41 lines
1.3 KiB
Python
41 lines
1.3 KiB
Python
from typing import Dict, Optional
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from hexbytes import HexBytes
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from eth_abi import decode_abi
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from eth_abi.exceptions import InsufficientDataBytes, NonEmptyPaddingBytes
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from mev_inspect.schemas.abi import ABI, ABIFunctionDescription
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from mev_inspect.schemas.call_data import CallData
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class ABIDecoder:
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def __init__(self, abi: ABI):
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self._functions_by_selector: Dict[str, ABIFunctionDescription] = {
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description.get_selector(): description
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for description in abi
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if isinstance(description, ABIFunctionDescription)
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}
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def decode(self, data: str) -> Optional[CallData]:
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hex_data = HexBytes(data)
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selector, params = hex_data[:4], hex_data[4:]
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func = self._functions_by_selector.get(selector)
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if func is None:
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return None
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names = [input.name for input in func.inputs]
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types = [input.type for input in func.inputs]
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try:
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decoded = decode_abi(types, params)
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except (InsufficientDataBytes, NonEmptyPaddingBytes):
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return None
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return CallData(
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function_name=func.name,
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function_signature=func.get_signature(),
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inputs={name: value for name, value in zip(names, decoded)},
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)
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