Add ConcurrencyLimit

client/concurrencylimit.go

@@ -0,0 +1,34 @@
+package client
+
+import "context"
+
+import "golang.org/x/sync/semaphore"
+
+type ConcurrencyLimit struct {
+	sem *semaphore.Weighted
+}
+
+func NewConcurrencyLimit(limit int64) *ConcurrencyLimit {
+	return &ConcurrencyLimit{
+		sem: semaphore.NewWeighted(limit),
+	}
+}
+
+func (cl *ConcurrencyLimit) Acquire1() {
+	cl.AcquireN(1)
+}
+
+func (cl *ConcurrencyLimit) AcquireN(cost int64) {
+	err := cl.sem.Acquire(context.TODO(), cost)
+	if err != nil {
+		panic(err)
+	}
+}
+
+func (cl *ConcurrencyLimit) Release1() {
+	cl.ReleaseN(1)
+}
+
+func (cl *ConcurrencyLimit) ReleaseN(cost int64) {
+	cl.sem.Release(cost)
+}