made indexAll and retagAll atomic and faster

pkg/db/mutex.go

@@ -0,0 +1,32 @@
+// Copyright (C) 2019 Marius Schellenberger
+
+package db
+
+import "sync/atomic"
+
+type countMutex struct {
+	mu  uint64
+	max uint64
+	c   uint64
+}
+
+func (cm *countMutex) Lock() (uint64, uint64, bool) {
+	if atomic.CompareAndSwapUint64(&cm.mu, 0, 1) {
+		return 0, 0, true
+	}
+	return atomic.LoadUint64(&cm.max), atomic.LoadUint64(&cm.c), false
+}
+
+func (cm *countMutex) Set(max uint64) {
+	atomic.StoreUint64(&cm.max, max)
+}
+
+func (cm *countMutex) Inc() {
+	atomic.AddUint64(&cm.c, 1)
+}
+
+func (cm *countMutex) Unlock() {
+	atomic.StoreUint64(&cm.max, 0)
+	atomic.StoreUint64(&cm.c, 0)
+	atomic.StoreUint64(&cm.mu, 0)
+}