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1 package com.tirsen.nanning.samples.prevayler;
2
3 import org.prevayler.Prevayler;
4 import org.prevayler.util.clock.ClockedSystem;
5
6 public class CurrentPrevayler {
7
8 private static ThreadLocal  isInTransaction = new ThreadLocal () {
9 protected Object initialValue() {
10 return new Integer (0);
11 }
12 };
13 private static ThreadLocal currentPrevayler = new InheritableThreadLocal ();
14 private static ThreadLocal currentSystem = new InheritableThreadLocal ();
15
16 public static boolean isInitialized() {
17 return currentSystem.get() != null;
18 }
19
20 public static Object getSystem() {
21 Object system;
22 if (hasPrevayler()) {
23 system = getPrevayler().prevalentSystem();
24 } else {
25 system = currentSystem.get();
26 }
27 assert system != null : "Prevayler not initialized for this thread, no current system";
28 return system;
29 }
30
31 public static void setSystem(Object system) {
32 currentSystem.set(system);
33 if (system != null) {
34 setPrevayler(null);
35 }
36 }
37
38 public static Prevayler getPrevayler() {
39 Prevayler prevayler = (Prevayler) currentPrevayler.get();
40 assert prevayler != null : "Prevayler not initialized for this thread, no current Prevayler";
41 return prevayler;
42 }
43
44 public static ClockedSystem clockedSystem() {
45 return (ClockedSystem) getSystem();
46 }
47
48 public static void setPrevayler(Prevayler prevayler) {
49 currentPrevayler.set(prevayler);
50 if (prevayler != null) {
51 setSystem(null);
52 }
53 }
54
55 public static boolean isReplaying() {
56 return getSystem() != null && getPrevayler() == null;
57 }
58
59 public static void enterTransaction() {
60 isInTransaction.set(new Integer (transactionCount() + 1));
61 }
62
63 public static void exitTransaction() {
64 assert isInTransaction() : "not in transaction";
65 isInTransaction.set(new Integer (transactionCount() - 1));
66 }
67
68 public static boolean isInTransaction() {
69 return transactionCount() != 0;
70 }
71
72 private static int transactionCount() {
73 return ((Integer ) isInTransaction.get()).intValue();
74 }
75
76 public static void withPrevayler(Prevayler prevayler, final Runnable runnable) {
77 try {
78 withPrevayler(prevayler, new PrevaylerAction() {
79 public Object run() throws Exception {
80 runnable.run();
81 return null;
82 }
83 });
84 } catch (Exception e) {
85 throw new RuntimeException (e);
86 }
87 }
88
89 public static Object withPrevayler(Prevayler prevayler, PrevaylerAction action) throws Exception {
90 Prevayler lastPrevayler = (Prevayler) currentPrevayler.get();
91 setPrevayler(prevayler);
92 try {
93 return action.run();
94 } finally {
95 setPrevayler(lastPrevayler);
96 }
97 }
98
99 public static boolean hasPrevayler() {
100 return currentPrevayler.get() != null;
101 }
102
103 public static boolean hasSystem() {
104 return hasPrevayler() || currentSystem.get() != null;
105 }
106 }
107 |
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