implement eth_estimateGas

nimbus/rpc/p2p.nim

@@ -27,63 +27,9 @@ import
 ]#
 
 # Work around for https://github.com/nim-lang/Nim/issues/8645
-#[proc `%`*(value: Time): JsonNode =
+# proc `%`*(value: Time): JsonNode =
-  result = %value.toUnix
+#  result = %value.toUnix
 
-template balance(addressDb: ReadOnlyStateDb, address: EthAddress): GasInt =
-  # TODO: Account balance u256 but GasInt is int64?
-  addressDb.getBalance(address).truncate(int64)
-
-proc binarySearchGas(vmState: var BaseVMState, transaction: Transaction, sender: EthAddress, gasPrice: GasInt, tolerance = 1): GasInt =
-  proc dummyComputation(vmState: var BaseVMState, transaction: Transaction, sender: EthAddress): Computation =
-    # Note that vmState may be altered
-    var chainDB = vmState.chainDB
-    let fork = chainDB.config.toFork(vmState.blockNumber)
-    setupComputation(
-        vmState,
-        transaction,
-        sender,
-        fork)
-
-  proc dummyTransaction(gasLimit, gasPrice: GasInt, destination: EthAddress, value: UInt256): Transaction =
-    Transaction(
-      accountNonce: 0.AccountNonce,
-      gasPrice: gasPrice,
-      gasLimit: gasLimit,
-      to: destination,
-      value: value
-    )
-  var
-    chainDB = vmState.chainDB
-    fork = chainDB.config.toFork(vmState.blockNumber)
-    hiGas = vmState.gasLimit
-    loGas = transaction.intrinsicGas(fork)
-    gasPrice = transaction.gasPrice # TODO: Or zero?
-
-  proc tryTransaction(vmState: var BaseVMState, gasLimit: GasInt): bool =
-    var
-      spoofTransaction = dummyTransaction(gasLimit, gasPrice, transaction.to, transaction.value)
-      computation = vmState.dummyComputation(spoofTransaction, sender)
-    computation.executeOpcodes
-    if not computation.isError:
-      return true
-
-  if vmState.tryTransaction(loGas):
-    return loGas
-  if not vmState.tryTransaction(hiGas):
-    return 0.GasInt # TODO: Reraise error from computation
-
-  var
-    minVal = vmState.gasLimit
-    maxVal = transaction.intrinsicGas(fork)
-  while loGas - hiGas > tolerance:
-    let midPoint = (loGas + hiGas) div 2
-    if vmState.tryTransaction(midPoint):
-      minVal = midPoint
-    else:
-      maxVal = midPoint
-  result = minVal
-]#
 proc setupEthRpc*(node: EthereumNode, chain: BaseChainDB , server: RpcServer) =
 
   proc getAccountDb(header: BlockHeader): ReadOnlyStateDB =
@@ -318,11 +264,10 @@ proc setupEthRpc*(node: EthereumNode, chain: BaseChainDB , server: RpcServer) =
     ## Returns the return value of executed contract.
     let
       header   = headerFromTag(chain, quantityTag)
-      callData = callData(call, true)
+      callData = callData(call, true, chain)
     result = doCall(callData, header, chain)
 
-#[
+  server.rpc("eth_estimateGas") do(call: EthCall, quantityTag: string) -> HexQuantityStr:
-  server.rpc("eth_estimateGas") do(call: EthCall, quantityTag: string) -> GasInt:
     ## Generates and returns an estimate of how much gas is necessary to allow the transaction to complete.
     ## The transaction will not be added to the blockchain. Note that the estimate may be significantly more than
     ## the amount of gas actually used by the transaction, for a variety of reasons including EVM mechanics and node performance.
@@ -330,39 +275,12 @@ proc setupEthRpc*(node: EthereumNode, chain: BaseChainDB , server: RpcServer) =
     ## call: the transaction call object.
     ## quantityTag:  integer block number, or the string "latest", "earliest" or "pending", see the default block parameter.
     ## Returns the amount of gas used.
-    var
-      header = chain.headerFromTag(quantityTag)
-      # TODO: header.stateRoot to prevStateRoot?
-      vmState = newBaseVMState(header.stateRoot, header, chain)
     let
-      gasLimit = if
+      header   = chain.headerFromTag(quantityTag)
-        call.gas.isSome and call.gas.get > 0.GasInt: call.gas.get
+      callData = callData(call, false, chain)
-        else: header.gasLimit
+    result = estimateGas(callData, header, chain, call.gas.isSome)
-      gasPrice = if
-        call.gasPrice.isSome and call.gasPrice.get > 0: call.gasPrice.get
-        else: 0.GasInt
-      sender = if
-        call.source.isSome: call.source.get.toAddress
-        else: ZERO_ADDRESS
-      destination = if
-        call.to.isSome: call.to.get.toAddress
-        else: ZERO_ADDRESS
-      curState = vmState.readOnlyStateDb()
-      nonce = curState.getNonce(sender)
-      value = if
-        call.value.isSome: call.value.get
-        else: 0.u256
-
-      transaction = Transaction(
-        accountNonce: nonce,
-        gasPrice: gasPrice,
-        gasLimit: gasLimit,
-        to: destination,
-        value: value,
-        payload: @[]
-      )
-    result = vmState.binarySearchGas(transaction, sender, gasPrice)
 
