org.jacoco.core.internal.instr.LazyFrameTracker.java Source code

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Here is the source code for org.jacoco.core.internal.instr.LazyFrameTracker.java

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/*******************************************************************************
 * Copyright (c) 2009, 2012 Mountainminds GmbH & Co. KG and Contributors
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Marc R. Hoffmann - initial API and implementation
 *    
 *******************************************************************************/
package org.jacoco.core.internal.instr;

import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;

/**
 * Internal wrapper for the FrameTracker which activates frame tracking lazily
 * when the first frame is reported.
 */
class LazyFrameTracker extends MethodVisitor implements IFrameInserter {

    private final String owner;
    private FrameTracker tracker;

    public LazyFrameTracker(final MethodVisitor mv, final String owner) {
        super(Opcodes.ASM4, mv);
        this.owner = owner;
        this.tracker = null;
    }

    @Override
    public void visitFrame(final int type, final int nLocal, final Object[] local, final int nStack,
            final Object[] stack) {
        if (tracker == null) {
            mv = tracker = new FrameTracker(mv, owner);
        }
        tracker.visitFrame(type, nLocal, local, nStack, stack);
    }

    public void insertFrame() {
        if (tracker != null) {
            tracker.insertFrame();
        }
    }

}