This repository has been archived on 2024-11-13. You can view files and clone it, but cannot push or open issues or pull requests.
fediversity.eu/node_modules/ulid/dist/index.esm.js
2024-03-26 16:28:28 +01:00

159 lines
4.8 KiB
JavaScript

function createError(message) {
var err = new Error(message);
err.source = "ulid";
return err;
}
// These values should NEVER change. If
// they do, we're no longer making ulids!
var ENCODING = "0123456789ABCDEFGHJKMNPQRSTVWXYZ"; // Crockford's Base32
var ENCODING_LEN = ENCODING.length;
var TIME_MAX = Math.pow(2, 48) - 1;
var TIME_LEN = 10;
var RANDOM_LEN = 16;
function replaceCharAt(str, index, char) {
if (index > str.length - 1) {
return str;
}
return str.substr(0, index) + char + str.substr(index + 1);
}
function incrementBase32(str) {
var done = undefined;
var index = str.length;
var char = void 0;
var charIndex = void 0;
var maxCharIndex = ENCODING_LEN - 1;
while (!done && index-- >= 0) {
char = str[index];
charIndex = ENCODING.indexOf(char);
if (charIndex === -1) {
throw createError("incorrectly encoded string");
}
if (charIndex === maxCharIndex) {
str = replaceCharAt(str, index, ENCODING[0]);
continue;
}
done = replaceCharAt(str, index, ENCODING[charIndex + 1]);
}
if (typeof done === "string") {
return done;
}
throw createError("cannot increment this string");
}
function randomChar(prng) {
var rand = Math.floor(prng() * ENCODING_LEN);
if (rand === ENCODING_LEN) {
rand = ENCODING_LEN - 1;
}
return ENCODING.charAt(rand);
}
function encodeTime(now, len) {
if (isNaN(now)) {
throw new Error(now + " must be a number");
}
if (now > TIME_MAX) {
throw createError("cannot encode time greater than " + TIME_MAX);
}
if (now < 0) {
throw createError("time must be positive");
}
if (Number.isInteger(now) === false) {
throw createError("time must be an integer");
}
var mod = void 0;
var str = "";
for (; len > 0; len--) {
mod = now % ENCODING_LEN;
str = ENCODING.charAt(mod) + str;
now = (now - mod) / ENCODING_LEN;
}
return str;
}
function encodeRandom(len, prng) {
var str = "";
for (; len > 0; len--) {
str = randomChar(prng) + str;
}
return str;
}
function decodeTime(id) {
if (id.length !== TIME_LEN + RANDOM_LEN) {
throw createError("malformed ulid");
}
var time = id.substr(0, TIME_LEN).split("").reverse().reduce(function (carry, char, index) {
var encodingIndex = ENCODING.indexOf(char);
if (encodingIndex === -1) {
throw createError("invalid character found: " + char);
}
return carry += encodingIndex * Math.pow(ENCODING_LEN, index);
}, 0);
if (time > TIME_MAX) {
throw createError("malformed ulid, timestamp too large");
}
return time;
}
function detectPrng() {
var allowInsecure = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : false;
var root = arguments[1];
if (!root) {
root = typeof window !== "undefined" ? window : null;
}
var browserCrypto = root && (root.crypto || root.msCrypto);
if (browserCrypto) {
return function () {
var buffer = new Uint8Array(1);
browserCrypto.getRandomValues(buffer);
return buffer[0] / 0xff;
};
} else {
try {
var nodeCrypto = require("crypto");
return function () {
return nodeCrypto.randomBytes(1).readUInt8() / 0xff;
};
} catch (e) {}
}
if (allowInsecure) {
try {
console.error("secure crypto unusable, falling back to insecure Math.random()!");
} catch (e) {}
return function () {
return Math.random();
};
}
throw createError("secure crypto unusable, insecure Math.random not allowed");
}
function factory(currPrng) {
if (!currPrng) {
currPrng = detectPrng();
}
return function ulid(seedTime) {
if (isNaN(seedTime)) {
seedTime = Date.now();
}
return encodeTime(seedTime, TIME_LEN) + encodeRandom(RANDOM_LEN, currPrng);
};
}
function monotonicFactory(currPrng) {
if (!currPrng) {
currPrng = detectPrng();
}
var lastTime = 0;
var lastRandom = void 0;
return function ulid(seedTime) {
if (isNaN(seedTime)) {
seedTime = Date.now();
}
if (seedTime <= lastTime) {
var incrementedRandom = lastRandom = incrementBase32(lastRandom);
return encodeTime(lastTime, TIME_LEN) + incrementedRandom;
}
lastTime = seedTime;
var newRandom = lastRandom = encodeRandom(RANDOM_LEN, currPrng);
return encodeTime(seedTime, TIME_LEN) + newRandom;
};
}
var ulid = factory();
export { replaceCharAt, incrementBase32, randomChar, encodeTime, encodeRandom, decodeTime, detectPrng, factory, monotonicFactory, ulid };