eq!(
+		load_all_blocks(store.as_ref(), &TEST_CONFIG).unwrap(),
+		vec![block_hash_a, block_hash_b, block_hash_c],
+	)
+}

pezkuwi/node/core/approval-voting/src/backend.rs

@@ -0,0 +1,249 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// This file is part of Pezkuwi.
+
+// Pezkuwi 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.
+
+// Pezkuwi 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 Pezkuwi.  If not, see <http://www.gnu.org/licenses/>.
+
+//! An abstraction over storage used by the chain selection subsystem.
+//!
+//! This provides both a [`Backend`] trait and an [`OverlayedBackend`]
+//! struct which allows in-memory changes to be applied on top of a
+//! [`Backend`], maintaining consistency between queries and temporary writes,
+//! before any commit to the underlying storage is made.
+
+use pezkuwi_node_subsystem::SubsystemResult;
+use pezkuwi_primitives::{BlockNumber, CandidateHash, CandidateIndex, Hash};
+
+use std::collections::HashMap;
+
+use super::{
+	approval_db::common::StoredBlockRange,
+	persisted_entries::{BlockEntry, CandidateEntry},
+};
+
+#[derive(Debug)]
+pub enum BackendWriteOp {
+	WriteStoredBlockRange(StoredBlockRange),
+	WriteBlocksAtHeight(BlockNumber, Vec<Hash>),
+	WriteBlockEntry(BlockEntry),
+	WriteCandidateEntry(CandidateEntry),
+	DeleteStoredBlockRange,
+	DeleteBlocksAtHeight(BlockNumber),
+	DeleteBlockEntry(Hash),
+	DeleteCandidateEntry(CandidateHash),
+}
+
+/// An abstraction over backend storage for the logic of this subsystem.
+/// Implementation must always target latest storage version.
+pub trait Backend {
+	/// Load a block entry from the DB.
+	fn load_block_entry(&self, hash: &Hash) -> SubsystemResult<Option<BlockEntry>>;
+	/// Load a candidate entry from the DB.
+	fn load_candidate_entry(
+		&self,
+		candidate_hash: &CandidateHash,
+	) -> SubsystemResult<Option<CandidateEntry>>;
+
+	/// Load all blocks at a specific height.
+	fn load_blocks_at_height(&self, height: &BlockNumber) -> SubsystemResult<Vec<Hash>>;
+	/// Load all block from the DB.
+	fn load_all_blocks(&self) -> SubsystemResult<Vec<Hash>>;
+	/// Load stored block range form the DB.
+	fn load_stored_blocks(&self) -> SubsystemResult<Option<StoredBlockRange>>;
+	/// Atomically write the list of operations, with later operations taking precedence over prior.
+	fn write<I>(&mut self, ops: I) -> SubsystemResult<()>
+	where
+		I: IntoIterator<Item = BackendWriteOp>;
+}
+
+/// A read only backend to enable db migration from version 1 of DB.
+pub trait V1ReadBackend: Backend {
+	/// Load a candidate entry from the DB with scheme version 1.
+	fn load_candidate_entry_v1(
+		&self,
+		candidate_hash: &CandidateHash,
+		candidate_index: CandidateIndex,
+	) -> SubsystemResult<Option<CandidateEntry>>;
+
+	/// Load a block entry from the DB with scheme version 1.
+	fn load_block_entry_v1(&self, block_hash: &Hash) -> SubsystemResult<Option<BlockEntry>>;
+}
+
+/// A read only backend to enable db migration from version 2 of DB.
+pub trait V2ReadBackend: Backend {
+	/// Load a candidate entry from the DB with scheme version 1.
+	fn load_candidate_entry_v2(
+		&self,
+		candidate_hash: &CandidateHash,
+		candidate_index: CandidateIndex,
+	) -> SubsystemResult<Option<CandidateEntry>>;
+
+	/// Load a block entry from the DB with scheme version 1.
+	fn load_block_entry_v2(&self, block_hash: &Hash) -> SubsystemResult<Option<BlockEntry>>;
+}
+
+// Status of block range in the `OverlayedBackend`.
+#[derive(PartialEq)]
+enum BlockRangeStatus {
+	// Value has not been modified.
+	NotModified,
+	// Value has been deleted
+	Deleted,
+	// Value has been updated.
+	Inserted(StoredBlockRange),
+}
+
+/// An in-memory overlay over the backend.
+///
+/// This maintains read-only access to the underlying backend, but can be
+/// converted into a set of write operations which will, when written to
+/// the underlying backend, give the same view as the state of the overlay.
+pub struct OverlayedBackend<'a, B: 'a> {
+	inner: &'a B,
+	// `Some(None)` means deleted. Missing (`None`) means query inner.
+	stored_block_range: BlockRangeStatus,
+	// `None` means 'deleted', missing means query inner.
+	blocks_at_height: HashMap<BlockNumber, Option<Vec<Hash>>>,
+	// `None` means 'deleted', missing means query inner.
+	block_entries: HashMap<Hash, Option<BlockEntry>>,
+	// `None` means 'deleted', missing means query inner.
