Init V4 community edition (#2265)

* Init V4 community edition

* Init V4 community edition

pkg/queue/metric.go

@@ -0,0 +1,79 @@
+package queue
+
+import "sync/atomic"
+
+// Metric interface
+type Metric interface {
+	IncBusyWorker()
+	DecBusyWorker()
+	BusyWorkers() uint64
+	SuccessTasks() uint64
+	FailureTasks() uint64
+	SubmittedTasks() uint64
+	IncSuccessTask()
+	IncFailureTask()
+	IncSubmittedTask()
+}
+
+var _ Metric = (*metric)(nil)
+
+type metric struct {
+	busyWorkers     uint64
+	successTasks    uint64
+	failureTasks    uint64
+	submittedTasks  uint64
+	suspendingTasks uint64
+}
+
+// NewMetric for default metric structure
+func NewMetric() Metric {
+	return &metric{}
+}
+
+func (m *metric) IncBusyWorker() {
+	atomic.AddUint64(&m.busyWorkers, 1)
+}
+
+func (m *metric) DecBusyWorker() {
+	atomic.AddUint64(&m.busyWorkers, ^uint64(0))
+}
+
+func (m *metric) BusyWorkers() uint64 {
+	return atomic.LoadUint64(&m.busyWorkers)
+}
+
+func (m *metric) IncSuccessTask() {
+	atomic.AddUint64(&m.successTasks, 1)
+}
+
+func (m *metric) IncFailureTask() {
+	atomic.AddUint64(&m.failureTasks, 1)
+}
+
+func (m *metric) IncSubmittedTask() {
+	atomic.AddUint64(&m.submittedTasks, 1)
+}
+
+func (m *metric) SuccessTasks() uint64 {
+	return atomic.LoadUint64(&m.successTasks)
+}
+
+func (m *metric) FailureTasks() uint64 {
+	return atomic.LoadUint64(&m.failureTasks)
+}
+
+func (m *metric) SubmittedTasks() uint64 {
+	return atomic.LoadUint64(&m.submittedTasks)
+}
+
+func (m *metric) SuspendingTasks() uint64 {
+	return atomic.LoadUint64(&m.suspendingTasks)
+}
+
+func (m *metric) IncSuspendingTask() {
+	atomic.AddUint64(&m.suspendingTasks, 1)
+}
+
+func (m *metric) DecSuspendingTask() {
+	atomic.AddUint64(&m.suspendingTasks, ^uint64(0))
+}