CODEWITHSUNDEEP
androidrealmrx-java
curiousily
curiousily

Reputation: 91

Is it ok to close Realm instance after each query/write?

I am trying to figure out what is the best way to open/close Realm instances. We are using Realm in 3 places - App, Activities and Worker thread. However, it might be pretty cool to access data from Realm from any place. Thus, we wrapped all our Realm queries/writes in a Data Layer. Is it ok (from performance point of view) to do the following for every query (and similar on each write)?

try (Realm realm = getRealm()) {
    return realm.copyFromRealm(realm.where(Task.class).isNull("name")
    .findAllSorted("createdAt", Sort.DESCENDING));
}

How do you do something similar in async transaction? Are there better approaches? (We are using RxJava).

Thank you!

EDIT: After quick response from @christian-melchior we will use it like this:

try (Realm realm = getRealm()) {
    return realm.copyFromRealm(realm.where(Task.class).isNull("name")
    .findAllSortedAsync("createdAt", Sort.DESCENDING));
}

EDIT2: We actually settled on this:

Realm realm = getRealm();
return realm.where(Task.class).isNull("name")
  .findAllSortedAsync("createdAt", Sort.DESCENDING)
  .asObservable()
  .filter(RealmResults::isLoaded)
  .first()
  .map(realmObjects -> {
      if (realmObjects.isEmpty()) {
          realm.close();
          return null;
      }
      List<Task> res = realm.copyFromRealm(realmObjects);
      realm.close();
      return res;
  });

Since we want our onComplete to be called after each query.

Upvotes: 1

Views: 2835

Answers (1)

Christian Melchior
Christian Melchior

Reputation: 20126

Using copyFromRealm will give you an in-memory copy of all the data, so as long as you are not loading huge lists, it should work fine. You will use more memory though, and there is a slight overhead in opening and closing Realms all the time.

One idea for controlling the Realm lifecycle can be seen here: https://realm.io/docs/java/latest/#controlling-the-lifecycle-of-realm-instances

Also note you in many cases can use our async API if you are concerned about loading data on the UI thread: https://realm.io/docs/java/latest/#asynchronous-queries

Upvotes: 1

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