+	candidate_entries: HashMap<CandidateHash, Option<CandidateEntry>>,
+}
+
+impl<'a, B: 'a + Backend> OverlayedBackend<'a, B> {
+	pub fn new(backend: &'a B) -> Self {
+		OverlayedBackend {
+			inner: backend,
+			stored_block_range: BlockRangeStatus::NotModified,
+			blocks_at_height: HashMap::new(),
+			block_entries: HashMap::new(),
+			candidate_entries: HashMap::new(),
+		}
+	}
+
+	pub fn is_empty(&self) -> bool {
+		self.block_entries.is_empty() &&
+			self.candidate_entries.is_empty() &&
+			self.blocks_at_height.is_empty() &&
+			self.stored_block_range == BlockRangeStatus::NotModified
+	}
+
+	pub fn load_all_blocks(&self) -> SubsystemResult<Vec<Hash>> {
+		let mut hashes = Vec::new();
+		if let Some(stored_blocks) = self.load_stored_blocks()? {
+			for height in stored_blocks.0..stored_blocks.1 {
+				hashes.extend(self.load_blocks_at_height(&height)?);
+			}
+		}
+
+		Ok(hashes)
+	}
+
+	pub fn load_stored_blocks(&self) -> SubsystemResult<Option<StoredBlockRange>> {
+		match self.stored_block_range {
+			BlockRangeStatus::Inserted(ref value) => Ok(Some(value.clone())),
+			BlockRangeStatus::Deleted => Ok(None),
+			BlockRangeStatus::NotModified => self.inner.load_stored_blocks(),
+		}
+	}
+
+	pub fn load_blocks_at_height(&self, height: &BlockNumber) -> SubsystemResult<Vec<Hash>> {
+		if let Some(val) = self.blocks_at_height.get(&height) {
+			return Ok(val.clone().unwrap_or_default());
+		}
+
+		self.inner.load_blocks_at_height(height)
+	}
+
+	pub fn load_block_entry(&self, hash: &Hash) -> SubsystemResult<Option<BlockEntry>> {
+		if let Some(val) = self.block_entries.get(&hash) {
+			return Ok(val.clone());
+		}
+
+		self.inner.load_block_entry(hash)
+	}
+
+	pub fn load_candidate_entry(
+		&self,
+		candidate_hash: &CandidateHash,
+	) -> SubsystemResult<Option<CandidateEntry>> {
+		if let Some(val) = self.candidate_entries.get(&candidate_hash) {
+			return Ok(val.clone());
+		}
+
+		self.inner.load_candidate_entry(candidate_hash)
+	}
+
+	pub fn write_stored_block_range(&mut self, range: StoredBlockRange) {
+		self.stored_block_range = BlockRangeStatus::Inserted(range);
+	}
+
+	pub fn delete_stored_block_range(&mut self) {
+		self.stored_block_range = BlockRangeStatus::Deleted;
+	}
+
+	pub fn write_blocks_at_height(&mut self, height: BlockNumber, blocks: Vec<Hash>) {
+		self.blocks_at_height.insert(height, Some(blocks));
+	}
+
+	pub fn delete_blocks_at_height(&mut self, height: BlockNumber) {
+		self.blocks_at_height.insert(height, None);
+	}
+
+	pub fn write_block_entry(&mut self, entry: BlockEntry) {
+		self.block_entries.insert(entry.block_hash(), Some(entry));
+	}
+
+	pub fn delete_block_entry(&mut self, hash: &Hash) {
+		self.block_entries.insert(*hash, None);
+	}
+
+	pub fn write_candidate_entry(&mut self, entry: CandidateEntry) {
+		self.candidate_entries.insert(entry.candidate_receipt().hash(), Some(entry));
+	}
+
+	pub fn delete_candidate_entry(&mut self, hash: &CandidateHash) {
+		self.candidate_entries.insert(*hash, None);
+	}
+
+	/// Transform this backend into a set of write-ops to be written to the
+	/// inner backend.
+	pub fn into_write_ops(self) -> impl Iterator<Item = BackendWriteOp> {
+		let blocks_at_height_ops = self.blocks_at_height.into_iter().map(|(h, v)| match v {
+			Some(v) => BackendWriteOp::WriteBlocksAtHeight(h, v),
+			None => BackendWriteOp::DeleteBlocksAtHeight(h),
+		});
+
+		let block_entry_ops = self.block_entries.into_iter().map(|(h, v)| match v {
+			Some(v) => BackendWriteOp::WriteBlockEntry(v),
+			None => BackendWriteOp::DeleteBlockEntry(h),
+		});
+
+		let candidate_entry_ops = self.candidate_entries.into_iter().map(|(h, v)| match v {
+			Some(v) => BackendWriteOp::WriteCandidateEntry(v),
+			None => BackendWriteOp::DeleteCandidateEntry(h),
+		});
+
+		let stored_block_range_ops = match self.stored_block_range {
+			BlockRangeStatus::Inserted(val) => Some(BackendWriteOp::WriteStoredBlockRange(val)),
+			BlockRangeStatus::Deleted => Some(BackendWriteOp::DeleteStoredBlockRange),
+			BlockRangeStatus::NotModified => None,
+		};
+
+		stored_block_range_ops
+			.into_iter()
+			.chain(blocks_at_height_ops)
+			.chain(block_entry_ops)
+			.chain(candidate_entry_ops)
+	}
+}

pezkuwi/node/core/approval-voting/src/ops.rs

@@ -0,0 +1,428 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// This file is part of Pezkuwi.
+
+// Pezkuwi 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.
+
+// Pezkuwi 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 Pezkuwi.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Middleware interface that leverages low-level database operations
+//! to provide a clean API for processing block and candidate imports.
+
+use pezkuwi_node_subsystem::{SubsystemError, SubsystemResult};
+
+use bitvec::order::Lsb0 as BitOrderLsb0;
+use pezkuwi_primitives::{
+	BlockNumber, CandidateHash, CandidateReceiptV2 as CandidateReceipt, GroupIndex, Hash,
+};
+
+use std::collections::{hash_map::Entry, BTreeMap, HashMap};
+
+use super::{
+	approval_db::{common::StoredBlockRange, v2::OurAssignment},
+	backend::{Backend, OverlayedBackend},
+	persisted_entries::{ApprovalEntry, BlockEntry, CandidateEntry},
+	LOG_TARGET,
+};
+
+/// Information about a new candidate necessary to instantiate the requisite
+/// candidate and approval entries.
+#[derive(Clone)]
+pub struct NewCandidateInfo {
+	candidate: CandidateReceipt,
+	backing_group: GroupIndex,
+	our_assignment: Option<OurAssignment>,
+}
+
+impl NewCandidateInfo {
+	/// Convenience constructor
+	pub fn new(
+		candidate: CandidateReceipt,
+		backing_group: GroupIndex,
+		our_assignment: Option<OurAssignment>,
+	) -> Self {
+		Self { candidate, backing_group, our_assignment }
+	}
+}
+
+fn visit_and_remove_block_entry(
+	block_hash: Hash,
+	overlayed_db: &mut OverlayedBackend<'_, impl Backend>,
+	visited_candidates: &mut HashMap<CandidateHash, CandidateEntry>,
+) -> SubsystemResult<Vec<Hash>> {
+	let block_entry = match overlayed_db.load_block_entry(&block_hash)? {
+		None => return Ok(Vec::new()),
+		Some(b) => b,
+	};
+
+	overlayed_db.delete_block_entry(&block_hash);
+	for (_, candidate_hash) in block_entry.candidates() {
+		let candidate = match visited_candidates.entry(*candidate_hash) {
+			Entry::Occupied(e) => e.into_mut(),
+			Entry::Vacant(e) => {
+				e.insert(match overlayed_db.load_candidate_entry(candidate_hash)? {
+					None => continue, // Should not happen except for corrupt DB
+					Some(c) => c,
+				})
+			},
+		};
+
+		candidate.block_assignments.remove(&block_hash);
+	}
+
+	Ok(block_entry.children)
+}
+
+/// Canonicalize some particular block, pruning everything before it and
+/// pruning any competing branches at the same height.
