Codeigniter查询缓存不使用文件锁

Question

I was reviewing the CodeIgniter code details and I've found (what I think is) a weird inconsistency between the caching techniques used for DB Queries vs. Views.

For caching Views (via the Output class) Codeigniter uses file locking. This is to ensure multiple simultaneous users do not accidentally write to the same cache file at the same time.

Now this makes absolute sense to me. The problem is, the DB query caching technique (via the DBCache class) does not seem to use this technique, and it's got me thinking.

Is this deliberate? Why would there be no need for file locking for database queries (given that they would also be prone to the same problem above)? Or this is a simple bug in the code?

Answer 1

Found the answer to this myself.

It turns out that Database queries also use file locking.

The DBCache class in Codeigniter uses the File helper - which in turn uses file locking in it's write_file() function.

The Output caching does this more explicitly without the File helper.