IndexedDB 写入队列与优先级调度实践

概述写入队列可在高并发下保证可靠性。本文提供优先级调度与重试封装。队列与调度const q = [];

function enqueue(task, priority = 0) { q.push({ task, priority }); q.sort((a,b) => b.priority - a.priority); }

async function runQueue() {

while (q.length) {

const { task } = q.shift();

try { await task(); } catch (e) { await new Promise(r => setTimeout(r, 200)); q.push({ task, priority: -1 }); }

}

}

function openDB(name) { return new Promise((resolve, reject) => { const r = indexedDB.open(name, 1); r.onupgradeneeded = () => { const db = r.result; if (!db.objectStoreNames.contains('items')) db.createObjectStore('items', { keyPath: 'id' }); }; r.onsuccess = () => resolve(r.result); r.onerror = () => reject(r.error); }); }

function putRecord(rec) {

enqueue(async () => {

const db = await openDB('qdb');

const tx = db.transaction('items','readwrite');

tx.objectStore('items').put(rec);

await new Promise((res, rej) => { tx.oncomplete = res; tx.onerror = () => rej(tx.error); });

db.close();

}, rec.priority || 0);

}