proc/Tracer.java

   1 import java.awt.*;
   2 import java.net.*;
   3 import java.io.*;
   4 import java.util.*;
   5 import java.applet.*;
   6
   7 public class Tracer extends Applet implements Runnable,CbButtonCallback
   8 {
   9         MultiColumn log;
  10         StringBuffer logbuffer = new StringBuffer();
  11         LineInputStream is;
  12         Thread th;
  13         CbButton pause, button;
  14         boolean paused = false;
  15         int MAX_ROWS = 1000;
  16         Vector buffer = new Vector();
  17
  18         public void init()
  19         {
  20         // Create the UI
  21         setLayout(new BorderLayout());
  22         String cols[] = { "Time", "System Call", "Parameters", "Return" };
  23         add("Center", log = new MultiColumn(cols));
  24         float widths[] = { .1f, .15f, .65f, .1f };
  25         log.setWidths(widths);
  26         Util.setFont(new Font("TimesRoman", Font.PLAIN, 12));
  27         Panel bot = new Panel();
  28         bot.setBackground(Color.white);
  29         bot.setForeground(Color.white);
  30         bot.setLayout(new FlowLayout(FlowLayout.RIGHT));
  31         bot.add(pause = new CbButton("  Pause  ", this));
  32         add("South", bot);
  33         }
  34
  35         public void start()
  36         {
  37         // Start download thread
  38         log.clear();
  39         th = new Thread(this);
  40         th.start();
  41         }
  42
  43         public void stop()
  44         {
  45         // Stop download
  46         try {
  47                 String killurl = getParameter("killurl");
  48                 if (killurl != null) {
  49                         // Call this CGI at stop time
  50                         try {
  51                                 URL u = new URL(getDocumentBase(), killurl);
  52                                 URLConnection uc = u.openConnection();
  53                                 String session = getParameter("session");
  54                                 if (session != null)
  55                                     uc.setRequestProperty("Cookie", session);
  56                                 uc.getInputStream().close();
  57                                 }
  58                         catch(Exception e2) { }
  59                         }
  60                 if (is != null) is.close();
  61                 if (th != null) th.stop();
  62                 }
  63         catch(Exception e) {
  64                 // ignore it
  65                 e.printStackTrace();
  66                 }
  67         }
  68
  69         public void run()
  70         {
  71         try {
  72                 URL u = new URL(getDocumentBase(), getParameter("url"));
  73                 URLConnection uc = u.openConnection();
  74                 String session = getParameter("session");
  75                 if (session != null)
  76                         uc.setRequestProperty("Cookie", session);
  77                 is = new LineInputStream(uc.getInputStream());
  78                 while(true) {
  79                         StringSplitter tok =
  80                                 new StringSplitter(is.gets(), '\t', false);
  81                         if (tok.countTokens() == 4) {
  82                                 Object row[] = { tok.nextToken(),
  83                                                  tok.nextToken(),
  84                                                  tok.nextToken(),
  85                                                  tok.nextToken() };
  86                                 if (paused) {
  87                                         // Store in temp buffer
  88                                         buffer.addElement(row);
  89                                         if (buffer.size() > MAX_ROWS) {
  90                                                 buffer.removeElementAt(0);
  91                                                 }
  92                                         }
  93                                 else {
  94                                         // Add immediately
  95                                         log.addItem(row);
  96                                         cleanup();
  97                                         log.scrollto(log.count()-1);
  98                                         }
  99                                 }
 100                         }
 101                 }
 102         catch(EOFException e) {
 103                 // end of file ..
 104                 }
 105         catch(IOException e) {
 106                 // shouldn't happen!
 107                 e.printStackTrace();
 108                 }
 109         }
 110
 111         void cleanup()
 112         {
 113         while(log.count() > MAX_ROWS) {
 114                 log.deleteItem(0);
 115                 }
 116         }
 117
 118         public void click(CbButton b) {
 119                 if (b == pause) {
 120                         if (paused) {
 121                                 // Resume display, and add missed stuff
 122                                 pause.setText("  Pause  ");
 123                                 for(int i=0; i<buffer.size(); i++) {
 124                                         Object row[] =
 125                                                 (Object[])buffer.elementAt(i);
 126                                         log.addItem(row);
 127                                         }
 128                                 cleanup();
 129                                 log.scrollto(log.count()-1);
 130                                 buffer.removeAllElements();
 131                         } else {
 132                                 // Stop display
 133                                 pause.setText("Resume");
 134                         }
 135                         paused = !paused;
 136                 }
 137         }
 138 }
 139