ULEB128_33

Encoding and decoding large numbers (uleb128 and uleb128_33)

Installation

npm install uleb128_33

Documentation

readUleb128: Gets the Uint8Array parameter, returns the object

const readUleb128: (buffer: Uint8Array) => {
    value: number;
    length: number;
};

readUleb128_33: Gets the Uint8Array parameter, returns the object

const readUleb128_33: (buffer: Uint8Array) => {
    value: number;
    length: number;
    isMark: number;
};

writeUleb128: Gets an integer parameter, can be a string or a number. Returns array of bytes

 const writeUleb128: (integer: number | string) => number[];

writeUleb128_33: Gets an integer parameter, can be a string or a number, and an optional isMark, boolean (see below). If not specified, it is determined automatically. Returns an array of bytes

const writeUleb128_33: (integer: number | string, isMark?: boolean) => number[];

getUleb128Length: Gets an integer parameter, can be a string or a number. Returns number length

const getUleb128Length: (integer: number | string) => number;

getUleb128_33Length: Gets an integer parameter, can be a string or a number. Returns number length

const getUleb128_33Length: (integer: number | string) => number;

isMark

If the "isMark" is 0, then the value read is a number (32-bit number) Otherwise, the value is a 64-bit number, and you need to read another ULEB128

Usage

ESNext

import {
  getUleb128Length,
  getUleb128_33Length,
  readUleb128,
  readUleb128_33,
  writeUleb128,
  writeUleb128_33,
} from "uleb128_33";

CommonJS

const {
  getUleb128Length,
  getUleb128_33Length,
  readUleb128,
  readUleb128_33,
  writeUleb128,
  writeUleb128_33,
} = require("uleb128_33");

readUleb128

const uintArray = new Uint8Array([
  133, 133, 133, 5, 255, 243, 151, 229, 228, 131, 24, 11, 35, 11, 111, 66,
]);
const dataOne = readUleb128(uintArray);
const dataTwo = readUleb128(uintArray.subarray(dataOne.length));
console.log(dataOne); // { length: 4, value: 10568325 }
console.log(dataTwo); // { length: 7, value: 105683251231231 }

readUleb128_33

const uintArray = new Uint8Array([
  138, 152, 184, 128, 1, 193, 253, 243, 174, 137, 188, 188, 222, 3,
]);
const dataOne = readUleb128_33(uintArray);
const dataTwo = readUleb128_33(uintArray.subarray(dataOne.length));
console.log(dataOne); // { isMark: 0, value: 134678021, length: 5 }
console.log(dataTwo); // { isMark: 1, value: 134678012312321888, length: 9 }

writeUleb128_33

const dataOne = writeUleb128_33(134678021);
const dataTwo = writeUleb128_33("134678012312321888");
console.log(dataOne); // [138, 152, 184, 128, 1]
console.log(dataTwo); // [193, 253, 243, 174, 137, 188, 188, 222, 3]

Test

You can run the tests through npm run test. You will need to install rimraf, typescript, and jest in the global area

LICENSE

The MIT License (MIT)