simplify API

watchdog.go

@@ -16,7 +16,7 @@ var (
 // Watchdog keeps checks to run either periodically
 // or on demand.
 type Watchdog struct {
-	checks checksMap
+	checks map[string]*wdCheck
 	mu     sync.Mutex
 
 	events  chan CheckResult // output channel
@@ -28,47 +28,6 @@ type Watchdog struct {
 	running    int  // number of active checks monitored
 }
 
-type checksMap struct {
-	m map[string]*wdCheck
-}
-
-func (c *checksMap) build() {
-	if c.m == nil {
-		c.m = make(map[string]*wdCheck)
-	}
-}
-
-func (c *checksMap) Map() map[string]*wdCheck {
-	c.build()
-
-	return c.m
-}
-
-func (c *checksMap) Set(key string, v *wdCheck) {
-	c.build()
-
-	c.m[key] = v
-}
-
-func (c *checksMap) Lookup(key string) (*wdCheck, bool) {
-	c.build()
-
-	v, ok := c.m[key]
-	return v, ok
-}
-
-func (c *checksMap) Delete(key string) {
-	c.build()
-
-	delete(c.m, key)
-}
-
-func (c *checksMap) Len() int {
-	c.build()
-
-	return len(c.m)
-}
-
 type wdCheck struct {
 	check Check
 	stop  chan struct{}
@@ -77,13 +36,16 @@ type wdCheck struct {
 // New creates instance of Watchdog with
 // provided checks.
 func New(checks ...Check) *Watchdog {
-	w := Watchdog{}
+	w := Watchdog{
+		checks: make(map[string]*wdCheck),
+	}
+
 	for _, c := range checks {
 		nc := &wdCheck{
 			check: c,
 		}
 
-		w.checks.Set(c.Name, nc)
+		w.checks[c.Name] = nc
 	}
 
 	return &w
@@ -121,14 +83,18 @@ func (w *Watchdog) AddChecks(checks ...Check) {
 	w.mu.Lock()
 	defer w.mu.Unlock()
 
+	if w.checks == nil {
+		w.checks = make(map[string]*wdCheck)
+	}
+
 	for _, c := range checks {
 		nc := &wdCheck{
 			check: c,
 		}
 
-		old, haveOld := w.checks.Lookup(c.Name)
+		old, haveOld := w.checks[c.Name]
 
-		w.checks.Set(c.Name, nc)
+		w.checks[c.Name] = nc
 
 		if w.monitoring {
 			w.startMonitoring(nc)
@@ -146,7 +112,7 @@ func (w *Watchdog) RemoveChecks(names ...string) {
 	defer w.mu.Unlock()
 
 	for _, name := range names {
-		c, ok := w.checks.Lookup(name)
+		c, ok := w.checks[name]
 		if !ok {
 			continue
 		}
@@ -155,7 +121,7 @@ func (w *Watchdog) RemoveChecks(names ...string) {
 			w.stopMonitoring(c)
 		}
 
-		w.checks.Delete(name)
+		delete(w.checks, name)
 	}
 }
 
@@ -172,7 +138,7 @@ func (w *Watchdog) Start(concurrency int) (<-chan CheckResult, error) {
 	w.mu.Lock()
 	defer w.mu.Unlock()
 
-	if w.checks.Len() == 0 {
+	if len(w.checks) == 0 {
 		return nil, ErrNotConfigured
 	}
 
@@ -181,7 +147,7 @@ func (w *Watchdog) Start(concurrency int) (<-chan CheckResult, error) {
 	}
 
 	if concurrency == 0 {
-		concurrency = w.checks.Len()
+		concurrency = len(w.checks)
 	}
 
 	if w.timeout == 0 {
@@ -191,7 +157,7 @@ func (w *Watchdog) Start(concurrency int) (<-chan CheckResult, error) {
 	w.events = make(chan CheckResult, concurrency)
 	w.limiter = make(chan struct{}, concurrency)
 
-	for _, c := range w.checks.Map() {
+	for _, c := range w.checks {
 		w.startMonitoring(c)
 	}
 
@@ -208,7 +174,7 @@ func (w *Watchdog) Stop() error {
 		return ErrNotRunning
 	}
 
-	for _, c := range w.checks.Map() {
+	for _, c := range w.checks {
 		w.stopMonitoring(c)
 	}
 
@@ -221,13 +187,13 @@ func (w *Watchdog) Stop() error {
 func (w *Watchdog) RunImmediately(ctx context.Context, concurrency int) ([]CheckResult, error) {
 	w.mu.Lock()
 
-	if w.checks.Len() == 0 {
+	if len(w.checks) == 0 {
 		w.mu.Unlock()
 		return nil, ErrNotConfigured
 	}
 
 	cp := w.copyChecks()
-	w.mu.Unlock() // release
+	w.mu.Unlock()
 
 	if concurrency == 0 {
 		concurrency = len(cp)
@@ -248,8 +214,8 @@ func (w *Watchdog) RunImmediately(ctx context.Context, concurrency int) ([]Check
 }
 
 func (w *Watchdog) copyChecks() []Check {
-	cp := make([]Check, 0, w.checks.Len())
-	for _, v := range w.checks.Map() {
+	cp := make([]Check, 0, len(w.checks))
+	for _, v := range w.checks {
 		cp = append(cp, v.check)
 	}
 
@@ -267,11 +233,7 @@ func (w *Watchdog) startMonitoring(wdc *wdCheck) {
 	w.running++
 
 	go func() {
-		state := CheckResult{
-			// on first run return anything
-			// other that OK
-			Status: StatusOK,
-		}
+		var curr error = nil
 
 		ticker := time.Tick(wdc.check.Interval)
 
@@ -281,23 +243,22 @@ func (w *Watchdog) startMonitoring(wdc *wdCheck) {
 			ctx, cancel := context.WithTimeout(context.Background(), w.timeout)
 			defer cancel()
 
-			status, err := c.Check(ctx)
+			err := c.Check(ctx)
 
 			<-w.limiter
 
 			r := CheckResult{
-				Name:   c.Name,
-				Status: status,
-				Error:  err,
+				Name:  c.Name,
+				Error: err,
 			}
 
 			// if status changed or we've got an error
 			// then report this
-			if r.Status != state.Status || r.Error != nil {
+			if !errors.Is(r.Error, curr) {
 				w.events <- r
 			}
 
-			state = r
+			curr = r.Error
 
 			select {
 			case <-ticker:
@@ -336,12 +297,11 @@ func runChecksConcurrently(ctx context.Context, ch []Check, concurrency int) []C
 
 			// relying on assumption that CheckFunc obeys context
 			// cancellation
-			status, err := e.Check(ctx)
+			err := e.Check(ctx)
 
 			r := CheckResult{
-				Name:   e.Name,
-				Status: status,
-				Error:  err,
+				Name:  e.Name,
+				Error: err,
 			}
 
 			done <- r