indexdb-prompt

gistfile1.txt

/**
 * GitHub Copilot prompt
 *
 * Goal: implement a performant frontend cache for huge PDF‑diff JSON blobs.
 *
 * Requirements
 * — Tech: TypeScript + React, Dexie.js (IndexedDB wrapper), lz‑string, Web Worker.
 * — Key format: `${pathname}/${fileName}?v1=${ver1}&v2=${ver2}` (strip base URL first).
 * — API surface:
 *    • generateCacheKey(pathname: string, file: string, ver1: string, ver2: string): string
 *    • saveDiff(key: string, json: string): Promise<void>  // compress→store
 *    • loadDiff(key: string): Promise<object|null>         // read→decompress→parse
 *    • purgeOld(days = 30): Promise<number>                // delete entries older than TTL
 * — Worker:  parses + compresses JSON off‑main‑thread; posts back Uint8Array & parsed object.
 * — Storage schema: { id (PK), payload (Uint8Array), createdAt (number ms) }.
 * — Optimizations: structuredClone to transfer Uint8Array, Dexie bulk delete, relaxed durability off.
 *
 * Deliverables
 * 1. cache.ts  – Dexie DB, helper fns, TTL purge.
 * 2. diffWorker.ts – Web Worker doing JSON.parse + lz-string compression.
 * 3. usePdfDiff.ts – React hook: given URLs & versions, returns diff (hits cache or computes).
 *
 * Keep code concise, typed, and ready to drop into a Vite React project.
 */