+pub fn canonicalize(
+	overlay_db: &mut OverlayedBackend<'_, impl Backend>,
+	canon_number: BlockNumber,
+	canon_hash: Hash,
+) -> SubsystemResult<()> {
+	let range = match overlay_db.load_stored_blocks()? {
+		None => return Ok(()),
+		Some(range) if range.0 > canon_number => return Ok(()),
+		Some(range) => range,
+	};
+
+	// Storing all candidates in memory is potentially heavy, but should be fine
+	// as long as finality doesn't stall for a long while. We could optimize this
+	// by keeping only the metadata about which blocks reference each candidate.
+	let mut visited_candidates = HashMap::new();
+
+	// All the block heights we visited but didn't necessarily delete everything from.
+	let mut visited_heights = HashMap::new();
+
+	// First visit everything before the height.
+	for i in range.0..canon_number {
+		let at_height = overlay_db.load_blocks_at_height(&i)?;
+		overlay_db.delete_blocks_at_height(i);
+
+		for b in at_height {
+			visit_and_remove_block_entry(b, overlay_db, &mut visited_candidates)?;
+		}
+	}
+
+	// Then visit everything at the height.
+	let pruned_branches = {
+		let at_height = overlay_db.load_blocks_at_height(&canon_number)?;
+		overlay_db.delete_blocks_at_height(canon_number);
+
+		// Note that while there may be branches descending from blocks at earlier heights,
+		// we have already covered them by removing everything at earlier heights.
+		let mut pruned_branches = Vec::new();
+
+		for b in at_height {
+			let children = visit_and_remove_block_entry(b, overlay_db, &mut visited_candidates)?;
+
+			if b != canon_hash {
+				pruned_branches.extend(children);
+			}
+		}
+
+		pruned_branches
+	};
+
+	// Follow all children of non-canonicalized blocks.
+	{
+		let mut frontier: Vec<(BlockNumber, Hash)> =
+			pruned_branches.into_iter().map(|h| (canon_number + 1, h)).collect();
+		while let Some((height, next_child)) = frontier.pop() {
+			let children =
+				visit_and_remove_block_entry(next_child, overlay_db, &mut visited_candidates)?;
+
+			// extend the frontier of branches to include the given height.
+			frontier.extend(children.into_iter().map(|h| (height + 1, h)));
+
+			// visit the at-height key for this deleted block's height.
+			let at_height = match visited_heights.entry(height) {
+				Entry::Occupied(e) => e.into_mut(),
+				Entry::Vacant(e) => e.insert(overlay_db.load_blocks_at_height(&height)?),
+			};
+			if let Some(i) = at_height.iter().position(|x| x == &next_child) {
+				at_height.remove(i);
+			}
+		}
+	}
+
+	// Update all `CandidateEntry`s, deleting all those which now have empty `block_assignments`.
+	for (candidate_hash, candidate) in visited_candidates.into_iter() {
+		if candidate.block_assignments.is_empty() {
+			overlay_db.delete_candidate_entry(&candidate_hash);
+		} else {
+			overlay_db.write_candidate_entry(candidate);
+		}
+	}
+
+	// Update all blocks-at-height keys, deleting all those which now have empty
+	// `block_assignments`.
+	for (h, at) in visited_heights.into_iter() {
+		if at.is_empty() {
+			overlay_db.delete_blocks_at_height(h);
+		} else {
+			overlay_db.write_blocks_at_height(h, at);
+		}
+	}
+
+	// due to the fork pruning, this range actually might go too far above where our actual highest
+	// block is, if a relatively short fork is canonicalized.
+	// TODO https://github.com/paritytech/polkadot/issues/3389
+	let new_range = StoredBlockRange(canon_number + 1, std::cmp::max(range.1, canon_number + 2));
+
+	overlay_db.write_stored_block_range(new_range);
+
+	Ok(())
+}
+
+/// Record a new block entry.
+///
+/// This will update the blocks-at-height mapping, the stored block range, if necessary,
+/// and add block and candidate entries. It will also add approval entries to existing
+/// candidate entries and add this as a child of any block entry corresponding to the
+/// parent hash.
+///
+/// Has no effect if there is already an entry for the block or `candidate_info` returns
+/// `None` for any of the candidates referenced by the block entry. In these cases,
+/// no information about new candidates will be referred to by this function.
+pub fn add_block_entry(
+	store: &mut OverlayedBackend<'_, impl Backend>,
+	entry: BlockEntry,
+	n_validators: usize,
+	candidate_info: impl Fn(&CandidateHash) -> Option<NewCandidateInfo>,
+) -> SubsystemResult<Vec<(CandidateHash, CandidateEntry)>> {
+	let session = entry.session();
+	let parent_hash = entry.parent_hash();
+	let number = entry.block_number();
+
+	// Update the stored block range.
+	{
+		let new_range = match store.load_stored_blocks()? {
+			None => Some(StoredBlockRange(number, number + 1)),
+			Some(range) if range.1 <= number => Some(StoredBlockRange(range.0, number + 1)),
+			Some(_) => None,
+		};
+
+		new_range.map(|n| store.write_stored_block_range(n));
+	};
+
+	// Update the blocks at height meta key.
+	{
+		let mut blocks_at_height = store.load_blocks_at_height(&number)?;
+		if blocks_at_height.contains(&entry.block_hash()) {
+			// seems we already have a block entry for this block. nothing to do here.
+			return Ok(Vec::new());
+		}
+
+		blocks_at_height.push(entry.block_hash());
+		store.write_blocks_at_height(number, blocks_at_height)
+	};
+
+	let mut candidate_entries = Vec::with_capacity(entry.candidates().len());
+
+	// read and write all updated entries.
+	{
+		for (_, candidate_hash) in entry.candidates() {
+			let NewCandidateInfo { candidate, backing_group, our_assignment } =
+				match candidate_info(candidate_hash) {
+					None => return Ok(Vec::new()),
+					Some(info) => info,
+				};
+
+			let mut candidate_entry =
+				store.load_candidate_entry(&candidate_hash)?.unwrap_or_else(move || {
+					CandidateEntry {
+						candidate,
+						session,
+						block_assignments: BTreeMap::new(),
+						approvals: bitvec::bitvec![u8, BitOrderLsb0; 0; n_validators],
+					}
+				});
+
+			candidate_entry.block_assignments.insert(
+				entry.block_hash(),
+				ApprovalEntry::new(
+					Vec::new(),
+					backing_group,
+					our_assignment.map(|v| v.into()),
+					None,
+					bitvec::bitvec![u8, BitOrderLsb0; 0; n_validators],
+					false,
+				),
+			);
+
+			store.write_candidate_entry(candidate_entry.clone());
+
+			candidate_entries.push((*candidate_hash, candidate_entry));
+		}
+	};
+
+	// Update the child index for the parent.
