Hi Bernard, >From my experience of trying to study the memory impact between builds, the >getRuntime().freeMemory() method I found was very unreliable due to the nature >of the JVM. I was getting back different results each time I ran it and even >after purposefully modifying one build to run inefficiently, it returned the >opposite to what I was expecting. As such, I ended up using a profiler which >allowed me to break it down to see what was being run and identify memory hot >spots and differences without being hampered by the somewhat random garbage >collection.
Another method would be to generate and compare hprof dump output. There are a few tools out there to do this like the Eclipse Memory Analyzer [1]. To generate the dump, I just add the following to the FOP args: -Xrunhprof:heap=sites,depth=<depth required> Regards, Robert Meyer [1] http://www.eclipse.org/mat/ From: thebernmeis...@hotmail.com To: fop-users@xmlgraphics.apache.org Subject: Memory usage and page numbering... Date: Fri, 9 Aug 2013 15:20:15 +1000 Hi, I have a Java desktop application, using embedded FOP to create PDFs from a data XML file and an XSLT file. I wanted to see how much memory is being used, given the point about memory usage, page numbers and page totals (http://xmlgraphics.apache.org/fop/1.1/running.html#memory). My PDF reports have a "page N of TOTAL" at the bottom right of each page and I wanted to see the memory usage and compare to no page numbers and just page numbers without totals. I also used the two variations for page number totals (XSL 1.0 and XSL 1.1). To work out the memory usage I computed the difference when calling Runtime.getRuntime().freeMemory() at the start and end of the render process. I ran each render variation 5 times from a shell script and each render kicked off a separate JVM to avoid any caching. Regardless of whether I had page numbers or not, and page totals or not, it seemed the result is that there is no difference between having page numbers/totals or not. Sometimes the memory usage was 50 MB and sometimes 200 MB. I then used the sample code and data files from embedded FOP, http://svn.apache.org/viewvc/xmlgraphics/fop/tags/fop-1_1/examples/embedding/. I modified the data XML file to contain lots of entries, giving a data file size of about 1 MB. I also modified the XLST file to include pages numbers and then also page totals. Again, I noticed no difference in memory usage. Given the varying values for memory usage I'm seeing, I assume my quick and dirty method is inadequate. I expected variation, but mostly to see far less memory usage when no page totals were used, but that's not the case. Has anyone seen similar results? Does using page totals really use THAT much more memory compared to not using page totals? Thanks in advance,Bernard.
