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 size of the selected representation that is to be partitioned into subranges. An array of subranges 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 subranges = parseRange(size, req.headers.range)

// the type of the subranges
if (subranges.type === 'bytes') {
  // the ranges
  subranges.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 subranges 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 }
//    ]

limit

Specifies total size for open ranges like bytes=50-, defaults not applyed. When used, end range part will be limited with selected value, this behavior allowed at RFC. Limit may be used to reduce load by greedy client.

parseRange(1000, 'bytes=20-', { limit: 300 })
// => [
//      { start: 20,  end: 320 }
//    ]

License

MIT

digimbyte/range-parser