java 集合性能测试
package fubar;
import gnu.trove.map.hash.TIntObjectHashMap;
import java.util.HashMap;
import javolution.util.FastMap;
import cern.colt.map.OpenIntIntHashMap;
import cern.colt.map.OpenIntObjectHashMap;
public class Compare {
public static void main(String args[]) {
System.out.println("1st line: time used(s)\n2nd line: heap memory used so far(MB)");
int n = 100000000;
long startTime = System.nanoTime();
long startHeapSize = Runtime.getRuntime().freeMemory();
// BEGIN: benchmark for Java's built-in hashmap
System.out.println("\n===== Java's built-in HashMap =====");
HashMap jIntIntMap = new HashMap();
System.out.println("\n-- " + n + " puts(key, value) --");
startTime = System.nanoTime();
for (int i = 0; i < n; i++) {
jIntIntMap.put(i, new float[] { 0f, 1f, 2f, 3f, 4f });
}
System.out.println((System.nanoTime() - startTime) / 1000000000.0);
System.out.println((startHeapSize - Runtime.getRuntime().freeMemory()) / 1048576.0);
System.out.println("\n-- " + n + " gets(key) --");
startTime = System.nanoTime();
for (int i = 0; i < n; i++) {
jIntIntMap.get(i);
}
System.out.println((System.nanoTime() - startTime) / 1000000000.0);
System.out.println((startHeapSize - Runtime.getRuntime().freeMemory()) / 1048576.0);
System.out.println("\n-- " + n + " containsKey(key) --");
startTime = System.nanoTime();
for (int i = 0; i < n; i++) {
jIntIntMap.containsKey(i);
}
System.out.println((System.nanoTime() - startTime) / 1000000000.0);
System.out.println((startHeapSize - Runtime.getRuntime().freeMemory()) / 1048576.0);
// END
// //////////////////////////////////////////////////////////////////////////////////////////
// BEGIN: benchmark for Java's built-in hashmap
{
System.out.println("\n===== Javolution HashMap =====");
FastMap fastMap = new FastMap();
System.out.println("\n-- " + n + " puts(key, value) --");
startTime = System.nanoTime();
for (int i = 0; i < n; i++) {
fastMap.put(i, new float[] { 0f, 1f, 2f, 3f, 4f });
}
System.out.println((System.nanoTime() - startTime) / 1000000000.0);
System.out.println((startHeapSize - Runtime.getRuntime().freeMemory()) / 1048576.0);
System.out.println("\n-- " + n + " gets(key) --");
startTime = System.nanoTime();
for (int i = 0; i < n; i++) {
fastMap.get(i);
}
System.out.println((System.nanoTime() - startTime) / 1000000000.0);
System.out.println((startHeapSize - Runtime.getRuntime().freeMemory()) / 1048576.0);
System.out.println("\n-- " + n + " containsKey(key) --");
startTime = System.nanoTime();
for (int i = 0; i < n; i++) {
fastMap.containsKey(i);
}
System.out.println((System.nanoTime() - startTime) / 1000000000.0);
System.out.println((startHeapSize - Runtime.getRuntime().freeMemory()) / 1048576.0);
}
// END
// //////////////////////////////////////////////////////////////////////////////////////////
// BEGIN: benchmark for Trove's TIntIntHashMap
System.out.println("\n===== Trove's TIntIntHashMap =====");
TIntObjectHashMap tIntIntMap = new TIntObjectHashMap();
System.out.println("\n-- " + n + " puts(key, value) --");
startTime = System.nanoTime();
for (int i = 0; i < n; i++) {
tIntIntMap.put(i, new float[] { 0f, 1f, 2f, 3f, 4f });
}
System.out.println((System.nanoTime() - startTime) / 1000000000.0);
System.out.println((startHeapSize - Runtime.getRuntime().freeMemory()) / 1048576.0);
System.out.println("\n-- " + n + " gets(key) --");
startTime = System.nanoTime();
for (int i = 0; i < n; i++) {
tIntIntMap.get(i);
}
System.out.println((System.nanoTime() - startTime) / 1000000000.0);
System.out.println((startHeapSize - Runtime.getRuntime().freeMemory()) / 1048576.0);
System.out.println("\n-- " + n + " containsKey(key) --");
startTime = System.nanoTime();
for (int i = 0; i < n; i++) {
tIntIntMap.containsKey(i);
}
System.out.println((System.nanoTime() - startTime) / 1000000000.0);
System.out.println((startHeapSize - Runtime.getRuntime().freeMemory()) / 1048576.0);
// END
// BEGIN: benchmark for Colt's OpenIntIntHashMap
System.out.println("\n===== Colt's OpenIntIntHashMap =====");
OpenIntObjectHashMap cIntIntMap = new OpenIntObjectHashMap();
System.out.println("\n-- " + n + " puts(key, value) --");
startTime = System.nanoTime();
for (int i = 0; i < n; i++) {
cIntIntMap.put(i, new float[] { 0f, 1f, 2f, 3f, 4f });
}
System.out.println((System.nanoTime() - startTime) / 1000000000.0);
System.out.println((startHeapSize - Runtime.getRuntime().freeMemory()) / 1048576.0);
System.out.println("\n-- " + n + " gets(key) --");
startTime = System.nanoTime();
for (int i = 0; i < n; i++) {
cIntIntMap.get(i);
}
System.out.println((System.nanoTime() - startTime) / 1000000000.0);
System.out.println((startHeapSize - Runtime.getRuntime().freeMemory()) / 1048576.0);
System.out.println("\n-- " + n + " containsKey(key) --");
startTime = System.nanoTime();
for (int i = 0; i < n; i++) {
cIntIntMap.containsKey(i);
}
System.out.println((System.nanoTime() - startTime) / 1000000000.0);
System.out.println((startHeapSize - Runtime.getRuntime().freeMemory()) / 1048576.0);
// END
}
}