Release of DTail v1.0.0v1.0.0

1 files changed, 81 insertions, 0 deletions

diff --git a/clients/stats.go b/clients/stats.go
new file mode 100644
index 0000000..e5b9bed
--- /dev/null
+++ b/clients/stats.go
@@ -0,0 +1,81 @@
+package clients
+
+import (
+	"dtail/logger"
+	"fmt"
+	"runtime"
+	"sync"
+	"time"
+)
+
+// Used to collect and display various client stats.
+type stats struct {
+	// Total amount servers to connect to.
+	connectionsTotal int
+	// To keep track of what connected and disconnected
+	connectionsEstCh chan struct{}
+	// Amount of servers connections are established.
+	connected int
+	// To synchronize concurrent access.
+	mutex sync.Mutex
+}
+
+func newTailStats(connectionsTotal int) *stats {
+	return &stats{
+		connectionsTotal: connectionsTotal,
+		connectionsEstCh: make(chan struct{}, connectionsTotal),
+		connected:        0,
+	}
+}
+
+func (s *stats) periodicLogStats(throttleCh chan struct{}, stop <-chan struct{}) {
+	connectedLast := 0
+	statsInterval := 5
+
+	for {
+		select {
+		case <-time.After(time.Second * time.Duration(statsInterval)):
+		case <-stop:
+			return
+		}
+
+		connected := len(s.connectionsEstCh)
+		throttle := len(throttleCh)
+
+		newConnections := connected - connectedLast
+		connectionsPerSecond := float64(newConnections) / float64(statsInterval)
+		s.log(connected, newConnections, connectionsPerSecond, throttle)
+
+		connectedLast = connected
+
+		s.mutex.Lock()
+		s.connected = connected
+		s.mutex.Unlock()
+	}
+}
+
+func (s *stats) numConnected() int {
+	s.mutex.Lock()
+	defer s.mutex.Unlock()
+
+	return s.connected
+}
+
+func (s *stats) log(connected, newConnections int, connectionsPerSecond float64, throttle int) {
+	percConnected := percentOf(float64(s.connectionsTotal), float64(connected))
+
+	connectedStr := fmt.Sprintf("connected=%d/%d(%d%%)", connected, s.connectionsTotal, int(percConnected))
+	newConnStr := fmt.Sprintf("new=%d", newConnections)
+	rateStr := fmt.Sprintf("rate=%2.2f/s", connectionsPerSecond)
+	throttleStr := fmt.Sprintf("throttle=%d", throttle)
+	cpusGoroutinesStr := fmt.Sprintf("cpus/goroutines=%d/%d", runtime.NumCPU(), runtime.NumGoroutine())
+
+	logger.Info("stats", connectedStr, newConnStr, rateStr, throttleStr, cpusGoroutinesStr)
+}
+
+func percentOf(total float64, value float64) float64 {
+	if total == 0 || total == value {
+		return 100
+	}
+	return value / (total / 100.0)
+}