Overview

export type EventLogType = {
  address: AddressType;
  topics: readonly HashType[];
  data: Uint8Array;
  blockNumber?: bigint;
  transactionHash?: HashType;
  transactionIndex?: number;
  blockHash?: HashType;
  logIndex?: number;
  removed?: boolean;
} & { readonly __tag: "EventLog" };

import { EventLogSchema } from '@tevm/voltaire/EventLog/effect'

// Construct from typed data
const addr = new Uint8Array(20)
const topic0 = new Uint8Array(32)
const log = EventLogSchema.from({ address: addr, topics: [topic0], data: new Uint8Array(0) })

// Filter logs
const filtered = EventLogSchema.filter([log], { address: addr })

import { EventLog, Address, Hash } from 'tevm';

// Transfer(address indexed from, address indexed to, uint256 value)
const TRANSFER_SIG = Hash(
  '0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef'
);

// Filter transfers to specific user
const userAddress = Address('0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb2');
const userAddressHash = Hash(
  new Uint8Array([...new Uint8Array(12).fill(0), ...userAddress])
);

const transfersToUser = EventLog.filterLogs(allLogs, {
  address: usdcAddress,
  topics: [
    TRANSFER_SIG,      // Event signature
    null,              // from: any address
    userAddressHash,   // to: user
  ],
  fromBlock: 18000000n,
  toBlock: 18500000n,
});

// Sort chronologically
const sorted = EventLog.sortLogs(transfersToUser);

// Decode values
for (const log of sorted) {
  const [fromHash, toHash] = log.getIndexedTopics();
  const value = new DataView(log.data.buffer).getBigUint64(24, false);

  console.log(`Transfer: ${value} tokens`);
  console.log(`Block: ${log.blockNumber}`);
}

import { EventLog, Address, Hash } from 'tevm';

const TRANSFER_SIG = Hash('0xddf252ad...');
const APPROVAL_SIG = Hash('0x8c5be1e5...');

// Monitor multiple ERC-20 tokens
const tokens = [
  Address('0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48'), // USDC
  Address('0x6B175474E89094C44Da98b954EedeAC495271d0F'), // DAI
  Address('0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2'), // WETH
];

// Get all Transfer and Approval events
const relevantLogs = EventLog.filterLogs(allLogs, {
  address: tokens,
  topics: [[TRANSFER_SIG, APPROVAL_SIG]], // OR: either event type
});

// Process by event type
const transfers = relevantLogs.filter(log => {
  const sig = log.getTopic0();
  return sig && Hash.equals(sig, TRANSFER_SIG);
});

const approvals = relevantLogs.filter(log => {
  const sig = log.getTopic0();
  return sig && Hash.equals(sig, APPROVAL_SIG);
});

console.log(`Found ${transfers.length} transfers, ${approvals.length} approvals`);

import { EventLog } from 'tevm';

// Filter active (non-removed) logs
const activeLogs = allLogs.filter(log => !log.isRemoved());

// Detect reorg events
const removedLogs = allLogs.filter(log => log.wasRemoved());
if (removedLogs.length > 0) {
  console.log(`Chain reorg detected: ${removedLogs.length} logs invalidated`);

  for (const log of removedLogs) {
    console.log(`  Block ${log.blockNumber}, Index ${log.logIndex}`);
  }
}

// Sort remaining logs chronologically
const sorted = EventLog.sortLogs(activeLogs);

import { EventLog } from 'tevm';

// Group logs by block
const byBlock = new Map<bigint, typeof allLogs>();

const sorted = EventLog.sortLogs(allLogs);
for (const log of sorted) {
  const blockNum = log.blockNumber ?? 0n;
  if (!byBlock.has(blockNum)) {
    byBlock.set(blockNum, []);
  }
  byBlock.get(blockNum)!.push(log);
}

// Analyze each block
for (const [blockNumber, blockLogs] of byBlock) {
  console.log(`\nBlock ${blockNumber}: ${blockLogs.length} logs`);

  // Count by contract
  const byContract = new Map<string, number>();
  for (const log of blockLogs) {
    const addr = Address.toHex(log.address);
    byContract.set(addr, (byContract.get(addr) || 0) + 1);
  }

  console.log('  Events per contract:', byContract);
}