resdb_driver/validate.py

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# to you under the Apache License, Version 2.0 (the
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# with the License.  You may obtain a copy of the License at
# 
#   http://www.apache.org/licenses/LICENSE-2.0
# 
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# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.    


# from resdb_driver.backend.schema import validate_language_key
from resdb_driver.exceptions import InvalidSignature, DuplicateTransaction

# from resdb_driver.schema import validate_transaction_schema
from resdb_driver.transaction import Transaction

# from resdb_driver.utils import (validate_txn_obj, validate_key)


class Transaction(Transaction):
    ASSET = "asset"
    METADATA = "metadata"
    DATA = "data"

    def validate(self, resdb, current_transactions=[]):
        """! Validate transaction spend
        @param resdb An instantiated resdb_driver.Resdb object.
        @return The transaction (Transaction) if the transaction is valid else it
                raises an exception describing the reason why the transaction is
                invalid.

        @exception ValidationError: If the transaction is invalid

        """
        input_conditions = []

        if self.operation == Transaction.CREATE:
            duplicates = any(
                txn for txn in current_transactions if txn.id == self.id)
            # TODO check if id already committed
            # if resdb.is_committed(self.id) or duplicates:
            #     raise DuplicateTransaction('transaction `{}` already exists'
            #                                .format(self.id))

            if not self.inputs_valid(input_conditions):
                raise InvalidSignature("Transaction signature is invalid.")

        elif self.operation == Transaction.TRANSFER:
            self.validate_transfer_inputs(resdb, current_transactions)

        return self

    @classmethod
    def from_dict(cls, tx_body):
        return super().from_dict(tx_body)

    # @classmethod
    # def validate_schema(cls, tx_body):
    #     validate_transaction_schema(tx_body)
    #     validate_txn_obj(cls.ASSET, tx_body[cls.ASSET], cls.DATA, validate_key)
    #     validate_txn_obj(cls.METADATA, tx_body, cls.METADATA, validate_key)
    #     validate_language_key(tx_body[cls.ASSET], cls.DATA)
    #     validate_language_key(tx_body, cls.METADATA)


class FastTransaction:
    """! A minimal wrapper around a transaction dictionary. This is useful for
    when validation is not required but a routine expects something that looks
    like a transaction, for example during block creation.

    Note: immutability could also be provided
    """

    def __init__(self, tx_dict):
        self.data = tx_dict

    @property
    def id(self):
        return self.data["id"]

    def to_dict(self):
        return self.data