dbx/apps/desktop/src/lib/schemaTreeCache.ts

42 lines
1.1 KiB
TypeScript

export const SCHEMA_TREE_CACHE_TTL_MS = 15 * 60 * 1000;
export interface SchemaTreeCacheEnvelope<T> {
version: 2;
cachedAt: string;
children: T;
}
export interface DecodedSchemaTreeCache<T> {
children: T;
isStale: boolean;
}
export function encodeSchemaTreeCache<T>(children: T, nowMs = Date.now()): SchemaTreeCacheEnvelope<T> {
return {
version: 2,
cachedAt: new Date(nowMs).toISOString(),
children,
};
}
export function decodeSchemaTreeCache<T>(payload: unknown, nowMs = Date.now(), ttlMs = SCHEMA_TREE_CACHE_TTL_MS): DecodedSchemaTreeCache<T> | null {
if (Array.isArray(payload)) {
return { children: payload as T, isStale: true };
}
if (!payload || typeof payload !== "object") return null;
const envelope = payload as Partial<SchemaTreeCacheEnvelope<unknown>>;
if (envelope.version !== 2 || !Array.isArray(envelope.children) || typeof envelope.cachedAt !== "string") {
return null;
}
const cachedAtMs = Date.parse(envelope.cachedAt);
if (!Number.isFinite(cachedAtMs)) return null;
return {
children: envelope.children as T,
isStale: nowMs - cachedAtMs >= ttlMs,
};
}