range-parser

What is range-parser?

The range-parser package is a utility for parsing HTTP range header fields. It's useful for handling requests for specific ranges of data, which is particularly relevant for serving large files in smaller chunks, such as videos or large documents.

What are range-parser's main functionalities?

Parse Range Header

This feature allows you to parse the 'Range' header from HTTP requests. It takes the size of the file and the range header as arguments and returns an array of ranges, or an error code if the range is unsatisfiable or syntactically invalid.

const rangeParser = require('range-parser');
const rangeHeader = 'bytes=0-499';
const fileSize = 1000;
const parsedRanges = rangeParser(fileSize, rangeHeader);

Other packages similar to range-parser

http-range

The http-range package is similar to range-parser in that it also parses HTTP range headers. However, it provides a more high-level API and includes additional features for creating and manipulating ranges.

accept-ranges

The accept-ranges package is designed to parse the Accept-Ranges header in HTTP. While it serves a different purpose from range-parser, it is related in the context of HTTP range requests and responses.

README

range-parser

Range header field parser.

Installation

This is a Node.js module available through the npm registry. Installation is done using the npm install command:

$ npm install range-parser

API

var parseRange = require('range-parser')

parseRange(size, header, options)

Parse the given header string where size is the maximum size of the resource. An array of ranges will be returned or negative numbers indicating an error parsing.

• -2 signals a malformed header string
• -1 signals an unsatisfiable range

// parse header from request
var range = parseRange(size, req.headers.range)

// the type of the range
if (range.type === 'bytes') {
  // the ranges
  range.forEach(function (r) {
    // do something with r.start and r.end
  })
}

Options

These properties are accepted in the options object.

combine

Specifies if overlapping & adjacent ranges should be combined, defaults to false. When true, ranges will be combined and returned as if they were specified that way in the header.

parseRange(100, 'bytes=50-55,0-10,5-10,56-60', { combine: true })
// => [
//      { start: 0,  end: 10 },
//      { start: 50, end: 60 }
//    ]

License

MIT