ethereum.forks.frontier.utils.message

Hardfork Utility Functions For The Message Data-structure.

.. contents:: Table of Contents :backlinks: none :local:

Introduction

Message specific functions used in this frontier version of specification.

prepare_message

Execute a transaction against the provided environment.

Parameters

block_env : Environment for the Ethereum Virtual Machine. tx_env : Environment for the transaction. tx : Transaction to be executed.

Returns

message: ethereum.forks.frontier.vm.Message Items containing contract creation or message call specific data.

def prepare_message(​block_env: BlockEnvironment, ​​tx_env: TransactionEnvironment, ​​tx: Transaction​) -> Message:
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    """
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    Execute a transaction against the provided environment.
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    Parameters
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    ----------
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    block_env :
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        Environment for the Ethereum Virtual Machine.
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    tx_env :
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        Environment for the transaction.
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    tx :
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        Transaction to be executed.
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    Returns
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    -------
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    message: `ethereum.forks.frontier.vm.Message`
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        Items containing contract creation or message call specific data.
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    """
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    if isinstance(tx.to, Bytes0):
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        current_target = compute_contract_address(
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            tx_env.origin,
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            get_account(block_env.state, tx_env.origin).nonce - Uint(1),
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        )
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        msg_data = Bytes(b"")
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        code = tx.data
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        code_address = None
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    elif isinstance(tx.to, Address):
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        current_target = tx.to
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        msg_data = tx.data
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        code = get_account(block_env.state, tx.to).code
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        code_address = tx.to
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    else:
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        raise AssertionError("Target must be address or empty bytes")
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    return Message(
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        block_env=block_env,
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        tx_env=tx_env,
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        caller=tx_env.origin,
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        target=tx.to,
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        gas=tx_env.gas,
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        value=tx.value,
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        data=msg_data,
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        code=code,
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        depth=Uint(0),
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        current_target=current_target,
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        code_address=code_address,
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        parent_evm=None,
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    )