rename rpcx to zrpc

zrpc/internal/serverinterceptors/sheddinginterceptor.go

@@ -0,0 +1,52 @@
+package serverinterceptors
+
+import (
+	"context"
+	"sync"
+
+	"github.com/tal-tech/go-zero/core/load"
+	"github.com/tal-tech/go-zero/core/stat"
+	"google.golang.org/grpc"
+)
+
+const serviceType = "rpc"
+
+var (
+	sheddingStat *load.SheddingStat
+	lock         sync.Mutex
+)
+
+func UnarySheddingInterceptor(shedder load.Shedder, metrics *stat.Metrics) grpc.UnaryServerInterceptor {
+	ensureSheddingStat()
+
+	return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo,
+		handler grpc.UnaryHandler) (val interface{}, err error) {
+		sheddingStat.IncrementTotal()
+		var promise load.Promise
+		promise, err = shedder.Allow()
+		if err != nil {
+			metrics.AddDrop()
+			sheddingStat.IncrementDrop()
+			return
+		}
+
+		defer func() {
+			if err == context.DeadlineExceeded {
+				promise.Fail()
+			} else {
+				sheddingStat.IncrementPass()
+				promise.Pass()
+			}
+		}()
+
+		return handler(ctx, req)
+	}
+}
+
+func ensureSheddingStat() {
+	lock.Lock()
+	if sheddingStat == nil {
+		sheddingStat = load.NewSheddingStat(serviceType)
+	}
+	lock.Unlock()
+}