nimbus-eth2/beacon_chain/beacon_chain_db_light_clien...

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Nim

# beacon_chain
# Copyright (c) 2022 Status Research & Development GmbH
# Licensed and distributed under either of
# * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT).
# * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0).
# at your option. This file may not be copied, modified, or distributed except according to those terms.
{.push raises: [Defect].}
# This implements the pre-release proposal of the libp2p based light client sync
# protocol. See https://github.com/ethereum/consensus-specs/pull/2802
import
# Status libraries
chronicles,
eth/db/kvstore_sqlite3,
# Beacon chain internals
spec/datatypes/altair,
spec/[eth2_ssz_serialization, helpers],
./filepath
logScope: topics = "lcdata"
# `altair_current_sync_committee_branches` holds merkle proofs needed to
# construct `LightClientBootstrap` objects. The sync committee needs to
# be computed from the main DAG on-demand (usually a fast state access).
# SSZ because this data does not compress well, and because this data
# needs to be bundled together with other data to fulfill requests.
#
# `altair_best_updates` holds full `LightClientUpdate` objects in SSZ form.
# These objects are frequently queried in bunk, but there is only one per
# sync committee period, so storing the full sync committee is acceptable.
# This data could be stored as SZSSZ to avoid on-the-fly compression when a
# libp2p request is handled. However, the space savings are quite small.
# Furthermore, `LightClientUpdate` is consulted on each new block to attempt
# improving it. Continuously decompressing and recompressing seems inefficient.
# Finally, the libp2p context bytes depend on `attested_header.slot` to derive
# the underlying fork digest. The table name is insufficient to determine this
# unless one is made for each fork, even if there was no structural change.
# SSZ storage selected due to the small size and reduced logic complexity.
#
# `sealed_sync_committee_periods` contains the sync committee periods for which
# full light client data was imported. Data for these periods may no longer
# improve regardless of further block processing. The listed periods are skipped
# when restarting the program.
type
CurrentSyncCommitteeBranchStore = object
containsStmt: SqliteStmt[int64, int64]
getStmt: SqliteStmt[int64, seq[byte]]
putStmt: SqliteStmt[(int64, seq[byte]), void]
keepFromStmt: SqliteStmt[int64, void]
BestLightClientUpdateStore = object
getStmt: SqliteStmt[int64, seq[byte]]
putStmt: SqliteStmt[(int64, seq[byte]), void]
delStmt: SqliteStmt[int64, void]
delFromStmt: SqliteStmt[int64, void]
keepFromStmt: SqliteStmt[int64, void]
SealedSyncCommitteePeriodStore = object
containsStmt: SqliteStmt[int64, int64]
putStmt: SqliteStmt[int64, void]
delFromStmt: SqliteStmt[int64, void]
keepFromStmt: SqliteStmt[int64, void]
