itextpdf-master/itext/src/main/java/com/itextpdf/text/pdf/PRStream.java
/*
 *
 * This file is part of the iText (R) project.
    Copyright (c) 1998-2022 iText Group NV
 * Authors: Bruno Lowagie, Paulo Soares, et al.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License version 3
 * as published by the Free Software Foundation with the addition of the
 * following permission added to Section 15 as permitted in Section 7(a):
 * FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY
 * ITEXT GROUP. ITEXT GROUP DISCLAIMS THE WARRANTY OF NON INFRINGEMENT
 * OF THIRD PARTY RIGHTS
 *
 * This program 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 Affero General Public License for more details.
 * You should have received a copy of the GNU Affero General Public License
 * along with this program; if not, see http://www.gnu.org/licenses or write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA, 02110-1301 USA, or download the license from the following URL:
 * http://itextpdf.com/terms-of-use/
 *
 * The interactive user interfaces in modified source and object code versions
 * of this program must display Appropriate Legal Notices, as required under
 * Section 5 of the GNU Affero General Public License.
 *
 * In accordance with Section 7(b) of the GNU Affero General Public License,
 * a covered work must retain the producer line in every PDF that is created
 * or manipulated using iText.
 *
 * You can be released from the requirements of the license by purchasing
 * a commercial license. Buying such a license is mandatory as soon as you
 * develop commercial activities involving the iText software without
 * disclosing the source code of your own applications.
 * These activities include: offering paid services to customers as an ASP,
 * serving PDFs on the fly in a web application, shipping iText with a closed
 * source product.
 *
 * For more information, please contact iText Software Corp. at this
 * address: sales@itextpdf.com
 */
package com.itextpdf.text.pdf;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.zip.Deflater;
import java.util.zip.DeflaterOutputStream;

import com.itextpdf.text.Document;
import com.itextpdf.text.ExceptionConverter;

public class PRStream extends PdfStream {
    
    protected PdfReader reader;
    protected long offset;
    protected int length;
    
    //added by ujihara for decryption
    protected int objNum = 0;
    protected int objGen = 0;
    
    public PRStream(PRStream stream, PdfDictionary newDic) {
        reader = stream.reader;
        offset = stream.offset;
        length = stream.length;
        compressed = stream.compressed;
        compressionLevel = stream.compressionLevel;
        streamBytes = stream.streamBytes;
        bytes = stream.bytes;
        objNum = stream.objNum;
        objGen = stream.objGen;
        if (newDic != null)
            putAll(newDic);
        else
            hashMap.putAll(stream.hashMap);
    }

    public PRStream(PRStream stream, PdfDictionary newDic, PdfReader reader) {
        this(stream, newDic);
        this.reader = reader;
    }

    public PRStream(PdfReader reader, long offset) {
        this.reader = reader;
        this.offset = offset;
    }

    public PRStream(PdfReader reader, byte conts[]) {
    	this(reader, conts, DEFAULT_COMPRESSION);
    }

    /**
     * Creates a new PDF stream object that will replace a stream
     * in a existing PDF file.
     * @param	reader	the reader that holds the existing PDF
     * @param	conts	the new content
     * @param	compressionLevel	the compression level for the content
     * @since	2.1.3 (replacing the existing constructor without param compressionLevel)
     */
    public PRStream(PdfReader reader, byte[] conts, int compressionLevel) {
        this.reader = reader;
        this.offset = -1;
        if (Document.compress) {
            try {
                ByteArrayOutputStream stream = new ByteArrayOutputStream();
                Deflater deflater = new Deflater(compressionLevel);
                DeflaterOutputStream zip = new DeflaterOutputStream(stream, deflater);
                zip.write(conts);
                zip.close();
                deflater.end();
                bytes = stream.toByteArray();
            }
            catch (IOException ioe) {
                throw new ExceptionConverter(ioe);
            }
            put(PdfName.FILTER, PdfName.FLATEDECODE);
        }
        else
            bytes = conts;
        setLength(bytes.length);
    }
    
    /**
     * Sets the data associated with the stream, either compressed or
     * uncompressed. Note that the data will never be compressed if
     * Document.compress is set to false.
     * 
     * @param data raw data, decrypted and uncompressed.
     * @param compress true if you want the stream to be compressed.
     * @since	iText 2.1.1
     */
    public void setData(byte[] data, boolean compress) {
    	setData(data, compress, DEFAULT_COMPRESSION);
    }
    
    /**
     * Sets the data associated with the stream, either compressed or
     * uncompressed. Note that the data will never be compressed if
     * Document.compress is set to false.
     * 
     * @param data raw data, decrypted and uncompressed.
     * @param compress true if you want the stream to be compressed.
     * @param compressionLevel	a value between -1 and 9 (ignored if compress == false)
     * @since	iText 2.1.3
     */
    public void setData(byte[] data, boolean compress, int compressionLevel) {
        remove(PdfName.FILTER);
        this.offset = -1;
        if (Document.compress && compress) {
            try {
                ByteArrayOutputStream stream = new ByteArrayOutputStream();
                Deflater deflater = new Deflater(compressionLevel);
                DeflaterOutputStream zip = new DeflaterOutputStream(stream, deflater);
                zip.write(data);
                zip.close();
                deflater.end();
                bytes = stream.toByteArray();
                this.compressionLevel = compressionLevel;
            }
            catch (IOException ioe) {
                throw new ExceptionConverter(ioe);
            }
            put(PdfName.FILTER, PdfName.FLATEDECODE);
        }
        else
            bytes = data;
        setLength(bytes.length);
    }
    
    /**
     * Sets the data associated with the stream, as-is.  This method will not
     * remove or change any existing filter: the data has to match an existing
     * filter or an appropriate filter has to be set.
     * 
     * @param data data, possibly encrypted and/or compressed
     * @since 5.5.0
     */
    public void setDataRaw(byte[] data) {
        this.offset = -1;
        bytes = data;
        setLength(bytes.length);
    }
    
    /**Sets the data associated with the stream
     * @param data raw data, decrypted and uncompressed.
     */
    public void setData(byte[] data) {
        setData(data, true);
    }

    public void setLength(int length) {
        this.length = length;
        put(PdfName.LENGTH, new PdfNumber(length));
    }
    
    public long getOffset() {
        return offset;
    }
    
    public int getLength() {
        return length;
    }
    
    public PdfReader getReader() {
        return reader;
    }
    
    public byte[] getBytes() {
        return bytes;
    }
    
    public void setObjNum(int objNum, int objGen) {
        this.objNum = objNum;
        this.objGen = objGen;
    }
    
    int getObjNum() {
        return objNum;
    }
    
    int getObjGen() {
        return objGen;
    }
    
    public void toPdf(PdfWriter writer, OutputStream os) throws IOException {
        byte[] b = PdfReader.getStreamBytesRaw(this);
        PdfEncryption crypto = null;
        if (writer != null)
            crypto = writer.getEncryption();
        PdfObject objLen = get(PdfName.LENGTH);
        int nn = b.length;
        if (crypto != null)
            nn = crypto.calculateStreamSize(nn);
        put(PdfName.LENGTH, new PdfNumber(nn));
        superToPdf(writer, os);
        put(PdfName.LENGTH, objLen);
        os.write(STARTSTREAM);
        if (length > 0) {
            if (crypto != null && !crypto.isEmbeddedFilesOnly())
                b = crypto.encryptByteArray(b);
            os.write(b);
        }
        os.write(ENDSTREAM);
    }
}
