save the total duraion of total.m3u8 to file total

@@ -303,6 +303,7 @@ SrsHlsMuxer::SrsHlsMuxer()
     async = new SrsAsyncCallWorker();
     context = new SrsTsContext();
     save_m3u8_total = false;
+    total_duraion = 0.0;
 }
 
 SrsHlsMuxer::~SrsHlsMuxer()
@@ -831,6 +832,28 @@ int SrsHlsMuxer::segment_close(string log_desc)
 				return ret;
 			}
 			srs_info("write total m3u8 %s success.", m3u8_total_file.c_str());
+
+			this->total_duraion += currentSeg->duration;
+			SrsFileWriter total_writer;
+			//write total duration to total
+			std::stringstream ss_total;
+
+			std::string total_tmp = total + ".tmp";
+			ret = total_writer.open(total_tmp);
+			ss_total.precision(3);
+			ss_total.setf(std::ios::fixed, std::ios::floatfield);
+			ss_total << total_duraion;
+
+			if ((ret = total_writer.write((char*) ss_total.str().c_str(),
+								(int) ss_total.str().length(), NULL)) != ERROR_SUCCESS) {
+							srs_error("write total temp:%s failed. ret=%d",(char*) total_tmp.c_str(), ret);
+							return ret;
+			}
+
+			if(rename(total_tmp.c_str(), total.c_str()) < 0) {
+			            ret = ERROR_HLS_WRITE_FAILED;
+			            srs_error("rename total file failed. %s => %s, ret=%d", total_tmp.c_str(), total.c_str(), ret);
+			}
 		}
 
     } else {

@@ -210,6 +210,8 @@ private:
     std::string total;
     std::string total_url;
     bool save_m3u8_total;
+    //total duration for all segments
+    double total_duraion;
 private:
     // TODO: FIXME: remove it.
     bool should_write_cache;