Source code for

"""Aave v3 event reader.

Efficiently read Aave v3 from a blockchain.

Currently we are tracking these events:

- ReserveDataUpdated
import csv
import datetime
import logging
from pathlib import Path

from requests.adapters import HTTPAdapter
from import tqdm
from web3 import Web3

from eth_defi.aave_v3.constants import (
from eth_defi.abi import get_contract
from eth_defi.event_reader.conversion import (
from eth_defi.event_reader.logresult import LogContext
from eth_defi.event_reader.reader import LogResult, read_events_concurrent
from eth_defi.event_reader.state import ScanState
from eth_defi.event_reader.web3factory import TunedWeb3Factory
from eth_defi.event_reader.web3worker import create_thread_pool_executor
from eth_defi.token import TokenDetails, fetch_erc20_details

# from eth_defi.token import TokenDetails, fetch_erc20_details

logger = logging.getLogger(__name__)

[docs]class TokenCache(LogContext): """Manage cache of token data when doing ReserveDataUpdated look-up. Do not do extra requests for already known tokens. """
[docs] def __init__(self): self.cache = {}
def get_token_info(self, web3: Web3, address: str) -> TokenDetails: if address not in self.cache: details = fetch_erc20_details(web3, address, raise_on_error=False) logging.warn(f"Fetched ERC20 details for {address}: {details}") self.cache[address] = details return self.cache[address]
[docs]def get_event_mapping(web3: Web3) -> dict: """Returns tracked event types and mapping. Currently we are tracking these events: - ReserveDataUpdated(address indexed reserve, uint256 liquidityRate, uint256 stableBorrowRate, uint256 variableBorrowRate, uint256 liquidityIndex, uint256 variableBorrowIndex) """ ReserveLogic = get_contract(web3, "aave_v3/ReserveLogic.json") return { "ReserveDataUpdated": { "contract_event":, "field_names": [ "block_number", "timestamp", "tx_hash", "log_index", "token", "contract_address", "reserve", "liquidity_rate", "stable_borrow_rate", "variable_borrow_rate", "liquidity_index", "variable_borrow_index", ], "decode_function": decode_reserve_data_updated, }, }
def _decode_base(log: LogResult) -> dict: block_time = datetime.datetime.utcfromtimestamp(log["timestamp"]) return { "block_number": convert_jsonrpc_value_to_int(log["blockNumber"]), "timestamp": block_time.isoformat(), "tx_hash": log["transactionHash"], "log_index": convert_jsonrpc_value_to_int(log["logIndex"]), }
[docs]def decode_reserve_data_updated(aave_network_name: str, log: LogResult) -> dict: """Process a ReserveDataUpdated event. The event signature is: .. code-block:: # topic0: signature 0x804c9b842b2748a22bb64b345453a3de7ca54a6ca45ce00d415894979e22897a event ReserveDataUpdated( address indexed reserve, # topic1 uint256 liquidityRate, # data0 uint256 stableBorrowRate, # data1 uint256 variableBorrowRate, # data2 uint256 liquidityIndex, # data3 uint256 variableBorrowIndex # data4 ); """ # Ensure the event comes from the correct smart contract if log["address"].lower() != AAVE_V3_NETWORKS[aave_network_name.lower()].pool_address.lower(): return None # Do additional lookup for the token data # web3 = log["event"].web3 # token_cache: TokenCache = log["context"] result = _decode_base(log) # Any indexed Solidity event parameter will be in topics data. # The first topics (0) is always the event signature. if len(log["topics"]) < 2: logging.warn(f'IGNORING EVENT: block={log["blockNumber"]} tx={log["transactionHash"]} topics={log["topics"]} data={log["data"]}') return None event_signature, reserve = log["topics"] deposit_address = convert_uint256_string_to_address(reserve) # Any non-indexed Solidity event parameter will be in the data section. # Chop data blob to byte32 entries liquidity_rate_raw, stable_borrow_rate_raw, variable_borrow_rate_raw, liquidity_index_raw, variable_borrow_index_raw = decode_data(log["data"]) liquidity_rate = convert_int256_bytes_to_int(liquidity_rate_raw) stable_borrow_rate = convert_int256_bytes_to_int(stable_borrow_rate_raw) variable_borrow_rate = convert_int256_bytes_to_int(variable_borrow_rate_raw) liquidity_index = convert_int256_bytes_to_int(liquidity_index_raw) variable_borrow_index = convert_int256_bytes_to_int(variable_borrow_index_raw) result.update( { "reserve": deposit_address, "liquidity_rate": liquidity_rate, "stable_borrow_rate": stable_borrow_rate, "variable_borrow_rate": variable_borrow_rate, "liquidity_index": liquidity_index, "variable_borrow_index": variable_borrow_index, "contract_address": log["address"], } ) # Detect token name from reserve address (None if not found) result["token"] = aave_v3_get_token_name_by_deposit_address(deposit_address) logger.debug(f'EVENT: block={log["blockNumber"]} tx={log["transactionHash"]} token={result["token"]} reserve={deposit_address} liquidity_rate={liquidity_rate} stable_borrow_rate={stable_borrow_rate} variable_borrow_rate={variable_borrow_rate} liquidity_index={liquidity_index} variable_borrow_index={variable_borrow_rate}') return result
