ethers.js/packages/basex/lib.esm/index.js
2020-07-13 08:03:56 -04:00

119 lines
4.4 KiB
JavaScript

/**
* var basex = require("base-x");
*
* This implementation is heavily based on base-x. The main reason to
* deviate was to prevent the dependency of Buffer.
*
* Contributors:
*
* base-x encoding
* Forked from https://github.com/cryptocoinjs/bs58
* Originally written by Mike Hearn for BitcoinJ
* Copyright (c) 2011 Google Inc
* Ported to JavaScript by Stefan Thomas
* Merged Buffer refactorings from base58-native by Stephen Pair
* Copyright (c) 2013 BitPay Inc
*
* The MIT License (MIT)
*
* Copyright base-x contributors (c) 2016
*
* 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.
*
*/
import { arrayify } from "@ethersproject/bytes";
import { defineReadOnly } from "@ethersproject/properties";
export class BaseX {
constructor(alphabet) {
defineReadOnly(this, "alphabet", alphabet);
defineReadOnly(this, "base", alphabet.length);
defineReadOnly(this, "_alphabetMap", {});
defineReadOnly(this, "_leader", alphabet.charAt(0));
// pre-compute lookup table
for (let i = 0; i < alphabet.length; i++) {
this._alphabetMap[alphabet.charAt(i)] = i;
}
}
encode(value) {
let source = arrayify(value);
if (source.length === 0) {
return "";
}
let digits = [0];
for (let i = 0; i < source.length; ++i) {
let carry = source[i];
for (let j = 0; j < digits.length; ++j) {
carry += digits[j] << 8;
digits[j] = carry % this.base;
carry = (carry / this.base) | 0;
}
while (carry > 0) {
digits.push(carry % this.base);
carry = (carry / this.base) | 0;
}
}
let string = "";
// deal with leading zeros
for (let k = 0; source[k] === 0 && k < source.length - 1; ++k) {
string += this._leader;
}
// convert digits to a string
for (let q = digits.length - 1; q >= 0; --q) {
string += this.alphabet[digits[q]];
}
return string;
}
decode(value) {
if (typeof (value) !== "string") {
throw new TypeError("Expected String");
}
let bytes = [];
if (value.length === 0) {
return new Uint8Array(bytes);
}
bytes.push(0);
for (let i = 0; i < value.length; i++) {
let byte = this._alphabetMap[value[i]];
if (byte === undefined) {
throw new Error("Non-base" + this.base + " character");
}
let carry = byte;
for (let j = 0; j < bytes.length; ++j) {
carry += bytes[j] * this.base;
bytes[j] = carry & 0xff;
carry >>= 8;
}
while (carry > 0) {
bytes.push(carry & 0xff);
carry >>= 8;
}
}
// deal with leading zeros
for (let k = 0; value[k] === this._leader && k < value.length - 1; ++k) {
bytes.push(0);
}
return arrayify(new Uint8Array(bytes.reverse()));
}
}
const Base32 = new BaseX("abcdefghijklmnopqrstuvwxyz234567");
const Base58 = new BaseX("123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz");
export { Base32, Base58 };
//console.log(Base58.decode("Qmd2V777o5XvJbYMeMb8k2nU5f8d3ciUQ5YpYuWhzv8iDj"))
//console.log(Base58.encode(Base58.decode("Qmd2V777o5XvJbYMeMb8k2nU5f8d3ciUQ5YpYuWhzv8iDj")))
//# sourceMappingURL=index.js.map