IndexedDB QuotaExceededError 容量不足处理与清理实践

概述容量不足会导致事务失败。本文提供错误捕获与按优先级清理示例。捕获与清理function openDB(name) { return new Promise((resolve, reject) => { const r = indexedDB.open(name, 1); r.onupgradeneeded = () => { const db = r.result; if (!db.objectStoreNames.contains('cache')) db.createObjectStore('cache', { keyPath:'key' }); }; r.onsuccess = () => resolve(r.result); r.onerror = () => reject(r.error); }); } async function putSafe(key, value, priority = 0) { try { const db = await openDB('quota'); const tx = db.transaction('cache','readwrite'); tx.objectStore('cache').put({ key, value, priority, ts: Date.now() }); await new Promise((res, rej) => { tx.oncomplete = res; tx.onerror = () => rej(tx.error); }); db.close(); } catch (e) { if (String(e.name).includes('QuotaExceededError')) { await cleanupLowPriority(); return putSafe(key, value, priority); } throw e; } } async function cleanupLowPriority(limit = 100) { const db = await openDB('quota'); const tx = db.transaction('cache','readwrite'); const s = tx.objectStore('cache'); const items = []; const req = s.openCursor(); await new Promise((res, rej) => { req.onsuccess = e => { const c = e.target.result; if (c) { items.push(c.value); c.continue(); } else res(); }; req.onerror = () => rej(req.error); }); items.sort((a,b) => a.priority - b.priority || a.ts - b.ts); for (const it of items.slice(0, Math.min(limit, Math.ceil(items.length * 0.1)))) s.delete(it.key); await new Promise((res, rej) => { tx.oncomplete = res; tx.onerror = () => rej(tx.error); }); db.close(); }