Circuit breaker refactor and enhance the scalability of stat module

api/slot_chain.go

@@ -2,6 +2,7 @@ package api
 
 import (
 	"github.com/alibaba/sentinel-golang/core/base"
+	"github.com/alibaba/sentinel-golang/core/circuitbreaker"
 	"github.com/alibaba/sentinel-golang/core/flow"
 	"github.com/alibaba/sentinel-golang/core/log"
 	"github.com/alibaba/sentinel-golang/core/stat"
@@ -28,7 +29,9 @@ func BuildDefaultSlotChain() *base.SlotChain {
 	sc.AddStatPrepareSlotLast(&stat.StatNodePrepareSlot{})
 	sc.AddRuleCheckSlotLast(&system.SystemAdaptiveSlot{})
 	sc.AddRuleCheckSlotLast(&flow.FlowSlot{})
+	sc.AddRuleCheckSlotLast(&circuitbreaker.CircuitBreakerSlot{})
 	sc.AddStatSlotLast(&stat.StatisticSlot{})
 	sc.AddStatSlotLast(&log.LogSlot{})
+	sc.AddStatSlotLast(&circuitbreaker.MetricStatSlot{})
 	return sc
 }

core/base/context.go

@@ -1,8 +1,15 @@
 package base
 
+import "github.com/alibaba/sentinel-golang/util"
+
 type EntryContext struct {
+	// internal error when sentinel entry or
+	// biz error of downstream
+	err error
 	// Use to calculate RT
 	startTime uint64
+	// the rt of this transaction
+	rt uint64
 
 	Resource *ResourceWrapper
 	StatNode StatNode
@@ -14,6 +21,14 @@ type EntryContext struct {
 	Data map[interface{}]interface{}
 }
 
+func (ctx *EntryContext) Err() error {
+	return ctx.err
+}
+
+func (ctx *EntryContext) SetError(err error) {
+	ctx.err = err
+}
+
 func (ctx *EntryContext) StartTime() uint64 {
 	return ctx.startTime
 }
@@ -25,6 +40,18 @@ func (ctx *EntryContext) IsBlocked() bool {
 	return ctx.RuleCheckResult.IsBlocked()
 }
 
+func (ctx *EntryContext) PutRt(rt uint64) {
+	ctx.rt = rt
+}
+
+func (ctx *EntryContext) Rt() uint64 {
+	if ctx.rt == 0 {
+		rt := util.CurrentTimeMillis() - ctx.StartTime()
+		return rt
+	}
+	return ctx.rt
+}
+
 func NewEmptyEntryContext() *EntryContext {
 	return &EntryContext{}
 }
@@ -50,7 +77,9 @@ func newEmptyInput() *SentinelInput {
 // Reset init EntryContext,
 func (ctx *EntryContext) Reset() {
 	// reset all fields of ctx
+	ctx.err = nil
 	ctx.startTime = 0
+	ctx.rt = 0
 	ctx.Resource = nil
 	ctx.StatNode = nil
 	ctx.Input = nil

core/base/entry.go

@@ -15,6 +15,20 @@ type SentinelEntry struct {
 	exitCtl sync.Once
 }
 
+func NewSentinelEntry(ctx *EntryContext, rw *ResourceWrapper, sc *SlotChain) *SentinelEntry {
+	return &SentinelEntry{
+		res: rw,
+		ctx: ctx,
+		sc:  sc,
+	}
+}
+
+func (e *SentinelEntry) SetError(err error) {
+	if e.ctx != nil {
+		e.ctx.SetError(err)
+	}
+}
+
 func (e *SentinelEntry) Context() *EntryContext {
 	return e.ctx
 }
@@ -23,12 +37,28 @@ func (e *SentinelEntry) Resource() *ResourceWrapper {
 	return e.res
 }
 
-func NewSentinelEntry(ctx *EntryContext, rw *ResourceWrapper, sc *SlotChain) *SentinelEntry {
-	return &SentinelEntry{res: rw, ctx: ctx, sc: sc}
+type ExitOptions struct {
+	err error
+}
+type ExitOption func(*ExitOptions)
+
+func WithError(err error) ExitOption {
+	return func(opts *ExitOptions) {
+		opts.err = err
+	}
 }
 
-func (e *SentinelEntry) Exit() {
+func (e *SentinelEntry) Exit(exitOps ...ExitOption) {
+	var options = ExitOptions{
+		err: nil,
+	}
+	for _, opt := range exitOps {
+		opt(&options)
+	}
 	ctx := e.ctx
+	if options.err != nil {
+		ctx.SetError(options.err)
+	}
 	e.exitCtl.Do(func() {
 		if e.sc != nil {
 			e.sc.exit(ctx)

core/base/slot_chain.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/alibaba/sentinel-golang/logging"
 	"github.com/alibaba/sentinel-golang/util"
+	"github.com/pkg/errors"
 )
 
 var logger = logging.GetDefaultLogger()
@@ -124,6 +125,7 @@ func (sc *SlotChain) Entry(ctx *EntryContext) *TokenResult {
 	defer func() {
 		if err := recover(); err != nil {
 			logger.Panicf("Sentinel internal panic in SlotChain, err: %+v", err)
+			ctx.SetError(errors.Errorf("%+v", err))
 			return
 		}
 	}()