mev-inspect-py/mev_inspect/inspector_uniswap.py
2021-07-15 11:36:40 -04:00

93 lines
3.4 KiB
Python

import json
from web3 import Web3
from mev_inspect import utils
from mev_inspect.config import load_config
config = load_config()
uniswap_router_abi = json.loads(config["ABI"]["UniswapV2Router"])
uniswap_router_address = config["ADDRESSES"]["UniswapV2Router"]
sushiswap_router_address = config["ADDRESSES"]["SushiswapV2Router"]
uniswap_pair_abi = json.loads(config["ABI"]["UniswapV2Pair"])
class UniswapInspector:
def __init__(self, base_provider) -> None:
self.w3 = Web3(base_provider)
self.trading_functions = self.get_trading_functions()
self.uniswap_v2_router_contract = self.w3.eth.contract(
abi=uniswap_router_abi, address=uniswap_router_address
)
self.uniswap_router_trade_signatures = self.get_router_signatures()
self.uniswap_v2_pair_contract = self.w3.eth.contract(abi=uniswap_pair_abi)
self.uniswap_v2_pair_swap_signatures = (
self.uniswap_v2_pair_contract.functions.swap(
0, 0, uniswap_router_address, ""
).selector
) ## Note the address here doesn't matter, but it must be filled out
self.uniswap_v2_pair_reserves_signatures = (
self.uniswap_v2_pair_contract.functions.getReserves().selector
) ## Called "checksigs" in mev-inpsect.ts
print("Built Uniswap inspector")
def get_trading_functions(self):
## Gets all functions used for swapping
result = []
## For each entry in the ABI
for abi in uniswap_router_abi:
## Check to see if the entry is a function and if it is if the function's name starts with swap
if abi["type"] == "function" and abi["name"].startswith("swap"):
## If so add it to our array
result.append(abi["name"])
return result
def get_router_signatures(self):
## Gets the selector / function signatures of all the router swap functions
result = []
## For each entry in the ABI
for abi in uniswap_router_abi:
## Check to see if the entry is a function and if it is if the function's name starts with swap
if abi["type"] == "function" and abi["name"].startswith("swap"):
## Add a parantheses
function = abi["name"] + "("
## For each input in the function's input
for input in abi["inputs"]:
## Concat them into a string with commas
function = function + input["internalType"] + ","
## Take off the last comma, add a ')' to close the parentheses
function = function[:-1] + ")"
## The result looks like this: 'swapETHForExactTokens(uint256,address[],address,uint256)'
## Take the first 4 bytes of the sha3 hash of the above string.
selector = Web3.sha3(text=function)[0:4]
## Add that to an array
result.append(selector)
return result
def inspect(self, calls):
for call in calls:
print("\n", call)
if (
call["action"]["to"] == uniswap_router_address.lower()
or call["action"]["to"] == sushiswap_router_address.lower()
) and utils.check_call_for_signature(
call, self.uniswap_router_trade_signatures
):
# print("WIP, here is where there is a call that matches what we are looking for")
1 == 1