Optimize UpdateStatuses function with cache

Author: pmysl

pkg/storage/status.go

@@ -2,6 +2,7 @@ package storage
 
 import (
 	"context"
+	"encoding/hex"
 	"fmt"
 	"net"
 
@@ -16,6 +17,8 @@ type UpdateStatusesArgs struct {
 	Counters           StatusTx
 }
 
+var bcryptCache = make(map[string]bool)
+
 // UpdateStatuses set online user fields, with any device's MAC equal to one
 // of addresses from given slice, to true and writes them to database.
 func UpdateStatuses(ctx context.Context, args UpdateStatusesArgs) error {
@@ -30,9 +33,21 @@ func UpdateStatuses(ctx context.Context, args UpdateStatusesArgs) error {
 
 	for _, address := range args.Addresses {
 		for _, device := range devices {
-			if err := bcrypt.CompareHashAndPassword(device.MAC, address); err == nil {
+			var matched bool
+			cacheKey := generateCacheKey(device.MAC, address)
+
+			if val, ok := bcryptCache[cacheKey]; ok {
+				matched = val
+			} else {
+				err := bcrypt.CompareHashAndPassword(device.MAC, address)
+				matched = err == nil
+				bcryptCache[cacheKey] = matched
+			}
+
+			if matched {
 				known += 1
 				onlineIDs = append(onlineIDs, device.OwnerID)
+				break
 			}
 		}
 	}
@@ -56,3 +71,7 @@ func UpdateStatuses(ctx context.Context, args UpdateStatusesArgs) error {
 			return nil
 		})
 }
+
+func generateCacheKey(mac []byte, address net.HardwareAddr) string {
+	return string(mac) + ":" + hex.EncodeToString(address)
+}