Feature: add experimental connections API

tunnel/manager.go

@@ -0,0 +1,87 @@
+package tunnel
+
+import (
+	"sync"
+	"time"
+)
+
+var DefaultManager *Manager
+
+func init() {
+	DefaultManager = &Manager{
+		upload:   make(chan int64),
+		download: make(chan int64),
+	}
+	DefaultManager.handle()
+}
+
+type Manager struct {
+	connections   sync.Map
+	upload        chan int64
+	download      chan int64
+	uploadTemp    int64
+	downloadTemp  int64
+	uploadBlip    int64
+	downloadBlip  int64
+	uploadTotal   int64
+	downloadTotal int64
+}
+
+func (m *Manager) Join(c tracker) {
+	m.connections.Store(c.ID(), c)
+}
+
+func (m *Manager) Leave(c tracker) {
+	m.connections.Delete(c.ID())
+}
+
+func (m *Manager) Upload() chan<- int64 {
+	return m.upload
+}
+
+func (m *Manager) Download() chan<- int64 {
+	return m.download
+}
+
+func (m *Manager) Now() (up int64, down int64) {
+	return m.uploadBlip, m.downloadBlip
+}
+
+func (m *Manager) Snapshot() *Snapshot {
+	connections := []tracker{}
+	m.connections.Range(func(key, value interface{}) bool {
+		connections = append(connections, value.(tracker))
+		return true
+	})
+
+	return &Snapshot{
+		UploadTotal:   m.uploadTotal,
+		DownloadTotal: m.downloadTotal,
+		Connections:   connections,
+	}
+}
+
+func (m *Manager) handle() {
+	go m.handleCh(m.upload, &m.uploadTemp, &m.uploadBlip, &m.uploadTotal)
+	go m.handleCh(m.download, &m.downloadTemp, &m.downloadBlip, &m.downloadTotal)
+}
+
+func (m *Manager) handleCh(ch <-chan int64, temp *int64, blip *int64, total *int64) {
+	ticker := time.NewTicker(time.Second)
+	for {
+		select {
+		case n := <-ch:
+			*temp += n
+			*total += n
+		case <-ticker.C:
+			*blip = *temp
+			*temp = 0
+		}
+	}
+}
+
+type Snapshot struct {
+	DownloadTotal int64     `json:"downloadTotal"`
+	UploadTotal   int64     `json:"uploadTotal"`
+	Connections   []tracker `json:"connections"`
+}