xid-ts
Version:
xid is a globally unique id generator thought for the web. A Typescript port of https://github.com/rs/xid.
171 lines • 6.2 kB
JavaScript
// (c) 2023-present, Yiwen AI Limited. All rights reserved.
// See the file LICENSE for licensing terms.
const encodedLen = 20; // string encoded len
const rawLen = 12; // binary raw len
const errInvalidID = 'xid: invalid ID';
const textEncoder = new TextEncoder();
const textDecoder = new TextDecoder();
const encoding = textEncoder.encode('0123456789abcdefghijklmnopqrstuv');
const dec = new Uint8Array(256).fill(0xff);
for (let i = 0; i < encoding.length; i++) {
dec[encoding[i]] = i;
}
const crypto_0 = typeof globalThis === 'object' && 'crypto' in globalThis
? globalThis.crypto
: undefined;
const start = getRandom3Bytes();
export class Xid extends Uint8Array {
static machineId = getRandom3Bytes();
static pid = getPid();
static counter = (start[0] << 16) | (start[1] << 8) | start[2];
constructor(id) {
super(rawLen);
if (id == null) {
const view = new DataView(this.buffer);
const timestamp = Math.floor(Date.now() / 1000);
view.setUint32(0, timestamp);
this[4] = Xid.machineId[0];
this[5] = Xid.machineId[1];
this[6] = Xid.machineId[2];
this[7] = Xid.pid >> 8;
this[8] = Xid.pid & 0x00ff;
Xid.counter += 1;
if (Xid.counter > 0xffffff) {
Xid.counter = 0;
}
this[9] = Xid.counter >> 16;
this[10] = Xid.counter & (0x00ffff >> 8);
this[11] = Xid.counter & 0x0000ff;
}
else if (!(id instanceof Uint8Array) || id.length !== rawLen) {
throw new Error(errInvalidID);
}
else {
this.set(id);
}
}
static default() {
return new Xid(new Uint8Array(rawLen).fill(0));
}
static fromValue(v) {
if (v instanceof Xid) {
return v;
}
if (typeof v === 'string') {
return Xid.parse(v);
}
if (v instanceof Uint8Array && v.length === rawLen) {
return new Xid(v);
}
if (v instanceof ArrayBuffer && v.byteLength === rawLen) {
return new Xid(new Uint8Array(v));
}
if (Array.isArray(v) &&
v.length === rawLen &&
v.every((byte) => typeof byte === 'number' && byte >= 0 && byte <= 255)) {
return new Xid(new Uint8Array(v));
}
throw new Error(errInvalidID);
}
static parse(id) {
if (id.length !== encodedLen) {
throw new Error(errInvalidID);
}
const xid = new Xid();
xid.decode(id);
return xid;
}
decode(str) {
const src = textEncoder.encode(str);
if (src.length !== encodedLen) {
throw new Error(errInvalidID);
}
for (const c of src) {
if (dec[c] == 0xff) {
throw new Error(errInvalidID);
}
}
this[11] = (dec[src[17]] << 6) | (dec[src[18]] << 1) | (dec[src[19]] >> 4);
if (encoding[(this[11] << 4) & 0x1f] != src[19]) {
throw new Error(errInvalidID);
}
this[10] = (dec[src[16]] << 3) | (dec[src[17]] >> 2);
this[9] = (dec[src[14]] << 5) | dec[src[15]];
this[8] = (dec[src[12]] << 7) | (dec[src[13]] << 2) | (dec[src[14]] >> 3);
this[7] = (dec[src[11]] << 4) | (dec[src[12]] >> 1);
this[6] = (dec[src[9]] << 6) | (dec[src[10]] << 1) | (dec[src[11]] >> 4);
this[5] = (dec[src[8]] << 3) | (dec[src[9]] >> 2);
this[4] = (dec[src[6]] << 5) | dec[src[7]];
this[3] = (dec[src[4]] << 7) | (dec[src[5]] << 2) | (dec[src[6]] >> 3);
this[2] = (dec[src[3]] << 4) | (dec[src[4]] >> 1);
this[1] = (dec[src[1]] << 6) | (dec[src[2]] << 1) | (dec[src[3]] >> 4);
this[0] = (dec[src[0]] << 3) | (dec[src[1]] >> 2);
}
encode() {
const dst = new Uint8Array(encodedLen);
dst[19] = encoding[(this[11] << 4) & 0x1f];
dst[18] = encoding[(this[11] >> 1) & 0x1f];
dst[17] = encoding[(this[11] >> 6) | ((this[10] << 2) & 0x1f)];
dst[16] = encoding[this[10] >> 3];
dst[15] = encoding[this[9] & 0x1f];
dst[14] = encoding[(this[9] >> 5) | ((this[8] << 3) & 0x1f)];
dst[13] = encoding[(this[8] >> 2) & 0x1f];
dst[12] = encoding[(this[8] >> 7) | ((this[7] << 1) & 0x1f)];
dst[11] = encoding[(this[7] >> 4) | ((this[6] << 4) & 0x1f)];
dst[10] = encoding[(this[6] >> 1) & 0x1f];
dst[9] = encoding[(this[6] >> 6) | ((this[5] << 2) & 0x1f)];
dst[8] = encoding[this[5] >> 3];
dst[7] = encoding[this[4] & 0x1f];
dst[6] = encoding[(this[4] >> 5) | ((this[3] << 3) & 0x1f)];
dst[5] = encoding[(this[3] >> 2) & 0x1f];
dst[4] = encoding[(this[3] >> 7) | ((this[2] << 1) & 0x1f)];
dst[3] = encoding[(this[2] >> 4) | ((this[1] << 4) & 0x1f)];
dst[2] = encoding[(this[1] >> 1) & 0x1f];
dst[1] = encoding[(this[1] >> 6) | ((this[0] << 2) & 0x1f)];
dst[0] = encoding[this[0] >> 3];
return textDecoder.decode(dst);
}
timestamp() {
return new DataView(this.buffer).getUint32(0);
}
machine() {
return new Uint8Array(this.buffer, 4, 3);
}
pid() {
return (this[7] << 8) | this[8];
}
counter() {
return (this[9] << 16) | (this[10] << 8) | this[11];
}
isZero() {
return super.every((byte) => byte === 0);
}
toString() {
return this.encode();
}
toBytes() {
return new Uint8Array(this.buffer, 0, rawLen);
}
toJSON() {
return this.encode();
}
equals(xid) {
for (let i = 0; i < rawLen; i++) {
if (this[i] !== xid[i]) {
return false;
}
}
return true;
}
}
function getRandom3Bytes() {
return crypto_0.getRandomValues(new Uint8Array(3));
}
function getPid() {
if (typeof globalThis === 'object' && 'process' in globalThis) {
return globalThis.process.pid & 0xffff;
}
const buf = crypto_0.getRandomValues(new Uint8Array(2));
return (buf[0] << 8) | buf[1];
}
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