LightClientDataDB* = ref object
backend: SqStoreRef
## SQLite backend
currentBranches: CurrentSyncCommitteeBranchStore
## Slot -> altair.CurrentSyncCommitteeBranch
## Cached data for creating future `LightClientBootstrap` instances.
## Key is the block slot of which the post state was used to get the data.
## Data stored for all finalized epoch boundary blocks.
bestUpdates: BestLightClientUpdateStore
## SyncCommitteePeriod -> altair.LightClientUpdate
## Stores the `LightClientUpdate` with the most `sync_committee_bits` per
## `SyncCommitteePeriod`. Sync committee finality gives precedence.
sealedPeriods: SealedSyncCommitteePeriodStore
## {SyncCommitteePeriod}
## Tracks the finalized sync committee periods for which complete data
## has been imported (from `dag.tail.slot`).
# No `uint64` support in Sqlite
template isSupportedBySQLite(slot: Slot): bool =
slot <= int64.high.Slot
template isSupportedBySQLite(period: SyncCommitteePeriod): bool =
period <= int64.high.SyncCommitteePeriod
proc initCurrentBranchesStore(
backend: SqStoreRef,
name: string): KvResult[CurrentSyncCommitteeBranchStore] =
? backend.exec("""
CREATE TABLE IF NOT EXISTS `""" & name & """` (
`slot` INTEGER PRIMARY KEY, -- `Slot` (up through 2^63-1)
`branch` BLOB -- `altair.CurrentSyncCommitteeBranch` (SSZ)
);
""")
let
containsStmt = backend.prepareStmt("""
SELECT 1 AS `exists`
FROM `""" & name & """`
WHERE `slot` = ?;
""", int64, int64, managed = false).expect("SQL query OK")
getStmt = backend.prepareStmt("""
SELECT `branch`
FROM `""" & name & """`
WHERE `slot` = ?;
""", int64, seq[byte], managed = false).expect("SQL query OK")
putStmt = backend.prepareStmt("""
INSERT INTO `""" & name & """` (
`slot`, `branch`
) VALUES (?, ?);
""", (int64, seq[byte]), void, managed = false).expect("SQL query OK")
keepFromStmt = backend.prepareStmt("""
DELETE FROM `""" & name & """`
WHERE `slot` < ?;
""", int64, void, managed = false).expect("SQL query OK")
ok CurrentSyncCommitteeBranchStore(
containsStmt: containsStmt,
getStmt: getStmt,
putStmt: putStmt,
keepFromStmt: keepFromStmt)
func close(store: CurrentSyncCommitteeBranchStore) =
store.containsStmt.dispose()
store.getStmt.dispose()
store.putStmt.dispose()
store.keepFromStmt.dispose()
func hasCurrentSyncCommitteeBranch*(
db: LightClientDataDB, slot: Slot): bool =
if not slot.isSupportedBySQLite:
return false
var exists: int64
for res in db.currentBranches.containsStmt.exec(slot.int64, exists):
res.expect("SQL query OK")
doAssert exists == 1
return true
false
proc getCurrentSyncCommitteeBranch*(
db: LightClientDataDB, slot: Slot): altair.CurrentSyncCommitteeBranch =
if not slot.isSupportedBySQLite:
return default(altair.CurrentSyncCommitteeBranch)
var branch: seq[byte]
for res in db.currentBranches.getStmt.exec(slot.int64, branch):
res.expect("SQL query OK")
try:
return SSZ.decode(branch, altair.CurrentSyncCommitteeBranch)
except MalformedSszError, SszSizeMismatchError:
error "LC store corrupted", store = "currentBranches", slot,
exc = getCurrentException().name, err = getCurrentExceptionMsg()
return default(altair.CurrentSyncCommitteeBranch)
func putCurrentSyncCommitteeBranch*(
db: LightClientDataDB, slot: Slot,
branch: altair.CurrentSyncCommitteeBranch) =
if not slot.isSupportedBySQLite:
return
let res = db.currentBranches.putStmt.exec((slot.int64, SSZ.encode(branch)))
res.expect("SQL query OK")
proc initBestUpdatesStore(
backend: SqStoreRef,
name: string): KvResult[BestLightClientUpdateStore] =
? backend.exec("""
CREATE TABLE IF NOT EXISTS `""" & name & """` (
`period` INTEGER PRIMARY KEY, -- `SyncCommitteePeriod`
`update` BLOB -- `altair.LightClientUpdate` (SSZ)
);
""")
let
getStmt = backend.prepareStmt("""
SELECT `update`
FROM `""" & name & """`
WHERE `period` = ?;
""", int64, seq[byte], managed = false).expect("SQL query OK")
putStmt = backend.prepareStmt("""
REPLACE INTO `""" & name & """` (
`period`, `update`
) VALUES (?, ?);
""", (int64, seq[byte]), void, managed = false).expect("SQL query OK")
delStmt = backend.prepareStmt("""
DELETE FROM `""" & name & """`
WHERE `period` = ?;
""", int64, void, managed = false).expect("SQL query OK")
delFromStmt = backend.prepareStmt("""
DELETE FROM `""" & name & """`
WHERE `period` >= ?;
""", int64, void, managed = false).expect("SQL query OK")
keepFromStmt = backend.prepareStmt("""
DELETE FROM `""" & name & """`
WHERE `period` < ?;
""", int64, void, managed = false).expect("SQL query OK")
ok BestLightClientUpdateStore(
getStmt: getStmt,
putStmt: putStmt,
delStmt: delStmt,
