Polygon ( aka Matic Network ) Mempool Exploration

catch.py

#!/usr/bin/python3

from python_graphql_client import GraphqlClient
from json import dumps
from asyncio import run
from re import compile as re_compile
from pytimeparse import parse

reg = re_compile(r'^(\d+(\.\d+)?)')
handle = None


def prettyPrint(data):
    tx = data["data"]["newConfirmedTx"]
    price = reg.search(tx['gasPrice'])
    if not price:
        return

    parsed = parse(tx["pendingFor"])
    if not parsed:
        return

    handle.write(f'{float(price.group())}; {parsed}\n')
    print(dumps(data, sort_keys=True, indent=2))


def main():
    try:
        client = GraphqlClient(endpoint="ws://localhost:7000/v1/graphql")
        query = """
            subscription {
                newConfirmedTx {
                    gasPrice
                    pendingFor
                }
            }
        """
        with open('log.csv', 'w+') as fd:
            global handle
            handle = fd

            print('Catching confirmed tx(s) ...')
            run(client.subscribe(query=query, handle=prettyPrint))

    except Exception as e:
        print(e)
    except KeyboardInterrupt:
        print('\nStopping')


if __name__ == '__main__':
    main()

requirements.txt

pandas==1.1.2
matplotlib==3.3.2
python_graphql_client==0.4.3
pytimeparse==1.1.8

viz.py

#!/usr/bin/python3

from matplotlib import pyplot as plt
from pandas.core.frame import DataFrame


def plot(df) -> bool:
    try:
        with plt.style.context('dark_background'):
            fig = plt.Figure(
                figsize=(18, 9),
                dpi=100)

            fig.gca().plot('x', 'y', 'wo ', data=df, markersize=1.0)

            fig.gca().set_xlabel('Gas Price ( in Gwei )', labelpad=12)
            fig.gca().set_ylabel('Waiting time in Mempool ( in Second )', labelpad=12)
            fig.suptitle('Polygon Mempool Analysis', fontsize=20, y=1)

            fig.savefig(
                'plot.png',
                bbox_inches='tight',
                pad_inches=.5)
            plt.close(fig)

            return True
    except Exception as e:
        print(f'Error : {e}')
        return False


def read() -> DataFrame:
    fd = open('log.csv', 'r')
    x = []
    y = []
    while True:
        ln = fd.readline()
        if not ln:
            break

        vals = [float(v.strip()) for v in ln.split(';')]
        x.append(vals[0])
        y.append(vals[1])

    return DataFrame({'x': x, 'y': y})


def main():
    if plot(read()):
        print('Plotted !')


if __name__ == '__main__':
    main()

What's this ?

These scripts are supposed to be used in conjunction with harmony - Reduce Chaos in Mempool, for exploring mempool data.

More about harmony

• First set up harmony by following respective README.md
• Make sure you've >= Python3.8
• Create virtual environment

python3 -m venv venv
source venv/bin/activate

• Install dependencies

pip install -r requirements.txt

• Run catch.py for catching confirmed txs & logging them in ./log.csv

python catch.py # let it run for sometime

• You must see log.csv generated in same directory

head log.csv

gas-price-in-gwei	time-spent-waiting-in-mempool-in-second
22.8658532;	2237.219117212
1.0;	3824.690001799
5.0;	1833.636202321
50.0;	984.657260686

• Now you can run viz.py for generating scatter plot of GasPrice vs Tx Waiting Period

python viz.py

• It should generate plot.png in same directory

file plot.png

When you're done, consider disabling virtual environment

deactivate