+	store.load_block_entry(&parent_hash)?.map(|mut e| {
+		e.children.push(entry.block_hash());
+		store.write_block_entry(e);
+	});
+
+	// Put the new block entry in.
+	store.write_block_entry(entry);
+
+	Ok(candidate_entries)
+}
+
+/// Forcibly approve all candidates included at up to the given relay-chain height in the indicated
+/// chain.
+pub fn force_approve(
+	store: &mut OverlayedBackend<'_, impl Backend>,
+	chain_head: Hash,
+	up_to: BlockNumber,
+) -> SubsystemResult<Vec<Hash>> {
+	#[derive(PartialEq, Eq)]
+	enum State {
+		WalkTo,
+		Approving,
+	}
+	let mut approved_hashes = Vec::new();
+
+	let mut cur_hash = chain_head;
+	let mut state = State::WalkTo;
+	let mut cur_block_number: BlockNumber = 0;
+
+	// iterate back to the `up_to` block, and then iterate backwards until all blocks
+	// are updated.
+	while let Some(mut entry) = store.load_block_entry(&cur_hash)? {
+		cur_block_number = entry.block_number();
+		if cur_block_number <= up_to {
+			if state == State::WalkTo {
+				gum::debug!(
+					target: LOG_TARGET,
+					block_hash = ?chain_head,
+					?cur_hash,
+					?cur_block_number,
+					"Start forced approval from block",
+				);
+			}
+			state = State::Approving;
+		}
+
+		cur_hash = entry.parent_hash();
+
+		match state {
+			State::WalkTo => {},
+			State::Approving => {
+				entry.approved_bitfield.iter_mut().for_each(|mut b| *b = true);
+				approved_hashes.push(entry.block_hash());
+				store.write_block_entry(entry);
+			},
+		}
+	}
+
+	if state == State::WalkTo {
+		gum::warn!(
+			target: LOG_TARGET,
+			?chain_head,
+			?cur_hash,
+			?cur_block_number,
+			?up_to,
+			"Missing block in the chain, cannot start force approval"
+		);
+	}
+
+	Ok(approved_hashes)
+}
+
+/// Revert to the block corresponding to the specified `hash`.
+/// The operation is not allowed for blocks older than the last finalized one.
+pub fn revert_to(
+	overlay: &mut OverlayedBackend<'_, impl Backend>,
+	hash: Hash,
+) -> SubsystemResult<()> {
+	let mut stored_range = overlay.load_stored_blocks()?.ok_or_else(|| {
+		SubsystemError::Context("no available blocks to infer revert point height".to_string())
+	})?;
+
+	let (children, children_height) = match overlay.load_block_entry(&hash)? {
+		Some(mut entry) => {
+			let children_height = entry.block_number() + 1;
+			let children = std::mem::take(&mut entry.children);
+			// Write revert point block entry without the children.
+			overlay.write_block_entry(entry);
+			(children, children_height)
+		},
+		None => {
+			let children_height = stored_range.0;
+			let children = overlay.load_blocks_at_height(&children_height)?;
+
+			let child_entry = children
+				.first()
+				.and_then(|hash| overlay.load_block_entry(hash).ok())
+				.flatten()
+				.ok_or_else(|| {
+					SubsystemError::Context("lookup failure for first block".to_string())
+				})?;
+
+			// The parent is expected to be the revert point
+			if child_entry.parent_hash() != hash {
+				return Err(SubsystemError::Context(
+					"revert below last finalized block or corrupted storage".to_string(),
+				));
+			}
+
+			(children, children_height)
+		},
+	};
+
+	let mut stack: Vec<_> = children.into_iter().map(|h| (h, children_height)).collect();
+	let mut range_end = stored_range.1;
+
+	while let Some((hash, number)) = stack.pop() {
+		let mut blocks_at_height = overlay.load_blocks_at_height(&number)?;
+		blocks_at_height.retain(|h| h != &hash);
+
+		// Check if we need to update the range top
+		if blocks_at_height.is_empty() && number < range_end {
+			range_end = number;
+		}
+
+		overlay.write_blocks_at_height(number, blocks_at_height);
+
+		if let Some(entry) = overlay.load_block_entry(&hash)? {
+			overlay.delete_block_entry(&hash);
+
+			// Cleanup the candidate entries by removing any reference to the
+			// removed block. If for a candidate entry the block block_assignments
+			// drops to zero then we remove the entry.
+			for (_, candidate_hash) in entry.candidates() {
+				if let Some(mut candidate_entry) = overlay.load_candidate_entry(candidate_hash)? {
+					candidate_entry.block_assignments.remove(&hash);
+					if candidate_entry.block_assignments.is_empty() {
+						overlay.delete_candidate_entry(candidate_hash);
+					} else {
+						overlay.write_candidate_entry(candidate_entry);
+					}
+				}
+			}
+
+			stack.extend(entry.children.into_iter().map(|h| (h, number + 1)));
+		}
+	}
+
+	// Check if our modifications to the dag has reduced the range top
+	if range_end != stored_range.1 {
+		if stored_range.0 < range_end {
+			stored_range.1 = range_end;
+			overlay.write_stored_block_range(stored_range);
+		} else {
+			overlay.delete_stored_block_range();
+		}
+	}
+
+	Ok(())
+}

pezkuwi/node/core/approval-voting/src/persisted_entries.rs

@@ -0,0 +1,769 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// This file is part of Pezkuwi.
+
+// Pezkuwi 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.
+
+// Pezkuwi 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 Pezkuwi.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Entries pertaining to approval which need to be persisted.
+//!
+//! The actual persisting of data is handled by the `approval_db` module.
+//! Within that context, things are plain-old-data. Within this module,
+//! data and logic are intertwined.
+
+use itertools::Itertools;
+use pezkuwi_node_primitives::approval::{
+	v1::{DelayTranche, RelayVRFStory},
+	v2::{AssignmentCertV2, CandidateBitfield},
+};
+use pezkuwi_primitives::{
+	BlockNumber, CandidateHash, CandidateIndex, CandidateReceiptV2 as CandidateReceipt, CoreIndex,
+	GroupIndex, Hash, SessionIndex, ValidatorIndex, ValidatorSignature,
+};
+use sp_consensus_slots::Slot;
+
+use bitvec::{order::Lsb0 as BitOrderLsb0, slice::BitSlice};
+use std::collections::BTreeMap;
+
+use crate::approval_db::v2::Bitfield;
+
+use super::criteria::OurAssignment;
+
+use pezkuwi_node_primitives::approval::time::Tick;
+
+/// Metadata regarding a specific tranche of assignments for a specific candidate.
