client: refactor intercepted client

internal/client/client_interceptor.go

@@ -41,23 +41,49 @@ func NewInterceptedClient(client Client) Client {
 	return interceptedClient{client}
 }
 
-func (r interceptedClient) SendRequest(ctx context.Context, addr string, req *tikvrpc.Request, timeout time.Duration) (*tikvrpc.Response, error) {
-	// Build the resource control interceptor.
-	var finalInterceptor interceptor.RPCInterceptor = buildResourceControlInterceptor(ctx, req)
-	// Chain the interceptors if there are multiple interceptors.
-	if it := interceptor.GetRPCInterceptorFromCtx(ctx); it != nil {
-		if finalInterceptor != nil {
-			finalInterceptor = interceptor.ChainRPCInterceptors(finalInterceptor, it)
-		} else {
-			finalInterceptor = it
+func (r interceptedClient) SendRequest(ctx context.Context, addr string, req *tikvrpc.Request, timeout time.Duration) (resp *tikvrpc.Response, err error) {
+	var ruDetails *util.RUDetails
+
+	resourceGroupName, resourceControlInterceptor, reqInfo := getResourceControlInfo(ctx, req)
+	if resourceControlInterceptor != nil {
+		consumption, penalty, waitDuration, priority, err := resourceControlInterceptor.OnRequestWait(ctx, resourceGroupName, reqInfo)
+		if err != nil {
+			return nil, err
+		}
+		req.GetResourceControlContext().Penalty = penalty
+		// override request priority with resource group priority if it's not set.
+		// Get the priority at tikv side has some performance issue, so we pass it
+		// at client side. See: https://github.com/tikv/tikv/issues/15994 for more details.
+		if req.GetResourceControlContext().OverridePriority == 0 {
+			req.GetResourceControlContext().OverridePriority = uint64(priority)
+		}
+
+		if val := ctx.Value(util.RUDetailsCtxKey); val != nil {
+			ruDetails = val.(*util.RUDetails)
+			ruDetails.Update(consumption, waitDuration)
 		}
 	}
-	if finalInterceptor != nil {
-		return finalInterceptor.Wrap(func(target string, req *tikvrpc.Request) (*tikvrpc.Response, error) {
+
+	if ctxInterceptor := interceptor.GetRPCInterceptorFromCtx(ctx); ctxInterceptor == nil {
+		resp, err = r.Client.SendRequest(ctx, addr, req, timeout)
+	} else {
+		resp, err = ctxInterceptor.Wrap(func(target string, req *tikvrpc.Request) (*tikvrpc.Response, error) {
 			return r.Client.SendRequest(ctx, target, req, timeout)
 		})(addr, req)
 	}
-	return r.Client.SendRequest(ctx, addr, req, timeout)
+
+	if resourceControlInterceptor != nil && resp != nil {
+		respInfo := resourcecontrol.MakeResponseInfo(resp)
+		consumption, waitDuration, err := resourceControlInterceptor.OnResponseWait(ctx, resourceGroupName, reqInfo, respInfo)
+		if err != nil {
+			return nil, err
+		}
+		if ruDetails != nil {
+			ruDetails.Update(consumption, waitDuration)
+		}
+	}
+
+	return resp, err
 }
 
 var (
@@ -67,9 +93,43 @@ var (
 	ResourceControlInterceptor atomic.Pointer[resourceControlClient.ResourceGroupKVInterceptor]
 )
 
+func getResourceControlInfo(ctx context.Context, req *tikvrpc.Request) (
+	string,
+	resourceControlClient.ResourceGroupKVInterceptor,
+	*resourcecontrol.RequestInfo,
+) {
+	resourceGroupName := req.GetResourceControlContext().GetResourceGroupName()
+	if len(resourceGroupName) == 0 {
+		return "", nil, nil
+	}
+	if !ResourceControlSwitch.Load().(bool) {
+		return "", nil, nil
+	}
+	rcInterceptor := ResourceControlInterceptor.Load()
+	if rcInterceptor == nil {
+		return "", nil, nil
+	}
+	// bypass some internal requests and it's may influence user experience. For example, the
+	// request of `alter user password`, totally bypasses the resource control. it's not cost
+	// many resources, but it's may influence the user experience.
+	// If the resource group has background jobs, we should not record consumption and wait for it.
+	// Background jobs will record and report in tikv side.
+	resourceControlInterceptor := *rcInterceptor
+	if resourceControlInterceptor.IsBackgroundRequest(ctx, resourceGroupName, req.RequestSource) {
+		return "", nil, nil
+	}
+	reqInfo := resourcecontrol.MakeRequestInfo(req)
+	if reqInfo.Bypass() {
+		return "", nil, nil
+	}
+	return resourceGroupName, resourceControlInterceptor, reqInfo
+}
+
 // buildResourceControlInterceptor builds a resource control interceptor with
 // the given resource group name.
-func buildResourceControlInterceptor(
+//
+// Deprecated: embedded in `interceptedClient.SendRequest` directly to reduce overhead.
+func buildResourceControlInterceptor( //nolint:unused
 	ctx context.Context,
 	req *tikvrpc.Request,
 ) interceptor.RPCInterceptor {