Gas2nel

A robust Node.js utility for tracking and estimating resource costs ("gas") during asynchronous function execution. Gas2nel monitors CPU usage, memory allocation, network I/O, and file system operations to provide realistic resource utilization metrics.

Features

• 🔍 Comprehensive resource tracking
  • CPU time and percentage
  • Memory usage (RSS, heap, external)
  • Network bandwidth (sent/received bytes)
  • File I/O operations
• 📊 Configurable metric reporting
• ⚡ Real-time resource monitoring
• 🎯 Accurate gas cost estimation
• 🔄 Event-driven architecture
• 💪 TypeScript-friendly API

Installation

npm install gas2nel

Quick Start

const Gas2nel = require('gas2nel');

// Initialize with optional configuration
const gas2nel = new Gas2nel({
  include: ["metric", "report"]  // Include detailed metrics and human-readable report
});

// Example async function to monitor
async function complexOperation() {
  const data = await fetch('https://api.example.com/data');
  await processData(data);
  return 'Operation completed';
}

// Estimate gas usage
const result = await gas2nel.estimateGas(complexOperation);
console.log(result);

Configuration Options

The Gas2nel constructor accepts an options object with the following properties:

{
  include: string[]  // Array of additional outputs to include: "metric" and/or "report"
}

API Reference

new Gas2nel(options?)

Creates a new Gas2nel instance.

const gas2nel = new Gas2nel({
  include: ["metric", "report"]
});

async estimateGas(fn, ...args)

Executes a function while monitoring resource usage and returns detailed metrics.

Parameters:

• fn: Async function to monitor
• ...args: Arguments to pass to the function

Returns:

{
  success: boolean,      // Whether the function executed successfully
  data: any,            // Function return value or error message
  gas: number,          // Estimated gas cost (0 to 1 scale)
  metric?: {            // Optional detailed metrics
    cpuTimeMs: number,
    cpuPercentage: number,
    memoryRSS: number,
    memoryHeapUsed: number,
    memoryExternal: number,
    sentBytes: number,
    receivedBytes: number,
    wallTimeMs: number,
    fileReadBytes: number,
    fileWriteBytes: number
  },
  report?: {            // Optional human-readable report
    cpuTimeMs: number,
    wallTimeMs: number,
    peakMemoryRSS: string,
    memoryHeapUsed: string,
    memoryExternal: string,
    networkTransferred: string,
    fileIO: string
  }
}

setOptions(options)

Updates the configuration options.

gas2nel.setOptions({
  include: ["report"]
});

reset()

Resets all counters (network and file I/O metrics).

gas2nel.reset();

Gas Estimation Details

Gas2nel uses a weighted combination of various metrics to estimate the total resource cost:

Metric	Weight	Description
CPU Time	35%	Process CPU time in milliseconds
CPU Percentage	20%	CPU utilization percentage
RSS Memory	15%	Resident Set Size memory usage
Heap Memory	10%	V8 heap memory usage
External Memory	5%	V8 external memory usage
Network Sent	5%	Bytes sent over network
Network Received	5%	Bytes received over network
Wall Time	5%	Total execution time

Examples

Basic Usage

const Gas2nel = require('gas2nel');
const gas2nel = new Gas2nel();

async function example() {
  // CPU-intensive operation
  const result = await gas2nel.estimateGas(async () => {
    let sum = 0;
    for (let i = 0; i < 1000000; i++) {
      sum += Math.sqrt(i);
    }
    return sum;
  });
  
  console.log(result);
}

Network Operations

const gas2nel = new Gas2nel({ include: ["metric"] });

const result = await gas2nel.estimateGas(async () => {
  const response = await fetch('https://api.example.com/data');
  return await response.json();
});

console.log(`Network usage: ${result.metric.sentBytes + result.metric.receivedBytes} bytes`);

File Operations

const gas2nel = new Gas2nel({ include: ["report"] });

const result = await gas2nel.estimateGas(async () => {
  await fs.promises.writeFile('output.txt', 'Hello World');
  const data = await fs.promises.readFile('output.txt');
  return data.toString();
});

console.log(`File I/O: ${result.report.fileIO}`);

Error Handling

Gas2nel gracefully handles errors in monitored functions:

const result = await gas2nel.estimateGas(async () => {
  throw new Error('Something went wrong');
});

console.log(result);
// {
//   success: false,
//   data: 'Something went wrong',
//   gas: 0.023,  // Resources used before error
//   ...
// }

Best Practices

1. Reset Between Operations

   gas2nel.reset();  // Clear previous metrics

2. Include Appropriate Metrics

   // For debugging
   gas2nel.setOptions({ include: ["metric", "report"] });
   
   // For production
   gas2nel.setOptions({});  // Minimal output

3. Monitor Specific Operations

   // Good: Monitoring specific operation
   await gas2nel.estimateGas(specificOperation);
   
   // Avoid: Monitoring too much
   await gas2nel.estimateGas(async () => {
     await operation1();
     await operation2();
     await operation3();
   });

Contributing

Contributions are welcome! Please read our Contributing Guide for details on our code of conduct and the process for submitting pull requests.

License

This project is licensed under the MIT License - see the LICENSE file for details.