1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 package org.apache.bcel; 19 20 import java.io.ByteArrayInputStream; 21 import java.io.IOException; 22 import java.util.concurrent.TimeUnit; 23 import java.util.jar.JarEntry; 24 import java.util.jar.JarFile; 25 26 import org.apache.bcel.classfile.ClassParser; 27 import org.apache.bcel.classfile.JavaClass; 28 import org.apache.bcel.classfile.Method; 29 import org.apache.bcel.generic.ClassGen; 30 import org.apache.bcel.generic.InstructionList; 31 import org.apache.bcel.generic.MethodGen; 32 import org.apache.commons.collections4.Predicate; 33 import org.apache.commons.collections4.iterators.EnumerationIterator; 34 import org.apache.commons.collections4.iterators.FilterIterator; 35 import org.apache.commons.collections4.iterators.IteratorIterable; 36 import org.apache.commons.io.IOUtils; 37 import org.openjdk.jmh.annotations.Benchmark; 38 import org.openjdk.jmh.annotations.BenchmarkMode; 39 import org.openjdk.jmh.annotations.Fork; 40 import org.openjdk.jmh.annotations.Measurement; 41 import org.openjdk.jmh.annotations.Mode; 42 import org.openjdk.jmh.annotations.OutputTimeUnit; 43 import org.openjdk.jmh.annotations.Threads; 44 import org.openjdk.jmh.annotations.Warmup; 45 import org.openjdk.jmh.infra.Blackhole; 46 47 @BenchmarkMode(Mode.AverageTime) 48 @Fork(value = 1, jvmArgs = "-server") 49 @Threads(1) 50 @Warmup(iterations = 10) 51 @Measurement(iterations = 20) 52 @OutputTimeUnit(TimeUnit.MILLISECONDS) 53 public class BCELBenchmark { 54 getJarFile()55 private JarFile getJarFile() throws IOException { 56 String javaHome = System.getProperty("java.home"); 57 return new JarFile(javaHome + "/lib/rt.jar"); 58 } 59 getClasses(JarFile jar)60 private Iterable<JarEntry> getClasses(JarFile jar) { 61 return new IteratorIterable<>(new FilterIterator<>(new EnumerationIterator<>(jar.entries()), new Predicate<JarEntry>() { 62 @Override 63 public boolean evaluate(JarEntry entry) { 64 return entry.getName().endsWith(".class"); 65 } 66 })); 67 } 68 69 /** 70 * Baseline benchmark. Read the classes but don't parse them. 71 */ 72 @Benchmark 73 public void baseline(Blackhole bh) throws IOException { 74 JarFile jar = getJarFile(); 75 76 for (JarEntry entry : getClasses(jar)) { 77 byte[] bytes = IOUtils.toByteArray(jar.getInputStream(entry)); 78 bh.consume(bytes); 79 } 80 81 jar.close(); 82 } 83 84 @Benchmark 85 public void parser(Blackhole bh) throws IOException { 86 JarFile jar = getJarFile(); 87 88 for (JarEntry entry : getClasses(jar)) { 89 byte[] bytes = IOUtils.toByteArray(jar.getInputStream(entry)); 90 91 JavaClass clazz = new ClassParser(new ByteArrayInputStream(bytes), entry.getName()).parse(); 92 bh.consume(clazz); 93 } 94 95 jar.close(); 96 } 97 98 @Benchmark 99 public void generator(Blackhole bh) throws IOException { 100 JarFile jar = getJarFile(); 101 102 for (JarEntry entry : getClasses(jar)) { 103 byte[] bytes = IOUtils.toByteArray(jar.getInputStream(entry)); 104 105 JavaClass clazz = new ClassParser(new ByteArrayInputStream(bytes), entry.getName()).parse(); 106 107 ClassGen cg = new ClassGen(clazz); 108 109 for (Method m : cg.getMethods()) { 110 MethodGen mg = new MethodGen(m, cg.getClassName(), cg.getConstantPool()); 111 InstructionList il = mg.getInstructionList(); 112 113 if (il != null) { 114 mg.getInstructionList().setPositions(); 115 mg.setMaxLocals(); 116 mg.setMaxStack(); 117 } 118 cg.replaceMethod(m, mg.getMethod()); 119 } 120 121 bh.consume(cg.getJavaClass().getBytes()); 122 } 123 124 jar.close(); 125 } 126 } 127