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.

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- 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.

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

``js
import {Int64BE} from "int64-buffer";

const big = new Int64BE(-1);

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

console.log(big.toBuffer()); //
`

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.

`js
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.

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- new Uint64BE(number)

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

- new Uint64BE(high, low)

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

- new Uint64BE(string, radix)

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

- new Uint64BE(buffer)

`js
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)

`js
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)

`js
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)

`js
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)

`js
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)

`js
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)

`js
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)

`js
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"
`

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- valueOf()

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

- toNumber()

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

- toString(radix)

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

- toBuffer()

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

- toArrayBuffer()

`js
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()

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

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

`html



``

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

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Copyright (c) 2015-2024 Yusuke Kawasaki

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