Lucene.NET is Ugly

If you've ever had to go through the Lucene.NET codebase, I'm sure you’ll agree that it's quite ugly. It does a lot of low-level stuff, which is almost always nasty. It's a port of code from another language and framework, which means that it isn’t idiomatic code, and it has a lot of…strange things going on there.

• Exceptions are used far too often.
• There is a strong tendency to delegate things in such a way that make it hard to figure out where things are actually happening.
• The big stick approach to thread safety (slap a lock on it).
• Some really horrible things with regards to mutable shared state with IndexInputs.

Here's a good example of many of the issues that I'm talking about:

https://github.com/apache/lucene.net/blob/trunk/src/core/Search/FieldCacheImpl.cs#L207

Read this method, and I think you’ll understand.

Then again, you can see methods of similar or greater complexity in RavenDB, for example:

https://github.com/ayende/ravendb/blob/1.2/Raven.Database/Indexing/IndexingExecuter.cs#L60

My main problem with the Lucene.NET codebase is that it feels alien. It isn’t .NET code, and it shows.

Then again, Lucene is also quite beautiful. I’ll talk about this in my next post.