perf(circuitbreak): no allocation for MW

goos: darwin
goarch: arm64
pkg: github.com/cloudwego/kitex/pkg/circuitbreak
             │  ./old.txt  │             ./new.txt              │
             │   sec/op    │   sec/op     vs base               │
CBSuiteMW-12   95.53n ± 4%   70.98n ± 7%  -25.69% (p=0.002 n=6)

             │ ./old.txt  │             ./new.txt             │
             │    B/op    │   B/op     vs base                │
CBSuiteMW-12   40.00 ± 0%   0.00 ± 0%  -100.00% (p=0.002 n=6)

             │ ./old.txt  │             ./new.txt              │
             │ allocs/op  │ allocs/op   vs base                │
CBSuiteMW-12   2.000 ± 0%   0.000 ± 0%  -100.00% (p=0.002 n=6)

.gitignore

@@ -50,9 +50,12 @@ tool/cmd/kitex/kitex
 # remote dump file
 *.json
 base1.go
-dump.txt
 base2.go
 
+# tmp files
+*.txt
+*.bak
+
 # Go workspace file
 go.work
 go.work.sum

pkg/circuitbreak/cbsuite.go

@@ -24,6 +24,7 @@ import (
 	"time"
 
 	"github.com/bytedance/gopkg/cloud/circuitbreaker"
+	"github.com/bytedance/gopkg/collection/skipmap"
 
 	"github.com/cloudwego/kitex/pkg/discovery"
 	"github.com/cloudwego/kitex/pkg/endpoint"
@@ -38,11 +39,11 @@ const (
 	cbConfig      = "cb_config"
 )
 
-var defaultCBConfig = CBConfig{Enable: true, ErrRate: 0.5, MinSample: 200}
+var defaultCBConfig = &CBConfig{Enable: true, ErrRate: 0.5, MinSample: 200}
 
 // GetDefaultCBConfig return defaultConfig of CircuitBreaker.
 func GetDefaultCBConfig() CBConfig {
-	return defaultCBConfig
+	return *defaultCBConfig
 }
 
 // CBConfig is policy config of CircuitBreaker.
@@ -96,13 +97,15 @@ type CBSuite struct {
 	instanceControl *Control
 
 	genServiceCBKey GenServiceCBKeyFunc
-	serviceCBConfig sync.Map // map[serviceCBKey]CBConfig
+	serviceCBConfig *skipmap.StringMap // map[serviceCBKey]*CBConfig
 
 	instanceCBConfig instanceCBConfig
 
 	events event.Queue
 
 	config CBSuiteConfig
+
+	mu sync.Mutex
 }
 
 // NewCBSuite to build a new CBSuite.
@@ -112,8 +115,9 @@ func NewCBSuite(genKey GenServiceCBKeyFunc, options ...CBSuiteOption) *CBSuite {
 	s := &CBSuite{
 		genServiceCBKey: genKey,
 		instanceCBConfig: instanceCBConfig{
-			CBConfig: defaultCBConfig,
+			CBConfig: GetDefaultCBConfig(),
 		},
+		serviceCBConfig: skipmap.NewString(),
 		config: CBSuiteConfig{
 			serviceGetErrorTypeFunc:  ErrorTypeOnServiceLevel,
 			instanceGetErrorTypeFunc: ErrorTypeOnInstanceLevel,
@@ -162,7 +166,7 @@ func (s *CBSuite) ServiceControl() *Control {
 // UpdateServiceCBConfig is to update service CircuitBreaker config.
 // This func is suggested to be called in remote config module.
 func (s *CBSuite) UpdateServiceCBConfig(key string, cfg CBConfig) {
-	s.serviceCBConfig.Store(key, cfg)
+	s.serviceCBConfig.Store(key, &cfg)
 }
 
 // UpdateInstanceCBConfig is to update instance CircuitBreaker param.
@@ -221,7 +225,7 @@ func (s *CBSuite) initServiceCB() {
 		ri := rpcinfo.GetRPCInfo(ctx)
 		serviceCBKey = s.genServiceCBKey(ri)
 		cbConfig, _ := s.serviceCBConfig.LoadOrStore(serviceCBKey, defaultCBConfig)
-		enabled = cbConfig.(CBConfig).Enable
+		enabled = cbConfig.(*CBConfig).Enable
 		return
 	}
 	s.serviceControl = &Control{
@@ -297,7 +301,7 @@ func (s *CBSuite) discoveryChangeHandler(e *event.Event) {
 
 func (s *CBSuite) svcTripFunc(key string) circuitbreaker.TripFunc {
 	pi, _ := s.serviceCBConfig.LoadOrStore(key, defaultCBConfig)
-	p := pi.(CBConfig)
+	p := pi.(*CBConfig)
 	return circuitbreaker.RateTripFunc(p.ErrRate, p.MinSample)
 }
 
@@ -338,18 +342,17 @@ func cbDebugInfo(panel circuitbreaker.Panel) map[string]interface{} {
 
 func (s *CBSuite) configInfo() map[string]interface{} {
 	svcCBMap := make(map[string]interface{})
-	s.serviceCBConfig.Range(func(key, value interface{}) bool {
-		svcCBMap[key.(string)] = value
+	s.serviceCBConfig.Range(func(key string, value interface{}) bool {
+		svcCBMap[key] = *value.(*CBConfig)
 		return true
 	})
 	s.instanceCBConfig.RLock()
 	instCBConfig := s.instanceCBConfig.CBConfig
 	s.instanceCBConfig.RUnlock()
-
-	cbMap := make(map[string]interface{}, 2)
-	cbMap[serviceCBKey] = svcCBMap
-	cbMap[instanceCBKey] = instCBConfig
-	return cbMap
+	return map[string]interface{}{
+		serviceCBKey:  svcCBMap,
+		instanceCBKey: instCBConfig,
+	}
 }
 
 // RPCInfo2Key is to generate circuit breaker key through rpcinfo

pkg/circuitbreak/cbsuite_test.go

@@ -48,7 +48,7 @@ func TestNewCBSuite(t *testing.T) {
 	cb := NewCBSuite(RPCInfo2Key)
 	test.Assert(t, cb.servicePanel == nil)
 	test.Assert(t, cb.instancePanel == nil)
-	test.Assert(t, cb.instanceCBConfig.CBConfig == defaultCBConfig)
+	test.Assert(t, cb.instanceCBConfig.CBConfig == GetDefaultCBConfig())
 	test.Assert(t, sameFuncPointer(cb.genServiceCBKey, RPCInfo2Key))
 	test.Assert(t, sameFuncPointer(cb.config.instanceGetErrorTypeFunc, ErrorTypeOnInstanceLevel))
 	test.Assert(t, sameFuncPointer(cb.config.serviceGetErrorTypeFunc, ErrorTypeOnServiceLevel))
@@ -661,3 +661,14 @@ func TestCBConfig_Equals(t *testing.T) {
 		})
 	}
 }
+
+func BenchmarkCBSuiteMW(b *testing.B) {
+	ctx := prepareCtx()
+	p := NewCBSuite(func(ri rpcinfo.RPCInfo) string { return "BenchmarkCBSuite" })
+	smw := p.ServiceCBMW()
+	noop := func(ctx context.Context, req, resp interface{}) (err error) { return nil }
+	ep := smw(noop)
+	for i := 0; i < b.N; i++ {
+		ep(ctx, b, b)
+	}
+}