[10.x] Prevent DB Cache::get() occur race condition

[xdevor]

Problem I

Database Cache::get() will delete expired cache record automatically, but the current implementation may occur race condition, for example:

imagine there're two process run parallell

• pA: exec Cache::get()
• pB: exec Cache:put()

if pA get a expired cache from DB but the deletion hasn't been executed yet, then pB put() a new cache record to DB, later when pA execute forget() it will delete the new cache which put from pB.

Solution

call forgetIfExpired() instead of forget() in Cache::get()

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Problem II

When i write integration tests for this pull request, I found that
current DB Cache::add() has a bug from this PR (I'm sorry 😢),
in add() method the $key which pass to get() already concat prefix and get() will concat prefix again it self so the result will be wrong

Solution

pass $noPrefixKey to get() on Cache::add()