From c9c3a9f5e247b29e18e1af45fb09e4b3b58e7d4b Mon Sep 17 00:00:00 2001
From: Mickael KERJEAN <mickael.kerjean@gmail.com>
Date: Mon, 25 Feb 2019 17:41:47 +1100
Subject: [PATCH] fix (concurrency): fix concurrency problem

---
 server/common/cache.go |  8 ++++++++
 server/common/utils.go | 28 ----------------------------
 server/ctrl/static.go  | 25 +++++--------------------
 server/model/files.go  |  3 +++
 4 files changed, 16 insertions(+), 48 deletions(-)

diff --git a/server/common/cache.go b/server/common/cache.go
index 814b82fd..e2e78817 100644
--- a/server/common/cache.go
+++ b/server/common/cache.go
@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"github.com/mitchellh/hashstructure"
 	"github.com/patrickmn/go-cache"
+	"sync"
 	"time"
 )
 
@@ -60,6 +61,7 @@ func NewAppCache(arg ...time.Duration) AppCache {
 
 type KeyValueStore struct {
 	cache map[string]interface{}
+	sync.RWMutex
 }
 
 func NewKeyValueStore() KeyValueStore {
@@ -67,13 +69,19 @@ func NewKeyValueStore() KeyValueStore {
 }
 
 func (this KeyValueStore) Get(key string) interface{} {
+	this.RLock()
+	defer this.RUnlock()
 	return this.cache[key]
 }
 
 func (this *KeyValueStore) Set(key string, value interface{}) {
+	this.Lock()
+	defer this.Unlock()
 	this.cache[key] = value
 }
 
 func (this *KeyValueStore) Clear() {
+	this.Lock()
+	defer this.Unlock()
 	this.cache = make(map[string]interface{})
 }
diff --git a/server/common/utils.go b/server/common/utils.go
index 6c1811a9..1263731f 100644
--- a/server/common/utils.go
+++ b/server/common/utils.go
@@ -3,7 +3,6 @@ package common
 import (
 	"bytes"
 	"encoding/json"
-	"sync"
 )
 
 func NewBool(t bool) *bool {
@@ -67,30 +66,3 @@ func PrettyPrint(json_dirty []byte) []byte {
 	json_pretty.Write([]byte("\n"))
 	return json_pretty.Bytes()
 }
-
-type SafeMapStringString struct {
-	sync.RWMutex
-	internal map[string]string
-}
-
-func NewSafeMapStringString() SafeMapStringString {
-	return SafeMapStringString{
-		internal: make(map[string]string),
-	}
-}
-
-func(this SafeMapStringString) Set(key string, value string) {
-	this.Lock()
-	this.internal[key] = value
-	this.Unlock()
-}
-
-func(this SafeMapStringString) Gets(keys ...string) []string{
-	this.RLock()
-	res := make([]string, len(keys))
-    for i, key := range keys {
-		res[i] = this.internal[key]
-    }
-	this.RUnlock()
-	return res
-}
diff --git a/server/ctrl/static.go b/server/ctrl/static.go
index 91f22085..0e064a30 100644
--- a/server/ctrl/static.go
+++ b/server/ctrl/static.go
@@ -11,8 +11,6 @@ import (
 	"strings"
 )
 
-var ETAGS     SafeMapStringString = NewSafeMapStringString()
-
 func StaticHandler(_path string) func(App, http.ResponseWriter, *http.Request) {
 	return func(ctx App, res http.ResponseWriter, req *http.Request) {
 		var base string = GetAbsolutePath(_path)
@@ -95,16 +93,15 @@ func hashFile (path string, n int) string {
 
 	stat, err := f.Stat()
 	if err != nil {
-		return "UNKNOWN"
+		return ""
 	}
 	return QuickHash(fmt.Sprintf("%s %d %d %s", path, stat.Size(), stat.Mode(), stat.ModTime()), n)
 }
 
 func ServeFile(res http.ResponseWriter, req *http.Request, filePath string) {
 	zFilePath := filePath + ".gz"
-	tags := ETAGS.Gets(filePath, zFilePath)
-	etagNormal := tags[0]
-	etagGzip := tags[1]
+	etagNormal := hashFile(filePath, 10)
+	etagGzip := hashFile(zFilePath, 10)
 
 	if req.Header.Get("If-None-Match") != "" {
 		browserTag := req.Header.Get("If-None-Match")
@@ -120,13 +117,7 @@ func ServeFile(res http.ResponseWriter, req *http.Request, filePath string) {
 	if strings.Contains(req.Header.Get("Accept-Encoding"), "gzip") {
 		if file, err := os.OpenFile(zFilePath, os.O_RDONLY, os.ModePerm); err == nil {
 			head.Set("Content-Encoding", "gzip")
-			if etagGzip == "" {
-				tag := hashFile(zFilePath, 10)
-				ETAGS.Set(zFilePath, tag)
-				head.Set("Etag", tag)
-			} else {
-				head.Set("Etag", etagGzip)
-			}
+			head.Set("Etag", etagGzip)
 			io.Copy(res, file)
 			file.Close()
 			return
@@ -138,13 +129,7 @@ func ServeFile(res http.ResponseWriter, req *http.Request, filePath string) {
 		http.NotFound(res, req)
 		return
 	}
-	if etagNormal == "" {
-		tag := hashFile(filePath, 10)
-		ETAGS.Set(filePath, tag)
-		head.Set("Etag", tag)
-	} else {
-		head.Set("Etag", etagNormal)
-	}
+	head.Set("Etag", etagNormal)
 	io.Copy(res, file)
 	file.Close()
 }
diff --git a/server/model/files.go b/server/model/files.go
index 842d00e4..f082837e 100644
--- a/server/model/files.go
+++ b/server/model/files.go
@@ -23,6 +23,9 @@ func NewBackend(ctx *App, conn map[string]string) (IBackend, error) {
 				}
 			}
 			if val, ok := d["path"]; ok == true {
+				if val == nil {
+					val = "/"
+				}
 				if val != conn["path"] {
 					continue
 				}