Which format to create logs in profilers?

In the profiler I am writing, which is in fact a JV开发者_StackOverflow社区MTI agent for Java programs, I need a format to log the events collected. Further these logs have to be send to a socket and read by a GUI somewhere else. So I need a working serialization between two languages.

I already implemented my own protocol in XML and it worked very well. However I was told to consider another format. As XML building might be very slow and every additional code executed in the profiler influences heavily the profiled program. This is true, but does XML DOM Building take that long?

I used TinyXML so far. I hope no one points to RapidXML, as I hope there are not that different on a not-embedded machine.

What do you think? Currently I am trying to reimplement it with protobuf, which claims to be n times faster then XML.

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I have a design I am working on for all log file in my remit. I record data in JSON but the JSON data is nested in a very simple xml format.

eg

<entry ts="2011-02-23T17:18:19.202" level="trc_1" typ="trace">New Message Received</entry>
<entry ts="2011-02-23T17:18:19.202" level="trace" typ="msg"><data>{"Name":"AgtConf","AgtId":1111,...}</data></entry>

That way I can easily separate out data and logging, but keep the logging directory from being complicated. Also saves having to write my own parser for a custom format. However given your situation I recommend using JSON only given that you are basically using to serialise. JSON is very much human-readable when it is formatted correctly, it can be very concise, and there are stable parsers for it.

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my first choice is always the traditional txt file.

you can append new entries at the end of file (bottom)