int64-buffer

64bit Long Integer on Buffer/Array/ArrayBuffer in Pure JavaScript

JavaScript's number based on IEEE-754 could only handle 53 bits precision. This module provides a couple of classes: Int64BE and Uint64BE which could hold 64 bits long integer and loose no bit.

Features

• Int64BE class for signed 64bit long integer and Uint64BE class for unsigned.
• Big endian representation in 8 bytes length internal Array-like buffer.
• No mathematical methods provided, such as add(), sub(), mul(), div() etc.
• Optimized only for 64 bits. If you need Int128, use bignum etc.
• Small. 3KB minified. No other module required. Portable pure JavaScript.
• Tested on node.js v0.10, v0.12, v4, v5 and Web browsers.

Usage

Int64BE is the class to host a 64bit long integer, int64.

var Int64BE = require("int64-buffer").Int64BE;

var big = new Int64BE(-1);

console.log(big - 0); // -1

console.log(big.toBuffer()); // <Buffer ff ff ff ff ff ff ff ff>

Uint64BE is the class to host a positive unsigned 64bit long integer, uint64.

var Uint64BE = require("int64-buffer").Uint64BE;

var big = new Uint64BE(Math.pow(2, 63)); // a big number with 64 bits

console.log(big - 0); // 9223372036854776000 = IEEE-754 loses last bits

console.log(big + ""); // "9223372036854775808" = perfectly correct

Input Constructor

• new Uint64BE(number)

var big = new Uint64BE(1234567890);
console.log(big - 0); // 1234567890

• new Uint64BE(high, low)

var big = new Uint64BE(0x12345678, 0x9abcdef0);
console.log(big.toString(16)); // "123456789abcdef0"

• new Uint64BE(string, radix)

var big = new Uint64BE("123456789abcdef0", 16);
console.log(big.toString(16)); // "123456789abcdef0"

• new Uint64BE(buffer)

var buffer = new Buffer([1,2,3,4,5,6,7,8]);
var big = new Uint64BE(buffer);
console.log(big.toString(16)); // "102030405060708"

• new Uint64BE(uint8array)

var uint8array = new Uint8Array([1,2,3,4,5,6,7,8]);
var big = new Uint64BE(uint8array);
console.log(big.toString(16)); // "102030405060708"

• new Uint64BE(arraybuffer)

var arraybuffer = (new Uint8Array([1,2,3,4,5,6,7,8])).buffer;
var big = new Uint64BE(arraybuffer);
console.log(big.toString(16)); // "102030405060708"

• new Uint64BE(array)

var array = [1,2,3,4,5,6,7,8];
var big = new Uint64BE(array);
console.log(big.toString(16)); // "102030405060708"

• new Uint64BE(buffer, offset)

var buffer = new Buffer([1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16]);
var big = new Uint64BE(buffer, 8);
console.log(big.toString(16)); // "90a0b0c0d0e0f10"

• new Uint64BE(buffer, offset, number)

var buffer = new Buffer(16);
var big = new Uint64BE(buffer, 8, 0x1234567890);
console.log(big.toString(16)); // "1234567890"
console.log(buffer[15].toString(16)); // "90"

• new Uint64BE(buffer, offset, high, low)

var buffer = new Uint8Array(16);
var big = new Uint64BE(buffer, 8, 0x12345678, 0x9abcdef0);
console.log(big.toString(16)); // "123456789abcdef0"
console.log(buffer[15].toString(16)); // "f0"

• new Uint64BE(buffer, offset, string, radix)

var buffer = new Array(16);
var big = new Uint64BE(buffer, 8, "123456789abcdef0", 16);
console.log(big.toString(16)); // "123456789abcdef0"
console.log(buffer[15].toString(16)); // "f0"

Output Methods

• Number context

var big = Uint64BE(1234567890);
console.log(big - 0); // 1234567890

• String context

var big = Uint64BE(1234567890);
console.log(big + ""); // "1234567890"

• JSON context

var big = Uint64BE();
console.log(JSON.stringify({big: big})); // {"big":1234567890}

• toNumber()

var big = Uint64BE(1234567890);
console.log(big.toNumber()); // 1234567890

• toString(radix)

var big = Uint64BE(0x1234567890);
console.log(big.toString()); // "78187493520"
console.log(big.toString(16)); // "1234567890"

• toBuffer()

var big = Uint64BE([1,2,3,4,5,6,7,8]);
console.log(big.toBuffer()); // <Buffer 01 02 03 04 05 06 07 08>

• toArrayBuffer()

var big = Uint64BE(0);
var buf = new Int8Array(big.toArrayBuffer());
console.log(buf); // Int8Array { '0': 1, '1': 2, '2': 3, '3': 4, '4': 5, '5': 6, '6': 7, '7': 8 }

• toArray()

var big = Uint64BE([1,2,3,4,5,6,7,8]);
console.log(big.toArray()); // [ 1, 2, 3, 4, 5, 6, 7, 8 ]

Browsers Build

int64-buffer.min.js is tested on modern Web browsers as well as legends of IE8.

<meta http-equiv="X-UA-Compatible" content="IE=edge">
<script src="https://rawgithub.com/kawanet/int64-buffer/master/dist/int64-buffer.min.js"></script>
<script>

  var i = Int64BE("1234567890123456789");
  console.log(i.toString(10)); // "1234567890123456789"
  
  var u = new Uint64BE([0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF]);
  console.log(u.toString(16)); // "123456789abcdef"

</script>

Installation

npm install int64-buffer --save

GitHub

• https://github.com/kawanet/int64-buffer

The MIT License (MIT)

Copyright (c) 2015-2016 Yusuke Kawasaki

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.