+#[
   func populateBlockObject(header: BlockHeader, blockBody: BlockBody): BlockObject =
     result.number = some(header.blockNumber)
     result.hash = some(header.hash)

nimbus/rpc/rpc_types.nim

@@ -34,7 +34,7 @@ type
     # Parameter from user
     source*: Option[EthAddressStr]   # (optional) The address the transaction is send from.
     to*: Option[EthAddressStr]       # (optional in eth_estimateGas, not in eth_call) The address the transaction is directed to.
-    gas*: Option[HexQuantityStr]     # (optional) Integer of the gas provided for the transaction execution. eth_call consumes zero gas, but this parameter may be needed by some executions.
+    gas*: Option[HexQuantityStr]# (optional) Integer of the gas provided for the transaction execution. eth_call consumes zero gas, but this parameter may be needed by some executions.
     gasPrice*: Option[HexQuantityStr]# (optional) Integer of the gasPrice used for each paid gas.
     value*: Option[HexQuantityStr]   # (optional) Integer of the value sent with this transaction.
     data*: Option[EthHashStr]        # (optional) Hash of the method signature and encoded parameters. For details see Ethereum Contract ABI.

nimbus/rpc/rpc_utils.nim

@@ -7,11 +7,11 @@
 # This file may not be copied, modified, or distributed except according to
 # those terms.
 
-import hexstrings, eth/[common, rlp, keys], stew/byteutils, nimcrypto,
+import hexstrings, eth/[common, rlp, keys, trie/db], stew/byteutils, nimcrypto,
-  ../db/[db_chain], strutils, algorithm, options,
+  ../db/[db_chain, accounts_cache], strutils, algorithm, options,
   ../constants, stint, hexstrings, rpc_types, ../config,
   ../vm_state_transactions, ../vm_state, ../vm_types, ../vm/interpreter/vm_forks,
-  ../vm/computation
+  ../vm/computation, ../p2p/executor
 
 type
   UnsignedTx* = object
@@ -30,6 +30,7 @@ type
     gasPrice: GasInt
     value: UInt256
     data: seq[byte]
+    contractCreation: bool
 
 proc read(rlp: var Rlp, t: var UnsignedTx, _: type EthAddress): EthAddress {.inline.} =
   if rlp.blobLen != 0:
@@ -160,7 +161,7 @@ proc signTransaction*(tx: UnsignedTx, chain: BaseChainDB, privateKey: PrivateKey
     S: Uint256.fromBytesBE(sig[32..63])
     )
 
-proc callData*(call: EthCall, callMode: bool = true): CallData =
+proc callData*(call: EthCall, callMode: bool = true, chain: BaseChainDB): CallData =
   if call.source.isSome:
     result.source = toAddress(call.source.get)
 
@@ -169,12 +170,17 @@ proc callData*(call: EthCall, callMode: bool = true): CallData =
   else:
     if callMode:
       raise newException(ValueError, "call.to required for eth_call operation")
+    else:
+      result.contractCreation = true
 
   if call.gas.isSome:
     result.gas = hexToInt(call.gas.get.string, GasInt)
 
   if call.gasPrice.isSome:
     result.gasPrice = hexToInt(call.gasPrice.get.string, GasInt)
+  else:
+    if not callMode:
+      result.gasPrice = calculateMedianGasPrice(chain)
 
   if call.value.isSome:
     result.value = UInt256.fromHex(call.value.get.string)
@@ -202,13 +208,11 @@ proc setupComputation(vmState: BaseVMState, call: CallData, fork: Fork) : Comput
 
   result = newComputation(vmState, msg)
 
-import json
-
 proc doCall*(call: CallData, header: BlockHeader, chain: BaseChainDB): HexDataStr =
   var
     # we use current header stateRoot, unlike block validation
     # which use previous block stateRoot
-    vmState = newBaseVMState(header.stateRoot, header, chain, {EnableTracing})
+    vmState = newBaseVMState(header.stateRoot, header, chain)
     fork    = toFork(chain.config, header.blockNumber)
     comp    = setupComputation(vmState, call, fork)
 
