serial-arithmetic

This is an implementation of RFC 1982, Serial Number Arithmetic in the Node.js runtime. Comparison and addition operations along with a variable serial number space size are supported.

Getting Started

Install serial-arithmetic with:

$ npm install serial-arithmetic

Almost all serial number methods are exposed:

var SerialNumber = require('serial-arithmetic').SerialNumber;
var timestamp = SerialNumber(0, 32);
var anotherTimestamp = SerialNumber(255, 32);

console.log(timestamp.getNumber()); // -> '0'
console.log(timestamp.getSpace()); // -> 32
console.log(timestamp.gt(anotherTimestamp)); // -> true

See Usage section or the tests folder for more examples.

Usage

SerialNumber([value,] [size])

Create a new SerialNumber object with an optional value and optional space size. These default to 0 and 32 bits respectively.

sn.getNumber([options])

Retrieve the current number of the SerialNumber object with an optional options object to format the returned number.

Available options are:

• options.radix = convert number to this base (i.e. 16 for hex output)
• options.encoding = currently supports 'BE' to encode output in big endian (for destination to network)
• options.string = false to output as number instead of default string

sn.add(other)

Add another SerialNumber to sn if the other SerialNumber is in range [0 .. 2 ^ (size - 1) - 1]

sn.getSpace([bytes])

Retrieve the serial number space size in bits or in bytes if bytes is true.

sn.{eq|ne}(other)

Test equality of the sn to another SerialNumber.

sn.{lt|le|gt|ge}(other)

Test comparison of the sn to another SerialNumber.

Tests

The current testing framework is tape. You may need to install tape globally:

npm install -g tape

Run test script:

npm test

Notes

This package was created in hopes of being used in a future RTMP Node.js package. I'll try to report back here if this implementation works for that specification or not!