/*

 * Copyright (c) 2005, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

import java.io.ByteArrayOutputStream;

import java.io.IOException;

import java.util.Properties;

import java.util.Set;

import java.util.jar.JarFile;

import java.util.jar.Manifest;

import java.util.jar.Attributes;

/*

 * Support class used by JVMTI and VM attach mechanism.

 */

public class VMSupport {

    private static Properties agentProps = null;

    /**

     * Returns the agent properties.

     */

    public static synchronized Properties getAgentProperties() {

        if (agentProps == null) {

            agentProps = new Properties();

            initAgentProperties(agentProps);

        }

        return agentProps;

    }

    private static native Properties initAgentProperties(Properties props);

    /**

     * Write the given properties list to a byte array and return it. Properties with

     * a key or value that is not a String is filtered out. The stream written to the byte

     * array is ISO 8859-1 encoded.

     */

    private static byte[] serializePropertiesToByteArray(Properties p) throws IOException {

        ByteArrayOutputStream out = new ByteArrayOutputStream(4096);

        Properties props = new Properties();

        // stringPropertyNames() returns a snapshot of the property keys

        Set<String> keyset = p.stringPropertyNames();

        for (String key : keyset) {

            String value = p.getProperty(key);

            props.put(key, value);

        }

        props.store(out, null);

        return out.toByteArray();

    }

    public static byte[] serializePropertiesToByteArray() throws IOException {

        return serializePropertiesToByteArray(System.getProperties());

    }

    public static byte[] serializeAgentPropertiesToByteArray() throws IOException {

        return serializePropertiesToByteArray(getAgentProperties());

    }

    /*

     * Returns true if the given JAR file has the Class-Path attribute in the

     * main section of the JAR manifest. Throws RuntimeException if the given

     * path is not a JAR file or some other error occurs.

     */

    public static boolean isClassPathAttributePresent(String path) {

        try {

            Manifest man = (new JarFile(path)).getManifest();

            if (man != null) {

                if (man.getMainAttributes().getValue(Attributes.Name.CLASS_PATH) != null) {

                    return true;

                }

            }

            return false;

        } catch (IOException ioe) {

            throw new RuntimeException(ioe.getMessage());

        }

    }

    /*

     * Return the temporary directory that the VM uses for the attach

     * and perf data files.

     *

     * It is important that this directory is well-known and the

     * same for all VM instances. It cannot be affected by configuration

     * variables such as java.io.tmpdir.

     */

    public static native String getVMTemporaryDirectory();

}