cic-stack/apps/cic-eth/cic_eth/eth/request.py

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2021-02-01 18:12:51 +01:00
# standard imports
import logging
# third-party imports
import web3
import celery
from erc20_approval_escrow import TransferApproval
from cic_registry import CICRegistry
from cic_registry.chain import ChainSpec
# local imports
from cic_eth.db.models.tx import TxCache
from cic_eth.db.models.base import SessionBase
from cic_eth.eth import RpcClient
from cic_eth.eth.factory import TxFactory
from cic_eth.eth.task import sign_and_register_tx
from cic_eth.eth.util import unpack_signed_raw_tx
from cic_eth.eth.task import create_check_gas_and_send_task
from cic_eth.error import TokenCountError
celery_app = celery.current_app
logg = logging.getLogger()
contract_function_signatures = {
'request': 'b0addede',
}
class TransferRequestTxFactory(TxFactory):
"""Factory for creating Transfer request transactions using the TransferApproval contract backend
"""
def request(
self,
token_address,
beneficiary_address,
amount,
chain_spec,
):
"""Create a new TransferApproval.request transaction
:param token_address: Token to create transfer request for
:type token_address: str, 0x-hex
:param beneficiary_address: Beneficiary of token transfer
:type beneficiary_address: str, 0x-hex
:param amount: Amount of tokens to transfer
:type amount: number
:param chain_spec: Chain spec
:type chain_spec: cic_registry.chain.ChainSpec
:returns: Transaction in standard Ethereum format
:rtype: dict
"""
transfer_approval = CICRegistry.get_contract(chain_spec, 'TransferApproval', 'TransferAuthorization')
fn = transfer_approval.function('createRequest')
tx_approval_buildable = fn(beneficiary_address, token_address, amount)
transfer_approval_gas = transfer_approval.gas('createRequest')
tx_approval = tx_approval_buildable.buildTransaction({
'from': self.address,
'gas': transfer_approval_gas,
'gasPrice': self.gas_price,
'chainId': chain_spec.chain_id(),
'nonce': self.next_nonce(),
})
return tx_approval
def unpack_transfer_approval_request(data):
"""Verifies that a transaction is an "TransferApproval.request" transaction, and extracts call parameters from it.
:param data: Raw input data from Ethereum transaction.
:type data: str, 0x-hex
:raises ValueError: Function signature does not match AccountRegister.add
:returns: Parsed parameters
:rtype: dict
"""
f = data[2:10]
if f != contract_function_signatures['request']:
raise ValueError('Invalid transfer request data ({})'.format(f))
d = data[10:]
return {
'to': web3.Web3.toChecksumAddress('0x' + d[64-40:64]),
'token': web3.Web3.toChecksumAddress('0x' + d[128-40:128]),
'amount': int(d[128:], 16)
}
@celery_app.task(bind=True)
def transfer_approval_request(self, tokens, holder_address, receiver_address, value, chain_str):
"""Creates a new transfer approval
:param tokens: Token to generate transfer request for
:type tokens: list with single token spec as dict
:param holder_address: Address to generate transfer on behalf of
:type holder_address: str, 0x-hex
:param receiver_address: Address to transfser tokens to
:type receiver_address: str, 0x-hex
:param value: Amount of tokens to transfer
:type value: number
:param chain_spec: Chain spec string representation
:type chain_spec: str
:raises cic_eth.error.TokenCountError: More than one token in tokens argument
:returns: Raw signed transaction
:rtype: list with transaction as only element
"""
if len(tokens) != 1:
raise TokenCountError
chain_spec = ChainSpec.from_chain_str(chain_str)
queue = self.request.delivery_info['routing_key']
t = tokens[0]
c = RpcClient(holder_address)
txf = TransferRequestTxFactory(holder_address, c)
tx_transfer = txf.request(t['address'], receiver_address, value, chain_spec)
(tx_hash_hex, tx_signed_raw_hex) = sign_and_register_tx(tx_transfer, chain_str, queue, 'cic_eth.eth.request.otx_cache_transfer_approval_request')
gas_budget = tx_transfer['gas'] * tx_transfer['gasPrice']
s = create_check_gas_and_send_task(
[tx_signed_raw_hex],
chain_str,
holder_address,
gas_budget,
[tx_hash_hex],
queue,
)
s.apply_async()
return [tx_signed_raw_hex]
@celery_app.task()
def otx_cache_transfer_approval_request(
tx_hash_hex,
tx_signed_raw_hex,
chain_str,
):
"""Generates and commits transaction cache metadata for an TransferApproval.request transaction
:param tx_hash_hex: Transaction hash
:type tx_hash_hex: str, 0x-hex
:param tx_signed_raw_hex: Raw signed transaction
:type tx_signed_raw_hex: str, 0x-hex
:param chain_str: Chain spec string representation
:type chain_str: str
:returns: Transaction hash and id of cache element in storage backend, respectively
:rtype: tuple
"""
chain_spec = ChainSpec.from_chain_str(chain_str)
tx_signed_raw_bytes = bytes.fromhex(tx_signed_raw_hex[2:])
tx = unpack_signed_raw_tx(tx_signed_raw_bytes, chain_spec.chain_id())
logg.debug('in otx acche transfer approval request')
(txc, cache_id) = cache_transfer_approval_request_data(tx_hash_hex, tx)
return txc
@celery_app.task()
def cache_transfer_approval_request_data(
tx_hash_hex,
tx,
):
"""Helper function for otx_cache_transfer_approval_request
:param tx_hash_hex: Transaction hash
:type tx_hash_hex: str, 0x-hex
:param tx: Signed raw transaction
:type tx: str, 0x-hex
:returns: Transaction hash and id of cache element in storage backend, respectively
:rtype: tuple
"""
tx_data = unpack_transfer_approval_request(tx['data'])
logg.debug('tx approval request data {}'.format(tx_data))
logg.debug('tx approval request {}'.format(tx))
session = SessionBase.create_session()
tx_cache = TxCache(
tx_hash_hex,
tx['from'],
tx_data['to'],
tx_data['token'],
tx_data['token'],
tx_data['amount'],
tx_data['amount'],
)
session.add(tx_cache)
session.commit()
cache_id = tx_cache.id
session.close()
return (tx_hash_hex, cache_id)