+#[derive(Debug, Clone, PartialEq)]
+pub struct TrancheEntry {
+	tranche: DelayTranche,
+	// Assigned validators, and the instant we received their assignment, rounded
+	// to the nearest tick.
+	assignments: Vec<(ValidatorIndex, Tick)>,
+}
+
+impl TrancheEntry {
+	/// Get the tranche of this entry.
+	pub fn tranche(&self) -> DelayTranche {
+		self.tranche
+	}
+
+	/// Get the assignments for this entry.
+	pub fn assignments(&self) -> &[(ValidatorIndex, Tick)] {
+		&self.assignments
+	}
+}
+
+impl From<crate::approval_db::v2::TrancheEntry> for TrancheEntry {
+	fn from(entry: crate::approval_db::v2::TrancheEntry) -> Self {
+		TrancheEntry {
+			tranche: entry.tranche,
+			assignments: entry.assignments.into_iter().map(|(v, t)| (v, t.into())).collect(),
+		}
+	}
+}
+
+impl From<TrancheEntry> for crate::approval_db::v2::TrancheEntry {
+	fn from(entry: TrancheEntry) -> Self {
+		Self {
+			tranche: entry.tranche,
+			assignments: entry.assignments.into_iter().map(|(v, t)| (v, t.into())).collect(),
+		}
+	}
+}
+
+impl From<crate::approval_db::v3::OurApproval> for OurApproval {
+	fn from(approval: crate::approval_db::v3::OurApproval) -> Self {
+		Self {
+			signature: approval.signature,
+			signed_candidates_indices: approval.signed_candidates_indices,
+		}
+	}
+}
+impl From<OurApproval> for crate::approval_db::v3::OurApproval {
+	fn from(approval: OurApproval) -> Self {
+		Self {
+			signature: approval.signature,
+			signed_candidates_indices: approval.signed_candidates_indices,
+		}
+	}
+}
+
+/// Metadata about our approval signature
+#[derive(Debug, Clone, PartialEq)]
+pub struct OurApproval {
+	/// The signature for the candidates hashes pointed by indices.
+	pub signature: ValidatorSignature,
+	/// The indices of the candidates signed in this approval.
+	pub signed_candidates_indices: CandidateBitfield,
+}
+
+impl OurApproval {
+	/// Converts a ValidatorSignature to an OurApproval.
+	/// It used in converting the database from v1 to latest.
+	pub fn from_v1(value: ValidatorSignature, candidate_index: CandidateIndex) -> Self {
+		Self { signature: value, signed_candidates_indices: candidate_index.into() }
+	}
+
+	/// Converts a ValidatorSignature to an OurApproval.
+	/// It used in converting the database from v2 to latest.
+	pub fn from_v2(value: ValidatorSignature, candidate_index: CandidateIndex) -> Self {
+		Self::from_v1(value, candidate_index)
+	}
+}
+/// Metadata regarding approval of a particular candidate within the context of some
+/// particular block.
+#[derive(Debug, Clone, PartialEq)]
+pub struct ApprovalEntry {
+	tranches: Vec<TrancheEntry>,
+	backing_group: GroupIndex,
+	our_assignment: Option<OurAssignment>,
+	our_approval_sig: Option<OurApproval>,
+	// `n_validators` bits.
+	assigned_validators: Bitfield,
+	approved: bool,
+}
+
+impl ApprovalEntry {
+	/// Convenience constructor
+	pub fn new(
+		tranches: Vec<TrancheEntry>,
+		backing_group: GroupIndex,
+		our_assignment: Option<OurAssignment>,
+		our_approval_sig: Option<OurApproval>,
+		// `n_validators` bits.
+		assigned_validators: Bitfield,
+		approved: bool,
+	) -> Self {
+		Self {
+			tranches,
+			backing_group,
+			our_assignment,
+			our_approval_sig,
+			assigned_validators,
+			approved,
+		}
+	}
+
+	// Access our assignment for this approval entry.
+	pub fn our_assignment(&self) -> Option<&OurAssignment> {
+		self.our_assignment.as_ref()
+	}
+
+	// Note that our assignment is triggered. No-op if already triggered.
+	pub fn trigger_our_assignment(
+		&mut self,
+		tick_now: Tick,
+	) -> Option<(AssignmentCertV2, ValidatorIndex, DelayTranche)> {
+		let our = self.our_assignment.as_mut().and_then(|a| {
+			if a.triggered() {
+				return None;
+			}
+			a.mark_triggered();
+
+			Some(a.clone())
+		});
+
+		our.map(|a| {
+			self.import_assignment(a.tranche(), a.validator_index(), tick_now, false);
+
+			(a.cert().clone(), a.validator_index(), a.tranche())
+		})
+	}
+
+	/// Import our local approval vote signature for this candidate.
+	pub fn import_approval_sig(&mut self, approval_sig: OurApproval) {
+		self.our_approval_sig = Some(approval_sig);
+	}
+
+	/// Whether a validator is already assigned.
+	pub fn is_assigned(&self, validator_index: ValidatorIndex) -> bool {
+		self.assigned_validators
+			.get(validator_index.0 as usize)
+			.map(|b| *b)
+			.unwrap_or(false)
+	}
+
+	/// Import an assignment. No-op if already assigned on the same tranche.
+	pub fn import_assignment(
+		&mut self,
+		tranche: DelayTranche,
+		validator_index: ValidatorIndex,
+		tick_now: Tick,
+		is_duplicate: bool,
+	) {
+		// linear search probably faster than binary. not many tranches typically.
+		let idx = match self.tranches.iter().position(|t| t.tranche >= tranche) {
+			Some(pos) => {
+				if self.tranches[pos].tranche > tranche {
+					self.tranches.insert(pos, TrancheEntry { tranche, assignments: Vec::new() });
+				}
+
+				pos
+			},
+			None => {
+				self.tranches.push(TrancheEntry { tranche, assignments: Vec::new() });
+
+				self.tranches.len() - 1
+			},
+		};
+		// At restart we might have duplicate assignments because approval-distribution is not
+		// persistent across restarts, so avoid adding duplicates.
+		// We already know if we have seen an assignment from this validator and since this
+		// function is on the hot path we can avoid iterating through tranches by using
+		// !is_duplicate to determine if it is already present in the vector and does not need
+		// adding.
+		if !is_duplicate {
+			self.tranches[idx].assignments.push((validator_index, tick_now));
+		}
+		self.assigned_validators.set(validator_index.0 as _, true);
+	}
+
+	// Produce a bitvec indicating the assignments of all validators up to and
+	// including `tranche`.
