refactor: use the built-in max/min to simplify the code

pkg/storer/cachestore.go

@@ -39,10 +39,9 @@ func (db *DB) cacheWorker(ctx context.Context) {
 				continue
 			}
 
-			evict := uint64(size - capc)
-			if evict < db.reserveOptions.cacheMinEvictCount { // evict at least a min count
-				evict = db.reserveOptions.cacheMinEvictCount
-			}
+			evict := max(uint64(size-capc),
+				// evict at least a min count
+				db.reserveOptions.cacheMinEvictCount)
 
 			dur := captureDuration(time.Now())
 			err := db.cacheObj.RemoveOldest(ctx, db.storage, evict)

pkg/storer/migration/refCntSize.go

@@ -124,10 +124,7 @@ func RefCountSizeInc(s storage.BatchStore, logger log.Logger) func() error {
 		}
 
 		for i := 0; i < len(itemsToDelete); i += 10000 {
-			end := i + 10000
-			if end > len(itemsToDelete) {
-				end = len(itemsToDelete)
-			}
+			end := min(i+10000, len(itemsToDelete))
 
 			b := s.Batch(context.Background())
 			for _, item := range itemsToDelete[i:end] {

pkg/storer/migration/reserveRepair.go

@@ -117,10 +117,7 @@ func ReserveRepairer(
 		batchSize := 1000
 
 		for i := 0; i < len(chunkBinItems); i += batchSize {
-			end := i + batchSize
-			if end > len(chunkBinItems) {
-				end = len(chunkBinItems)
-			}
+			end := min(i+batchSize, len(chunkBinItems))
 			err := st.Run(context.Background(), func(s transaction.Store) error {
 				for _, item := range chunkBinItems[i:end] {
 					err := s.IndexStore().Delete(item)

pkg/storer/reserve.go

@@ -369,10 +369,9 @@ func (db *DB) unreserve(ctx context.Context) (err error) {
 			default:
 			}
 
-			evict := target - totalEvicted
-			if evict < int(db.reserveOptions.minEvictCount) { // evict at least a min count
-				evict = int(db.reserveOptions.minEvictCount)
-			}
+			evict := max(target-totalEvicted,
+				// evict at least a min count
+				int(db.reserveOptions.minEvictCount))
 
 			binEvicted, err := db.evictBatch(ctx, b, evict, radius)
 			// eviction happens in batches, so we need to keep track of the total