fix readme and add some document

cmd/Caddyfile

@@ -15,13 +15,6 @@
 
         cache_type in_memory
         match_path /
-        path /tmp/cache
-
-        distributed consul {
-           service_name "cache_server"
-            addr "127.0.0.1:8500"
-            health_check ":7777/health"
-        }
 
     }
 

readme.org

@@ -149,8 +149,7 @@
 
 ** Test Result
 
-   The following benchmark is analysized by =wrk -c 50 -d 30s --latency -t 4 http://localhost:9991/pg31674.txt=
-   the file size is 100KB
+   The following benchmark is analysized by =wrk -c 50 -d 30s --latency -t 4 http://localhost:9991/pg31674.txt= without log open
 
    |                         | req/s | latency (50% 90% 99%)     |
    | proxy + file cache      | 13853 | 3.29ms /  4.09ms / 5.26ms |

response.go

@@ -49,6 +49,7 @@ func NewResponse() *Response {
 	return r
 }
 
+// Header return the header from the upstream response
 func (r *Response) Header() http.Header {
 	return r.HeaderMap
 }
@@ -81,6 +82,7 @@ func (r *Response) writeHeader(b []byte, str string) {
 	r.WriteHeader(200)
 }
 
+// Write writes the upstream's content in the backend's storage
 func (r *Response) Write(buf []byte) (int, error) {
 
 	// debug.PrintStack()
@@ -99,26 +101,31 @@ func (r *Response) Write(buf []byte) (int, error) {
 	return 0, errors.New("No storage provided")
 }
 
+// WaitClose waits the response to be closed.
 func (r *Response) WaitClose() {
 	<-r.closedChan
 }
 
+// GetReader gets the reader from the setted backend
 func (r *Response) GetReader() (io.ReadCloser, error) {
 	if r.bodyComplete == false {
 		<-r.bodyCompleteChan
 	}
 	return r.body.GetReader()
 }
 
+// SetBody sets the backend to body for the further write usage
 func (r *Response) SetBody(body backends.Backend) {
 	r.body = body
 	r.bodyChan <- struct{}{}
 }
 
+// WaitHeaders waits the header to be written
 func (r *Response) WaitHeaders() {
 	<-r.headersChan
 }
 
+// WriteHeader keeps the upstream response header
 func (r *Response) WriteHeader(code int) {
 	if r.wroteHeader {
 		return
@@ -179,6 +186,7 @@ func isWebSocket(h http.Header) bool {
 	return false
 }
 
+// Flush flushes the backend's storage (currently, only file storage need to call this)
 func (r *Response) Flush() {
 	if !r.wroteHeader {
 		r.WriteHeader(200)