From c128865c4c7411c29a59fca9a3a2f95537686d7b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Paul=20B=C3=BCtow?= <pbuetow@mimecast.com>
Date: Mon, 20 Jan 2020 18:41:05 +0000
Subject: Move commands to cmd/ and move internal dependencies to internal/

---
 internal/server/stats.go | 88 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 88 insertions(+)
 create mode 100644 internal/server/stats.go

(limited to 'internal/server/stats.go')

diff --git a/internal/server/stats.go b/internal/server/stats.go
new file mode 100644
index 0000000..beb1885
--- /dev/null
+++ b/internal/server/stats.go
@@ -0,0 +1,88 @@
+package server
+
+import (
+	"github.com/mimecast/dtail/internal/config"
+	"github.com/mimecast/dtail/internal/logger"
+	"fmt"
+	"runtime"
+	"sync"
+	"time"
+)
+
+// Used to collect and display various server stats.
+type stats struct {
+	mutex               sync.Mutex
+	currentConnections  int
+	lifetimeConnections uint64
+}
+
+func (s *stats) incrementConnections() {
+	defer s.logServerStats()
+
+	s.mutex.Lock()
+	s.currentConnections++
+	s.lifetimeConnections++
+	s.mutex.Unlock()
+}
+
+func (s *stats) decrementConnections() {
+	defer s.logServerStats()
+
+	s.mutex.Lock()
+	s.currentConnections--
+	s.mutex.Unlock()
+}
+
+func (s *stats) hasConnections() bool {
+	s.mutex.Lock()
+	currentConnections := s.currentConnections
+	s.mutex.Unlock()
+
+	has := currentConnections > 0
+	logger.Info("stats", "Server with open connections?", has, currentConnections)
+
+	return has
+}
+
+func (s *stats) logServerStats() {
+	s.mutex.Lock()
+	defer s.mutex.Unlock()
+
+	currentConnections := fmt.Sprintf("currentConnections=%d", s.currentConnections)
+	lifetimeConnections := fmt.Sprintf("lifetimeConnections=%d", s.lifetimeConnections)
+	goroutines := fmt.Sprintf("goroutines=%d", runtime.NumGoroutine())
+	logger.Info("stats", currentConnections, lifetimeConnections, goroutines)
+}
+
+func (s *stats) serverLimitExceeded() error {
+	s.mutex.Lock()
+	defer s.mutex.Unlock()
+
+	if s.currentConnections >= config.Server.MaxConnections {
+		return fmt.Errorf("Exceeded max allowed concurrent connections of %d", config.Server.MaxConnections)
+	}
+
+	return nil
+}
+
+func (s *stats) periodicLogServerStats(stop <-chan struct{}) {
+	for {
+		select {
+		case <-time.NewTimer(time.Second * 10).C:
+			s.logServerStats()
+		case <-stop:
+			return
+		}
+	}
+}
+
+func (s *stats) waitForConnections() {
+	for {
+		select {
+		case <-time.NewTimer(time.Second).C:
+			if !s.hasConnections() {
+				return
+			}
+		}
+	}
+}
-- 
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