Fix: DeFi Balances Not Cached In Vultisig IOS

Introduction

In this article, we'll dive deep into a specific bug encountered in the Vultisig iOS application related to DeFi (Decentralized Finance) balances. Specifically, we'll be addressing the issue where DeFi balances are not being cached properly. This lack of caching leads to a degraded user experience, particularly when users navigate in and out of the Chain detail view within the DeFi section of the app. We'll explore the steps to reproduce this bug, the expected behavior, and provide a detailed explanation of the problem, along with a potential solution to enhance the user experience. Caching DeFi balances is crucial for providing a seamless and responsive user interface. Without it, users experience delays and unnecessary data fetching, making the app feel sluggish and less intuitive.

The goal here is to ensure that users always see the latest stored information, even when rapidly navigating between different sections of the app. By implementing proper caching mechanisms, we can significantly reduce the load on the system, minimize data consumption, and provide a more satisfying and efficient user experience. Let’s get started on fixing this issue and optimizing the Vultisig iOS app for DeFi enthusiasts.

Understanding the Bug: DeFi Balances Not Cached

The core of the problem lies in how the Vultisig iOS app manages and stores DeFi balances. When a user navigates to the DeFi tab and views specific chain details, such as Thorchain, the app fetches the relevant balance information. However, instead of caching this data for quick retrieval, the app re-fetches it every time the user returns to that view. This redundant data fetching is inefficient and leads to a noticeable delay, negatively impacting the user experience. Efficiently managing DeFi balances requires a robust caching strategy that minimizes the need for repeated data retrieval.

To better understand the issue, let's consider a typical user scenario: A user checks their Thorchain balance, navigates to another section of the app (e.g., to view other chains or settings), and then returns to the Thorchain view. Without caching, the app must re-fetch the balance information, causing a brief but noticeable delay. This delay, repeated multiple times, can become frustrating and make the app feel unresponsive. The lack of caching is particularly problematic in DeFi applications, where users often need to monitor their balances and transactions frequently. A responsive and up-to-date display of balance information is essential for building trust and confidence in the app. Therefore, implementing a caching mechanism is not just a performance optimization; it's a critical factor in enhancing the overall user experience.

Steps to Reproduce the Bug

To reliably reproduce this bug, follow these steps within the Vultisig iOS application:

1. Navigate to the DeFi Tab: Open the Vultisig app and tap on the DeFi tab located in the main navigation.
2. Enter Thorchain View: Select Thorchain from the list of available chains to view the details of your Thorchain assets.
3. Leave Thorchain View: Navigate away from the Thorchain view by selecting another tab or going back to the main DeFi screen.
4. Re-enter Thorchain View: Return to the Thorchain view by selecting it again from the DeFi tab.
5. Observe the Delay: Notice the delay as the app re-fetches the balance information. This delay indicates that the balances are not being cached.

By consistently following these steps, you can easily observe the issue and confirm that the DeFi balances are indeed not being cached. This reproduction process is crucial for developers to understand the scope and impact of the bug and to verify that the fix is effective. Ensuring that balances are cached significantly improves the responsiveness of the application, especially in scenarios where users frequently switch between different views. This simple test can highlight the importance of caching in enhancing the overall user experience.

Expected Behavior: Caching DeFi Balances

The expected behavior is that the Vultisig iOS app should cache DeFi balances, so users always see the latest stored information without unnecessary delays. When a user navigates to a chain detail view (e.g., Thorchain) for the first time, the app should fetch the balance information from the network. However, instead of discarding this data when the user leaves the view, the app should store it in a cache. The cache can be a local database, an in-memory store, or any other suitable storage mechanism. Subsequent visits to the same chain detail view should retrieve the balance information from the cache instead of re-fetching it from the network. This would result in a significantly faster load time and a smoother user experience. Properly cached DeFi balances ensures a seamless and efficient user experience.

To ensure that the cached data remains up-to-date, the app should implement a mechanism to refresh the cache periodically or when the user explicitly requests a refresh. This could involve setting a timer to automatically refresh the cache every few minutes or providing a “refresh” button that allows the user to manually update the balance information. The caching mechanism should also handle potential errors, such as network connectivity issues or data inconsistencies. In such cases, the app should display an appropriate error message to the user and provide an option to retry fetching the data. By implementing these caching strategies, the Vultisig iOS app can provide a more responsive and reliable user experience, even in situations with limited network connectivity. The primary goal is to minimize the perceived latency and ensure that users always have access to the most recent and accurate information.

