nimbus-eth1/nimbus/db/db_chain.nim
2018-06-26 13:46:54 +03:00

233 lines
8.8 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.
import stint, tables, sequtils, algorithm, rlp, ranges, state_db, nimcrypto,
../errors, ../block_types, ../utils/header, ../constants, eth_common, byteutils,
./storage_types.nim, backends/memory_backend
type
BaseChainDB* = ref object
db*: MemoryDB
# TODO db*: JournalDB
KeyType = enum
blockNumberToHash
blockHashToScore
TransactionKey = tuple
blockNumber: BlockNumber
index: int
proc newBaseChainDB*(db: MemoryDB): BaseChainDB =
new(result)
result.db = db
proc contains*(self: BaseChainDB; key: Hash256): bool =
return self.db.contains(genericHashKey(key))
proc `$`*(db: BaseChainDB): string =
result = "BaseChainDB"
proc getBlockHeaderByHash*(self: BaseChainDB; blockHash: Hash256): BlockHeader =
## Returns the requested block header as specified by block hash.
##
## Raises BlockNotFound if it is not present in the db.
try:
let blk = self.db.get(genericHashKey(blockHash))
return decode(blk, BlockHeader)
except KeyError:
raise newException(BlockNotFound, "No block with hash " & blockHash.data.toHex)
proc getHash(self: BaseChainDB, key: DbKey): Hash256 {.inline.} =
rlp.decode(self.db.get(key).toRange, Hash256)
proc getCanonicalHead*(self: BaseChainDB): BlockHeader =
let k = canonicalHeadHashKey()
if k notin self.db:
raise newException(CanonicalHeadNotFound,
"No canonical head set for this chain")
return self.getBlockHeaderByHash(self.getHash(k))
proc lookupBlockHash*(self: BaseChainDB; n: BlockNumber): Hash256 {.inline.} =
## Return the block hash for the given block number.
self.getHash(blockNumberToHashKey(n))
proc getCanonicalBlockHeaderByNumber*(self: BaseChainDB; n: BlockNumber): BlockHeader =
## Returns the block header with the given number in the canonical chain.
##
## Raises BlockNotFound if there's no block header with the given number in the
## canonical chain.
self.getBlockHeaderByHash(self.lookupBlockHash(n))
proc getScore*(self: BaseChainDB; blockHash: Hash256): int =
rlp.decode(self.db.get(blockHashToScoreKey(blockHash)).toRange, int)
iterator findNewAncestors(self: BaseChainDB; header: BlockHeader): BlockHeader =
## Returns the chain leading up from the given header until the first ancestor it has in
## common with our canonical chain.
var h = header
while true:
try:
let orig = self.getCanonicalBlockHeaderByNumber(h.blockNumber)
if orig.hash == h.hash:
break
except BlockNotFound:
discard
yield h
if h.parentHash == GENESIS_PARENT_HASH:
break
else:
h = self.getBlockHeaderByHash(h.parentHash)
proc addBlockNumberToHashLookup(self: BaseChainDB; header: BlockHeader) =
self.db.set(blockNumberToHashKey(header.blockNumber), rlp.encode(header.hash))
iterator getBlockTransactionHashes(self: BaseChainDB, blockHeader: BlockHeader): Hash256 =
## Returns an iterable of the transaction hashes from th block specified
## by the given block header.
doAssert(false, "TODO: Implement me")
# let all_encoded_transactions = self._get_block_transaction_data(
# blockHeader.transactionRoot,
# )
# for encoded_transaction in all_encoded_transactions:
# yield keccak(encoded_transaction)
proc removeTransactionFromCanonicalChain(self: BaseChainDB, transactionHash: Hash256) {.inline.} =
## Removes the transaction specified by the given hash from the canonical chain.
self.db.delete(transactionHashToBlockKey(transactionHash))
proc setAsCanonicalChainHead(self: BaseChainDB; headerHash: Hash256): seq[BlockHeader] =
## Sets the header as the canonical chain HEAD.
let header = self.getBlockHeaderByHash(headerHash)
var newCanonicalHeaders = sequtils.toSeq(findNewAncestors(self, header))
reverse(newCanonicalHeaders)
for h in newCanonicalHeaders:
var oldHash: Hash256
try:
oldHash = self.lookupBlockHash(h.blockNumber)
except BlockNotFound:
break
let oldHeader = self.getBlockHeaderByHash(oldHash)
for txHash in self.getBlockTransactionHashes(oldHeader):
self.removeTransactionFromCanonicalChain(txHash)
# TODO re-add txn to internal pending pool (only if local sender)
for h in newCanonicalHeaders:
self.addBlockNumberToHashLookup(h)
self.db.set(canonicalHeadHashKey(), rlp.encode(header.hash))
