import tables, hashes, sets, eth/[common, rlp], eth/trie/[hexary, db, trie_defs], ../constants, ../utils, storage_types type AccountFlag = enum IsAlive IsNew IsDirty IsTouched IsClone CodeLoaded CodeChanged StorageChanged AccountFlags = set[AccountFlag] RefAccount = ref object account: Account flags: AccountFlags code: ByteRange originalStorage: TableRef[UInt256, UInt256] overlayStorage: Table[UInt256, UInt256] AccountsCache* = object db: TrieDatabaseRef trie: SecureHexaryTrie savePoint: SavePoint unrevertablyTouched: HashSet[EthAddress] TransactionState = enum Pending Committed RolledBack SavePoint* = ref object parentSavepoint: SavePoint cache: Table[EthAddress, RefAccount] state: TransactionState proc beginSavepoint*(ac: var AccountsCache): SavePoint {.gcsafe.} # The AccountsCache is modeled after TrieDatabase for it's transaction style proc init*(x: typedesc[AccountsCache], db: TrieDatabaseRef, root: KeccakHash, pruneTrie: bool): AccountsCache = result.db = db result.trie = initSecureHexaryTrie(db, root, pruneTrie) result.unrevertablyTouched = initHashSet[EthAddress]() discard result.beginSavepoint proc beginSavepoint*(ac: var AccountsCache): SavePoint = new result result.cache = initTable[EthAddress, RefAccount]() result.state = Pending result.parentSavepoint = ac.savePoint ac.savePoint = result proc rollback*(ac: var AccountsCache, sp: Savepoint) = # Transactions should be handled in a strictly nested fashion. # Any child transaction must be committed or rolled-back before # its parent transactions: doAssert ac.savePoint == sp and sp.state == Pending ac.savePoint = sp.parentSavepoint sp.state = RolledBack proc commit*(ac: var AccountsCache, sp: Savepoint) = # Transactions should be handled in a strictly nested fashion. # Any child transaction must be committed or rolled-back before # its parent transactions: doAssert ac.savePoint == sp and sp.state == Pending # cannot commit most inner savepoint doAssert not sp.parentSavepoint.isNil ac.savePoint = sp.parentSavepoint for k, v in sp.cache: sp.parentSavepoint.cache[k] = v sp.state = Committed proc dispose*(ac: var AccountsCache, sp: Savepoint) {.inline.} = if sp.state == Pending: ac.rollback(sp) proc safeDispose*(ac: var AccountsCache, sp: Savepoint) {.inline.} = if (not isNil(sp)) and (sp.state == Pending): ac.rollback(sp) template createRangeFromAddress(address: EthAddress): ByteRange = ## XXX: The name of this proc is intentionally long, because it ## performs a memory allocation and data copying that may be eliminated ## in the future. Avoid renaming it to something similar as `toRange`, so ## it can remain searchable in the code. toRange(@address) proc getAccount(ac: AccountsCache, address: EthAddress): RefAccount = # search account from layers of cache var sp = ac.savePoint while sp != nil: result = sp.cache.getOrDefault(address) if not result.isNil: return sp = sp.parentSavepoint # not found in cache, look into state trie let recordFound = ac.trie.get(createRangeFromAddress address) if recordFound.len > 0: # we found it result = RefAccount( account: rlp.decode(recordFound, Account), flags: {IsAlive} ) else: # it's a request for new account result = RefAccount( account: newAccount(), flags: {IsAlive, IsNew} ) # cache the account ac.savePoint.cache[address] = result proc clone(acc: RefAccount, cloneStorage: bool): RefAccount = new(result) result.account = acc.account result.flags = acc.flags + {IsClone} result.code = acc.code if cloneStorage: result.originalStorage = acc.originalStorage # it's ok to clone a table this way result.overlayStorage = acc.overlayStorage proc isEmpty(acc: RefAccount): bool = result = acc.account.codeHash == EMPTY_SHA3 and acc.account.balance.isZero and acc.account.nonce == 0 proc exists(acc: RefAccount): bool = if IsAlive notin acc.flags: return false if IsClone in acc.flags: result = true else: result = IsNew notin acc.flags template createTrieKeyFromSlot(slot: UInt256): ByteRange = # XXX: This is too expensive. Similar to `createRangeFromAddress` # Converts a number to hex big-endian representation including # prefix and leading