Migrate message ids to UUIDv7

ts/util/generateMessageId.ts

@@ -0,0 +1,47 @@
+// Copyright 2024 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import { stringify } from 'uuid';
+
+import { getRandomBytes } from '../Crypto';
+
+export type GeneratedMessageIdType = Readonly<{
+  id: string;
+  received_at: number;
+}>;
+
+// See https://datatracker.ietf.org/doc/html/draft-ietf-uuidrev-rfc4122bis-00#section-5.7
+export function generateMessageId(counter: number): GeneratedMessageIdType {
+  const uuid = getRandomBytes(16);
+
+  /* eslint-disable no-bitwise */
+
+  // We compose uuid out of 48 bits (6 bytes of) timestamp-like counter:
+  // `incrementMessageCounter`. Note big-endian encoding (which ensures proper
+  // lexicographical order), and floating point divisions (because `&` operator
+  // coerces to 32bit integers)
+
+  uuid[0] = (counter / 0x10000000000) & 0xff;
+  uuid[1] = (counter / 0x00100000000) & 0xff;
+  uuid[2] = (counter / 0x00001000000) & 0xff;
+  uuid[3] = (counter / 0x00000010000) & 0xff;
+  uuid[4] = (counter / 0x00000000100) & 0xff;
+  uuid[5] = (counter / 0x00000000001) & 0xff;
+
+  // Mask out 4 bits of version number
+  uuid[6] &= 0x0f;
+  // And set the version to 7
+  uuid[6] |= 0x70;
+
+  // Mask out 2 bits of variant
+  uuid[8] &= 0x3f;
+  // And set it to "2"
+  uuid[8] |= 0x80;
+
+  /* eslint-enable no-bitwise */
+
+  return {
+    id: stringify(uuid),
+    received_at: counter,
+  };
+}