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

 

}

 

}