zeros: @(slot.toByteArrayBE).toRange # Original py-evm code: # pad32(int_to_big_endian(slot)) # morally equivalent to toByteRange_Unnecessary but with different types template getAccountTrie(db: TrieDatabaseRef, acc: RefAccount): auto = # TODO: implement `prefix-db` to solve issue #228 permanently. # the `prefix-db` will automatically insert account address to the # underlying-db key without disturb how the trie works. # it will create virtual container for each account. # see nim-eth#9 initSecureHexaryTrie(db, acc.account.storageRoot, false) proc originalStorageValue(acc: RefAccount, slot: UInt256, db: TrieDatabaseRef): UInt256 = # share the same original storage between multiple # versions of account if acc.originalStorage.isNil: acc.originalStorage = newTable[UInt256, UInt256]() else: if slot in acc.originalStorage: result = acc.originalStorage[slot] return # Not in the original values cache - go to the DB. let slotAsKey = createTrieKeyFromSlot slot accountTrie = getAccountTrie(db, acc) foundRecord = accountTrie.get(slotAsKey) result = if foundRecord.len > 0: rlp.decode(foundRecord, UInt256) else: UInt256.zero() acc.originalStorage[slot] = result proc storageValue(acc: RefAccount, slot: UInt256, db: TrieDatabaseRef): UInt256 = if slot in acc.overlayStorage: return acc.overlayStorage[slot] acc.originalStorageValue(slot, db) proc kill(acc: RefAccount) = acc.flags.excl IsAlive acc.overlayStorage.clear() acc.originalStorage = nil acc.account = newAccount() acc.code = default(ByteRange) type PersistMode = enum DoNothing Update Remove proc persistMode(acc: RefAccount): PersistMode = result = DoNothing if IsAlive in acc.flags: if IsNew in acc.flags or IsDirty in acc.flags: result = Update else: if IsNew notin acc.flags: result = Remove proc persistCode(acc: RefAccount, db: TrieDatabaseRef) = if acc.code.len != 0: db.put(contractHashKey(acc.account.codeHash).toOpenArray, acc.code.toOpenArray) proc persistStorage(acc: RefAccount, db: TrieDatabaseRef) = if acc.account.storageRoot == emptyRlpHash: # TODO: remove the storage too if we figure out # how to create 'virtual' storage room for each account return var accountTrie = getAccountTrie(db, acc) for slot, value in acc.overlayStorage: let slotAsKey = createTrieKeyFromSlot slot if value > 0: let encodedValue = rlp.encode(value).toRange accountTrie.put(slotAsKey, encodedValue) else: accountTrie.del(slotAsKey) # map slothash back to slot value # see iterator storage below # slotHash can be obtained from accountTrie.put? let slotHash = keccakHash(slotAsKey.toOpenArray) db.put(slotHashToSlotKey(slotHash.data).toOpenArray, rlp.encode(slot)) acc.account.storageRoot = accountTrie.rootHash proc makeDirty(ac: AccountsCache, address: EthAddress, cloneStorage = true): RefAccount = result = ac.getAccount(address) if address in ac.savePoint.cache: # it's already in latest savepoint result.flags.incl IsDirty return # put a copy into latest savepoint result = result.clone(cloneStorage) result.flags.incl IsDirty ac.savePoint.cache[address] = result proc getCodeHash*(ac: AccountsCache, address: EthAddress): Hash256 {.inline.} = ac.getAccount(address).account.codeHash proc getBalance*(ac: AccountsCache, address: EthAddress): UInt256 {.inline.} = ac.getAccount(address).account.balance proc getNonce*(ac: AccountsCache, address: EthAddress): AccountNonce {.inline.} = ac.getAccount(address).account.nonce proc getCode*(ac: AccountsCache, address: EthAddress): ByteRange = let acc = ac.getAccount(address) if CodeLoaded in acc.flags or CodeChanged in acc.flags: result = acc.code else: let data = ac.db.get(contractHashKey(acc.account.codeHash).toOpenArray) acc.code = data.toRange acc.flags.incl CodeLoaded result = acc.code proc getCodeSize*(ac: AccountsCache, address: EthAddress): int {.inline.} = ac.getCode(address).len proc getCommittedStorage*(ac: AccountsCache, address: EthAddress, slot: UInt256): UInt256 {.inline.} = let acc = ac.getAccount(address) acc.originalStorageValue(slot, ac.db) proc getStorage*(ac: AccountsCache, address: EthAddress, slot: UInt256): UInt256 {.inline.