add an options

gomore/06_circuit_breaker/breaker_options.go

@@ -0,0 +1,42 @@
+package circuit
+
+import "time"
+
+//Options for breaker
+type Options struct {
+	Name           string
+	Expiry         time.Time
+	Interval       time.Duration
+	Timeout        time.Duration
+	MaxRequests    uint32
+	ReadyToTrip    StateCheckerHandler
+	OnStateChanged StateChangedEventHandler
+}
+
+//SetName of breaker
+func SetName(name string) Option {
+	return func(opts *Options) {
+		opts.Name = name
+	}
+}
+
+//SetExpiry of breaker
+func SetExpiry(expiry time.Time) Option {
+	return func(opts *Options) {
+		opts.Expiry = expiry
+	}
+}
+
+//SetStateChangedHandle set handle of ChangedHandle
+func SetStateChangedHandle(handler StateChangedEventHandler) Option {
+	return func(opts *Options) {
+		opts.OnStateChanged = handler
+	}
+}
+
+//SetReadyToTrip check traffic state ,to see if request can go
+func SetReadyToTrip(readyToGo StateCheckerHandler) Option {
+	return func(opts *Options) {
+		opts.ReadyToTrip = readyToGo
+	}
+}

gomore/06_circuit_breaker/circuit_breaker.go

@@ -1,11 +1,25 @@
 package circuit
 
+/*
+ * @Description: https://github.com/crazybber
+ * @Author: Edward
+ * @Date: 2020-05-10 22:00:58
+ * @Last Modified by: Edward
+ * @Last Modified time: 2020-05-10 22:02:18
+ */
+
 import (
 	"context"
 	"errors"
+	"sync"
 	"time"
 )
 
+////////////////////////////////
+///使用HTTP请求的例子
+//每个搜索引擎时时刻刻都会遇到超大规模的请求的流量.
+//这里演示一个复杂一点的例子，同时使用Option 模式
+
 //ErrServiceUnavailable for error
 var (
 	ErrTooManyRequests    = errors.New("too many requests")
@@ -13,6 +27,29 @@ var (
 	FailureThreshold      = 10
 )
 
+//StateCheckerHandler check state
+type StateCheckerHandler func(counts counters) bool
+
+//StateChangedEventHandler set event handle
+type StateChangedEventHandler func(name string, from State, to State)
+
+//Option set Options
+type Option func(opts *Options)
+
+//RequestBreaker for protection
+type RequestBreaker struct {
+	options    Options
+	mutex      sync.Mutex
+	state      State
+	generation uint64
+	counts     Counter
+}
+
+//NewRequestBreaker return a breaker
+func NewRequestBreaker() *RequestBreaker {
+
+}
+
 //State of current switch
 type State int
 

gomore/06_circuit_breaker/circuit_breaker_test.go

@@ -1,9 +1,51 @@
 package circuit
 
 import (
+	"fmt"
+	"io/ioutil"
+	"net/http"
 	"testing"
 )
 
+var breaker *RequestBreaker
+
 func TestBasicBreaker(t *testing.T) {
 
+	var st Options
+	st.Name = "HTTP GET"
+	st.ReadyToTrip = func(counts counters) bool {
+		failureRatio := float64(counts.TotalFailures) / float64(counts.Requests)
+		return counts.Requests >= 3 && failureRatio >= 0.6
+	}
+
+	breaker = NewRequestBreaker(st)
+
+	body, err := Get("https://bing.com/robots.txt")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	fmt.Println(string(body))
+}
+
+// Get wraps http.Get in CircuitBreaker.
+func Get(url string) ([]byte, error) {
+	body, err := breaker.Execute(func() (interface{}, error) {
+		resp, err := http.Get(url)
+		if err != nil {
+			return nil, err
+		}
+		defer resp.Body.Close()
+		body, err := ioutil.ReadAll(resp.Body)
+		if err != nil {
+			return nil, err
+		}
+		return body, nil
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	return body.([]byte), nil
+
 }