Restore doesn't work; store meta info in idb

[saizai]

If downloads.cache isn't populated (e.g. the extension crashed & was reloaded), then this will fail.

turbo-download-manager-v2/v3/downloads/manager.js

Lines 457 to 482 in 6b565b0

	// restore indexdb
	{
	const restore = async () => {
	const os = 'databases' in indexedDB ? await indexedDB.databases() : Object.keys(localStorage)
	.filter(name => name.startsWith('file:'))
	.map(name => ({
	name: name.replace('file:', '')
	}));
	for (const o of os) {
	downloads.download({}, id => {
	const {core} = downloads.cache[id];
	core.restore(o.name).catch(e => {
	console.warn('Cannot restore segments. This database will be removed', e, core);
	try {
	core.properties.file.remove();
	delete downloads.cache[id];
	}
	catch (e) {}
	});
	}, undefined, false);
	}
	};
	chrome.runtime.onStartup.addListener(restore);
	chrome.runtime.onInstalled.addListener(restore);
	}

This could be fixed by adding this to manager.js:

manager.updateDb = (obj) => {
  if (manager.db) {
    const transaction = manager.db.transaction('downloads', 'readwrite');
//    transaction.oncomplete = resolve;
    transaction.onerror = e => reject(Error('Manager.updateDb, ' + e.target.error));
    transaction.objectStore('downloads').put(JSON.parse(JSON.stringify(downloads.cache[obj.id])));
    transaction.commit();
  };
};

{
  request = indexedDB.open('downloads', 1);
  request.onupgradeneeded = () => {
    // TODO - Remove this line when Firefox supports indexedDB.databases()
    if (('databases' in indexedDB) === false) {
      localStorage.setItem('downloads', true);
    }
    request.result.createObjectStore('downloads', {
      keyPath: 'id'
    });
  };
  request.onerror = e => reject(Error('File.open, ' + e.target.error));
  request.onsuccess = () => {
    manager.db = request.result;
    manager.opened = true;
  };
}

downloads.onChanged.addListener(manager.updateDb);

Then one could do something like this at that restore:

req = manager.db.transaction('downloads','readonly').objectStore('downloads').getAll()
req.onSuccess = () => { 
 ...
}

However, the IDB storage necessarily removes functions, callbacks, etc. So downloads.download would need to be refactored to accept this.

[inbasic]

I am not sure how to replicate this. As far as I see, the function does not rely on the existing entries of downloads.cache after a restart. The downloads.download({}, id => {..}) is supposed to prepare a new download entry so the cache must be available.