App performance become slow after added realm

Goals

Our app is a chat app , we are going to use local realm database to save all message and we are using AsyncStorage now. We think realm is better after we read the doc, so we want to use it.

Expected Results

All message saved in realm database and encrypted. Chatroom will update and show the messages from database.

Actual Results

Messages are displayed, but the app become very slow for any actions.

Steps to Reproduce

Code Sample

This is the realmHelper.js

import Realm from 'realm'

export const DB_CHATROOM = 'ChatRoom'
export const DB_MESSAGE = 'Message'
export const DB_USER = 'User'

export const chatRoomSchema = {
    name: DB_CHATROOM,
    primaryKey: 'id',
    properties: {
        id: { type: 'string' },
        userId: { type: 'string' },
        messages: { type: 'list', objectType: DB_MESSAGE },
    }
}

export const messageSchema = {
    name: DB_MESSAGE,
    primaryKey: '_id',
    properties: {
        _id: { type: 'string' },
        type: { type: 'string' },
        text: { type: 'string' },
        createdAt: { type: 'date', indexed: true },
        user: { type: DB_USER },
    }
}

export const userSchema = {
    name: DB_USER,
    primaryKey: '_id',
    properties: {
        _id: { type: 'string' },
        name: { type: 'string' },
        avatar: { type: 'string', optional: true },
    }
}

const realmConfig = {
    path: 'theartalke.realm',
    schema: [chatRoomSchema, messageSchema, userSchema],
    schemaVersion: 1,
}

export const queryOrCreateChatRoom = (chatRoomId, userId) => new Promise((resolve, reject) => {
    Realm.open(realmConfig).then(realm => {
        realm.write(() => {
            let existQueryChatRoom = realm.objectForPrimaryKey(DB_CHATROOM, chatRoomId)
            if (!existQueryChatRoom) {
                existQueryChatRoom = realm.create(DB_CHATROOM, {
                    id: chatRoomId,
                    userId: userId,
                })
            }

            resolve(existQueryChatRoom)
        })
    }).catch(error => reject(error))
})

export const insertMessage = (chatRoom, incomeMessage) => new Promise((resolve, reject) => {
    Realm.open(realmConfig).then(realm => {
        realm.write(() => {
            let existMessage = realm.objectForPrimaryKey(DB_MESSAGE, incomeMessage._id)
            if (!existMessage) {
                let existUser = realm.objectForPrimaryKey(DB_USER, incomeMessage.user._id)
                if (!existUser) {
                    existUser = realm.create(DB_USER, {
                        _id: incomeMessage.user._id,
                        name: incomeMessage.user.name,
                        avatar: incomeMessage.user.avatar,
                    })
                }

                existMessage = realm.create(DB_MESSAGE, {
                    _id: incomeMessage._id,
                    type: incomeMessage.type,
                    text: incomeMessage.text,
                    createdAt: incomeMessage.createdAt,
                    user: existUser,
                })

                chatRoom.messages.push(existMessage)
            }

            resolve()
        })
    }).catch(error => reject(error))
})

---

we create or get the chatroom first.

const chatRoom = await realmHelper.queryOrCreateChatRoom(this.props.chatRoomId,
      this.props.userInfo.userId)

insert the new message

realmHelper.insertMessage(this.props.chatRoom, incomeMessages)

show the messages using GiftedChat ( FlatList )

<GiftedChat
messages={Array.from(this.props.chatRoom.messages.sorted([['createdAt', true], ['_id', true]]))}
....
/>

Version of Realm and Tooling

• Realm JS SDK Version: 2.15.3
• React Native: 0.56.1
• Client OS & Version: IOS 11.4 and android 8.0
• Which debugger for React Native: both tried

[nirinchev]

Just briefly looking at the code, you probably don’t want to open the Realm every time you want to insert an object - instead save it as a class-level variable upon first opening it and work with that single instance.

[tudiantuan]

Just briefly looking at the code, you probably don’t want to open the Realm every time you want to insert an object - instead save it as a class-level variable upon first opening it and work with that single instance.

Im newbie. You can show code example for me!