+	pub fn assignments_up_to(&self, tranche: DelayTranche) -> Bitfield {
+		self.tranches.iter().take_while(|e| e.tranche <= tranche).fold(
+			bitvec::bitvec![u8, BitOrderLsb0; 0; self.assigned_validators.len()],
+			|mut a, e| {
+				for &(v, _) in &e.assignments {
+					a.set(v.0 as _, true);
+				}
+
+				a
+			},
+		)
+	}
+
+	/// Whether the approval entry is approved
+	pub fn is_approved(&self) -> bool {
+		self.approved
+	}
+
+	/// Mark the approval entry as approved.
+	pub fn mark_approved(&mut self) {
+		self.approved = true;
+	}
+
+	/// Access the tranches.
+	pub fn tranches(&self) -> &[TrancheEntry] {
+		&self.tranches
+	}
+
+	/// Get the number of validators in this approval entry.
+	pub fn n_validators(&self) -> usize {
+		self.assigned_validators.len()
+	}
+
+	/// Get the number of assignments by validators, including the local validator.
+	pub fn n_assignments(&self) -> usize {
+		self.assigned_validators.count_ones()
+	}
+
+	/// Get the backing group index of the approval entry.
+	pub fn backing_group(&self) -> GroupIndex {
+		self.backing_group
+	}
+
+	/// Get the assignment cert & approval signature.
+	///
+	/// The approval signature will only be `Some` if the assignment is too.
+	pub fn local_statements(&self) -> (Option<OurAssignment>, Option<OurApproval>) {
+		let approval_sig = self.our_approval_sig.clone();
+		if let Some(our_assignment) = self.our_assignment.as_ref().filter(|a| a.triggered()) {
+			(Some(our_assignment.clone()), approval_sig)
+		} else {
+			(None, None)
+		}
+	}
+
+	// Convert an ApprovalEntry from v1 version to latest version
+	pub fn from_v1(
+		value: crate::approval_db::v1::ApprovalEntry,
+		candidate_index: CandidateIndex,
+	) -> Self {
+		ApprovalEntry {
+			tranches: value.tranches.into_iter().map(|tranche| tranche.into()).collect(),
+			backing_group: value.backing_group,
+			our_assignment: value.our_assignment.map(|assignment| assignment.into()),
+			our_approval_sig: value
+				.our_approval_sig
+				.map(|sig| OurApproval::from_v1(sig, candidate_index)),
+			assigned_validators: value.assignments,
+			approved: value.approved,
+		}
+	}
+
+	// Convert an ApprovalEntry from v1 version to latest version
+	pub fn from_v2(
+		value: crate::approval_db::v2::ApprovalEntry,
+		candidate_index: CandidateIndex,
+	) -> Self {
+		ApprovalEntry {
+			tranches: value.tranches.into_iter().map(|tranche| tranche.into()).collect(),
+			backing_group: value.backing_group,
+			our_assignment: value.our_assignment.map(|assignment| assignment.into()),
+			our_approval_sig: value
+				.our_approval_sig
+				.map(|sig| OurApproval::from_v2(sig, candidate_index)),
+			assigned_validators: value.assigned_validators,
+			approved: value.approved,
+		}
+	}
+}
+
+impl From<crate::approval_db::v3::ApprovalEntry> for ApprovalEntry {
+	fn from(entry: crate::approval_db::v3::ApprovalEntry) -> Self {
+		ApprovalEntry {
+			tranches: entry.tranches.into_iter().map(Into::into).collect(),
+			backing_group: entry.backing_group,
+			our_assignment: entry.our_assignment.map(Into::into),
+			our_approval_sig: entry.our_approval_sig.map(Into::into),
+			assigned_validators: entry.assigned_validators,
+			approved: entry.approved,
+		}
+	}
+}
+
+impl From<ApprovalEntry> for crate::approval_db::v3::ApprovalEntry {
+	fn from(entry: ApprovalEntry) -> Self {
+		Self {
+			tranches: entry.tranches.into_iter().map(Into::into).collect(),
+			backing_group: entry.backing_group,
+			our_assignment: entry.our_assignment.map(Into::into),
+			our_approval_sig: entry.our_approval_sig.map(Into::into),
+			assigned_validators: entry.assigned_validators,
+			approved: entry.approved,
+		}
+	}
+}
+
+/// Metadata regarding approval of a particular candidate.
+#[derive(Debug, Clone, PartialEq)]
+pub struct CandidateEntry {
+	pub candidate: CandidateReceipt,
+	pub session: SessionIndex,
+	// Assignments are based on blocks, so we need to track assignments separately
+	// based on the block we are looking at.
+	pub block_assignments: BTreeMap<Hash, ApprovalEntry>,
+	pub approvals: Bitfield,
+}
+
+impl CandidateEntry {
+	/// Access the bit-vec of approvals.
+	pub fn approvals(&self) -> &BitSlice<u8, BitOrderLsb0> {
+		&self.approvals
+	}
+
+	/// Note that a given validator has approved. Return the previous approval state.
+	pub fn mark_approval(&mut self, validator: ValidatorIndex) -> bool {
+		let prev = self.has_approved(validator);
+		self.approvals.set(validator.0 as usize, true);
+		prev
+	}
+
+	/// Query whether a given validator has approved the candidate.
+	pub fn has_approved(&self, validator: ValidatorIndex) -> bool {
+		self.approvals.get(validator.0 as usize).map(|b| *b).unwrap_or(false)
+	}
+
+	/// Get the candidate receipt.
+	pub fn candidate_receipt(&self) -> &CandidateReceipt {
+		&self.candidate
+	}
+
+	/// Get the approval entry, mutably, for this candidate under a specific block.
+	pub fn approval_entry_mut(&mut self, block_hash: &Hash) -> Option<&mut ApprovalEntry> {
+		self.block_assignments.get_mut(block_hash)
+	}
+
+	/// Get the approval entry for this candidate under a specific block.
+	pub fn approval_entry(&self, block_hash: &Hash) -> Option<&ApprovalEntry> {
+		self.block_assignments.get(block_hash)
+	}
+
+	/// Convert a CandidateEntry from a v1 to its latest equivalent.
+	pub fn from_v1(
+		value: crate::approval_db::v1::CandidateEntry,
+		candidate_index: CandidateIndex,
+	) -> Self {
+		Self {
+			approvals: value.approvals,
+			block_assignments: value
+				.block_assignments
+				.into_iter()
+				.map(|(h, ae)| (h, ApprovalEntry::from_v1(ae, candidate_index)))
+				.collect(),
+			candidate: value.candidate,
+			session: value.session,
+		}
+	}
+
+	/// Convert a CandidateEntry from a v2 to its latest equivalent.
