alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Java example source code file (CodeSizeEvaluator.java)

This example Java source code file (CodeSizeEvaluator.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

codesizeevaluator, double, goto, handle, jsr, label, long, methodvisitor, object, opcodes, override, ret, sipush, string

The CodeSizeEvaluator.java Java example source code

/***
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000-2011 INRIA, France Telecom
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */
package clojure.asm.commons;

import clojure.asm.Handle;
import clojure.asm.Label;
import clojure.asm.MethodVisitor;
import clojure.asm.Opcodes;

/**
 * A {@link MethodVisitor} that can be used to approximate method size.
 *
 * @author Eugene Kuleshov
 */
public class CodeSizeEvaluator extends MethodVisitor implements Opcodes {

    private int minSize;

    private int maxSize;

    public CodeSizeEvaluator(final MethodVisitor mv) {
        this(Opcodes.ASM4, mv);
    }

    protected CodeSizeEvaluator(final int api, final MethodVisitor mv) {
        super(api, mv);
    }

    public int getMinSize() {
        return this.minSize;
    }

    public int getMaxSize() {
        return this.maxSize;
    }

    @Override
    public void visitInsn(final int opcode) {
        minSize += 1;
        maxSize += 1;
        if (mv != null) {
            mv.visitInsn(opcode);
        }
    }

    @Override
    public void visitIntInsn(final int opcode, final int operand) {
        if (opcode == SIPUSH) {
            minSize += 3;
            maxSize += 3;
        } else {
            minSize += 2;
            maxSize += 2;
        }
        if (mv != null) {
            mv.visitIntInsn(opcode, operand);
        }
    }

    @Override
    public void visitVarInsn(final int opcode, final int var) {
        if (var < 4 && opcode != RET) {
            minSize += 1;
            maxSize += 1;
        } else if (var >= 256) {
            minSize += 4;
            maxSize += 4;
        } else {
            minSize += 2;
            maxSize += 2;
        }
        if (mv != null) {
            mv.visitVarInsn(opcode, var);
        }
    }

    @Override
    public void visitTypeInsn(final int opcode, final String type) {
        minSize += 3;
        maxSize += 3;
        if (mv != null) {
            mv.visitTypeInsn(opcode, type);
        }
    }

    @Override
    public void visitFieldInsn(final int opcode, final String owner,
            final String name, final String desc) {
        minSize += 3;
        maxSize += 3;
        if (mv != null) {
            mv.visitFieldInsn(opcode, owner, name, desc);
        }
    }

    @Override
    public void visitMethodInsn(final int opcode, final String owner,
            final String name, final String desc) {
        if (opcode == INVOKEINTERFACE) {
            minSize += 5;
            maxSize += 5;
        } else {
            minSize += 3;
            maxSize += 3;
        }
        if (mv != null) {
            mv.visitMethodInsn(opcode, owner, name, desc);
        }
    }

    @Override
    public void visitInvokeDynamicInsn(String name, String desc, Handle bsm,
            Object... bsmArgs) {
        minSize += 5;
        maxSize += 5;
        if (mv != null) {
            mv.visitInvokeDynamicInsn(name, desc, bsm, bsmArgs);
        }
    }

    @Override
    public void visitJumpInsn(final int opcode, final Label label) {
        minSize += 3;
        if (opcode == GOTO || opcode == JSR) {
            maxSize += 5;
        } else {
            maxSize += 8;
        }
        if (mv != null) {
            mv.visitJumpInsn(opcode, label);
        }
    }

    @Override
    public void visitLdcInsn(final Object cst) {
        if (cst instanceof Long || cst instanceof Double) {
            minSize += 3;
            maxSize += 3;
        } else {
            minSize += 2;
            maxSize += 3;
        }
        if (mv != null) {
            mv.visitLdcInsn(cst);
        }
    }

    @Override
    public void visitIincInsn(final int var, final int increment) {
        if (var > 255 || increment > 127 || increment < -128) {
            minSize += 6;
            maxSize += 6;
        } else {
            minSize += 3;
            maxSize += 3;
        }
        if (mv != null) {
            mv.visitIincInsn(var, increment);
        }
    }

    @Override
    public void visitTableSwitchInsn(final int min, final int max,
            final Label dflt, final Label... labels) {
        minSize += 13 + labels.length * 4;
        maxSize += 16 + labels.length * 4;
        if (mv != null) {
            mv.visitTableSwitchInsn(min, max, dflt, labels);
        }
    }

    @Override
    public void visitLookupSwitchInsn(final Label dflt, final int[] keys,
            final Label[] labels) {
        minSize += 9 + keys.length * 8;
        maxSize += 12 + keys.length * 8;
        if (mv != null) {
            mv.visitLookupSwitchInsn(dflt, keys, labels);
        }
    }

    @Override
    public void visitMultiANewArrayInsn(final String desc, final int dims) {
        minSize += 4;
        maxSize += 4;
        if (mv != null) {
            mv.visitMultiANewArrayInsn(desc, dims);
        }
    }
}

Other Java examples (source code examples)

Here is a short list of links related to this Java CodeSizeEvaluator.java source code file:

... this post is sponsored by my books ...

#1 New Release!

FP Best Seller

 

new blog posts

 

Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.