Reduce unnecessary MutableCFOptions copies and parameters #13301
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Summary: As follow-up to facebook#13239, this change is primarily motivated by simplifying the calling conventions of LogAndApply. Since it must be called while holding the DB mutex, it can read safely read cfd->GetLatestMutableCFOptions(), until it releases the mutex. Before it releases the mutex, it makes a copy of the mutable options in a new, unpublished Version object, which can be used when not holding the DB mutex. This eliminates the need for callers of LogAndApply to copy mutable options for its sake, or even specify mutable options at all. And it eliminates the need for *another* copy saved in ManifestWriter. Other functions that don't need the mutable options parameter: * ColumnFamilyData::CreateNewMemtable() * CompactionJob::Install() / InstallCompactionResults() * MemTableList::*InstallMemtable*() * Version::PrepareAppend() Test Plan: existing tests, CI with sanitizers
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mszeszko-meta
approved these changes
Jan 16, 2025
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Summary: As follow-up to #13239, this change is primarily motivated by simplifying the calling conventions of LogAndApply. Since it must be called while holding the DB mutex, it can read safely read cfd->GetLatestMutableCFOptions(), until it releases the mutex within ProcessManifestWrites. Before it releases the mutex, it makes a copy of the mutable options in a new, unpublished Version object, which can be used when not holding the DB mutex. This eliminates the need for callers of LogAndApply to copy mutable options for its sake, or even specify mutable options at all. And it eliminates the need for another copy to be saved in ManifestWriter.
Other functions that don't need the mutable options parameter:
Test Plan: existing tests, CI with sanitizers