Transaction: Move `setupComputation` to its own file

Signed-off-by: Jamie Lokier <jamie@shareable.org>

nimbus/transaction/call_common.nim

@@ -0,0 +1,79 @@
+# Nimbus - Common entry point to the EVM from all different callers
+#
+# Copyright (c) 2018-2021 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
+  eth/common/eth_types, stint, options, stew/ranges/ptr_arith,
+  ".."/[vm_types, vm_types2, vm_state, vm_computation, vm_state_transactions],
+  ".."/[db/accounts_cache, transaction, vm_precompiles, vm_gas_costs],
+  ".."/vm_internals,
+  ./host_types
+
+type
+  # Standard call parameters.
+  CallParams* = object
+    vmState*:      BaseVMState          # Chain, database, state, block, fork.
+    forkOverride*: Option[Fork]         # Default fork is usually correct.
+    origin*:       Option[HostAddress]  # Default origin is `sender`.
+    gasPrice*:     GasInt               # Gas price for this call.
+    gasLimit*:     GasInt               # Maximum gas available for this call.
+    sender*:       HostAddress          # Sender account.
+    to*:           HostAddress          # Recipient (ignored when `isCreate`).
+    isCreate*:     bool                 # True if this is a contract creation.
+    value*:        HostValue            # Value sent from sender to recipient.
+    input*:        seq[byte]            # Input data.
+
+proc hostToComputationMessage(msg: EvmcMessage): Message =
+  Message(
+    kind:            CallKind(msg.kind),
+    depth:           msg.depth,
+    gas:             msg.gas,
+    sender:          msg.sender.fromEvmc,
+    contractAddress: msg.destination.fromEvmc,
+    codeAddress:     msg.destination.fromEvmc,
+    value:           msg.value.fromEvmc,
+    # When input size is zero, input data pointer may be null.
+    data:            if msg.input_size <= 0: @[]
+                     else: @(makeOpenArray(msg.input_data, msg.input_size.int)),
+    flags:           if msg.isStatic: emvcStatic else: emvcNoFlags
+  )
+
+proc setupCall(call: CallParams): TransactionHost =
+  let vmState = call.vmState
+  vmState.setupTxContext(
+    origin       = call.origin.get(call.sender),
+    gasPrice     = call.gasPrice,
+    forkOverride = call.forkOverride
+  )
+
+  let host = TransactionHost(
+    vmState:       vmState,
+    msg: EvmcMessage(
+      kind:        if call.isCreate: EVMC_CREATE else: EVMC_CALL,
+      # Default: flags:       {},
+      # Default: depth:       0,
+      gas:         call.gasLimit,
+      destination: call.to.toEvmc,
+      sender:      call.sender.toEvmc,
+      value:       call.value.toEvmc,
+    )
+    # All other defaults in `TransactionHost` are fine.
+  )
+
+  if call.input.len > 0:
+    host.msg.input_size = call.input.len.csize_t
+    # Must copy the data so the `host.msg.input_data` pointer
+    # remains valid after the end of `call` lifetime.
+    host.input = call.input
+    host.msg.input_data = host.input[0].addr
+
+  let cMsg = hostToComputationMessage(host.msg)
+  host.computation = newComputation(vmState, cMsg)
+  return host
+
+proc setupComputation*(call: CallParams): Computation =
+  return setupCall(call).computation

nimbus/transaction/call_evm.nim

@@ -7,76 +7,12 @@
 # at your option. This file may not be copied, modified, or distributed except according to those terms.
 
 import
-  eth/common/eth_types, stint, options, stew/byteutils, stew/ranges/ptr_arith,
+  eth/common/eth_types, stint, options, stew/byteutils,
   ".."/[vm_types, vm_types2, vm_state, vm_computation, utils],
   ".."/[db/db_chain, config, vm_state_transactions, rpc/hexstrings],
   ".."/[db/accounts_cache, transaction, vm_precompiles, vm_gas_costs], eth/trie/db,
   ".."/vm_internals,
-  ./host_types
+  ./call_common
-
-proc hostToComputationMessage(msg: EvmcMessage): Message =
-  Message(
-    kind:            CallKind(msg.kind),
-    depth:           msg.depth,
-    gas:             msg.gas,
-    sender:          msg.sender.fromEvmc,
-    contractAddress: msg.destination.fromEvmc,
-    codeAddress:     msg.destination.fromEvmc,
-    value:           msg.value.fromEvmc,
-    # When input size is zero, input data pointer may be null.
-    data:            if msg.input_size <= 0: @[]
-                     else: @(makeOpenArray(msg.input_data, msg.input_size.int)),
-    flags:           if msg.isStatic: emvcStatic else: emvcNoFlags
-  )
-
-type
-  CallParams = object
-    vmState:      BaseVMState
-    forkOverride: Option[Fork]
-    origin:       Option[HostAddress]
-    gasPrice:     GasInt
-    gasLimit:     GasInt
-    sender:       HostAddress
-    to:           HostAddress
-    isCreate:     bool
-    value:        HostValue
-    input:        seq[byte]
-
-proc setupCall(call: CallParams): TransactionHost =
-  let vmState = call.vmState
-  vmState.setupTxContext(
-    origin       = call.origin.get(call.sender),
-    gasPrice     = call.gasPrice,
-    forkOverride = call.forkOverride
-  )
-
-  let host = TransactionHost(
-    vmState:       vmState,
-    msg: EvmcMessage(
-      kind:        if call.isCreate: EVMC_CREATE else: EVMC_CALL,
-      # Default: flags:       {},
-      # Default: depth:       0,
-      gas:         call.gasLimit,
-      destination: call.to.toEvmc,
-      sender:      call.sender.toEvmc,
-      value:       call.value.toEvmc,
-    )
-    # All other defaults in `TransactionHost` are fine.
-  )
-
-  if call.input.len > 0:
-    host.msg.input_size = call.input.len.csize_t
-    # Must copy the data so the `host.msg.input_data` pointer
-    # remains valid after the end of `call` lifetime.
-    host.input = call.input
-    host.msg.input_data = host.input[0].addr
-
-  let cMsg = hostToComputationMessage(host.msg)
-  host.computation = newComputation(vmState, cMsg)
-  return host
-
-proc setupComputation(call: CallParams): Computation =
-  return setupCall(call).computation
 
 type
   RpcCallData* = object