/*

 * 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

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 */

/*

 * This file is available under and governed by the GNU General Public

 * License version 2 only, as published by the Free Software Foundation.

 * However, the following notice accompanied the original version of this

 * file:

 *

 * 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 jdk.internal.org.objectweb.asm.commons;

import java.util.ArrayList;

import java.util.List;

import jdk.internal.org.objectweb.asm.Attribute;

import jdk.internal.org.objectweb.asm.ByteVector;

import jdk.internal.org.objectweb.asm.ClassReader;

import jdk.internal.org.objectweb.asm.ClassWriter;

import jdk.internal.org.objectweb.asm.Label;

/**

 * ModuleHashes attribute.

 * This attribute is specific to the OpenJDK and may change in the future.

 *

 * @author Remi Forax

 */

public final class ModuleHashesAttribute extends Attribute {

    public String algorithm;

    public List<String> modules;

    public List<byte[]> hashes;

    /**

     * Creates an attribute with a hashing algorithm, a list of module names,

     * and a list of the same length of hashes.

     * @param algorithm the hashing algorithm name.

     * @param modules a list of module name

     * @param hashes a list of hash, one for each module name.

     */

    public ModuleHashesAttribute(final String algorithm,

            final List<String> modules, final List<byte[]> hashes) {

        super("ModuleHashes");

        this.algorithm = algorithm;

        this.modules = modules;

        this.hashes = hashes;

    }

    /**

     * Creates an empty attribute that can be used as prototype

     * to be passed as argument of the method

     * {@link ClassReader#accept(org.objectweb.asm.ClassVisitor, Attribute[], int)}.

     */

    public ModuleHashesAttribute() {

        this(null, null, null);

    }

    @Override

    protected Attribute read(ClassReader cr, int off, int len, char[] buf,

            int codeOff, Label[] labels) {

        String hashAlgorithm = cr.readUTF8(off, buf);

        int count = cr.readUnsignedShort(off + 2);

        ArrayList<String> modules = new ArrayList<String>(count);

        ArrayList<byte[]> hashes = new ArrayList<byte[]>(count);

        off += 4;

        for (int i = 0; i < count; i++) {

            String module = cr.readModule(off, buf);

            int hashLength = cr.readUnsignedShort(off + 2);

            off += 4;

            byte[] hash = new byte[hashLength];

            for (int j = 0; j < hashLength; j++) {

                hash[j] = (byte) (cr.readByte(off + j) & 0xff);

            }

            off += hashLength;

            modules.add(module);

            hashes.add(hash);

        }

        return new ModuleHashesAttribute(hashAlgorithm, modules, hashes);

    }

    @Override

    protected ByteVector write(ClassWriter cw, byte[] code, int len,

            int maxStack, int maxLocals) {

        ByteVector v = new ByteVector();

        int index = cw.newUTF8(algorithm);

        v.putShort(index);

        int count = (modules == null)? 0: modules.size();

        v.putShort(count);

        for(int i = 0; i < count; i++) {

            String module = modules.get(i);

            v.putShort(cw.newModule(module));

            byte[] hash = hashes.get(i);

            v.putShort(hash.length);

            for(byte b: hash) {

                v.putByte(b);

            }

        }

        return v;

    }

}