班级太大了吗？

Question

I'm planning on adding Steam-like achievement to my gaming site. The calculations will be handled by scheduled cron, with the results stored in a typical MySQL database. For convenience's sake I was considering just dumping all the various calculation methods into one giant STATS class. These are methods that would never be called on by any other aspects of the site, only for this particular achievements cron.

Do I need to worry about this class growing too large? It's about 2k LOC now, but there's no reason it couldn't expand to 10k, or 50k, over time...

This is on shared hosting btw, so memory constraints do exist to some degree...

Answer 1

Yes, classes can definitely grow too big.

When that happens, it is usually a sign of misplaced responsibilities. Classes that do too much are an AntiPattern called The Blob aka God class. Those classes violate the Single Responsibiliy Principle and will have a negative impact on coupling and cohesion. That in turn will make your application less reusable and harder to extend and maintain.

To divide Responsibilities properly, consider which data you can logically group together and then make that into a separate object. The same is true for overlongy long methods. Divide them. If you find that a particular subroutine is taking a lot of space in an object, see if you can promote that code to a Strategy encapsulating that algorithm.

In your specific case, it sounds like you could benefit from a Command Pattern, e.g. have one StatsCommander that uses many StatCommands (which are Strategies). That keeps the logic required to get the various stats cleanly separated from each other. When you need to add a new Stat, just add a new Strategy/Command.