entity manager question
I have a Asynchronous method which calls ffmpeg (to convert an uploaded video). Every 2% I would like to update the percentage that users will see when viewing the status of their uploaded videos... I don't particularly care if it is immediately writen to the database, but I do want it to be updated when the user refreshes the page...
"select v from Video v where v.userid = :userid"
above is my SQL query, which returns all videos for the user. with the code below it works perfect, however, if I remove the em.flush(); the percent doesn't change until the video is completly done processing. is this normal behaviour? is there a better way to do this? I always thought using em.flush() should be avoided?
Thanks
Derek
package wyd.ffmpeg;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import javax.persistence.EntityManager;
import org.jboss.seam.annotations.AutoCreate;
import org.jboss.seam.annotations.In;
import org.jboss.seam.annotations.Name;
import org.jboss.seam.annotations.Transactional;
import org.jboss.seam.annotations.async.Asynchronous;
import wyd.entity.Video;
/**
*
* @author Derek Knapp
*/
@Name("convert")
@AutoCreate
public class ffmpegService
{
@In
EntityManager em;
public String[] getONE(String[] a1, String[] a2)
{
String[] result = new String[a1.length + a2.length];
System.arraycopy(a1, 0, result, 0, a1.length);
System.arraycopy(a2, 0, result, a1.length, a2.length);
return result;
}
@Asynchronous
@Transactional
public void run(Video video)
{
try
{
String in = "/ffmpeg/in/" + video.getUuid();
String out = "/ffmpeg/out/" + video.getUuid() + ".mp4";
String[] common = {
"/ffmpeg/ffmpeg",
"-y",
"-i", in,
"-vcodec", "libx264",
"-b", "256k",
//"-b", "512k",
"-bf", "3",
"-subq", "6",
"-cmp", "256",
"-refs", "5",
"-qmin", "10",
"-qmax", "51",
"-qdiff", "4",
"-coder", "1",
"-loop", "1",
"-me_method", "hex",
"-me_range", "16",
"-trellis", "1",
"-flags", "+mv4",
"-flags2", "+bpyramid+wpred+mixed_refs+dct8x8",
"-partitions", "parti4x4+parti8x8+partp4x4+partp8x8+partb8x8",
"-g", "250",
"-keyint_min", "25",
"-sc_threshold", "40",
"-i_qfactor", "0.71",
"-vhook", "/ffmpeg/watermark.so -f /ffmpeg/wm.gif"
};
String[][] pass = {
{
"-an",
"-pass", "1",
"-threads", "2",
out
},
{
"-acodec", "libfaac",
"-ar", "22050",
"-ab", "64k",
"-pass", "2",
"-threads", "2",
out
}
};
for (int i = 0; i < pass.length; i++)
{
Process p = Runtime.getRuntime().exec(getONE(common, pass[i]));
BufferedReader stderr = new BufferedReader(new InputStreamReader(p.getErrorStream()));
String line;
while ((line = stderr.readLine()) != null)
{
if (line.contains("time="))
{
int pos = line.indexOf("time=");
line = line.substring(pos + 5, line.indexOf(" ", pos));
Double percent = Double.valueOf(line.trim()) / video.getDuration() * 100 / pass.length + 100 / pass.length * i;
if (Math.abs(video.getPercent() - percent) > 2)
{
System.out.println("percent = " + percent.intValue());
System.out.println("em = " + em);
video.setPercent(percent.intValue());
em.merge(video);
em.flush();
}
}
}
}
video.setPercent(100);
em.merge(video);
em.flush();
}
catch (Exception e)
{
e.printStackTrace();
}
}
}