return newCanonicalHeaders
proc headerExists*(self: BaseChainDB; blockHash: Hash256): bool =
## Returns True if the header with the given block hash is in our DB.
self.contains(blockHash)
iterator getBlockTransactionData(self: BaseChainDB, transactionRoot: Hash256): BytesRange =
doAssert(false, "TODO: Implement me")
# var transactionDb = HexaryTrie(self.db, transactionRoot)
# var transactionIdx = 0
# while true:
# var transactionKey = rlp.encode(transactionIdx)
# if transactionKey in transactionDb:
# var transactionData = transactionDb[transactionKey]
# yield transactionDb[transactionKey]
# else:
# break
# inc transactionIdx
# iterator getReceipts*(self: BaseChainDB; header: BlockHeader; receiptClass: typedesc): Receipt =
# var receiptDb = HexaryTrie()
# for receiptIdx in itertools.count():
# var receiptKey = rlp.encode(receiptIdx)
# if receiptKey in receiptDb:
# var receiptData = receiptDb[receiptKey]
# yield rlp.decode(receiptData)
# else:
# break
iterator getBlockTransactions(self: BaseChainDB; transactionRoot: Hash256;
transactionClass: typedesc): transactionClass =
for encodedTransaction in self.getBlockTransactionData(transactionRoot):
yield rlp.decode(encodedTransaction, transactionClass)
proc persistHeaderToDb*(self: BaseChainDB; header: BlockHeader): seq[BlockHeader] =
let isGenesis = header.parentHash == GENESIS_PARENT_HASH
if not isGenesis and not self.headerExists(header.parentHash):
raise newException(ParentNotFound, "Cannot persist block header " &
$header.hash & " with unknown parent " & $header.parentHash)
self.db.set(genericHashKey(header.hash), rlp.encode(header))
let score = if isGenesis: header.difficulty
else: self.getScore(header.parentHash).u256 + header.difficulty
self.db.set(blockHashToScoreKey(header.hash), rlp.encode(score))
var headScore: int
try:
headScore = self.getScore(self.getCanonicalHead().hash)
except CanonicalHeadNotFound:
return self.setAsCanonicalChainHead(header.hash)
if score > headScore.u256:
result = self.setAsCanonicalChainHead(header.hash)
proc addTransactionToCanonicalChain(self: BaseChainDB, txHash: Hash256,
blockHeader: BlockHeader, index: int) =
let k: TransactionKey = (blockHeader.blockNumber, index)
self.db.set(transactionHashToBlockKey(txHash), rlp.encode(k))
proc persistUncles*(self: BaseChainDB, uncles: openarray[BlockHeader]): Hash256 =
## Persists the list of uncles to the database.
## Returns the uncles hash.
let enc = rlp.encode(uncles)
result = keccak256.digest(enc.toOpenArray())
self.db.set(genericHashKey(result), enc)
proc persistBlockToDb*(self: BaseChainDB; blk: Block) =
## Persist the given block's header and uncles.
## Assumes all block transactions have been persisted already.
let newCanonicalHeaders = self.persistHeaderToDb(blk.header)
for header in newCanonicalHeaders:
var index = 0
for txHash in self.getBlockTransactionHashes(header):
self.addTransactionToCanonicalChain(txHash, header, index)
inc index
if blk.uncles.len != 0:
let ommersHash = self.persistUncles(blk.uncles)
assert ommersHash == blk.header.ommersHash
# proc addTransaction*(self: BaseChainDB; blockHeader: BlockHeader; indexKey: cstring;
# transaction: FrontierTransaction): cstring =
# var transactionDb = HexaryTrie(self.db)
# transactionDb[indexKey] = rlp.encode(transaction)
# return transactionDb.rootHash
# proc addReceipt*(self: BaseChainDB; blockHeader: BlockHeader; indexKey: cstring;
# receipt: Receipt): cstring =
# var receiptDb = HexaryTrie()
# receiptDb[indexKey] = rlp.encode(receipt)
# return receiptDb.rootHash
# proc snapshot*(self: BaseChainDB): UUID =
# return self.db.snapshot()
# proc commit*(self: BaseChainDB; checkpoint: UUID): void =
# self.db.commit(checkpoint)
# proc clear*(self: BaseChainDB): void =
# self.db.clear()
method getStateDb*(self: BaseChainDB; stateRoot: Hash256; readOnly: bool = false): AccountStateDB =
# TODO
result = newAccountStateDB(initTable[string, string]())