feat: UUID V7

uuid.html

@@ -36,6 +36,17 @@
                max="100"
         />
       </div>
+      <div class="col">
+        <label id="uuidVersionLabel" for="uuidVersion">Version</label>
+        <select id="uuidVersion"
+                name="uuidVersion"
+                class="form-control"
+                aria-labelledby="uuidVersionLabel"
+        >
+          <option value="V4" selected>UUID V4</option>
+          <option value="V7">UUID V7</option>
+        </select>
+      </div>
     </form>
     <form id="uuidForm">
       <div class="mb-3">
@@ -62,7 +73,7 @@
   </div>
   <script type="module">
     import { fromEvent, concat, of, merge, switchMap, map, tap, startWith, distinctUntilChanged } from "https://esm.sh/rxjs@7.8.1";
-    import { randomUUID } from "./uuid.js";
+    import { randomUUIDV4, randomUUIDV7 } from "./uuid.js";
 
     const configForm = document.forms.config;
     const configuration = merge(
@@ -93,7 +104,7 @@
         switchMap(conf => concat(of(undefined), regenerate).pipe(
           map(() => conf),
         )),
-        map(({uuidCount}) => Array.from({length: uuidCount}, randomUUID).join("\n")),
+        map(({uuidCount, uuidVersion}) => Array.from({length: uuidCount}, uuidVersion === "V7" ? randomUUIDV7 : randomUUIDV4 ).join("\n")),
       )
       .subscribe(r => result.value = r);
 

uuid.js

@@ -1 +1,31 @@
-export const randomUUID = crypto.randomUUID?(()=>crypto.randomUUID()):((r,h)=>(n=>(s=>()=>'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g,c=>s[c]()))({x:()=>h[n()],y:()=>h[n()%4+8]}))(()=>r.next().value))((function*(b){while(!0){for(var i of crypto.getRandomValues(b)){yield Math.trunc(i/16);yield i%16;}}})(new Uint8Array(256)),'0123456789abcdef');
+function* randomNumberGenerator(buffer) {
+  while(true) {
+    for(const byte of crypto.getRandomValues(buffer)) {
+      yield Math.trunc(byte/16);
+      yield byte%16;
+    }
+  }
+}
+
+function uuidV7Timestamp() {
+  const unpaddedTimestamp = new Date().getTime().toString(16);
+  const timestamp = ('000000000000' + unpaddedTimestamp).substring(unpaddedTimestamp.length);
+  return `${timestamp.substring(0,8)}-${timestamp.substring(8)}`
+}
+
+const hexAlphabet = '0123456789abcdef';
+const randomNumbers = randomNumberGenerator(new Uint8Array(256));
+const hexDigitGenerators = {
+  x: () => hexAlphabet[randomNumbers.next().value],
+  y: () => hexAlphabet[randomNumbers.next().value % 4 + 8],
+}
+
+function withHexDigit(character) {
+  return hexDigitGenerators[character]();
+}
+
+export const randomUUIDV4 = crypto.randomUUID
+  ? (()=>crypto.randomUUID())
+  : (()=>'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, withHexDigit))
+
+export const randomUUIDV7 = (() => uuidV7Timestamp() + '-7xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, withHexDigit))