Angular2 - 检查 IndexedDB 的使用情况

Question

我需要检查 indexedDb 的使用情况，以了解我可以使用多少可用空间。

我必须在 Angular2-4 应用程序中检查这一点。

如何做到这一点？

感谢支持

Answer 1

你可以试试这个。

// ##### START BOILERPLATE ######
var db;
var databaseName = 'database';
var objectStoreName = 'store1';
var req = indexedDB.open(databaseName);
req.onupgradeneeded = function() {
  db = req.result;
  db.createObjectStore(objectStoreName);
};
req.onsuccess = function() {
  db = req.result;
  main();
}
// ##### END BOILERPLATE ######

var control;
function main() {
  var txn = db.transaction([objectStoreName], 'readonly'];
  control = txn.observe(observerFunction);
  txn.oncomplete = function() {
    console.log('Observing is starting!');
  }
}

function observerFunction(changes) {
  console.log('Observer received changes!');
  // An object store that we're observing has changed.
  changes.records.forEach(function(records, objectStoreName) {
    console.log('Got changes for object store: ', objectStoreName);
    records.forEach(function(change) {
      // do something with change.type and change.key
      var type = change.type;
      switch (type) {
        case 'clear':
          console.log('object store cleared.');
          break;
        case 'add':
          console.log('key "', change.key, '" added.');
          break;
        case 'put':
          console.log('key "', change.key, '" putted.');
          break;
        case 'delete':
          console.log('key or range "', change.key, '" deleted.');
          break;
      }
    });
  });
}