ethereum.byzantium.utils.message
Hardfork Utility Functions For The Message Data-structure ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. contents:: Table of Contents :backlinks: none :local:
Introduction
Message specific functions used in this byzantium 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.
is_static:
if True then it prevents all state-changing operations from being
executed.
Returns
message: ethereum.byzantium.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, is_static: bool) -> Message:
37 | """ |
---|---|
38 | Execute a transaction against the provided environment. |
39 |
|
40 | Parameters |
41 | ---------- |
42 | caller : |
43 | Address which initiated the transaction |
44 | target : |
45 | Address whose code will be executed |
46 | value : |
47 | Value to be transferred. |
48 | data : |
49 | Array of bytes provided to the code in `target`. |
50 | gas : |
51 | Gas provided for the code in `target`. |
52 | env : |
53 | Environment for the Ethereum Virtual Machine. |
54 | code_address : |
55 | This is usually same as the `target` address except when an alternative |
56 | accounts code needs to be executed. |
57 | eg. `CALLCODE` calling a precompile. |
58 | should_transfer_value : |
59 | if True ETH should be transferred while executing a message call. |
60 | is_static: |
61 | if True then it prevents all state-changing operations from being |
62 | executed. |
63 |
|
64 | Returns |
65 | ------- |
66 | message: `ethereum.byzantium.vm.Message` |
67 | Items containing contract creation or message call specific data. |
68 | """ |
69 | if isinstance(target, Bytes0): |
70 | current_target = compute_contract_address( |
71 | caller, |
72 | get_account(env.state, caller).nonce - Uint(1), |
73 | ) |
74 | msg_data = Bytes(b"") |
75 | code = data |
76 | elif isinstance(target, Address): |
77 | current_target = target |
78 | msg_data = data |
79 | code = get_account(env.state, target).code |
80 | if code_address is None: |
81 | code_address = target |
82 | else: |
83 | raise AssertionError("Target must be address or empty bytes") |
84 | |
85 | return Message( |
86 | caller=caller, |
87 | target=target, |
88 | gas=gas, |
89 | value=value, |
90 | data=msg_data, |
91 | code=code, |
92 | depth=Uint(0), |
93 | current_target=current_target, |
94 | code_address=code_address, |
95 | should_transfer_value=should_transfer_value, |
96 | is_static=is_static, |
97 | parent_evm=None, |
98 | ) |