io.netty.microbenchmark.common.AsciiStringBenchmark Maven / Gradle / Ivy
/*
* Copyright 2015 The Netty Project
*
* The Netty Project 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 io.netty.microbenchmark.common;
import io.netty.microbench.util.AbstractMicrobenchmark;
import io.netty.util.AsciiString;
import io.netty.util.CharsetUtil;
import io.netty.util.internal.PlatformDependent;
import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.Level;
import org.openjdk.jmh.annotations.Measurement;
import org.openjdk.jmh.annotations.Param;
import org.openjdk.jmh.annotations.Setup;
import org.openjdk.jmh.annotations.Threads;
import org.openjdk.jmh.annotations.Warmup;
import java.util.Random;
@Threads(1)
@Measurement(iterations = 5)
@Warmup(iterations = 5)
public class AsciiStringBenchmark extends AbstractMicrobenchmark {
@Param({ "3", "5", "7", "8", "10", "20", "50", "100", "1000" })
public int size;
private AsciiString asciiString;
private String string;
private static final Random random = new Random();
@Setup(Level.Trial)
public void setup() {
byte[] bytes = new byte[size];
random.nextBytes(bytes);
asciiString = new AsciiString(bytes, false);
string = new String(bytes, CharsetUtil.US_ASCII);
}
@Benchmark
public int hashCodeBenchBytesOld() {
int h = 0;
final int end = asciiString.arrayOffset() + asciiString.length();
for (int i = asciiString.arrayOffset(); i < end; ++i) {
// masking with 0x1F reduces the number of overall bits that impact the hash code but makes the hash
// code the same regardless of character case (upper case or lower case hash is the same).
h = h * 31 + (asciiString.array()[i] & 0x1F);
}
return h;
}
@Benchmark
public int hashCodeBenchBytesNew() {
return PlatformDependent.hashCodeAscii(asciiString.array(), asciiString.arrayOffset(), asciiString.length());
}
@Benchmark
public int hashCodeBenchCharSequenceOld() {
int h = 0;
for (int i = 0; i < string.length(); ++i) {
// masking with 0x1F reduces the number of overall bits that impact the hash code but makes the hash
// code the same regardless of character case (upper case or lower case hash is the same).
h = h * 31 + (string.charAt(i) & 0x1F);
}
return h;
}
@Benchmark
public int hashCodeBenchCharSequenceNew() {
return PlatformDependent.hashCodeAscii(string);
}
}
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