From 58907d03a2e76470c10c98dc2e57c52ce04fe0f2 Mon Sep 17 00:00:00 2001
From: Gregor Noczinski <gregor@noczinski.eu>
Date: Mon, 29 Jun 2020 16:10:18 +0200
Subject: [PATCH] Adding some more meaningful metrics

---
 lingress.go | 43 ++++++++++++++++++++---------------
 utils.go    | 65 ++++++++++++++++++++++++-----------------------------
 2 files changed, 54 insertions(+), 54 deletions(-)

diff --git a/lingress.go b/lingress.go
index c93ad7c..ea2b4ef 100644
--- a/lingress.go
+++ b/lingress.go
@@ -20,13 +20,14 @@ import (
 )
 
 type Lingress struct {
-	RulesRepository rules.CombinedRepository
-	Proxy           *proxy.Proxy
-	Fallback        *fallback.Fallback
-	Management      *management.Management
-	http            http.Server
-	https           http.Server
-	accessLogQueue  chan accessLogEntry
+	RulesRepository       rules.CombinedRepository
+	Proxy                 *proxy.Proxy
+	Fallback              *fallback.Fallback
+	Management            *management.Management
+	http                  http.Server
+	https                 http.Server
+	accessLogQueue        chan accessLogEntry
+	connectionInformation *ConnectionInformation
 
 	HttpListenAddr    string
 	HttpsListenAddr   string
@@ -71,13 +72,14 @@ func New(fps support.FileProviders) (*Lingress, error) {
 					"context": "server.https",
 				}, log.DebugLevel),
 			},
-			HttpListenAddr:     ":8080",
-			HttpsListenAddr:    ":8443",
-			MaxHeaderBytes:     2 << 20, // 2MB,
-			ReadHeaderTimeout:  30 * time.Second,
-			WriteTimeout:       30 * time.Second,
-			IdleTimeout:        5 * time.Minute,
-			AccessLogQueueSize: 5000,
+			connectionInformation: NewConnectionInformation(),
+			HttpListenAddr:        ":8080",
+			HttpsListenAddr:       ":8443",
+			MaxHeaderBytes:        2 << 20, // 2MB,
+			ReadHeaderTimeout:     30 * time.Second,
+			WriteTimeout:          30 * time.Second,
+			IdleTimeout:           5 * time.Minute,
+			AccessLogQueueSize:    5000,
 		}
 
 		result.http.Handler = result
@@ -146,13 +148,17 @@ func (instance *Lingress) ServeHTTP(resp http.ResponseWriter, req *http.Request)
 }
 
 func (instance *Lingress) onConnState(conn net.Conn, state http.ConnState) {
-	previous := SetConnState(conn, state)
+	previous := instance.connectionInformation.SetState(conn, state, func(target http.ConnState) bool {
+		return target != http.StateNew &&
+			target != http.StateActive &&
+			target != http.StateIdle
+	})
+
 	if previous == state {
 		return
 	}
 
 	source := instance.Management.Metrics.Client.Connections.Source
-
 	switch previous {
 	case http.StateNew:
 		atomic.AddUint64(&source.New, ^uint64(0))
@@ -161,7 +167,7 @@ func (instance *Lingress) onConnState(conn net.Conn, state http.ConnState) {
 	case http.StateIdle:
 		atomic.AddUint64(&source.Idle, ^uint64(0))
 	case -1:
-		// Ignore
+		// ignore
 	default:
 		return
 	}
@@ -178,6 +184,8 @@ func (instance *Lingress) onConnState(conn net.Conn, state http.ConnState) {
 	default:
 		atomic.AddUint64(&source.Current, ^uint64(0))
 	}
+
+	return
 }
 
 func (instance *Lingress) Init(stop support.Channel) error {
@@ -229,7 +237,6 @@ func (instance *Lingress) serve(target *http.Server, addr string, tlsConfig *tls
 		return err
 	}
 	ln = tcpKeepAliveListener{ln.(*net.TCPListener)}
-	ln = stateTrackingListener{ln}
 
 	serve := func() error {
 		return target.Serve(ln)
diff --git a/utils.go b/utils.go
index f6406d1..709ca91 100644
--- a/utils.go
+++ b/utils.go
@@ -1,12 +1,10 @@
 package lingress
 
 import (
-	"fmt"
 	"github.com/echocat/lingress/support"
 	"net"
 	"net/http"
-	"reflect"
-	"sync/atomic"
+	"sync"
 	"time"
 )
 
@@ -39,47 +37,42 @@ func (ln tcpKeepAliveListener) Accept() (net.Conn, error) {
 	return tc, nil
 }
 
-type stateTrackingListener struct {
-	net.Listener
+type ConnectionInformation struct {
+	all map[net.Conn]http.ConnState
+
+	mutex *sync.Mutex
 }
 
-func (ln stateTrackingListener) Accept() (net.Conn, error) {
-	conn, err := ln.Listener.Accept()
-	if err != nil {
-		return nil, err
+func NewConnectionInformation() *ConnectionInformation {
+	return &ConnectionInformation{
+		all:   make(map[net.Conn]http.ConnState),
+		mutex: new(sync.Mutex),
 	}
-	return ConnectionWithConnStateTracking(conn), nil
 }
 
-type stateTrackingConnection struct {
-	net.Conn
-	current int64
-}
+func (instance *ConnectionInformation) SetState(
+	conn net.Conn,
+	newState http.ConnState,
+	keepFunc func(http.ConnState) bool,
+) (previousState http.ConnState) {
+	instance.mutex.Lock()
+	defer instance.mutex.Unlock()
 
-func (instance *stateTrackingConnection) SetConnState(newState http.ConnState) (previousState http.ConnState) {
-	for {
-		current := atomic.LoadInt64(&instance.current)
-		if atomic.CompareAndSwapInt64(&instance.current, current, int64(newState)) {
-			return http.ConnState(current)
-		}
-	}
-}
+	keep := newState >= 0 || keepFunc(newState)
 
-func SetConnState(conn net.Conn, newState http.ConnState) (previousState http.ConnState) {
-	stc, ok := conn.(*stateTrackingConnection)
-	if !ok {
-		panic(fmt.Sprintf("%v is not of type %v", conn, reflect.TypeOf(&stateTrackingConnection{})))
+	result, exists := instance.all[conn]
+	if exists {
+		if !keep {
+			delete(instance.all, conn)
+			return result
+		}
+		previousState = result
+		instance.all[conn] = newState
+		return previousState
 	}
-	return stc.SetConnState(newState)
-}
 
-func ConnectionWithConnStateTracking(in net.Conn) net.Conn {
-	stc, ok := in.(*stateTrackingConnection)
-	if ok {
-		return stc
-	}
-	return &stateTrackingConnection{
-		Conn:    in,
-		current: -1,
+	if keep {
+		instance.all[conn] = newState
 	}
+	return -1
 }