int64-buffer

What is int64-buffer?

The int64-buffer npm package provides utilities for handling 64-bit integers in JavaScript. It allows you to create, manipulate, and convert 64-bit integers, which are not natively supported by JavaScript's number type.

What are int64-buffer's main functionalities?

Creating Int64 and Uint64 instances

This feature allows you to create instances of 64-bit signed and unsigned integers using high and low 32-bit parts.

const Int64 = require('int64-buffer').Int64;
const Uint64 = require('int64-buffer').Uint64;

const int64 = new Int64(0x12345678, 0x9abcdef0);
const uint64 = new Uint64(0x12345678, 0x9abcdef0);

console.log(int64.toString()); // '1311768467463790320'
console.log(uint64.toString()); // '1311768467463790320'

Converting between different formats

This feature allows you to convert 64-bit integers to different formats such as Buffer, hexadecimal string, and JavaScript number.

const Int64 = require('int64-buffer').Int64;

const int64 = new Int64(0x12345678, 0x9abcdef0);

const buffer = int64.toBuffer();
const hexString = int64.toString(16);
const number = int64.toNumber();

console.log(buffer); // <Buffer 12 34 56 78 9a bc de f0>
console.log(hexString); // '123456789abcdef0'
console.log(number); // 1311768467463790320

Reading and writing from/to Buffers

This feature allows you to read 64-bit integers from Buffers and write 64-bit integers to Buffers.

const Int64 = require('int64-buffer').Int64;

const buffer = Buffer.from([0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, 0xde, 0xf0]);
const int64 = new Int64(buffer);

console.log(int64.toString()); // '1311768467463790320'

const newBuffer = Buffer.alloc(8);
int64.toBuffer().copy(newBuffer);

console.log(newBuffer); // <Buffer 12 34 56 78 9a bc de f0>

Other packages similar to int64-buffer

long

The 'long' package provides a Long class for representing a 64-bit two's-complement integer. It offers similar functionality to int64-buffer, including arithmetic operations, bitwise operations, and conversion to/from various formats. However, 'long' is more focused on arithmetic operations and less on buffer manipulation.

int64

The 'int64' package provides a way to work with 64-bit integers in JavaScript. It offers similar functionality to int64-buffer, including creating 64-bit integers, converting to/from buffers, and performing arithmetic operations. The main difference is that 'int64' is designed to be simpler and more lightweight.

big-integer

The 'big-integer' package provides arbitrary-precision integers in JavaScript. While it can handle 64-bit integers, it is more general-purpose and can handle integers of any size. It offers a wide range of arithmetic and bitwise operations, but it is not specifically optimized for 64-bit integers like int64-buffer.

README

int64-buffer

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

JavaScript's number type, based on IEEE-754, can only handle 53 bits of precision. This module provides two pairs of classes: Int64BE/Uint64BE and Int64LE/Uint64LE, which can hold 64-bit long integers without losing any bits.

Features

• Int64BE/Int64LE for signed integers, Uint64BE/Uint64LE for unsigned integers.
• Int64BE/Uint64BE for big-endian, Int64LE/Uint64LE for little-endian.
• Buffer/Uint8Array/Array/Array-like storage of 8 bytes length with offset.
• No mathematical methods provided, such as add(), sub(), mul(), div(), etc.
• Optimized only for 64 bits. If you need Int128, use bignum or similar libraries.
• Small. 3KB when minified. No other modules required. Portable pure JavaScript.
• Tested on node.js v18, v20, v22 and Web browsers.

Usage

Int64BE is the class to host a 64-bit signed long integer int64_t.

import {Int64BE} from "int64-buffer";

const big = new Int64BE(-1);

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

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

It uses Buffer on Node.js and Uint8Array on modern Web browsers.

Uint64BE is the class to host a 64-bit unsigned positive long integer uint64_t.

import {Uint64BE} from "int64-buffer";

const 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

Int64LE and Uint64LE work the same way as above but with little-endian storage.

Input Constructor

• new Uint64BE(number)

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

• new Uint64BE(high, low)

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

• new Uint64BE(string, radix)

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

• new Uint64BE(buffer)

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

• new Uint64BE(uint8array)

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

• new Uint64BE(arraybuffer)

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

• new Uint64BE(array)

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

• new Uint64BE(buffer, offset)

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

• new Uint64BE(buffer, offset, number)

const buffer = Buffer.from(16);
const 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)

const buffer = new Uint8Array(16);
const 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)

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

Output Methods

• valueOf()

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

• toNumber()

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

• toString(radix)

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

• toBuffer()

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

• toArrayBuffer()

const big = new Uint64BE(0);
const 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()

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

Browsers Build

• https://cdn.jsdelivr.net/npm/int64-buffer/dist/int64-buffer.min.js

<meta http-equiv="X-UA-Compatible" content="IE=edge">
<script src="https://cdn.jsdelivr.net/npm/int64-buffer/dist/int64-buffer.min.js"></script>
<script>

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

</script>

Links

• https://github.com/kawanet/int64-buffer
• https://www.npmjs.com/package/int64-buffer

The MIT License (MIT)

Copyright (c) 2015-2024 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.