Merge branch 'delayedClosing' into vecToDocMap

faiss_vector_cache.go

@@ -238,6 +238,28 @@ func (vc *vecIndexCache) monitor() {
 	}
 }
 
+func (vc *vecIndexCache) update(fieldIDPlus1 uint16,
+	index *faiss.IndexImpl, vecDocIDMap map[int64]uint32) {
+	vc.m.Lock()
+
+	// the first time we've hit the cache, try to spawn a monitoring routine
+	// which will reconcile the moving averages for all the fields being hit
+	if len(vc.cache) == 0 {
+		go vc.monitor()
+	}
+
+	_, ok := vc.cache[fieldIDPlus1]
+	if !ok {
+		//  initializing the alpha with 0.4 essentially means that we are favoring
+		// 	the history a little bit more relative to the current sample value.
+		// 	this makes the average to be kept above the threshold value for a
+		// 	longer time and thereby the index to be resident in the cache
+		// 	for longer time.
+		vc.cache[fieldIDPlus1] = initCacheEntry(index, vecDocIDMap, 0.4)
+	}
+	vc.m.Unlock()
+}
+
 func (e *ewma) add(val uint64) {
 	if e.avg == 0.0 {
 		e.avg = float64(val)