[FIX] Limit new message list query size to 50 (#2947)

* Limit query to 50

* Remove observable

app/views/NewMessageView.js

@@ -4,7 +4,6 @@ import {
 	View, StyleSheet, FlatList, Text
 } from 'react-native';
 import { connect } from 'react-redux';
-import orderBy from 'lodash/orderBy';
 import { Q } from '@nozbe/watermelondb';
 import * as List from '../containers/List';
 
@@ -27,6 +26,8 @@ import { createChannelRequest } from '../actions/createChannel';
 import { goRoom } from '../utils/goRoom';
 import SafeAreaView from '../containers/SafeAreaView';
 
+const QUERY_SIZE = 50;
+
 const styles = StyleSheet.create({
 	button: {
 		height: 46,
@@ -74,25 +75,20 @@ class NewMessageView extends React.Component {
 		};
 	}
 
-	componentWillUnmount() {
-		if (this.querySubscription && this.querySubscription.unsubscribe) {
-			this.querySubscription.unsubscribe();
-		}
-	}
-
 	// eslint-disable-next-line react/sort-comp
 	init = async() => {
 		try {
 			const db = database.active;
-			const observable = await db.collections
+			const chats = await db.collections
 				.get('subscriptions')
-				.query(Q.where('t', 'd'))
-				.observeWithColumns(['room_updated_at']);
+				.query(
+					Q.where('t', 'd'),
+					Q.experimentalTake(QUERY_SIZE),
+					Q.experimentalSortBy('room_updated_at', Q.desc)
+				)
+				.fetch();
 
-			this.querySubscription = observable.subscribe((data) => {
-				const chats = orderBy(data, ['roomUpdatedAt'], ['desc']);
-				this.setState({ chats });
-			});
+			this.setState({ chats });
 		} catch (e) {
 			log(e);
 		}