2017-01-11 09:11:59 -08:00

95 lines
2.2 KiB
Java

// collectiontopics/jmh/Lists.java
// (c)2017 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.
// Performance differences between Lists
package collectiontopics.jmh;
import org.openjdk.jmh.annotations.*;
import java.util.*;
import java.util.concurrent.*;
@State(Scope.Thread)
@OutputTimeUnit(TimeUnit.MICROSECONDS)
@Warmup(iterations = 5, batchSize = 5000)
@Measurement(iterations = 5, batchSize = 5000)
@BenchmarkMode(Mode.SingleShotTime)
@Fork(1)
public class Lists {
private List<String> list;
@Param({
"java.util.ArrayList",
"java.util.Vector",
"java.util.LinkedList",
"java.util.concurrent.CopyOnWriteArrayList"
})
private String type;
@Param({
"1",
"10",
"100",
"1000",
"10000",
"100000"
})
private int size;
private int middle;
private ListIterator<String> it;
@Setup
@SuppressWarnings("unchecked")
public void setup() throws Exception {
list = (List<String>)
Class.forName(type).newInstance();
for(int i = 0; i < size; i++)
list.add(Integer.toString(i));
middle = size / 2;
it = list.listIterator(middle);
}
@Benchmark
public List<String> append() {
list.add("test");
return list;
}
@Benchmark
public List<String> insert() {
list.add(middle, "test");
return list;
}
@Benchmark
public String get() {
return list.get(middle);
}
@Benchmark
public List<String> set() {
list.set(middle, "test");
return list;
}
@Benchmark
public List<String> iteradd() {
try {
it.add("test");
} catch(UnsupportedOperationException e) {
System.err.println(
"-> Unsupported: listIterator.add() in " +
list.getClass().getSimpleName());
}
return list;
}
@Benchmark
public List<String> remove() {
middle = list.size() / 2;
if(middle - 1 > 0)
try {
list.remove(middle - 1);
} catch(ArrayIndexOutOfBoundsException e) {
System.out.println("Out of bounds -> size: "
+ list.size() + " middle - 1: " + (middle - 1) +
" for " + list.getClass().getSimpleName());
}
return list;
}
}