RCORE-2059 Truncate the metadata realm in-place rather than deleting and recreating it #7526
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…ing it This solves some locking problems in multi-process scenarios. The flow of checking if the key is valid, deleting the file if not, and then recreating the file if needed needs to be done with an exclusive lock on the file held. This can't be done with DB::call_with_lock() because there isn't a good way to initialize the new file from within the call_with_lock() callback, and instead needs to be pushed into the file initialization guarded by the control mutex.
Pull Request Test Coverage Report for Build thomas.goyne_257Details
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finnschiermer
approved these changes
Apr 3, 2024
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This solves some locking problems in multi-process scenarios. The flow of checking if the key is valid, deleting the file if not, and then recreating the file if needed needs to be done with an exclusive lock on the file held. This can't be done with DB::call_with_lock() because there isn't a good way to initialize the new file from within the call_with_lock() callback, and instead needs to be pushed into the file initialization guarded by the control mutex.
This maps and reads from the file before the call to
note_reader_start(). I think this is fine because it's just validating the header and then unmapping, but I'm not completely sure?