tiny-ulid/monotonic.js

Make and decode ULIDs.

import {
	cloneUlidBuffer,
	incrementUlidBuffer,
	makeEmptyUlidBuffer,
	makeUlidBuffer as makeUlidBuffer$1,
	setUlidBufferTime
} from "./default.js"
let lastGeneratedBuffer = !1,
	stateTime = 0
const stateUlidBuffer = makeEmptyUlidBuffer(),
	stateUlidBytes = new Uint8Array(stateUlidBuffer),
	makeUlidBuffer = () => {
		const time = Date.now()
		if (stateTime < time) {
			stateTime = time
			makeUlidBuffer$1({ ulidBuffer: stateUlidBuffer })
			stateUlidBytes[6] &= 127
		} else {
			if (!lastGeneratedBuffer) {
				setUlidBufferTime(stateUlidBuffer, stateTime)
				for (let bytesIndex = 0, ulidIndex = 0; bytesIndex < 15; bytesIndex++) {
					stateUlidBytes[bytesIndex] =
						(CROCKFORD_BASE32_CHAR_CODES.indexOf(stateUlidStringBytes[ulidIndex]) << 5) |
						CROCKFORD_BASE32_CHAR_CODES.indexOf(stateUlidStringBytes[++ulidIndex])
					stateUlidBytes[++bytesIndex] =
						(CROCKFORD_BASE32_CHAR_CODES.indexOf(stateUlidStringBytes[++ulidIndex]) << 3) |
						(CROCKFORD_BASE32_CHAR_CODES.indexOf(stateUlidStringBytes[++ulidIndex]) >> 2)
					stateUlidBytes[++bytesIndex] =
						(CROCKFORD_BASE32_CHAR_CODES.indexOf(stateUlidStringBytes[ulidIndex]) << 6) |
						(CROCKFORD_BASE32_CHAR_CODES.indexOf(stateUlidStringBytes[++ulidIndex]) << 1) |
						(CROCKFORD_BASE32_CHAR_CODES.indexOf(stateUlidStringBytes[++ulidIndex]) >> 4)
					stateUlidBytes[++bytesIndex] =
						(CROCKFORD_BASE32_CHAR_CODES.indexOf(stateUlidStringBytes[ulidIndex]) << 4) |
						(CROCKFORD_BASE32_CHAR_CODES.indexOf(stateUlidStringBytes[++ulidIndex]) >> 1)
					stateUlidBytes[++bytesIndex] =
						(CROCKFORD_BASE32_CHAR_CODES.indexOf(stateUlidStringBytes[ulidIndex]) << 7) |
						(CROCKFORD_BASE32_CHAR_CODES.indexOf(stateUlidStringBytes[++ulidIndex]) << 2) |
						(CROCKFORD_BASE32_CHAR_CODES.indexOf(stateUlidStringBytes[++ulidIndex]) >> 3)
				}
				stateUlidBytes[15] =
					(CROCKFORD_BASE32_CHAR_CODES.indexOf(stateUlidStringBytes[24]) << 5) |
					CROCKFORD_BASE32_CHAR_CODES.indexOf(stateUlidStringBytes[25])
			}
			incrementUlidBuffer(stateUlidBuffer, { throwOnOverflow: !0 })
		}
		lastGeneratedBuffer = !0
		return cloneUlidBuffer(stateUlidBuffer)
	},
	stateUlidStringBytes = new Uint8Array(26),
	textDecoder = new TextDecoder(),
	CROCKFORD_BASE32_CHAR_CODES = new Uint8Array([
		48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 65, 66, 67, 68, 69, 70, 71, 72, 74, 75, 77, 78, 80, 81, 82, 83, 84, 86,
		87, 88, 89, 90
	]),
	makeUlid = () => {
		const time = Date.now()
		if_: {
			if (!(stateTime < time)) {
				if (lastGeneratedBuffer) {
					const dataView = new DataView(stateUlidBuffer)
					stateUlidStringBytes[0] = CROCKFORD_BASE32_CHAR_CODES[dataView.getUint8(0) >> 5]
					for (let bitOffset = 3, index = 1; bitOffset < 123; bitOffset += 5, index++) {
						const byteOffset = Math.floor(bitOffset / 8)
						stateUlidStringBytes[index] =
							CROCKFORD_BASE32_CHAR_CODES[(dataView.getUint16(byteOffset) >> (11 - (bitOffset % 8))) & 31]
					}
					stateUlidStringBytes[25] = CROCKFORD_BASE32_CHAR_CODES[31 & dataView.getUint8(15)]
				}
				for (let index = 25; index > 9; index--) {
					const value = (CROCKFORD_BASE32_CHAR_CODES.indexOf(stateUlidStringBytes[index]) + 1) & 31
					stateUlidStringBytes[index] = CROCKFORD_BASE32_CHAR_CODES[value]
					if (value) break if_
				}
				throw Error("Overflow when incrementing ULID")
			}
			stateTime = time
			for (let offset = 50, index = 0; offset;)
				stateUlidStringBytes[index++] = CROCKFORD_BASE32_CHAR_CODES[(time / 2 ** (offset -= 5)) & 31]
			crypto.getRandomValues(new Uint8Array(stateUlidStringBytes.buffer, 10))
			stateUlidStringBytes[10] = CROCKFORD_BASE32_CHAR_CODES[15 & stateUlidStringBytes[10]]
			for (let index = 11; index < 26;)
				stateUlidStringBytes[index] = CROCKFORD_BASE32_CHAR_CODES[31 & stateUlidStringBytes[index++]]
		}
		lastGeneratedBuffer = !1
		return textDecoder.decode(stateUlidStringBytes)
	}
export { makeUlid, makeUlidBuffer }