Generalize iterator interface, locking fixes

provider/mem.go

@@ -85,6 +85,9 @@ func (a *MemAlerts) IterActive() AlertIterator {
 }
 
 func (a *MemAlerts) All() ([]*types.Alert, error) {
+	a.mtx.RLock()
+	defer a.mtx.RUnlock()
+
 	var alerts []*types.Alert
 	for _, a := range a.alerts {
 		alerts = append(alerts, a)
@@ -93,8 +96,8 @@ func (a *MemAlerts) All() ([]*types.Alert, error) {
 }
 
 func (a *MemAlerts) Put(alerts ...*types.Alert) error {
-	a.mtx.RLock()
-	defer a.mtx.RUnlock()
+	a.mtx.Lock()
+	defer a.mtx.Unlock()
 
 	for _, alert := range alerts {
 		a.alerts[alert.Fingerprint()] = alert

provider/provider.go

@@ -20,12 +20,16 @@ import (
 	"github.com/prometheus/alertmanager/types"
 )
 
-type AlertIterator interface {
-	Next() <-chan *types.Alert
+type Iterator interface {
 	Err() error
 	Close()
 }
 
+type AlertIterator interface {
+	Iterator
+	Next() <-chan *types.Alert
+}
+
 // Alerts gives access to a set of alerts.
 type Alerts interface {
 	// IterActive returns an iterator over active alerts from the
@@ -48,7 +52,7 @@ type Silences interface {
 	types.Silencer
 
 	// All returns all existing silences.
-	All() []*types.Silence
+	All() ([]*types.Silence, error)
 	// Set a new silence.
 	Set(*types.Silence) error
 	// Del removes a silence.
@@ -57,6 +61,27 @@ type Silences interface {
 	Get(model.Fingerprint) (*types.Silence, error)
 }
 
+type Notify struct {
+	Target  string
+	Alerts  []model.Fingerprint
+	Pending bool
+}
+
+type NotifyIterator interface {
+	Iterator
+	Next() <-chan *Notify
+}
+
+// Notifies provides information about pending and successful
+// notifications.
+type Notifies interface {
+	// IterPending returns an iterator over all notifies that have not
+	// yet been sent successfully.
+	IterPending() NotifyIterator
+	//
+	Set(*Notify) error
+}
+
 // Reloadable is a component that can change its state based
 // on a new configuration.
 type Reloadable interface {