[docs]def aave_v3_fetch_events_to_csv( json_rpc_url: str, state: ScanState, aave_network_name: str, start_block: int, end_block: int, output_folder: str = "/tmp", max_workers: int = 16, log_info=print, ): """Fetch all tracked Aave v3 events to CSV files for notebook analysis. Creates couple of CSV files with the event data: - `/tmp/aave-v3-{aave_network_name.lower()}-reservedataupdated.csv` A progress bar and estimation on the completion is rendered for console / Jupyter notebook using `tqdm`. The scan be resumed using `state` storage to retrieve the last scanned block number from the previous round. However, the mechanism here is no perfect and only good for notebook use - for advanced persistent usage like database backed scans, please write your own scan loop using proper transaction management. .. note :: Any Ethereum address is lowercased in the resulting dataset and is not checksummed. :param json_rpc_url: JSON-RPC URL :param start_block: First block to process (inclusive), default is block xxx (when Aave v3 xxx was created on mainnet) :param end_block: Last block to process (inclusive), default is block xxx (1000 block after default start block) :param aave_network_name: Network name, e.g. 'Polygon' :param state: Store the current scan state, so we can resume :param output_folder: Folder to contain output CSV files, default is /tmp folder :param max_workers: How many threads to allocate for JSON-RPC IO. You can increase your EVM node output a bit by making a lot of parallel requests, until you exhaust your nodes IO capacity. Experiement with different values and see how your node performs. :param log_info: Which function to use to output info messages about the progress """ token_cache = TokenCache() http_adapter = HTTPAdapter(pool_connections=max_workers, pool_maxsize=max_workers) web3_factory = TunedWeb3Factory(json_rpc_url, http_adapter) web3 = web3_factory(token_cache) executor = create_thread_pool_executor(web3_factory, token_cache, max_workers=max_workers) event_mapping = get_event_mapping(web3) contract_events = [event_data["contract_event"] for event_data in event_mapping.values()] # Start scanning restored, restored_start_block = state.restore_state(start_block) original_block_range = end_block - start_block if restored: log_info(f"Restored previous scan state, data until block {restored_start_block:,}, we are skipping {restored_start_block - start_block:,} blocks out of {original_block_range:,} total") else: log_info( f"No previous scan done, starting fresh from block {start_block:,}, total {original_block_range:,} blocks", ) # Prepare local buffers and files. # Buffers is a context dictionary that is passed around # by the event scanner. buffers = {} for event_name, mapping in event_mapping.items(): file_path = f"{output_folder}/aave-v3-{aave_network_name.lower()}-{event_name.lower()}.csv" exists_already = Path(file_path).exists() file_handler = open(file_path, "a") csv_writer = csv.DictWriter(file_handler, fieldnames=mapping["field_names"]) if not exists_already: csv_writer.writeheader() # For each event, we have its own # counters and handlers in the context dictionary buffers[event_name] = { "buffer": [], "total": 0, "file_handler": file_handler, "csv_writer": csv_writer, } log_info(f"Scanning block range {restored_start_block:,} - {end_block:,}") with tqdm(total=end_block - restored_start_block) as progress_bar: # 1. update the progress bar # 2. save any events in the buffer in to a file in one go def update_progress( current_block, start_block, end_block, chunk_size: int, total_events: int, last_timestamp: int, context: TokenCache, ): nonlocal buffers if last_timestamp: # Display progress with the date information d = datetime.datetime.utcfromtimestamp(last_timestamp) formatted_time = d.strftime("%Y-%m-%d") progress_bar.set_description(f"Block: {current_block:,}, events: {total_events:,}, time:{formatted_time}") else: progress_bar.set_description(f"Block: {current_block:,}, events: {total_events:,}") progress_bar.update(chunk_size) # Update event specific contexes for buffer_data in buffers.values(): buffer = buffer_data["buffer"] # log_info(f'Writing buffer to file {len(buffer)} events') # write events to csv for entry in buffer: buffer_data["csv_writer"].writerow(entry) buffer_data["total"] += 1 # then reset buffer buffer_data["buffer"] = [] # Sync the state of updated events state.save_state(current_block) # Read specified events in block range for log_result in read_events_concurrent( executor, restored_start_block, end_block, events=contract_events, notify=update_progress, chunk_size=100, context=token_cache, ): try: # write to correct buffer event_name = log_result["event"].event_name buffer = buffers[event_name]["buffer"] decode_function = event_mapping[event_name]["decode_function"] decoded_result = decode_function(aave_network_name, log_result) # Note: decoded_result is None if the event is e.g. from Aave v2 contract if decoded_result: logger.debug(f"Adding event to buffer: {event_name}") buffer.append(decoded_result) except Exception as e: raise RuntimeError(f"Could not decode {log_result}") from e # Write remaining events, close files and print stats for event_name, buffer in buffers.items(): if len(buffer["buffer"]) > 0: for entry in buffer["buffer"]: buffer["csv_writer"].writerow(entry) buffer["total"] += 1 buffer["buffer"] = [] buffer["file_handler"].close() state.save_state(end_block)