+	pub fn from_v2(
+		value: crate::approval_db::v2::CandidateEntry,
+		candidate_index: CandidateIndex,
+	) -> Self {
+		Self {
+			approvals: value.approvals,
+			block_assignments: value
+				.block_assignments
+				.into_iter()
+				.map(|(h, ae)| (h, ApprovalEntry::from_v2(ae, candidate_index)))
+				.collect(),
+			candidate: value.candidate,
+			session: value.session,
+		}
+	}
+}
+
+impl From<crate::approval_db::v3::CandidateEntry> for CandidateEntry {
+	fn from(entry: crate::approval_db::v3::CandidateEntry) -> Self {
+		CandidateEntry {
+			candidate: entry.candidate,
+			session: entry.session,
+			block_assignments: entry
+				.block_assignments
+				.into_iter()
+				.map(|(h, ae)| (h, ae.into()))
+				.collect(),
+			approvals: entry.approvals,
+		}
+	}
+}
+
+impl From<CandidateEntry> for crate::approval_db::v3::CandidateEntry {
+	fn from(entry: CandidateEntry) -> Self {
+		Self {
+			candidate: entry.candidate,
+			session: entry.session,
+			block_assignments: entry
+				.block_assignments
+				.into_iter()
+				.map(|(h, ae)| (h, ae.into()))
+				.collect(),
+			approvals: entry.approvals,
+		}
+	}
+}
+
+/// Metadata regarding approval of a particular block, by way of approval of the
+/// candidates contained within it.
+#[derive(Debug, Clone, PartialEq)]
+pub struct BlockEntry {
+	block_hash: Hash,
+	parent_hash: Hash,
+	block_number: BlockNumber,
+	session: SessionIndex,
+	slot: Slot,
+	relay_vrf_story: RelayVRFStory,
+	// The candidates included as-of this block and the index of the core they are
+	// leaving.
+	candidates: Vec<(CoreIndex, CandidateHash)>,
+	// A bitfield where the i'th bit corresponds to the i'th candidate in `candidates`.
+	// The i'th bit is `true` iff the candidate has been approved in the context of this
+	// block. The block can be considered approved if the bitfield has all bits set to `true`.
+	pub approved_bitfield: Bitfield,
+	pub children: Vec<Hash>,
+	// A list of candidates we have checked, but didn't not sign and
+	// advertise the vote yet.
+	candidates_pending_signature: BTreeMap<CandidateIndex, CandidateSigningContext>,
+	// A list of assignments for which we already distributed the assignment.
+	// We use this to ensure we don't distribute multiple core assignments twice as we track
+	// individual wakeups for each core.
+	distributed_assignments: Bitfield,
+}
+
+#[derive(Debug, Clone, PartialEq)]
+pub struct CandidateSigningContext {
+	pub candidate_hash: CandidateHash,
+	pub sign_no_later_than_tick: Tick,
+}
+
+impl BlockEntry {
+	/// Mark a candidate as fully approved in the bitfield.
+	pub fn mark_approved_by_hash(&mut self, candidate_hash: &CandidateHash) {
+		if let Some(p) = self.candidates.iter().position(|(_, h)| h == candidate_hash) {
+			self.approved_bitfield.set(p, true);
+		}
+	}
+
+	/// Whether a candidate is approved in the bitfield.
+	pub fn is_candidate_approved(&self, candidate_hash: &CandidateHash) -> bool {
+		self.candidates
+			.iter()
+			.position(|(_, h)| h == candidate_hash)
+			.and_then(|p| self.approved_bitfield.get(p).map(|b| *b))
+			.unwrap_or(false)
+	}
+
+	/// Whether the block entry is fully approved.
+	pub fn is_fully_approved(&self) -> bool {
+		self.approved_bitfield.all()
+	}
+
+	/// Iterate over all unapproved candidates.
+	pub fn unapproved_candidates(&self) -> impl Iterator<Item = CandidateHash> + '_ {
+		self.approved_bitfield.iter().enumerate().filter_map(move |(i, a)| {
+			if !*a {
+				Some(self.candidates[i].1)
+			} else {
+				None
+			}
+		})
+	}
+
+	/// Get the slot of the block.
+	pub fn slot(&self) -> Slot {
+		self.slot
+	}
+
+	/// Get the relay-vrf-story of the block.
+	pub fn relay_vrf_story(&self) -> RelayVRFStory {
+		self.relay_vrf_story.clone()
+	}
+
+	/// Get the session index of the block.
+	pub fn session(&self) -> SessionIndex {
+		self.session
+	}
+
+	/// Get the i'th candidate.
+	pub fn candidate(&self, i: usize) -> Option<&(CoreIndex, CandidateHash)> {
+		self.candidates.get(i)
+	}
+
+	/// Access the underlying candidates as a slice.
+	pub fn candidates(&self) -> &[(CoreIndex, CandidateHash)] {
+		&self.candidates
+	}
+
+	/// Access the block number of the block entry.
+	pub fn block_number(&self) -> BlockNumber {
+		self.block_number
+	}
+
+	/// Access the block hash of the block entry.
+	pub fn block_hash(&self) -> Hash {
+		self.block_hash
+	}
+
+	/// Access the parent hash of the block entry.
+	pub fn parent_hash(&self) -> Hash {
+		self.parent_hash
+	}
+
+	/// Mark distributed assignment for many candidate indices.
+	/// Returns `true` if an assignment was already distributed for the `candidates`.
+	pub fn mark_assignment_distributed(&mut self, candidates: CandidateBitfield) -> bool {
+		let bitfield = candidates.into_inner();
+		let total_one_bits = self.distributed_assignments.count_ones();
+
+		let new_len = std::cmp::max(self.distributed_assignments.len(), bitfield.len());
+		self.distributed_assignments.resize(new_len, false);
+		self.distributed_assignments |= bitfield;
+
+		// If an operation did not change our current bitfield, we return true.
+		let distributed = total_one_bits == self.distributed_assignments.count_ones();
+
+		distributed
+	}
+
+	/// Defer signing and issuing an approval for a candidate no later than the specified tick
+	pub fn defer_candidate_signature(
+		&mut self,
+		candidate_index: CandidateIndex,
+		candidate_hash: CandidateHash,
+		sign_no_later_than_tick: Tick,
+	) -> Option<CandidateSigningContext> {
+		self.candidates_pending_signature.insert(
+			candidate_index,
+			CandidateSigningContext { candidate_hash, sign_no_later_than_tick },
+		)
+	}
+
+	/// Returns the number of candidates waiting for an approval to be issued.
+	pub fn num_candidates_pending_signature(&self) -> usize {
+		self.candidates_pending_signature.len()
+	}
+
+	/// Return if we have candidates waiting for signature to be issued
+	pub fn has_candidates_pending_signature(&self) -> bool {
+		!self.candidates_pending_signature.is_empty()
+	}
+
+	/// Returns true if candidate hash is in the queue for a signature.
