Fix: Correct connection counters for hijacked connections

This patch fixes connection counters for v2 endpoints

Idletracker was moved to a new package to prevent package cycle.
Hijacking code still remains in wrong place and should be moved
later to isolated package

Signed-off-by: Sami Korhonen <skorhone@gmail.com>

1 files changed, 74 insertions, 0 deletions

diff --git a/pkg/api/server/idletracker/idletracker.go b/pkg/api/server/idletracker/idletracker.go
new file mode 100644
index 000000000..1ee905a99
--- /dev/null
+++ b/pkg/api/server/idletracker/idletracker.go
@@ -0,0 +1,74 @@
+package idletracker
+
+import (
+	"net"
+	"net/http"
+	"sync"
+	"time"
+
+	"github.com/sirupsen/logrus"
+)
+
+type IdleTracker struct {
+	http     map[net.Conn]struct{}
+	hijacked int
+	total    int
+	mux      sync.Mutex
+	timer    *time.Timer
+	Duration time.Duration
+}
+
+func NewIdleTracker(idle time.Duration) *IdleTracker {
+	return &IdleTracker{
+		http:     make(map[net.Conn]struct{}),
+		Duration: idle,
+		timer:    time.NewTimer(idle),
+	}
+}
+
+func (t *IdleTracker) ConnState(conn net.Conn, state http.ConnState) {
+	t.mux.Lock()
+	defer t.mux.Unlock()
+
+	oldActive := t.ActiveConnections()
+	logrus.Debugf("IdleTracker %p:%v %d/%d connection(s)", conn, state, oldActive, t.TotalConnections())
+	switch state {
+	case http.StateNew, http.StateActive:
+		t.http[conn] = struct{}{}
+		// stop the timer if we transitioned from idle
+		if oldActive == 0 {
+			t.timer.Stop()
+		}
+		t.total++
+	case http.StateHijacked:
+		// hijacked connections are handled elsewhere
+		delete(t.http, conn)
+		t.hijacked++
+	case http.StateIdle, http.StateClosed:
+		delete(t.http, conn)
+		// Restart the timer if we've become idle
+		if oldActive > 0 && len(t.http) == 0 {
+			t.timer.Stop()
+			t.timer.Reset(t.Duration)
+		}
+	}
+}
+
+func (t *IdleTracker) TrackHijackedClosed() {
+	t.mux.Lock()
+	defer t.mux.Unlock()
+
+	t.hijacked--
+}
+
+func (t *IdleTracker) ActiveConnections() int {
+	return len(t.http) + t.hijacked
+}
+
+func (t *IdleTracker) TotalConnections() int {
+	return t.total
+}
+
+func (t *IdleTracker) Done() <-chan time.Time {
+	return t.timer.C
+}