54 lines
1.3 KiB
TypeScript
54 lines
1.3 KiB
TypeScript
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import { getBytes } from "./data.js";
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import { throwArgumentError } from "./errors.js";
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import { toBigInt, toHex } from "./maths.js";
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import type { BytesLike } from "./index.js";
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const Alphabet = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
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let Lookup: null | Record<string, bigint> = null;
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function getAlpha(letter: string): bigint {
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if (Lookup == null) {
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Lookup = { };
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for (let i = 0; i < Alphabet.length; i++) {
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Lookup[Alphabet[i]] = BigInt(i);
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}
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}
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const result = Lookup[letter];
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if (result == null) {
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throwArgumentError(`invalid base58 value`, "letter", letter);
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}
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return result;
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}
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const BN_0 = BigInt(0);
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const BN_58 = BigInt(58);
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/**
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* Encode %%value%% as Base58-encoded data.
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*/
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export function encodeBase58(_value: BytesLike): string {
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let value = toBigInt(getBytes(_value));
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let result = "";
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while (value) {
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result = Alphabet[Number(value % BN_58)] + result;
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value /= BN_58;
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}
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return result;
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}
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/**
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* Decode the Base58-encoded %%value%%.
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*/
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export function decodeBase58(value: string): Uint8Array {
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let result = BN_0;
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for (let i = 0; i < value.length; i++) {
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result *= BN_58;
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result += getAlpha(value[i]);
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}
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return getBytes(toHex(result));
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}
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