org.objectweb.asm.commons.CodeSizeEvaluator.java Source code

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Here is the source code for org.objectweb.asm.commons.CodeSizeEvaluator.java

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// 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 org.objectweb.asm.commons;

import org.objectweb.asm.ConstantDynamic;
import org.objectweb.asm.Handle;
import org.objectweb.asm.Label;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;

/**
 * A {@link MethodVisitor} that approximates the size of the methods it visits.
 *
 * @author Eugene Kuleshov
 */
public class CodeSizeEvaluator extends MethodVisitor implements Opcodes {

    /** The minimum size in bytes of the visited method. */
    private int minSize;

    /** The maximum size in bytes of the visited method. */
    private int maxSize;

    public CodeSizeEvaluator(final MethodVisitor methodVisitor) {
        this(/* latest api = */ Opcodes.ASM7, methodVisitor);
    }

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

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

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

    @Override
    public void visitInsn(final int opcode) {
        minSize += 1;
        maxSize += 1;
        super.visitInsn(opcode);
    }

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

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

    @Override
    public void visitFieldInsn(final int opcode, final String owner, final String name, final String descriptor) {
        minSize += 3;
        maxSize += 3;
        super.visitFieldInsn(opcode, owner, name, descriptor);
    }

    @Override
    public void visitMethodInsn(final int opcodeAndSource, final String owner, final String name,
            final String descriptor, final boolean isInterface) {
        if (api < Opcodes.ASM5 && (opcodeAndSource & Opcodes.SOURCE_DEPRECATED) == 0) {
            // Redirect the call to the deprecated version of this method.
            super.visitMethodInsn(opcodeAndSource, owner, name, descriptor, isInterface);
            return;
        }
        int opcode = opcodeAndSource & ~Opcodes.SOURCE_MASK;

        if (opcode == INVOKEINTERFACE) {
            minSize += 5;
            maxSize += 5;
        } else {
            minSize += 3;
            maxSize += 3;
        }
        super.visitMethodInsn(opcodeAndSource, owner, name, descriptor, isInterface);
    }

    @Override
    public void visitInvokeDynamicInsn(final String name, final String descriptor,
            final Handle bootstrapMethodHandle, final Object... bootstrapMethodArguments) {
        minSize += 5;
        maxSize += 5;
        super.visitInvokeDynamicInsn(name, descriptor, bootstrapMethodHandle, bootstrapMethodArguments);
    }

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

    @Override
    public void visitLdcInsn(final Object value) {
        if (value instanceof Long || value instanceof Double
                || (value instanceof ConstantDynamic && ((ConstantDynamic) value).getSize() == 2)) {
            minSize += 3;
            maxSize += 3;
        } else {
            minSize += 2;
            maxSize += 3;
        }
        super.visitLdcInsn(value);
    }

    @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;
        }
        super.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;
        super.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;
        super.visitLookupSwitchInsn(dflt, keys, labels);
    }

    @Override
    public void visitMultiANewArrayInsn(final String descriptor, final int numDimensions) {
        minSize += 4;
        maxSize += 4;
        super.visitMultiANewArrayInsn(descriptor, numDimensions);
    }
}