chore: initialize from frontend template 4dc033c

2026-08-13 18:23:26 +09:00
commit 40107eec84
897 changed files with 234824 additions and 0 deletions
@@ -0,0 +1,185 @@
+import {
+  REALTIME_EVENT_PROTOCOL,
+  type EventTypeId,
+  type StreamRegistrationId,
+} from "./realtime-streams.ts";
+
+export const REALTIME_EVENT_FIELD_LIMITS = Object.freeze({
+  maxOpaqueIdentifierLength: 128,
+  maxScopeBindingLength: 256,
+  maxResumeCursorLength: 1_024,
+  maxSequenceDigits: 20,
+  maxTimestampFractionDigits: 9,
+});
+
+export const REALTIME_MAX_SEQUENCE = "18446744073709551615";
+
+export type RealtimeEventBase<Payload> = Readonly<{
+  protocol: typeof REALTIME_EVENT_PROTOCOL;
+  streamId: StreamRegistrationId;
+  streamEpoch: string;
+  eventType: EventTypeId;
+  eventId: string;
+  sequence: string;
+  occurredAt: string;
+  scopeBinding: string;
+  payload: Payload;
+}>;
+
+export type RealtimeEventEnvelope<Payload = unknown> = Readonly<
+  RealtimeEventBase<Payload> &
+    (
+      | Readonly<{
+          recoveryMode: "CURSOR";
+          resumeCursor: string;
+        }>
+      | Readonly<{
+          recoveryMode: "SNAPSHOT_ONLY" | "SESSION_REBUILD";
+          resumeCursor: null;
+        }>
+    )
+>;
+
+export type SnapshotCheckpoint = Readonly<
+  {
+    streamEpoch: string;
+    lastAppliedSequence: string;
+    snapshotRevision: string;
+  } & (
+    | Readonly<{
+        recoveryMode: "CURSOR";
+        resumeCursor: string;
+      }>
+    | Readonly<{
+        recoveryMode: "SNAPSHOT_ONLY";
+        resumeCursor: null;
+      }>
+  )
+>;
+
+export type RealtimeResumeState = Readonly<
+  {
+    streamEpoch: string;
+    lastAppliedSequence: string;
+  } & (
+    | Readonly<{
+        recoveryMode: "CURSOR";
+        resumeCursor: string;
+      }>
+    | Readonly<{
+        recoveryMode: "SNAPSHOT_ONLY" | "SESSION_REBUILD";
+        resumeCursor: null;
+      }>
+  )
+>;
+
+const OPAQUE_IDENTIFIER = /^[A-Za-z0-9][A-Za-z0-9._:~+/=-]*$/u;
+const HEADER_SAFE_CURSOR = /^[\x21-\x7e]+$/u;
+const CANONICAL_SEQUENCE = /^(?:0|[1-9][0-9]{0,19})$/u;
+const RFC_3339 =
+  /^([0-9]{4})-(0[1-9]|1[0-2])-([0-2][0-9]|3[01])T([01][0-9]|2[0-3]):([0-5][0-9]):([0-5][0-9])(?:\.([0-9]{1,9}))?(Z|([+-])([01][0-9]|2[0-3]):([0-5][0-9]))$/u;
+
+export function isRealtimeOpaqueIdentifier(
+  value: unknown,
+): value is string {
+  return (
+    typeof value === "string" &&
+    value.length >= 1 &&
+    value.length <=
+      REALTIME_EVENT_FIELD_LIMITS.maxOpaqueIdentifierLength &&
+    OPAQUE_IDENTIFIER.test(value)
+  );
+}
+
+export function isRealtimeScopeBinding(
+  value: unknown,
+): value is string {
+  return (
+    typeof value === "string" &&
+    value.length >= 1 &&
+    value.length <= REALTIME_EVENT_FIELD_LIMITS.maxScopeBindingLength &&
+    OPAQUE_IDENTIFIER.test(value)
+  );
+}
+
+export function isRealtimeResumeCursor(
+  value: unknown,
+): value is string {
+  return (
+    typeof value === "string" &&
+    value.length >= 1 &&
+    value.length <=
+      REALTIME_EVENT_FIELD_LIMITS.maxResumeCursorLength &&
+    HEADER_SAFE_CURSOR.test(value) &&
+    !value.includes("\0") &&
+    !value.includes("\r") &&
+    !value.includes("\n")
+  );
+}
+
+export function isCanonicalRealtimeSequence(
+  value: unknown,
+): value is string {
+  if (
+    typeof value !== "string" ||
+    value.length > REALTIME_EVENT_FIELD_LIMITS.maxSequenceDigits ||
+    !CANONICAL_SEQUENCE.test(value)
+  ) {
+    return false;
+  }
+  try {
+    return BigInt(value) <= BigInt(REALTIME_MAX_SEQUENCE);
+  } catch {
+    return false;
+  }
+}
+
+export function compareRealtimeSequences(
+  left: string,
+  right: string,
+): -1 | 0 | 1 {
+  if (
+    !isCanonicalRealtimeSequence(left) ||
+    !isCanonicalRealtimeSequence(right)
+  ) {
+    throw new TypeError("Realtime sequence is invalid.");
+  }
+  const leftValue = BigInt(left);
+  const rightValue = BigInt(right);
+  return leftValue < rightValue ? -1 : leftValue > rightValue ? 1 : 0;
+}
+
+export function nextRealtimeSequence(value: string): string | null {
+  if (!isCanonicalRealtimeSequence(value)) {
+    throw new TypeError("Realtime sequence is invalid.");
+  }
+  const next = BigInt(value) + 1n;
+  return next > BigInt(REALTIME_MAX_SEQUENCE) ? null : next.toString(10);
+}
+
+/**
+ * A bounded RFC 3339 profile: uppercase T/Z, a required offset, real calendar
+ * dates, seconds 00-59 and at most nanosecond fractional precision.
+ */
+export function isStrictRealtimeTimestamp(
+  value: unknown,
+): value is string {
+  if (typeof value !== "string") return false;
+  const match = RFC_3339.exec(value);
+  if (!match) return false;
+  const year = Number(match[1]);
+  const month = Number(match[2]);
+  const day = Number(match[3]);
+  if (year < 1 || day > daysInMonth(year, month)) return false;
+  return Number.isFinite(Date.parse(value));
+}
+
+function daysInMonth(year: number, month: number): number {
+  if (month === 2) {
+    return year % 4 === 0 && (year % 100 !== 0 || year % 400 === 0)
+      ? 29
+      : 28;
+  }
+  return [4, 6, 9, 11].includes(month) ? 30 : 31;
+}
+