+	pub fn candidate_is_pending_signature(&self, candidate_hash: CandidateHash) -> bool {
+		self.candidates_pending_signature
+			.values()
+			.any(|context| context.candidate_hash == candidate_hash)
+	}
+
+	/// Candidate hashes  for candidates pending signatures
+	fn candidate_hashes_pending_signature(&self) -> Vec<CandidateHash> {
+		self.candidates_pending_signature
+			.values()
+			.map(|unsigned_approval| unsigned_approval.candidate_hash)
+			.collect()
+	}
+
+	/// Candidate indices for candidates pending signature
+	fn candidate_indices_pending_signature(&self) -> Option<CandidateBitfield> {
+		self.candidates_pending_signature
+			.keys()
+			.map(|val| *val)
+			.collect_vec()
+			.try_into()
+			.ok()
+	}
+
+	/// Returns a list of candidates hashes that need need signature created at the current tick:
+	/// This might happen in other of the two reasons:
+	/// 1. We queued more than max_approval_coalesce_count candidates.
+	/// 2. We have candidates that waiting in the queue past their `sign_no_later_than_tick`
+	///
+	/// Additionally, we also return the first tick when we will have to create a signature,
+	/// so that the caller can arm the timer if it is not already armed.
+	pub fn get_candidates_that_need_signature(
+		&self,
+		tick_now: Tick,
+		max_approval_coalesce_count: u32,
+	) -> (Option<(Vec<CandidateHash>, CandidateBitfield)>, Option<Tick>) {
+		let sign_no_later_than_tick = self
+			.candidates_pending_signature
+			.values()
+			.min_by(|a, b| a.sign_no_later_than_tick.cmp(&b.sign_no_later_than_tick))
+			.map(|val| val.sign_no_later_than_tick);
+
+		if let Some(sign_no_later_than_tick) = sign_no_later_than_tick {
+			if sign_no_later_than_tick <= tick_now ||
+				self.num_candidates_pending_signature() >= max_approval_coalesce_count as usize
+			{
+				(
+					self.candidate_indices_pending_signature().and_then(|candidate_indices| {
+						Some((self.candidate_hashes_pending_signature(), candidate_indices))
+					}),
+					Some(sign_no_later_than_tick),
+				)
+			} else {
+				// We can still wait for other candidates to queue in, so just make sure
+				// we wake up at the tick we have to sign the longest waiting candidate.
+				(Default::default(), Some(sign_no_later_than_tick))
+			}
+		} else {
+			// No cached candidates, nothing to do here, this just means the timer fired,
+			// but the signatures were already sent because we gathered more than
+			// max_approval_coalesce_count.
+			(Default::default(), sign_no_later_than_tick)
+		}
+	}
+
+	/// Clears the candidates pending signature because the approval was issued.
+	pub fn issued_approval(&mut self) {
+		self.candidates_pending_signature.clear();
+	}
+}
+
+impl From<crate::approval_db::v3::BlockEntry> for BlockEntry {
+	fn from(entry: crate::approval_db::v3::BlockEntry) -> Self {
+		BlockEntry {
+			block_hash: entry.block_hash,
+			parent_hash: entry.parent_hash,
+			block_number: entry.block_number,
+			session: entry.session,
+			slot: entry.slot,
+			relay_vrf_story: RelayVRFStory(entry.relay_vrf_story),
+			candidates: entry.candidates,
+			approved_bitfield: entry.approved_bitfield,
+			children: entry.children,
+			candidates_pending_signature: entry
+				.candidates_pending_signature
+				.into_iter()
+				.map(|(candidate_index, signing_context)| (candidate_index, signing_context.into()))
+				.collect(),
+			distributed_assignments: entry.distributed_assignments,
+		}
+	}
+}
+
+impl From<crate::approval_db::v1::BlockEntry> for BlockEntry {
+	fn from(entry: crate::approval_db::v1::BlockEntry) -> Self {
+		BlockEntry {
+			block_hash: entry.block_hash,
+			parent_hash: entry.parent_hash,
+			block_number: entry.block_number,
+			session: entry.session,
+			slot: entry.slot,
+			relay_vrf_story: RelayVRFStory(entry.relay_vrf_story),
+			candidates: entry.candidates,
+			approved_bitfield: entry.approved_bitfield,
+			children: entry.children,
+			distributed_assignments: Default::default(),
+			candidates_pending_signature: Default::default(),
+		}
+	}
+}
+
+impl From<crate::approval_db::v2::BlockEntry> for BlockEntry {
+	fn from(entry: crate::approval_db::v2::BlockEntry) -> Self {
+		BlockEntry {
+			block_hash: entry.block_hash,
+			parent_hash: entry.parent_hash,
+			block_number: entry.block_number,
+			session: entry.session,
+			slot: entry.slot,
+			relay_vrf_story: RelayVRFStory(entry.relay_vrf_story),
+			candidates: entry.candidates,
+			approved_bitfield: entry.approved_bitfield,
+			children: entry.children,
+			distributed_assignments: entry.distributed_assignments,
+			candidates_pending_signature: Default::default(),
+		}
+	}
+}
+
+impl From<BlockEntry> for crate::approval_db::v3::BlockEntry {
+	fn from(entry: BlockEntry) -> Self {
+		Self {
+			block_hash: entry.block_hash,
+			parent_hash: entry.parent_hash,
+			block_number: entry.block_number,
+			session: entry.session,
+			slot: entry.slot,
+			relay_vrf_story: entry.relay_vrf_story.0,
+			candidates: entry.candidates,
+			approved_bitfield: entry.approved_bitfield,
+			children: entry.children,
+			candidates_pending_signature: entry
+				.candidates_pending_signature
+				.into_iter()
+				.map(|(candidate_index, signing_context)| (candidate_index, signing_context.into()))
+				.collect(),
+			distributed_assignments: entry.distributed_assignments,
+		}
+	}
+}
+
+impl From<crate::approval_db::v3::CandidateSigningContext> for CandidateSigningContext {
+	fn from(signing_context: crate::approval_db::v3::CandidateSigningContext) -> Self {
+		Self {
+			candidate_hash: signing_context.candidate_hash,
+			sign_no_later_than_tick: signing_context.sign_no_later_than_tick.into(),
+		}
+	}
+}
+
+impl From<CandidateSigningContext> for crate::approval_db::v3::CandidateSigningContext {
+	fn from(signing_context: CandidateSigningContext) -> Self {
+		Self {
+			candidate_hash: signing_context.candidate_hash,
+			sign_no_later_than_tick: signing_context.sign_no_later_than_tick.into(),
+		}
+	}
+}