for #381, refine the hls notify, report one by one.

@@ -794,6 +794,7 @@ vhost hooks.callback.srs.com {
         #       [stream], replace with the stream.
         #       [ts_url], replace with the ts url.
         # ignore any return data of server.
+        # @remark random select a url to report, not report all.
         on_hls_notify   http://127.0.0.1:8085/api/v1/hls/[app]/[stream][ts_url];
     }
 }

@@ -240,13 +240,17 @@ int SrsDvrAsyncCallOnHlsNotify::call()
             return ret;
         }
         
+        std::string url;
+        if (true) {
+            static u_int32_t nb_call = 0;
+            int index = nb_call++ % on_hls->args.size();
+            url = on_hls->args.at(index);
+        }
+        
         int nb_notify = _srs_config->get_vhost_hls_nb_notify(req->vhost);
-        for (int i = 0; i < (int)on_hls->args.size(); i++) {
-            std::string url = on_hls->args.at(i);
-            if ((ret = SrsHttpHooks::on_hls_notify(url, req, ts_url, nb_notify)) != ERROR_SUCCESS) {
-                srs_error("hook client on_hls_notify failed. url=%s, ts=%s, ret=%d", url.c_str(), ts_url.c_str(), ret);
-                return ret;
-            }
+        if ((ret = SrsHttpHooks::on_hls_notify(url, req, ts_url, nb_notify)) != ERROR_SUCCESS) {
+            srs_error("hook client on_hls_notify failed. url=%s, ts=%s, ret=%d", url.c_str(), ts_url.c_str(), ret);
+            return ret;
         }
     }
 #endif