Efficient Contact Syncing For Android Apps

Certainly! Here's a summary of your problem:

Problem Statement: Contact Syncing Between Two Android Apps

You have two Android applications:

App1: This app reads contacts from the device, stores them in a local database using the contact ID as a unique key, and syncs this data to a cloud service. It checks for updates by comparing the contact IDs in the device's contact list with those in the local database. If a contact is missing or has a new ID, App1 updates the local database and syncs the changes to the server.

App2: This new app reads contacts from the cloud and writes them to the device's contact list. When App2 writes these contacts, it generates new contact IDs, which then triggers App1 to resync the contacts. This creates a cycle where App1 syncs the cloud contacts, and then App2 reads and writes these contacts back to the device, causing further updates and resyncs.

Issue: The interaction between App1 and App2 leads to a feedback loop of continuous syncing, causing inefficiencies and potential data inconsistencies. Each app triggers the other, leading to unnecessary updates and synchronization tasks.