add observer

service/status.go

@@ -0,0 +1,76 @@
+package service
+
+import (
+	"sync"
+	"time"
+
+	"github.com/go-gost/x/stats"
+)
+
+const (
+	MaxEventSize = 20
+)
+
+type State string
+
+const (
+	StateRunning State = "running"
+	StateReady   State = "ready"
+	StateFailed  State = "failed"
+	StateClosed  State = "closed"
+)
+
+type Event struct {
+	Time    time.Time
+	Message string
+}
+
+type Status struct {
+	createTime time.Time
+	state      State
+	events     []Event
+	stats      *stats.Stats
+	mu         sync.RWMutex
+}
+
+func (p *Status) CreateTime() time.Time {
+	return p.createTime
+}
+
+func (p *Status) State() State {
+	p.mu.RLock()
+	defer p.mu.RUnlock()
+	return p.state
+}
+
+func (p *Status) setState(state State) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	p.state = state
+}
+
+func (p *Status) Events() []Event {
+	events := make([]Event, MaxEventSize)
+
+	p.mu.RLock()
+	defer p.mu.RUnlock()
+
+	copy(events, p.events)
+	return events
+}
+
+func (p *Status) addEvent(event Event) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+
+	if len(p.events) == MaxEventSize {
+		events := make([]Event, MaxEventSize-1, MaxEventSize)
+		copy(events, p.events[1:])
+		p.events = events
+	}
+	p.events = append(p.events, event)
+}
+
+func (p *Status) Stats() *stats.Stats {
+	return p.stats
+}