delFromStmt: delFromStmt,
keepFromStmt: keepFromStmt)
func close(store: BestLightClientUpdateStore) =
store.getStmt.dispose()
store.putStmt.dispose()
store.delStmt.dispose()
store.delFromStmt.dispose()
store.keepFromStmt.dispose()
proc getBestUpdate*(
db: LightClientDataDB, period: SyncCommitteePeriod
): altair.LightClientUpdate =
doAssert period.isSupportedBySQLite
var update: seq[byte]
for res in db.bestUpdates.getStmt.exec(period.int64, update):
res.expect("SQL query OK")
try:
return SSZ.decode(update, altair.LightClientUpdate)
except MalformedSszError, SszSizeMismatchError:
error "LC store corrupted", store = "bestUpdates", period,
exc = getCurrentException().name, err = getCurrentExceptionMsg()
return default(altair.LightClientUpdate)
func putBestUpdate*(
db: LightClientDataDB, period: SyncCommitteePeriod,
update: altair.LightClientUpdate) =
doAssert period.isSupportedBySQLite
let numParticipants = countOnes(update.sync_aggregate.sync_committee_bits)
if numParticipants < MIN_SYNC_COMMITTEE_PARTICIPANTS:
let res = db.bestUpdates.delStmt.exec(period.int64)
res.expect("SQL query OK")
else:
let res = db.bestUpdates.putStmt.exec(
(period.int64, SSZ.encode(update)))
res.expect("SQL query OK")
proc putUpdateIfBetter*(
db: LightClientDataDB, period: SyncCommitteePeriod,
update: altair.LightClientUpdate) =
let existing = db.getBestUpdate(period)
if is_better_update(update, existing):
db.putBestUpdate(period, update)
proc initSealedPeriodsStore(
backend: SqStoreRef,
name: string): KvResult[SealedSyncCommitteePeriodStore] =
? backend.exec("""
CREATE TABLE IF NOT EXISTS `""" & name & """` (
`period` INTEGER PRIMARY KEY -- `SyncCommitteePeriod`
);
""")
let
containsStmt = backend.prepareStmt("""
SELECT 1 AS `exists`
FROM `""" & name & """`
WHERE `period` = ?;
""", int64, int64, managed = false).expect("SQL query OK")
putStmt = backend.prepareStmt("""
INSERT INTO `""" & name & """` (
`period`
) VALUES (?);
""", int64, void, managed = false).expect("SQL query OK")
delFromStmt = backend.prepareStmt("""
DELETE FROM `""" & name & """`
WHERE `period` >= ?;
""", int64, void, managed = false).expect("SQL query OK")
keepFromStmt = backend.prepareStmt("""
DELETE FROM `""" & name & """`
WHERE `period` < ?;
""", int64, void, managed = false).expect("SQL query OK")
ok SealedSyncCommitteePeriodStore(
containsStmt: containsStmt,
putStmt: putStmt,
delFromStmt: delFromStmt,
keepFromStmt: keepFromStmt)
func close(store: SealedSyncCommitteePeriodStore) =
store.containsStmt.dispose()
store.putStmt.dispose()
store.delFromStmt.dispose()
store.keepFromStmt.dispose()
func isPeriodSealed*(
db: LightClientDataDB, period: SyncCommitteePeriod): bool =
doAssert period.isSupportedBySQLite
var exists: int64
for res in db.sealedPeriods.containsStmt.exec(period.int64, exists):
res.expect("SQL query OK")
doAssert exists == 1
return true
false
func sealPeriod*(
db: LightClientDataDB, period: SyncCommitteePeriod) =
doAssert period.isSupportedBySQLite
let res = db.sealedPeriods.putStmt.exec(period.int64)
res.expect("SQL query OK")
func delPeriodsFrom*(
db: LightClientDataDB, minPeriod: SyncCommitteePeriod) =
doAssert minPeriod.isSupportedBySQLite
let res1 = db.sealedPeriods.delFromStmt.exec(minPeriod.int64)
res1.expect("SQL query OK")
let res2 = db.bestUpdates.delFromStmt.exec(minPeriod.int64)
res2.expect("SQL query OK")
func keepPeriodsFrom*(
db: LightClientDataDB, minPeriod: SyncCommitteePeriod) =
doAssert minPeriod.isSupportedBySQLite
let res1 = db.sealedPeriods.keepFromStmt.exec(minPeriod.int64)
res1.expect("SQL query OK")
let res2 = db.bestUpdates.keepFromStmt.exec(minPeriod.int64)
res2.expect("SQL query OK")
let
minSlot = min(minPeriod.start_slot, int64.high.Slot)
res3 = db.currentBranches.keepFromStmt.exec(minSlot.int64)
res3.expect("SQL query OK")
type LightClientDataDBNames* = object
altairCurrentBranches*: string
altairBestUpdates*: string
sealedPeriods*: string
proc initLightClientDataDB*(
backend: SqStoreRef,
names: LightClientDataDBNames): KvResult[LightClientDataDB] =
let
currentBranches =
? backend.initCurrentBranchesStore(names.altairCurrentBranches)
bestUpdates =
? backend.initBestUpdatesStore(names.altairBestUpdates)
sealedPeriods =
? backend.initSealedPeriodsStore(names.sealedPeriods)
ok LightClientDataDB(
backend: backend,
currentBranches: currentBranches,
bestUpdates: bestUpdates,
sealedPeriods: sealedPeriods)
proc close*(db: LightClientDataDB) =
if db.backend != nil:
db.currentBranches.close()
db.bestUpdates.close()
db.sealedPeriods.close()
db[].reset()