org.jacoco.core.runtime.SystemPropertiesRuntime.java Source code

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Here is the source code for org.jacoco.core.runtime.SystemPropertiesRuntime.java

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/*******************************************************************************
 * Copyright (c) 2009, 2013 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.runtime;

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

/**
 * This {@link IRuntime} implementation makes the execution data available
 * through a special entry in the {@link System#getProperties()} hash table. The
 * advantage is, that the instrumented classes do not get dependencies to other
 * classes than the JRE library itself.
 * 
 * This runtime may cause problems in environments with security restrictions,
 * in applications that replace the system properties or in applications that
 * fail if non-String values are placed in the system properties.
 */
public class SystemPropertiesRuntime extends AbstractRuntime {

    private static final String KEYPREFIX = "jacoco-";

    private final String key;

    /**
     * Creates a new runtime.
     */
    public SystemPropertiesRuntime() {
        super();
        this.key = KEYPREFIX + Integer.toHexString(hashCode());
    }

    public int generateDataAccessor(final long classid, final String classname, final int probecount,
            final MethodVisitor mv) {
        mv.visitMethodInsn(Opcodes.INVOKESTATIC, "java/lang/System", "getProperties", "()Ljava/util/Properties;");

        // Stack[0]: Ljava/util/Properties;

        mv.visitLdcInsn(key);

        // Stack[1]: Ljava/lang/String;
        // Stack[0]: Ljava/util/Properties;

        mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/util/Properties", "get",
                "(Ljava/lang/Object;)Ljava/lang/Object;");

        // Stack[0]: Ljava/lang/Object;

        RuntimeData.generateAccessCall(classid, classname, probecount, mv);

        // Stack[0]: [Z

        return 6; // Maximum local stack size is 3
    }

    @Override
    public void startup(final RuntimeData data) throws Exception {
        super.startup(data);
        System.getProperties().put(key, data);
    }

    public void shutdown() {
        System.getProperties().remove(key);
    }

}