} = let acc = ac.getAccount(address) acc.storageValue(slot, ac.db) proc hasCodeOrNonce*(ac: AccountsCache, address: EthAddress): bool {.inline.} = let acc = ac.getAccount(address) acc.account.nonce != 0 or acc.account.codeHash != EMPTY_SHA3 proc accountExists*(ac: AccountsCache, address: EthAddress): bool {.inline.} = let acc = ac.getAccount(address) acc.exists() proc isEmptyAccount*(ac: AccountsCache, address: EthAddress): bool {.inline.} = let acc = ac.getAccount(address) doAssert acc.exists() result = acc.isEmpty() proc isDeadAccount*(ac: AccountsCache, address: EthAddress): bool = let acc = ac.getAccount(address) if not acc.exists(): result = true else: result = acc.isEmpty() proc setBalance*(ac: var AccountsCache, address: EthAddress, balance: UInt256) = let acc = ac.getAccount(address) acc.flags.incl {IsTouched, IsAlive} if acc.account.balance != balance: ac.makeDirty(address).account.balance = balance proc addBalance*(ac: var AccountsCache, address: EthAddress, delta: UInt256) {.inline.} = ac.setBalance(address, ac.getBalance(address) + delta) proc subBalance*(ac: var AccountsCache, address: EthAddress, delta: UInt256) {.inline.} = ac.setBalance(address, ac.getBalance(address) - delta) proc setNonce*(ac: var AccountsCache, address: EthAddress, nonce: AccountNonce) = let acc = ac.getAccount(address) acc.flags.incl {IsTouched, IsAlive} if acc.account.nonce != nonce: ac.makeDirty(address).account.nonce = nonce proc incNonce*(ac: var AccountsCache, address: EthAddress) {.inline.} = ac.setNonce(address, ac.getNonce(address) + 1) proc setCode*(ac: var AccountsCache, address: EthAddress, code: ByteRange) = let acc = ac.getAccount(address) acc.flags.incl {IsTouched, IsAlive} let codeHash = keccakHash(code.toOpenArray) if acc.account.codeHash != codeHash: var acc = ac.makeDirty(address) acc.account.codeHash = codeHash acc.code = code acc.flags.incl CodeChanged proc setStorage*(ac: var AccountsCache, address: EthAddress, slot, value: UInt256) = let acc = ac.getAccount(address) acc.flags.incl {IsTouched, IsAlive} let oldValue = acc.storageValue(slot, ac.db) if oldValue != value: var acc = ac.makeDirty(address) acc.overlayStorage[slot] = value acc.flags.incl StorageChanged proc clearStorage*(ac: var AccountsCache, address: EthAddress) = let acc = ac.getAccount(address) acc.flags.incl {IsTouched, IsAlive} if acc.account.storageRoot != emptyRlpHash: # there is no point to clone the storage since we want to remove it ac.makeDirty(address, cloneStorage = false).account.storageRoot = emptyRlpHash #proc deleteAccount*(ac: var AccountsCache, address: EthAddress) = # let acc = ac.getAccount(address) # if IsAlive in acc.flags: proc unrevertableTouch*(ac: var AccountsCache, address: EthAddress) = ac.unrevertablyTouched.incl address proc removeEmptyAccounts*(ac: var AccountsCache) = # make sure all savepoints already committed doAssert(ac.savePoint.parentSavePoint.isNil) for _, acc in ac.savePoint.cache: if IsTouched in acc.flags and acc.isEmpty: acc.kill() for address in ac.unrevertablyTouched: var acc = ac.getAccount(address) if acc.isEmpty: acc.kill() proc persist*(ac: var AccountsCache) = # make sure all savepoint already committed doAssert(ac.savePoint.parentSavePoint.isNil) for address, acc in ac.savePoint.cache: case acc.persistMode() of Update: if CodeChanged in acc.flags: acc.persistCode(ac.db) if StorageChanged in acc.flags: # storageRoot must be updated first # before persisting account into merkle trie acc.persistStorage(ac.db) ac.trie.put createRangeFromAddress(address), rlp.encode(acc.account).toRange of Remove: ac.trie.del createRangeFromAddress(address) of DoNothing: discard iterator storage*(ac: AccountsCache, address: EthAddress): (UInt256, UInt256) = # beware that if the account not persisted, # the storage root will not be updated let storageRoot = ac.getAccount(address).account.storageRoot var trie = initHexaryTrie(ac.db, storageRoot) for slot, value in trie: if slot.len != 0: var keyData = ac.db.get(slotHashToSlotKey(slot.toOpenArray).toOpenArray).toRange yield (rlp.decode(keyData, UInt256), rlp.decode(value, UInt256))