194 lines
6.4 KiB
Nim
194 lines
6.4 KiB
Nim
# Nimbus
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# Copyright (c) 2018 Status Research & Development GmbH
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# Licensed under either of
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# * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
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# http://www.apache.org/licenses/LICENSE-2.0)
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# * MIT license ([LICENSE-MIT](LICENSE-MIT) or
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# http://opensource.org/licenses/MIT)
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# at your option. This file may not be copied, modified, or distributed except
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# according to those terms.
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##
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## Snapshot Structure for Clique PoA Consensus Protocol
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## ====================================================
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##
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## For details see
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## `EIP-225 <https://github.com/ethereum/EIPs/blob/master/EIPS/eip-225.md>`_
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## and
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## `go-ethereum <https://github.com/ethereum/EIPs/blob/master/EIPS/eip-225.md>`_
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##
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import
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std/[tables],
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../../../db/storage_types,
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../clique_cfg,
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../clique_defs,
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../clique_helpers,
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./ballot,
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chronicles,
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eth/[rlp],
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stew/results
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export tables
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type
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SnapshotResult* = ##\
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## Snapshot/error result type
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Result[Snapshot,CliqueError]
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AddressHistory* = Table[BlockNumber,EthAddress]
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SnapshotData* = object
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blockNumber: BlockNumber ## block number where snapshot was created on
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blockHash: Hash256 ## block hash where snapshot was created on
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recents: AddressHistory ## recent signers for spam protections
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# clique/snapshot.go(58): Recents map[uint64]common.Address [..]
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ballot: Ballot ## Votes => authorised signers
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# clique/snapshot.go(50): type Snapshot struct [..]
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Snapshot* = ref object ## Snapshot is the state of the authorization
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## voting at a given point in time.
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cfg: CliqueCfg ## parameters to fine tune behavior
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data*: SnapshotData ## real snapshot
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{.push raises: [Defect].}
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logScope:
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topics = "clique PoA snapshot"
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# ------------------------------------------------------------------------------
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# Private functions needed to support RLP conversion
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# ------------------------------------------------------------------------------
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proc append[K,V](rw: var RlpWriter; tab: Table[K,V]) =
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rw.startList(tab.len)
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for key,value in tab.pairs:
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rw.append((key,value))
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proc read[K,V](rlp: var Rlp;
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Q: type Table[K,V]): Q {.raises: [Defect,CatchableError].} =
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for w in rlp.items:
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let (key,value) = w.read((K,V))
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result[key] = value
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# ------------------------------------------------------------------------------
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# Private constructor helper
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# ------------------------------------------------------------------------------
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# clique/snapshot.go(72): func newSnapshot(config [..]
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proc initSnapshot(s: Snapshot; cfg: CliqueCfg;
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number: BlockNumber; hash: Hash256; signers: openArray[EthAddress]) =
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## Initalise a new snapshot.
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s.cfg = cfg
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s.data.blockNumber = number
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s.data.blockHash = hash
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s.data.recents = initTable[BlockNumber,EthAddress]()
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s.data.ballot.initBallot(signers)
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# ------------------------------------------------------------------------------
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# Public Constructor
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# ------------------------------------------------------------------------------
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proc newSnapshot*(cfg: CliqueCfg; header: BlockHeader): Snapshot =
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## Create a new snapshot for the given header. The header need not be on the
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## block chain, yet. The trusted signer list is derived from the
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## `extra data` field of the header.
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new result
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let signers = header.extraData.extraDataAddresses
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result.initSnapshot(cfg, header.blockNumber, header.blockHash, signers)
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# ------------------------------------------------------------------------------
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# Public getters
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# ------------------------------------------------------------------------------
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proc cfg*(s: Snapshot): CliqueCfg =
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## Getter
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s.cfg
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proc blockNumber*(s: Snapshot): BlockNumber =
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## Getter
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s.data.blockNumber
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proc blockHash*(s: Snapshot): Hash256 =
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## Getter
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s.data.blockHash
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proc recents*(s: Snapshot): var AddressHistory =
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## Retrieves the list of recently added addresses
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s.data.recents
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proc ballot*(s: Snapshot): var Ballot =
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## Retrieves the ballot box descriptor with the votes
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s.data.ballot
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# ------------------------------------------------------------------------------
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# Public setters
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# ------------------------------------------------------------------------------
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proc `blockNumber=`*(s: Snapshot; number: BlockNumber) =
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## Getter
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s.data.blockNumber = number
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proc `blockHash=`*(s: Snapshot; hash: Hash256) =
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## Getter
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s.data.blockHash = hash
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# ------------------------------------------------------------------------------
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# Public load/store support
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# ------------------------------------------------------------------------------
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# clique/snapshot.go(88): func loadSnapshot(config [..]
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proc loadSnapshot*(cfg: CliqueCfg; hash: Hash256):
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Result[Snapshot,CliqueError] =
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## Load an existing snapshot from the database.
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var s = Snapshot(cfg: cfg)
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try:
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let db = s.cfg.com.db.db
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let rlpData = db.get(hash.cliqueSnapshotKey.toOpenArray)
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# The following check is only needed for Github/CI for 64bit Windows (not
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# reproducible on my local Win7 -- jordan). What normally happens when
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# `rlpData == @[]` holds is that the library function `eth.readImpl()`
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# throws an `RlpTypeMismatch` error as the inner function `isList()` fails.
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# On Github CI for 64bit Windows, the unit test crashes with a segmentation
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# fault.
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if rlpData.len == 0:
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return err((errSnapshotLoad,""))
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s.data = rlpData.decode(SnapshotData)
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except CatchableError as e:
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return err((errSnapshotLoad, $e.name & ": " & e.msg))
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ok(s)
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# clique/snapshot.go(104): func (s *Snapshot) store(db [..]
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proc storeSnapshot*(cfg: CliqueCfg; s: Snapshot): CliqueOkResult =
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## Insert the snapshot into the database.
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try:
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let
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key = s.data.blockHash.cliqueSnapshotKey
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val = rlp.encode(s.data)
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db = s.cfg.com.db.db
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db.put(key.toOpenArray, val)
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cfg.nSnaps.inc
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cfg.snapsData += val.len.uint
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except CatchableError as e:
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return err((errSnapshotStore, $e.name & ": " & e.msg))
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ok()
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# ------------------------------------------------------------------------------
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# Public deep copy
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# ------------------------------------------------------------------------------
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proc cloneSnapshot*(s: Snapshot): Snapshot =
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## Clone the snapshot
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Snapshot(
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cfg: s.cfg, # copy ref
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data: s.data) # copy data
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# ------------------------------------------------------------------------------
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# End
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# ------------------------------------------------------------------------------
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