def __init__(self, callbackSchedulerFactory, callbackScheduler, ramCacheSize = None):
self.callbackScheduler = callbackScheduler
self.lock_ = threading.RLock()
self.vectorDataIDRequestCount_ = {}
self.vectorDataIDToVectorSlices_ = {}
self.vdm = VectorDataManager.constructVDM(callbackScheduler, ramCacheSize)
self.vdm.setDropUnreferencedPagesWhenFull(True)
self.ramCacheOffloadRecorder = CumulusNative.TrackingOfflineStorage(self.callbackScheduler)
self.vdm.setOfflineCache(self.ramCacheOffloadRecorder)