update breaker patterns

gomore/06_circuit_breaker/breaker/breaker.go

@@ -21,11 +21,10 @@ const (
 type Breaker struct {
 	errorThreshold, successThreshold int
 	timeout                          time.Duration
-
+	lock                             sync.Mutex
-	lock              sync.Mutex
+	state                            uint32
-	state             uint32
+	errors, successes                int
-	errors, successes int
+	lastError                        time.Time
-	lastError         time.Time
 }
 
 // New constructs a new circuit-breaker that starts closed.

gomore/06_circuit_breaker/breaker/breaker_test.go

@@ -20,6 +20,27 @@ func returnsSuccess() error {
 	return nil
 }
 
+func TestExampleBreaker(t *testing.T) {
+	breaker := New(3, 1, 5*time.Second)
+
+	for {
+		result := breaker.Run(func() error {
+			// communicate with some external service and
+			// return an error if the communication failed
+			return nil
+		})
+
+		switch result {
+		case nil:
+			// success!
+		case ErrBreakerOpen:
+			// our function wasn't run because the breaker was open
+		default:
+			// some other error
+		}
+	}
+}
+
 func TestBreakerErrorExpiry(t *testing.T) {
 	breaker := New(2, 1, 1*time.Second)
 
@@ -173,24 +194,3 @@ func TestBreakerAsyncStateTransitions(t *testing.T) {
 		t.Error(err)
 	}
 }
-
-func ExampleBreaker() {
-	breaker := New(3, 1, 5*time.Second)
-
-	for {
-		result := breaker.Run(func() error {
-			// communicate with some external service and
-			// return an error if the communication failed
-			return nil
-		})
-
-		switch result {
-		case nil:
-			// success!
-		case ErrBreakerOpen:
-			// our function wasn't run because the breaker was open
-		default:
-			// some other error
-		}
-	}
-}

gomore/06_circuit_breaker/circuit_breaker.go

@@ -8,13 +8,17 @@ import (
 
 //ErrServiceUnavailable for error
 var (
-	ErrServiceUnavailable = errors.New("Service Unavailable")
+	ErrTooManyRequests    = errors.New("too many requests")
+	ErrServiceUnavailable = errors.New("service unavailable")
 	FailureThreshold      = 10
 )
 
 //State of current switch
+type State int
+
+//states of CircuitBreaker
 const (
-	UnknownState uint = iota
+	UnknownState State = iota
 	FailureState
 	SuccessState
 )
@@ -24,19 +28,19 @@ type Circuit func(context.Context) error
 
 //Counter interface
 type Counter interface {
-	Count(uint)
+	Count(State)
 	ConsecutiveFailures() uint32
 	LastActivity() time.Time
 	Reset()
 }
 
 type counters struct {
-	state        uint
+	state        State
 	lastActivity time.Time
 	counts       uint32 //counts of failures
 }
 
-func (c *counters) Count(state uint) {
+func (c *counters) Count(state State) {
 
 }