/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.lucene.util;
import java.util.Random;
public class TestStringIntern extends LuceneTestCase {
String[] testStrings;
String[] internedStrings;
private String randStr(int len) {
char[] arr = new char[len];
for (int i=0; i<len; i++) {
arr[i] = (char)('a' + random.nextInt(26));
}
return new String(arr);
}
private void makeStrings(int sz) {
testStrings = new String[sz];
internedStrings = new String[sz];
for (int i=0; i<sz; i++) {
testStrings[i] = randStr(random.nextInt(8)+3);
}
}
public void testStringIntern() throws InterruptedException {
makeStrings(1024*10); // something greater than the capacity of the default cache size
// makeStrings(100); // realistic for perf testing
int nThreads = 20;
// final int iter=100000;
final int iter = atLeast(100000);
// try native intern
// StringHelper.interner = new StringInterner();
Thread[] threads = new Thread[nThreads];
for (int i=0; i<nThreads; i++) {
final int seed = i;
threads[i] = new Thread() {
@Override
public void run() {
Random rand = new Random(seed);
String[] myInterned = new String[testStrings.length];
for (int j=0; j<iter; j++) {
int idx = rand.nextInt(testStrings.length);
String s = testStrings[idx];
if (rand.nextBoolean()) s = new String(s); // make a copy half of the time
String interned = StringHelper.intern(s);
String prevInterned = myInterned[idx];
String otherInterned = internedStrings[idx];
// test against other threads
if (otherInterned != null && otherInterned != interned) {
fail();
}
internedStrings[idx] = interned;
// test against local copy
if (prevInterned != null && prevInterned != interned) {
fail();
}
myInterned[idx] = interned;
}
}
};
threads[i].start();
}
for (int i=0; i<nThreads; i++) {
threads[i].join();
}
}
}