[#1639] qos: Add interceptors for limiting active RPCs

Signed-off-by: Aleksey Savchuk <a.savchuk@yadro.com>

internal/qos/grpc.go

@@ -0,0 +1,43 @@
+package qos
+
+import (
+	"context"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-qos/limiting"
+	"git.frostfs.info/TrueCloudLab/frostfs-qos/tagging"
+	apistatus "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/client/status"
+	"google.golang.org/grpc"
+)
+
+func NewMaxActiveRPCLimiterUnaryServerInterceptor(lr *limiting.Limiter) grpc.UnaryServerInterceptor {
+	return func(ctx context.Context, req any, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (resp any, err error) {
+		if tag, ok := tagging.IOTagFromContext(ctx); ok && tag == IOTagCritical.String() {
+			return handler(ctx, req)
+		}
+
+		release, ok := lr.TryAcquire(info.FullMethod)
+		if !ok {
+			return nil, new(apistatus.ResourceExhausted)
+		}
+		defer release()
+
+		return handler(ctx, req)
+	}
+}
+
+//nolint:contextcheck
+func NewMaxActiveRPCLimiterStreamServerInterceptor(lr *limiting.Limiter) grpc.StreamServerInterceptor {
+	return func(srv any, ss grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
+		if tag, ok := tagging.IOTagFromContext(ss.Context()); ok && tag == IOTagCritical.String() {
+			return handler(srv, ss)
+		}
+
+		release, ok := lr.TryAcquire(info.FullMethod)
+		if !ok {
+			return new(apistatus.ResourceExhausted)
+		}
+		defer release()
+
+		return handler(srv, ss)
+	}
+}