Add defragment support for HFE (#13229)
## Background 1. All hash objects that contain HFE are referenced by db->hexpires. 2. All fields in a dict hash object with HFE are referenced by an ebucket. So when we defrag the hash object or the field in a dict with HFE, we also need to update the references in them. ## Interface 1. Add a new interface `ebDefragItem`, which can accept a defrag callback to defrag items in ebuckets, and simultaneously update their references in the ebucket. ## Mainly changes 1. The key type of dict of hash object is no longer sds, so add new `activeDefragHfieldDict()` to defrag the dict instead of `activeDefragSdsDict()`. 2. When we defrag the dict of hash object by using `dictScanDefrag()`, we always set the defrag callback `defragKey` of `dictDefragFunctions` to NULL, because we can't reallocate a field with out updating it's reference in ebuckets. Instead, we will defrag the field of the dict and update its reference in the callback `dictScanDefrag` of dictScanFunction(). 3. When we defrag the hash robj with HFE, we will use `ebDefragItem` to defrag the robj and update the reference in db->hexpires. ## TODO: Defrag ebucket structure incremently, which will be handler in a future PR. --------- Co-authored-by:Ozan Tezcan <ozantezcan@gmail.com> Co-authored-by:
Moti Cohen <moti.cohen@redis.com>
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