com.github.stephenc.javaisotools.iso9660.impl.LogicalSectorPaddingHandler Maven / Gradle / Ivy

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/*
 * Copyright (c) 2010. Stephen Connolly.
 * Copyright (C) 2007. Jens Hatlak 
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

package com.github.stephenc.javaisotools.iso9660.impl;

import java.util.Stack;

import com.github.stephenc.javaisotools.iso9660.sabre.impl.EmptyByteArrayDataReference;
import com.github.stephenc.javaisotools.sabre.ContentHandler;
import com.github.stephenc.javaisotools.sabre.DataReference;
import com.github.stephenc.javaisotools.sabre.Element;
import com.github.stephenc.javaisotools.sabre.HandlerException;
import com.github.stephenc.javaisotools.sabre.Fixup;
import com.github.stephenc.javaisotools.sabre.StructureHandler;
import com.github.stephenc.javaisotools.sabre.impl.ChainingStreamHandler;

public class LogicalSectorPaddingHandler extends ChainingStreamHandler {

    private long bytesWritten;
    private Stack elements;
    private boolean padEnd;

    public LogicalSectorPaddingHandler(StructureHandler chainingStructureHandler,
                                       ContentHandler chainingContentHandler) {
        super(chainingStructureHandler, chainingContentHandler);
        bytesWritten = 0;
        elements = new Stack();
    }

    public void setPadEnd(boolean padEnd) {
        this.padEnd = padEnd;
    }

    public void startElement(Element element) throws HandlerException {
        if (element instanceof LogicalSectorElement || isSAElement(element)) {
            // Reset byte counter
            bytesWritten = 0;
        }
        elements.push(element);
        super.startElement(element);
    }

    private boolean isSAElement(Object element) {
        if (element instanceof ISO9660Element) {
            String id = (String) ((ISO9660Element) element).getId();
            if (id.equals("SA")) {
                return true;
            }
        }
        return false;
    }

    public void data(DataReference reference) throws HandlerException {
        bytesWritten += reference.getLength();
        super.data(reference);
    }

    public Fixup fixup(DataReference reference) throws HandlerException {
        bytesWritten += reference.getLength();
        return super.fixup(reference);
    }

    public void endElement() throws HandlerException {
        Object element = elements.pop();
        if (element instanceof LogicalSectorElement) {
            // Pad to one logical block
            int pad =
                    (int) (ISO9660Constants.LOGICAL_SECTOR_SIZE - bytesWritten % ISO9660Constants.LOGICAL_SECTOR_SIZE);
            super.data(new EmptyByteArrayDataReference(pad));
        } else if (isSAElement(element)) {
            // Pad to 16 sectors
            int pad = (int) (16 * ISO9660Constants.LOGICAL_SECTOR_SIZE -
                    bytesWritten % 16 * ISO9660Constants.LOGICAL_SECTOR_SIZE);
            super.data(new EmptyByteArrayDataReference(pad));
        }
        super.endElement();
    }

    public void endDocument() throws HandlerException {
        if (padEnd) {
            // Pad to 150 sectors (like mkisofs -pad does)
            int pad = (int) (150 * ISO9660Constants.LOGICAL_SECTOR_SIZE -
                    bytesWritten % 16 * ISO9660Constants.LOGICAL_SECTOR_SIZE);
            super.data(new EmptyByteArrayDataReference(pad));
        }
        super.endDocument();
    }
}