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lz_db 0fab423a18 add
2025-11-16 12:31:03 +08:00

218 lines
6.7 KiB
Python

from typing import (
Any,
Iterable,
Tuple,
)
import warnings
from ..typing.abi import (
Decodable,
TypeStr,
)
from ..utils import (
is_bytes,
)
from .decoding import (
ContextFramesBytesIO,
TupleDecoder,
)
from .encoding import (
TupleEncoder,
)
from .exceptions import (
EncodingError,
)
from .registry import (
ABIRegistry,
)
class BaseABICoder:
"""
Base class for porcelain coding APIs. These are classes which wrap
instances of :class:`~.registry.ABIRegistry` to provide last-mile
coding functionality.
"""
def __init__(self, registry: ABIRegistry):
"""
Constructor.
:param registry: The registry providing the encoders to be used when
encoding values.
"""
self._registry = registry
class ABIEncoder(BaseABICoder):
"""
Wraps a registry to provide last-mile encoding functionality.
"""
def encode_single(self, typ: TypeStr, arg: Any) -> bytes:
"""
Encodes the python value ``arg`` as a binary value of the ABI type
``typ``.
:param typ: The string representation of the ABI type that will be used
for encoding e.g. ``'uint256'``, ``'bytes[]'``, ``'(int,int)'``,
etc.
:param arg: The python value to be encoded.
:returns: The binary representation of the python value ``arg`` as a
value of the ABI type ``typ``.
"""
warnings.warn(
"abi.encode_single() and abi.encode_single_packed() are deprecated "
"and will be removed in version 4.0.0 in favor of abi.encode() and "
"abi.encode_packed(), respectively",
category=DeprecationWarning,
)
encoder = self._registry.get_encoder(typ)
return encoder(arg)
def encode_abi(self, types: Iterable[TypeStr], args: Iterable[Any]) -> bytes:
"""
Encodes the python values in ``args`` as a sequence of binary values of
the ABI types in ``types`` via the head-tail mechanism.
:param types: An iterable of string representations of the ABI types
that will be used for encoding e.g. ``('uint256', 'bytes[]',
'(int,int)')``
:param args: An iterable of python values to be encoded.
:returns: The head-tail encoded binary representation of the python
values in ``args`` as values of the ABI types in ``types``.
"""
warnings.warn(
"abi.encode_abi() and abi.encode_abi_packed() are deprecated and will be "
"removed in version 4.0.0 in favor of abi.encode() and "
"abi.encode_packed(), respectively",
category=DeprecationWarning,
)
return self.encode(types, args)
def encode(self, types, args):
encoders = [self._registry.get_encoder(type_str) for type_str in types]
encoder = TupleEncoder(encoders=encoders)
return encoder(args)
def is_encodable(self, typ: TypeStr, arg: Any) -> bool:
"""
Determines if the python value ``arg`` is encodable as a value of the
ABI type ``typ``.
:param typ: A string representation for the ABI type against which the
python value ``arg`` will be checked e.g. ``'uint256'``,
``'bytes[]'``, ``'(int,int)'``, etc.
:param arg: The python value whose encodability should be checked.
:returns: ``True`` if ``arg`` is encodable as a value of the ABI type
``typ``. Otherwise, ``False``.
"""
encoder = self._registry.get_encoder(typ)
try:
encoder.validate_value(arg)
except EncodingError:
return False
except AttributeError:
try:
encoder(arg)
except EncodingError:
return False
return True
def is_encodable_type(self, typ: TypeStr) -> bool:
"""
Returns ``True`` if values for the ABI type ``typ`` can be encoded by
this codec.
:param typ: A string representation for the ABI type that will be
checked for encodability e.g. ``'uint256'``, ``'bytes[]'``,
``'(int,int)'``, etc.
:returns: ``True`` if values for ``typ`` can be encoded by this codec.
Otherwise, ``False``.
"""
return self._registry.has_encoder(typ)
class ABIDecoder(BaseABICoder):
"""
Wraps a registry to provide last-mile decoding functionality.
"""
stream_class = ContextFramesBytesIO
def decode_single(self, typ: TypeStr, data: Decodable) -> Any:
"""
Decodes the binary value ``data`` of the ABI type ``typ`` into its
equivalent python value.
:param typ: The string representation of the ABI type that will be used for
decoding e.g. ``'uint256'``, ``'bytes[]'``, ``'(int,int)'``, etc.
:param data: The binary value to be decoded.
:returns: The equivalent python value of the ABI value represented in
``data``.
"""
warnings.warn(
"abi.decode_single() is deprecated and will be removed in version 4.0.0 "
"in favor of abi.decode()",
category=DeprecationWarning,
)
if not is_bytes(data):
raise TypeError(
"The `data` value must be of bytes type. Got {0}".format(type(data))
)
decoder = self._registry.get_decoder(typ)
stream = self.stream_class(data)
return decoder(stream)
def decode_abi(self, types: Iterable[TypeStr], data: Decodable) -> Tuple[Any, ...]:
"""
Decodes the binary value ``data`` as a sequence of values of the ABI types
in ``types`` via the head-tail mechanism into a tuple of equivalent python
values.
:param types: An iterable of string representations of the ABI types that
will be used for decoding e.g. ``('uint256', 'bytes[]', '(int,int)')``
:param data: The binary value to be decoded.
:returns: A tuple of equivalent python values for the ABI values
represented in ``data``.
"""
warnings.warn(
"abi.decode_abi() is deprecated and will be removed in version 4.0.0 in "
"favor of abi.decode()",
category=DeprecationWarning,
)
return self.decode(types, data)
def decode(self, types, data):
if not is_bytes(data):
raise TypeError(
f"The `data` value must be of bytes type. Got {type(data)}"
)
decoders = [self._registry.get_decoder(type_str) for type_str in types]
decoder = TupleDecoder(decoders=decoders)
stream = self.stream_class(data)
return decoder(stream)
class ABICodec(ABIEncoder, ABIDecoder):
pass