ethereum.homestead.utils.message
Hardfork Utility Functions For The Message Data-structure ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. contents:: Table of Contents :backlinks: none :local:
Introduction
Message specific functions used in this homestead version of specification.
prepare_message
Execute a transaction against the provided environment.
Parameters
caller :
Address which initiated the transaction
target :
Address whose code will be executed
value :
Value to be transferred.
data :
Array of bytes provided to the code in target.
gas :
Gas provided for the code in target.
env :
Environment for the Ethereum Virtual Machine.
code_address :
This is usually same as the target address except when an alternative
accounts code needs to be executed.
eg. CALLCODE calling a precompile.
should_transfer_value :
if True ETH should be transferred while executing a message call.
Returns
message: ethereum.homestead.vm.Message
Items containing contract creation or message call specific data.
def prepare_message(caller: Address, target: Union[Bytes0, Address], value: U256, data: Bytes, gas: Uint, env: Environment, code_address: Optional[Address], should_transfer_value: bool) -> Message:
| 35 | """ |
|---|---|
| 36 | Execute a transaction against the provided environment. |
| 37 | |
| 38 | Parameters |
| 39 | ---------- |
| 40 | caller : |
| 41 | Address which initiated the transaction |
| 42 | target : |
| 43 | Address whose code will be executed |
| 44 | value : |
| 45 | Value to be transferred. |
| 46 | data : |
| 47 | Array of bytes provided to the code in `target`. |
| 48 | gas : |
| 49 | Gas provided for the code in `target`. |
| 50 | env : |
| 51 | Environment for the Ethereum Virtual Machine. |
| 52 | code_address : |
| 53 | This is usually same as the `target` address except when an alternative |
| 54 | accounts code needs to be executed. |
| 55 | eg. `CALLCODE` calling a precompile. |
| 56 | should_transfer_value : |
| 57 | if True ETH should be transferred while executing a message call. |
| 58 | |
| 59 | Returns |
| 60 | ------- |
| 61 | message: `ethereum.homestead.vm.Message` |
| 62 | Items containing contract creation or message call specific data. |
| 63 | """ |
| 64 | if isinstance(target, Bytes0): |
| 65 | current_target = compute_contract_address( |
| 66 | caller, |
| 67 | get_account(env.state, caller).nonce - Uint(1), |
| 68 | ) |
| 69 | msg_data = Bytes(b"") |
| 70 | code = data |
| 71 | elif isinstance(target, Address): |
| 72 | current_target = target |
| 73 | msg_data = data |
| 74 | code = get_account(env.state, target).code |
| 75 | if code_address is None: |
| 76 | code_address = target |
| 77 | else: |
| 78 | raise AssertionError("Target must be address or empty bytes") |
| 79 | |
| 80 | return Message( |
| 81 | caller=caller, |
| 82 | target=target, |
| 83 | gas=gas, |
| 84 | value=value, |
| 85 | data=msg_data, |
| 86 | code=code, |
| 87 | depth=Uint(0), |
| 88 | current_target=current_target, |
| 89 | code_address=code_address, |
| 90 | should_transfer_value=should_transfer_value, |
| 91 | parent_evm=None, |
| 92 | ) |