Does Firebase listeners take up huge memory?

Question

Does Firebase listeners like this take up huge heap memory?

ref.addListenerForSingleValueEvent(new com.google.firebase.database.ValueEventListener() {
    @Override
    public void onDataChange(com.google.firebase.database.DataSnapshot snapshot) {
    }
});

At least when the snapshot is taken?

Currently your question is not really specific. Maybe change it to: "How much heap memory do firebase listeners take up?" And maybe add samples of the data you put the listeners on. Memory use should be different for a listener on a single string or a listener on a complex object. — André Kool, Feb 26 '18 at 10:42

score 1 · Answer 1 · edited Feb 26 '18 at 10:37

1

addListenerForSingleValueEvent() will take snapshot or sync data only once when called, if there is a change in the data of that node and internet connection is available.

addValueEventListener() will take snapshot or sync data from node whenever there is a change in data of that node and internet connection is available.

edited Feb 26 '18 at 10:37

AskNilesh

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answered Feb 26 '18 at 10:35

Shilpy Samaddar

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score 1 · Accepted Answer · answered Feb 26 '18 at 12:51

1

The Firebase Database client keeps a copy of all data that you're listening to in memory of your app. Once you remove the last listener for a location, as we have already discussed here, the data is removed from memory.

When we are speaking about Firebase, everything is about listeners and as a quick response to your question, no, a listener doesn't take huge memory and you can use as many listeners as you want, if remove them correctly.

Using addListenerForSingleValueEvent() means that:

Add a listener for a single change in the data at this location.

So there is no need to remove the listener.

If you have used for example, ref.keepSynced(true), all data at ref location would be kept in memory, and kept up to date.

If you enable persistence, the client will also persist active and recent data to disk.

answered Feb 26 '18 at 12:51

Alex Mamo

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Does ref.keepSynced consume heap memory? – Sreekanth Karumanaghat Feb 26 '18 at 13:33
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Yes, because you'll keep all data at that particular location in memory. – Alex Mamo Feb 26 '18 at 13:33
Does snapShot consume heap memory? – Sreekanth Karumanaghat Feb 26 '18 at 14:09
`Java Heap Space` is the location where are placed the new objects that are created. So when creating a new object of the [DataSnapshot](https://firebase.google.com/docs/reference/android/com/google/firebase/database/DataSnapshot) class you are using heap sapce. – Alex Mamo Feb 26 '18 at 14:13
Does that heap gets deallocated automatically? – Sreekanth Karumanaghat Feb 26 '18 at 14:15
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Yes, it does as in case of all new objects creation. – Alex Mamo Feb 26 '18 at 14:17
Is there everything alright? Can I help you with other informations? – Alex Mamo Mar 19 '18 at 09:16
Thanks for the help. – Sreekanth Karumanaghat Mar 19 '18 at 09:22
You're welcome! If you think that my answer helped you, please consider accepting it. Thanks! – Alex Mamo Mar 19 '18 at 09:23

Does Firebase listeners take up huge memory?

2 Answers2