src/java/ibex/xt/Prevalence.java

   1 package ibex.xt;
   2
   3 import java.io.*;
   4
   5 import java.net.*;
   6 import javax.servlet.ServletContext; // FIXME: remove references
   7
   8 import java.util.*;
   9 import ibex.util.*;
  10 import ibex.js.*;
  11
  12 import org.prevayler.*;
  13 import org.prevayler.implementation.snapshot.*;
  14 //import com.thoughtworks.xstream.*; // FIXME find
  15
  16 public class Prevalence {
  17
  18     static final Hashtable prevaylers = new Hashtable();
  19
  20     public static void destroy(ServletContext cx, Prevayler prevayler) { try {
  21         prevaylers.remove(cx);
  22         prevayler.takeSnapshot();
  23         prevayler.close();
  24     } catch (Exception e) { e.printStackTrace(); } }
  25
  26     private static class SnapshotThread extends Thread {
  27         ServletContext cx;
  28         public SnapshotThread(ServletContext cx) { this.cx = cx; }
  29         public void run() {
  30             try {
  31                 Thread.sleep(10000);
  32                 Prevayler privatePrevayler = (Prevayler)prevaylers.get(cx);
  33                 if (privatePrevayler == null) return;
  34                 privatePrevayler.takeSnapshot();
  35             } catch (Exception e) {
  36                 e.printStackTrace();
  37             }
  38         }
  39     }
  40
  41     public static Prevayler getPrevayler(ServletContext cx) {
  42         try {
  43             Prevayler prevayler;
  44             synchronized(cx) {
  45                 prevayler = (Prevayler)prevaylers.get(cx);
  46                 if (prevayler == null) {
  47                     PrevaylerFactory pf = new PrevaylerFactory();
  48                     String base = cx.getRealPath("/") + "WEB-INF" + File.separatorChar + "prevalent";
  49                     System.err.println("prevayling to " + base);
  50                     pf.configurePrevalenceBase(base);
  51                     /*
  52                     XStreamSnapshotManager manager = new XStreamSnapshotManager(new JS(), base, null) {
  53                             protected XStream createXStream() {
  54                                 XStream xstream = new XStream();
  55                                 xstream.alias("js", JS.class);
  56                                 xstream.alias("jsdate", JSDate.class);
  57                                 return xstream;
  58                             }
  59                         };
  60                     System.err.println("configuring with " + manager);
  61                     pf.configureSnapshotManager(manager);
  62                     */
  63                     pf.configureSnapshotManager(new SnapshotManager(new JS(), base));
  64                     //pf.configureClassLoader(JSTransaction.class.getClassLoader());
  65                     prevayler = pf.create();
  66                     prevaylers.put(cx, prevayler);
  67                     new SnapshotThread(cx).start();
  68                 }
  69             }
  70             return prevayler;
  71         } catch (Exception e) { throw new RuntimeException(e); } }
  72
  73     public static class JSTransaction implements Transaction {
  74         public static final long serialVersionUid = 0xfb2aa281;
  75         private JS js;
  76         JSScope newscope;
  77         List v;
  78         public JSTransaction(JS js) throws JSExn {
  79             newscope = new JSScope(null);
  80             this.js = JS.cloneWithNewParentScope(js, newscope);
  81             v = JS.getFormalArgs(this.js);
  82             for(int i=0; i<v.size(); i++) {
  83                 if ("prevalent".equals(v.get(i))) continue;
  84                 newscope.put(v.get(i), JS.getParentScope(js).get(v.get(i)));
  85             }
  86         }
  87         public void executeOn(Object o, Date now) {
  88             try {
  89                 newscope.put("prevalent", o);
  90                 newscope.put("now", new JSDate(now.getTime()));
  91                 Object a = v.size() <= 0 ? null : newscope.get(v.get(0));
  92                 Object b = v.size() <= 1 ? null : newscope.get(v.get(1));
  93                 Object c = v.size() <= 2 ? null : newscope.get(v.get(2));
  94                 Object[] rest = v.size() <= 3 ? null : new Object[v.size() - 3];
  95                 for(int i=3; i<v.size(); i++) rest[i-3] = v.get(i);
  96                 js.call(a, b, c, rest, v.size());
  97             } catch (Exception e) { throw new RuntimeException(e); }
  98         }
  99     }
 100
 101     public static class JSQuery implements Query {
 102         public static final long serialVersionUid = 0xfb2aa282;
 103         private JS js;
 104         private Object a;
 105         public JSQuery(JS js, Object a) { this.js = JS.cloneWithNewParentScope(js, null); this.a = a; }
 106         public Object query(Object o, Date now) {
 107             try {
 108                 return js.call(o, a, new JSDate(now.getTime()), null, 3);
 109             } catch (Exception e) { throw new RuntimeException(e); }
 110         }
 111     }
 112 }