@@ -216,3 +220,26 @@ proc doCall*(call: CallData, header: BlockHeader, chain: BaseChainDB): HexDataSt
   result = hexDataStr(comp.output)
   # TODO: handle revert and error
   # TODO: handle contract ABI
+
+proc estimateGas*(call: CallData, header: BlockHeader, chain: BaseChainDB, haveGasLimit: bool): HexQuantityStr =
+  var
+    # we use current header stateRoot, unlike block validation
+    # which use previous block stateRoot
+    vmState = newBaseVMState(header.stateRoot, header, chain)
+    fork    = toFork(chain.config, header.blockNumber)
+    tx      = Transaction(
+      accountNonce: vmState.accountdb.getNonce(call.source),
+      gasPrice: call.gasPrice,
+      gasLimit: if haveGasLimit: call.gas else: header.gasLimit - vmState.cumulativeGasUsed,
+      to      : call.to,
+      value   : call.value,
+      payload : call.data,
+      isContractCreation:  call.contractCreation
+    )
+
+  var dbTx = chain.db.beginTransaction()
+  defer: dbTx.dispose()
+  let gasUsed = processTransaction(tx, call.source, vmState, fork)
+  result = encodeQuantity(gasUsed.uint64)
+  dbTx.dispose()
+  # TODO: handle revert and error

premix/prestate.nim

@@ -13,7 +13,7 @@ proc generatePrestate*(nimbus, geth: JsonNode, blockNumber: Uint256, parent, hea
     chainDB = newBaseChainDB(memoryDB, false)
 
   chainDB.setHead(parent, true)
-  chainDB.persistTransactions(blockNumber, body.transactions)
+  discard chainDB.persistTransactions(blockNumber, body.transactions)
   discard chainDB.persistUncles(body.uncles)
 
   memoryDB.put(genericHashKey(headerHash).toOpenArray, rlp.encode(header))

tests/rpcclient/ethcallsigs.nim

@@ -39,8 +39,8 @@ proc eth_signTransaction(data: TxSend): HexDataStr
 proc eth_sendTransaction(data: TxSend): EthHashStr
 proc eth_sendRawTransaction(data: HexDataStr): EthHashStr
 proc eth_call(call: EthCall, quantityTag: string): HexDataStr
-
 proc eth_estimateGas(call: EthCall, quantityTag: string): HexQuantityStr
+
 proc eth_getBlockByHash(data: Hash256, fullTransactions: bool): BlockObject
 proc eth_getBlockByNumber(quantityTag: string, fullTransactions: bool): BlockObject
 proc eth_getTransactionByHash(data: Hash256): TransactionObject

tests/test_rpc.nim

@@ -48,7 +48,7 @@ proc setupEnv(chain: BaseChainDB, signer, ks2: EthAddress, conf: NimbusConfigura
     RETURN
 
   ac.setCode(ks2, code)
-  ac.addBalance(signer, 1_000_000.u256)
+  ac.addBalance(signer, 9_000_000_000.u256)
   var vmState = newBaseVMState(ac.rootHash, BlockHeader(parentHash: parentHash), chain)
 
   let
@@ -94,7 +94,7 @@ proc setupEnv(chain: BaseChainDB, signer, ks2: EthAddress, conf: NimbusConfigura
     bloom       : createBloom(vmState.receipts),
     difficulty  : difficulty,
     blockNumber : blockNumber,
-    gasLimit    : vmState.cumulativeGasUsed + 1000,
+    gasLimit    : vmState.cumulativeGasUsed + 1_000_000,
     gasUsed     : vmState.cumulativeGasUsed,
     timestamp   : timeStamp
     #extraData:     Blob
@@ -309,12 +309,17 @@ proc doTests {.async.} =
       let res = await client.eth_call(ec, "latest")
       check hexToByteArray[4](res.string) == hexToByteArray[4]("deadbeef")
 
-    #test "eth_estimateGas":
+    test "eth_estimateGas":
-    #  let
+      var ec = EthCall(
-    #    call = EthCall()
+        source: ethAddressStr(signer).some,
-    #    blockNum = state.blockheader.blockNumber
+        to: ethAddressStr(ks3).some,
-    #    r4 = await client.eth_estimateGas(call, "0x" & blockNum.toHex)
+        gas: encodeQuantity(42000'u).some,
-    #  check r4 == 21_000
+        gasPrice: encodeQuantity(100'u).some,
+        value: encodeQuantity(100'u).some
+        )
+
+      let res = await client.eth_estimateGas(ec, "latest")
+      check hexToInt(res.string, int) == 21000
 
   rpcServer.stop()
   rpcServer.close()