http-parser-js

What is http-parser-js?

The http-parser-js npm package is a pure JavaScript implementation of the HTTP parsing component of Node.js. It can be used as a drop-in replacement for the built-in http parser in Node.js, providing a way to parse HTTP messages (requests and responses) without relying on the native parser. This can be useful in environments where the native parser is not available or when a different parsing behavior is desired.

What are http-parser-js's main functionalities?

Parsing HTTP Requests

This code sample demonstrates how to use http-parser-js to parse an HTTP request. The parser object is created with the type HTTPParser.REQUEST, and callback functions are assigned to handle headers, body, and the completion of the message.

const httpParser = require('http-parser-js').HTTPParser;
const parser = new httpParser(httpParser.REQUEST);

parser[httpParser.kOnHeadersComplete] = function(headers, url) {
  // Use headers and url
};

parser[httpParser.kOnBody] = function(body) {
  // Use body
};

parser[httpParser.kOnMessageComplete] = function() {
  // Message is complete
};

// Simulate receiving data
const data = Buffer.from('GET / HTTP/1.1\r\nHost: example.com\r\n\r\n');
parser.execute(data);

Parsing HTTP Responses

This code sample shows how to parse an HTTP response using http-parser-js. The parser object is created with the type HTTPParser.RESPONSE, and callback functions are set up to process headers, body, and the end of the message.

const httpParser = require('http-parser-js').HTTPParser;
const parser = new httpParser(httpParser.RESPONSE);

parser[httpParser.kOnHeadersComplete] = function(headers, statusCode) {
  // Use headers and statusCode
};

parser[httpParser.kOnBody] = function(body) {
  // Use body
};

parser[httpParser.kOnMessageComplete] = function() {
  // Message is complete
};

// Simulate receiving data
const data = Buffer.from('HTTP/1.1 200 OK\r\nContent-Type: text/plain\r\n\r\nHello World');
parser.execute(data);

Other packages similar to http-parser-js

http-message-parser

http-message-parser is a package that parses raw HTTP message strings into an object representation. It differs from http-parser-js in that it works with complete message strings and does not stream the data. This can be simpler for certain applications but less efficient for others.

README

HTTP Parser

This library parses HTTP protocol for requests and responses. It was created to replace http_parser.c since calling C++ function from JS is really slow in V8.

This was further modified by Jimbly to be useable in parsing responses, specifically tested with the "request" module, and addresses issues such as corrupt HTTP headers, which would otherwise cause Node's parser to throw a fatal error (HPE_INVALID_HEADER_TOKEN).

This is packaged as a standalone npm module. To use in node, monkeypatch HTTPParser.

// Monkey patch before you require http for the first time.
process.binding("http_parser").HTTPParser = require('http-parser-js').HTTPParser;

var http = require('http');
// ...

Status

This has been used sucessfully in some site scraping tools using "request" which otherwise failed due to node HTTP parsing issues.

Old Status

This is still in early development. It can respond to basic HTTP GET requests like the standard HTTP hello-world. In initial testing it's 8% faster for non-keepalive requests.

The plan is to port the unit tests from the http-parser. Once we have all tests passing the node http tests can be run using the monkey-patch method above. Once all those pass, we're good to go. Hopefully this will still be faster by then.