When we trace to file, add eol of each trace message.

webrtc/system_wrappers/source/trace_impl.cc

 /*
  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 384 matching lines @@
   if (row_count_text_ == 0) {
     char message[WEBRTC_TRACE_MAX_MESSAGE_SIZE + 1];
     int32_t length = AddDateTimeInfo(message);
     if (length != -1) {
       message[length] = 0;
       message[length - 1] = '\n';
       trace_file_->Write(message, length);
       row_count_text_++;
     }
   }
   trace_file_->Write(msg, length);

[pbos-webrtc, 2015/07/24 09:47:34]

Isn't here where you want to add the '\n'? You shouldn't add it to all logging
right?

[braveyao1, 2015/07/24 10:02:39]

It used to be here. But now since the input parameter is a const. So it need
some buffer copy. Not necessary I suppose.
Yes we should add new line to all the logging.

   row_count_text_++;
 }
 
 void TraceImpl::AddImpl(const TraceLevel level,
                         const TraceModule module,
                         const int32_t id,
                         const char msg[WEBRTC_TRACE_MAX_MESSAGE_SIZE]) {
   if (!TraceCheck(level))
     return;
 
@@ skipping 25 matching lines @@
     return;
 
   message_ptr += len;
   ack_len += len;
 
   len = AddMessage(message_ptr, msg, static_cast<uint16_t>(ack_len));
   if (len == -1)
     return;
 
   ack_len += len;
+  trace_message[ack_len] = 0;
+  trace_message[ack_len - 1] = '\n';

[pbos-webrtc, 2015/07/24 08:29:11]

Doesn't this truncate the last character?

[braveyao1, 2015/07/24 10:02:39]

I was afraid so. But magically it doesn't. It's equivalence as before. 

   AddMessageToList(trace_message, static_cast<uint16_t>(ack_len), level);
 }
 
 bool TraceImpl::TraceCheck(const TraceLevel level) const {
   return (level & level_filter()) ? true : false;
 }
 
 bool TraceImpl::UpdateFileName(
     const char file_name_utf8[FileWrapper::kMaxFileNameSize],
     char file_name_with_counter_utf8[FileWrapper::kMaxFileNameSize],
@@ skipping 129 matching lines @@
         va_end(args);
         buff = temp_buff;
       }
       trace->AddImpl(level, module, id, buff);
     }
     ReturnTrace();
   }
 }
 
 }  // namespace webrtc