symfony/symfony — pull request #4321 by simon-n (2012-05-18 08:54:16+00:00)
Title: [HttpKernel] prevent loading complete profile structures upon writes

The abstract class "PdoProfilerStorage" uses its ::read() method to decide if a profiler record has to be updated or initially created upon a ::write() call. This possibly causes huge memory consumption, as ::read() recursively reads all existing profiles using ::createProfileFromData() calls. When handling many sub-request this may lead into either a "out of memory" or XDebug's "maximum nesting level reached" - whichever comes first.
To prevent this issue, I added a new protected method ::tokenDataExists() that simply checks whether a record for the token in question already exists in storage.