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1
5 package org.h2.test.unit;
6
7 import java.util.Random  ;
8
9 import org.h2.test.TestBase;
10 import org.h2.util.StringCache;
11
12 public class TestStringCache extends TestBase {
13
14 public static void main(String [] args) throws Exception {
15 new TestStringCache().runBenchmark();
16 }
17
18 private void runBenchmark() throws Exception {
19 returnNew = false;
20 for(int i=0; i<6; i++) {
21 useIntern = (i % 2) == 1;
22 long time = System.currentTimeMillis();
23 testSingleThread(100000);
24 time = System.currentTimeMillis()-time;
25 System.out.println(time + " ms (useIntern=" + useIntern+")");
26 }
27
28 }
29
30 private Random random = new Random (1);
31 private String [] some = new String [] { null, "", "ABC", "this is a medium sized string", "1", "2"};
32 private volatile boolean stop;
33 private boolean returnNew;
34 private boolean useIntern;
35
36 public void test() throws Exception {
37 returnNew = true;
38 StringCache.clearCache();
39 testSingleThread(getSize(5000, 20000));
40 testMultiThreads();
41 returnNew = false;
42 StringCache.clearCache();
43 testSingleThread(getSize(5000, 20000));
44 testMultiThreads();
45 }
46
47 String randomString() {
48 if(random.nextBoolean()) {
49 String s = some[random.nextInt(some.length)];
50 if(s != null && random.nextBoolean()) {
51 s = new String (s);
52 }
53 return s;
54 } else {
55 int len = random.nextBoolean() ? random.nextInt(1000) : random.nextInt(10);
56 StringBuffer buff = new StringBuffer (len);
57 for(int i=0; i<len; i++) {
58 buff.append(random.nextInt(0xfff));
59 }
60 return buff.toString();
61 }
62 }
63
64 void testString() {
65 String a = randomString();
66 if(returnNew) {
67 String b = StringCache.getNew(a);
68 try {
69 check(a, b);
70 } catch (Exception e) {
71 TestBase.logError("error", e);
72 }
73 if(a != null && a == b && a.length()>0) {
74 throw new Error ("a=" + System.identityHashCode(a) + " b=" + System.identityHashCode(b));
75 }
76 } else {
77 String b;
78 if(useIntern) {
79 b = a == null ? null : a.intern();
80 } else {
81 b = StringCache.get(a);
82 }
83 try {
84 check(a, b);
85 } catch (Exception e) {
86 TestBase.logError("error", e);
87 }
88 }
89 }
90
91 private void testSingleThread(int len) throws Exception {
92 for(int i=0; i<len; i++) {
93 testString();
94 }
95 }
96
97 private void testMultiThreads() throws Exception {
98 int threadCount = getSize(3, 100);
99 Thread [] threads = new Thread [threadCount];
100 for(int i=0; i<threadCount; i++) {
101 Thread t = new Thread (new Runnable () {
102 public void run() {
103 while(!stop) {
104 testString();
105 }
106 }
107 });
108 threads[i] = t;
109 }
110 for(int i=0; i<threadCount; i++) {
111 threads[i].start();
112 }
113 int wait = getSize(200, 2000);
114 Thread.sleep(wait);
115 stop = true;
116 for(int i=0; i<threadCount; i++) {
117 threads[i].join();
118 }
119 }
120
121 }
122 |
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