nimbus-eth1/nimbus/core/clique/snapshot/snapshot_apply.nim

183 lines
6.1 KiB
Nim

# Nimbus
# Copyright (c) 2018 Status Research & Development GmbH
# Licensed under either of
# * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
# http://www.apache.org/licenses/LICENSE-2.0)
# * MIT license ([LICENSE-MIT](LICENSE-MIT) or
# http://opensource.org/licenses/MIT)
# at your option. This file may not be copied, modified, or distributed except
# according to those terms.
##
## Snapshot Processor for Clique PoA Consensus Protocol
## ====================================================
##
## For details see
## `EIP-225 <https://github.com/ethereum/EIPs/blob/master/EIPS/eip-225.md>`_
## and
## `go-ethereum <https://github.com/ethereum/EIPs/blob/master/EIPS/eip-225.md>`_
##
import
std/times,
chronicles,
eth/common,
stew/results,
".."/[clique_cfg, clique_defs],
"."/[ballot, snapshot_desc]
{.push raises: [].}
logScope:
topics = "clique PoA snapshot-apply"
# ------------------------------------------------------------------------------
# Private functions
# ------------------------------------------------------------------------------
template pairWalkIj(first, last: int; offTop: Positive; code: untyped) =
if first <= last:
for n in first .. last - offTop:
let
i {.inject.} = n
j {.inject.} = n + 1
code
else:
for n in first.countdown(last + offTop):
let
i {.inject.} = n
j {.inject.} = n - 1
code
template doWalkIt(first, last: int; code: untyped) =
if first <= last:
for n in first .. last:
let it {.inject.} = n
code
else:
for n in first.countdown(last):
let it {.inject.} = n
code
# ------------------------------------------------------------------------------
# Public functions
# ------------------------------------------------------------------------------
# clique/snapshot.go(185): func (s *Snapshot) apply(headers [..]
proc snapshotApplySeq*(s: Snapshot; headers: var seq[BlockHeader],
first, last: int): CliqueOkResult
{.gcsafe, raises: [CatchableError].} =
## Initialises an authorization snapshot `snap` by applying the `headers`
## to the argument snapshot desciptor `s`.
# Sanity check that the headers can be applied
if headers[first].blockNumber != s.blockNumber + 1:
return err((errInvalidVotingChain,""))
# clique/snapshot.go(191): for i := 0; i < len(headers)-1; i++ {
first.pairWalkIj(last, 1):
if headers[j].blockNumber != headers[i].blockNumber+1:
return err((errInvalidVotingChain,""))
# Iterate through the headers and create a new snapshot
let
start = getTime()
var
logged = start
# clique/snapshot.go(206): for i, header := range headers [..]
first.doWalkIt(last):
let
# headersIndex => also used for logging at the end of this loop
headersIndex = it
header = headers[headersIndex]
number = header.blockNumber
# Remove any votes on checkpoint blocks
if (number mod s.cfg.epoch) == 0:
# Note that the correctness of the authorised accounts list is verified in
# clique/clique.verifyCascadingFields(),
# see clique/clique.go(355): if number%c.config.Epoch == 0 {
# This means, the account list passed with the epoch header is verified
# to be the same as the one we already have.
#
# clique/snapshot.go(210): snap.Votes = nil
s.ballot.flushVotes
# Delete the oldest signer from the recent list to allow it signing again
block:
let limit = s.ballot.authSignersThreshold.u256
if limit <= number:
s.recents.del(number - limit)
# Resolve the authorization key and check against signers
let signer = s.cfg.ecRecover(header)
if signer.isErr:
return err((errEcRecover,$signer.error))
if not s.ballot.isAuthSigner(signer.value):
return err((errUnauthorizedSigner,""))
for recent in s.recents.values:
if recent == signer.value:
return err((errRecentlySigned,""))
s.recents[number] = signer.value
# Header authorized, discard any previous vote from the signer
# clique/snapshot.go(233): for i, vote := range snap.Votes {
s.ballot.delVote(signer = signer.value, address = header.coinbase)
# Tally up the new vote from the signer
# clique/snapshot.go(244): var authorize bool
var authOk = false
if header.nonce == NONCE_AUTH:
authOk = true
elif header.nonce != NONCE_DROP:
return err((errInvalidVote,""))
let vote = Vote(address: header.coinbase,
signer: signer.value,
blockNumber: number,
authorize: authOk)
# clique/snapshot.go(253): if snap.cast(header.Coinbase, authorize) {
s.ballot.addVote(vote)
# clique/snapshot.go(269): if limit := uint64(len(snap.Signers)/2 [..]
if s.ballot.isAuthSignersListShrunk:
# Signer list shrunk, delete any leftover recent caches
let limit = s.ballot.authSignersThreshold.u256
if limit <= number:
# Pop off least block number from the list
let item = number - limit
s.recents.del(item)
# If we're taking too much time (ecrecover), notify the user once a while
if s.cfg.logInterval < getTime() - logged:
debug "Reconstructing voting history",
processed = headersIndex,
total = headers.len,
elapsed = getTime() - start
logged = getTime()
let sinceStart = getTime() - start
if s.cfg.logInterval < sinceStart:
debug "Reconstructed voting history",
processed = headers.len,
elapsed = sinceStart
# clique/snapshot.go(303): snap.Number += uint64(len(headers))
doAssert headers[last].blockNumber == s.blockNumber+(1+(last-first).abs).u256
s.blockNumber = headers[last].blockNumber
s.blockHash = headers[last].blockHash
ok()
proc snapshotApply*(s: Snapshot; headers: var seq[BlockHeader]): CliqueOkResult
{.gcsafe, raises: [CatchableError].} =
if headers.len == 0:
return ok()
s.snapshotApplySeq(headers, 0, headers.len - 1)
# ------------------------------------------------------------------------------
# End
# ------------------------------------------------------------------------------