Analyzing the Problem: Why Caching Is Essential

Caching is a fundamental technique in software development used to improve performance and reduce latency. In the context of DeFi applications, caching is particularly crucial due to the nature of blockchain data. Fetching data from a blockchain network can be time-consuming and resource-intensive, as it involves querying distributed nodes and waiting for responses. Without caching, the app would need to repeat this process every time the user requests the same data, leading to a poor user experience. Caching DeFi balances is not just about improving speed; it's about providing a usable and enjoyable app.

The benefits of caching extend beyond just faster load times. Caching can also reduce the load on the blockchain network, which can help to improve the overall stability and scalability of the system. By minimizing the number of requests to the network, the app can conserve bandwidth and reduce the risk of overloading the network infrastructure. Furthermore, caching can improve the app's resilience to network outages. If the app is unable to connect to the network, it can still display the cached data, providing the user with at least some information. While the cached data may not be the absolute latest, it is better than displaying an error message or a blank screen. In essence, caching is a critical component of any well-designed DeFi application. It is essential for providing a responsive, reliable, and scalable user experience. The absence of proper caching can significantly degrade the user experience and make the app less competitive in the market. Therefore, investing in a robust caching strategy is a wise decision for any developer building DeFi applications.

Proposed Solution: Implementing a Caching Mechanism

To address the issue of DeFi balances not being cached in the Vultisig iOS app, a robust caching mechanism needs to be implemented. This mechanism should store the balance information retrieved from the blockchain network and serve it from the cache on subsequent requests. Here’s a detailed approach to implementing such a mechanism:

1. Choose a Caching Strategy:

   • In-Memory Cache: Suitable for temporary storage and quick retrieval. Ideal for frequently accessed data that doesn't need to persist across app restarts.
   • Disk-Based Cache: Uses the device's storage to persist data. Useful for caching data that needs to be available even after the app is closed and reopened.
   • Database Cache: Employs a local database (e.g., SQLite) to store data. Provides more structured storage and querying capabilities.

2. Implement the Caching Logic:

   • When the user navigates to a chain detail view, the app should first check if the balance information is available in the cache.
   • If the data is in the cache, it should be displayed immediately.
   • If the data is not in the cache or is stale (e.g., older than a predefined time), the app should fetch the latest balance information from the network.
   • Once the data is fetched, it should be stored in the cache, replacing any existing data.

3. Handle Cache Invalidation:

   • Implement a mechanism to invalidate the cache when the balance information is likely to have changed (e.g., after a transaction).
   • Provide a “refresh” button that allows the user to manually invalidate the cache and fetch the latest data.

4. Manage Cache Expiration:

   • Set an expiration time for the cached data to ensure that it doesn't become too stale.
   • Automatically refresh the cache when the expiration time is reached.

5. Handle Errors Gracefully:

   • If the app is unable to fetch the balance information from the network, it should display an appropriate error message to the user.
   • If the cache is corrupted or unavailable, the app should attempt to recover gracefully or display an error message.

By following these steps, the Vultisig iOS app can effectively cache DeFi balances and provide a much smoother and more responsive user experience. This solution not only addresses the immediate bug but also lays the foundation for future performance optimizations and enhancements.

Conclusion

In conclusion, the lack of caching for DeFi balances in the Vultisig iOS app significantly impacts the user experience. By implementing a robust caching mechanism, the app can provide faster load times, reduce network load, and improve overall responsiveness. The proposed solution involves choosing an appropriate caching strategy, implementing the caching logic, handling cache invalidation, managing cache expiration, and handling errors gracefully. Addressing this bug is crucial for ensuring that the Vultisig iOS app remains competitive and provides a seamless experience for DeFi enthusiasts. Caching DeFi balances is essential for a positive user experience.

By prioritizing performance optimizations and user experience enhancements, the Vultisig team can build a more reliable and user-friendly application. This not only benefits existing users but also attracts new users to the platform. The investment in caching and other performance improvements is a long-term strategy that will pay off in increased user satisfaction and retention. By focusing on the user experience, the Vultisig iOS app can establish itself as a leader in the DeFi space.

For more information on best practices for mobile development and caching strategies, consider visiting Apple's Developer Documentation.