EDMC Journal Events Crashing Plugins: A Fix

Hey guys! Ever been in a situation where Elite: Dangerous Market Connector (EDMC) throws a wrench in your plugin operations? Specifically, have you experienced that sinking feeling when your favorite plugins stop working because of some error in the journal event processing? Well, you're not alone. I've been there, and this article is all about how EDMC's journal event handling can go wrong, causing runtime errors that break plugins. We'll dive deep into the problem, why it happens, and how to potentially fix it.

The Core Issue: Runtimes and Journal Events

Let's start by getting to the heart of the matter. The main culprit here is how EDMC processes journal events. The code in EDMarketConnector.py:journal_event() is a crucial piece of the puzzle. This section is responsible for handling the data from the game's journal files. However, a major design flaw is the lack of try-except blocks around critical operations. This means if anything goes wrong during event processing – a missing file, a misconfigured directory, or any other unexpected issue – the entire process grinds to a halt. This disruption can then prevent plugins from receiving the data they need, causing them to fail.

I’ve seen firsthand how this can cripple things. For instance, if your ships.json file isn’t up-to-date, a simple key error can bring everything crashing down. Moreover, a misconfigured output directory is another common pitfall. Once the output directory is not properly set up, and you’ve enabled ship loadout exports, plugins that rely on Loadout events will be left high and dry because EDMC errors out before the data is passed to them. Basically, a single runtime error can cascade, taking down multiple plugins.

Understanding the Bug: How It Manifests

Let's break down the issue. The primary problem lies in the fact that EDMC doesn't gracefully handle exceptions within the journal event processing. A snippet from the logs highlights this: the code is unable to find a specified directory due to a FileNotFoundError. Since this error isn't caught, it interrupts the entire journal event processing, including the vital plug.notify_journal_entry() calls. This interruption means that plugins miss out on important updates, leading to a host of problems. In essence, any small hiccup can have huge consequences.

Imagine you're trying to use a plugin that tracks your ship's loadout. If the export process fails due to a missing directory, the plugin won't receive the loadout data, making the plugin useless. So, the bug is a failure to catch runtime exceptions and keep the journal event process flowing. In a perfect world, EDMC would catch these errors, log them, and keep passing data to the plugins.

How to Reproduce the Issue: A Step-by-Step Guide

Recreating this bug isn't always straightforward because it depends on specific conditions. However, here's a general guide to help you reproduce the issue. To reproduce the bug, you'll need to create a scenario where EDMC encounters an error while processing journal events. A common way to do this is to mess with the output directory settings. Start by clearing your output directory. Then, make sure ship loadout exports are enabled within EDMC's settings. With these settings, any failure during the export process will cause the journal event processing to halt, breaking any plugins. This setup simulates the real-world scenarios where the bug is most likely to appear.

Expected Behavior vs. Reality

So, what should happen? The expected behavior is pretty simple: EDMC should be robust enough to handle errors gracefully. When an error occurs during journal event processing, EDMC should catch it, log the error, and continue processing. It should ideally still call plug.notify_journal_entry(). This design would prevent a single error from bringing everything down. By implementing try-except blocks, the application can isolate the errors and make sure that a single problem doesn't affect the entire system.

In reality, however, the lack of error handling causes EDMC to crash. This crash then stops the journal event processing, which cuts off plugins. This is a critical problem because it can lead to data loss or plugin failure, especially if the data is crucial for the plugin to work.

Why This Matters: Impact on Users and Plugins

The impact of this bug is significant for both users and developers of plugins. For users, it means that plugins might not function correctly, leading to a disrupted gaming experience. Important features, like tracking market data or managing ship builds, could become unavailable. The whole point of EDMC is to enhance the game experience; however, this bug directly contradicts that purpose.

For plugin developers, the bug creates a frustrating situation. Plugins that rely on journal events could become unreliable. This unreliability increases development time and maintenance. Developers must spend extra effort trying to work around the bug, and constantly monitoring the program for potential issues. The bug can erode trust in EDMC, which is a key tool for a lot of people.

Potential Solutions and Workarounds

Here are some possible solutions and workarounds for the problem. The most effective solution is to add try-except blocks around the critical operations in EDMarketConnector.py:journal_event(). These blocks would catch any runtime errors, allowing EDMC to continue processing events and notify plugins. Additionally, specific error handling for common issues, such as missing files or misconfigured directories, could be implemented. This would improve EDMC's resilience to errors.

As for workarounds, users can manually check output directories and make sure that files are up-to-date. Users could also try to validate plugin configurations. These steps can help minimize the impact of the bug. Keep in mind that these workarounds are temporary and should not be used as a replacement for fixing the core problem.

Confirming the Issue and Gathering Information

Before we dive deeper, it's always good practice to check a few things. First, check the Known Issues list on the EDCD GitHub repository. See if the bug has already been reported or addressed. If you find a duplicate entry, you can contribute to the existing discussion. Next, review the Troubleshooting Guide to look for workarounds. The guide might offer temporary solutions to keep EDMC running smoothly.

When reporting this type of issue, always include your EDMC version, game version, and operating system details. Provide detailed steps on how to reproduce the bug, along with any relevant log files. Include all the details to help the developers understand the issue and create a fix.

Conclusion: Making EDMC More Robust

To wrap it up, the lack of proper error handling in EDMC's journal event processing can lead to significant issues, impacting plugin functionality and user experience. Addressing this bug will increase the reliability of EDMC and improve the overall experience. By implementing robust error handling with try-except blocks, EDMC can become more resilient. This will then reduce the chances of plugin failures and ensure a smoother gameplay experience. I hope that by highlighting this problem, it will lead to a more stable and user-friendly experience for everyone! Keep on exploring, commanders!