359 lines
14 KiB
C#
359 lines
14 KiB
C#
using System;
|
|
using System.IO;
|
|
using System.Collections;
|
|
|
|
using System.util.zlib;
|
|
|
|
/*
|
|
* $Id: PdfStream.cs,v 1.12 2008/05/13 11:25:23 psoares33 Exp $
|
|
*
|
|
*
|
|
* Copyright 1999, 2000, 2001, 2002 Bruno Lowagie
|
|
*
|
|
* The contents of this file are subject to the Mozilla Public License Version 1.1
|
|
* (the "License"); you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at http://www.mozilla.org/MPL/
|
|
*
|
|
* Software distributed under the License is distributed on an "AS IS" basis,
|
|
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
|
|
* for the specific language governing rights and limitations under the License.
|
|
*
|
|
* The Original Code is 'iText, a free JAVA-PDF library'.
|
|
*
|
|
* The Initial Developer of the Original Code is Bruno Lowagie. Portions created by
|
|
* the Initial Developer are Copyright (C) 1999, 2000, 2001, 2002 by Bruno Lowagie.
|
|
* All Rights Reserved.
|
|
* Co-Developer of the code is Paulo Soares. Portions created by the Co-Developer
|
|
* are Copyright (C) 2000, 2001, 2002 by Paulo Soares. All Rights Reserved.
|
|
*
|
|
* Contributor(s): all the names of the contributors are added in the source code
|
|
* where applicable.
|
|
*
|
|
* Alternatively, the contents of this file may be used under the terms of the
|
|
* LGPL license (the "GNU LIBRARY GENERAL PUBLIC LICENSE"), in which case the
|
|
* provisions of LGPL are applicable instead of those above. If you wish to
|
|
* allow use of your version of this file only under the terms of the LGPL
|
|
* License and not to allow others to use your version of this file under
|
|
* the MPL, indicate your decision by deleting the provisions above and
|
|
* replace them with the notice and other provisions required by the LGPL.
|
|
* If you do not delete the provisions above, a recipient may use your version
|
|
* of this file under either the MPL or the GNU LIBRARY GENERAL PUBLIC LICENSE.
|
|
*
|
|
* This library is free software; you can redistribute it and/or modify it
|
|
* under the terms of the MPL as stated above or under the terms of the GNU
|
|
* Library General Public License as published by the Free Software Foundation;
|
|
* either version 2 of the License, or 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 Library general Public License for more
|
|
* details.
|
|
*
|
|
* If you didn't download this code from the following link, you should check if
|
|
* you aren't using an obsolete version:
|
|
* http://www.lowagie.com/iText/
|
|
*/
|
|
|
|
namespace iTextSharp.text.pdf {
|
|
/**
|
|
* <CODE>PdfStream</CODE> is the Pdf stream object.
|
|
* <P>
|
|
* A stream, like a string, is a sequence of characters. However, an application can
|
|
* read a small portion of a stream at a time, while a string must be read in its entirety.
|
|
* For this reason, objects with potentially large amounts of data, such as images and
|
|
* page descriptions, are represented as streams.<BR>
|
|
* A stream consists of a dictionary that describes a sequence of characters, followed by
|
|
* the keyword <B>stream</B>, followed by zero or more lines of characters, followed by
|
|
* the keyword <B>endstream</B>.<BR>
|
|
* All streams must be <CODE>PdfIndirectObject</CODE>s. The stream dictionary must be a direct
|
|
* object. The keyword <B>stream</B> that follows the stream dictionary should be followed by
|
|
* a carriage return and linefeed or just a linefeed.<BR>
|
|
* Remark: In this version only the FLATEDECODE-filter is supported.<BR>
|
|
* This object is described in the 'Portable Document Format Reference Manual version 1.3'
|
|
* section 4.8 (page 41-53).<BR>
|
|
*
|
|
* @see PdfObject
|
|
* @see PdfDictionary
|
|
*/
|
|
|
|
public class PdfStream : PdfDictionary {
|
|
|
|
// membervariables
|
|
|
|
/**
|
|
* A possible compression level.
|
|
* @since 2.1.3
|
|
*/
|
|
public const int DEFAULT_COMPRESSION = -1;
|
|
/**
|
|
* A possible compression level.
|
|
* @since 2.1.3
|
|
*/
|
|
public const int NO_COMPRESSION = 0;
|
|
/**
|
|
* A possible compression level.
|
|
* @since 2.1.3
|
|
*/
|
|
public const int BEST_SPEED = 1;
|
|
/**
|
|
* A possible compression level.
|
|
* @since 2.1.3
|
|
*/
|
|
public const int BEST_COMPRESSION = 9;
|
|
|
|
/** is the stream compressed? */
|
|
protected bool compressed = false;
|
|
|
|
/**
|
|
* The level of compression.
|
|
* @since 2.1.3
|
|
*/
|
|
protected int compressionLevel = NO_COMPRESSION;
|
|
|
|
protected MemoryStream streamBytes = null;
|
|
|
|
protected Stream inputStream;
|
|
protected PdfIndirectReference iref;
|
|
protected int inputStreamLength = -1;
|
|
protected PdfWriter writer;
|
|
protected int rawLength;
|
|
|
|
internal static byte[] STARTSTREAM = DocWriter.GetISOBytes("stream\n");
|
|
internal static byte[] ENDSTREAM = DocWriter.GetISOBytes("\nendstream");
|
|
internal static int SIZESTREAM = STARTSTREAM.Length + ENDSTREAM.Length;
|
|
|
|
// constructors
|
|
|
|
/**
|
|
* Constructs a <CODE>PdfStream</CODE>-object.
|
|
*
|
|
* @param bytes content of the new <CODE>PdfObject</CODE> as an array of <CODE>byte</CODE>.
|
|
*/
|
|
|
|
public PdfStream(byte[] bytes) : base() {
|
|
type = STREAM;
|
|
this.bytes = bytes;
|
|
rawLength = bytes.Length;
|
|
Put(PdfName.LENGTH, new PdfNumber(bytes.Length));
|
|
}
|
|
|
|
/**
|
|
* Creates an efficient stream. No temporary array is ever created. The <CODE>InputStream</CODE>
|
|
* is totally consumed but is not closed. The general usage is:
|
|
* <p>
|
|
* <pre>
|
|
* InputStream in = ...;
|
|
* PdfStream stream = new PdfStream(in, writer);
|
|
* stream.FlateCompress();
|
|
* writer.AddToBody(stream);
|
|
* stream.WriteLength();
|
|
* in.Close();
|
|
* </pre>
|
|
* @param inputStream the data to write to this stream
|
|
* @param writer the <CODE>PdfWriter</CODE> for this stream
|
|
*/
|
|
public PdfStream(Stream inputStream, PdfWriter writer) {
|
|
type = STREAM;
|
|
this.inputStream = inputStream;
|
|
this.writer = writer;
|
|
iref = writer.PdfIndirectReference;
|
|
Put(PdfName.LENGTH, iref);
|
|
}
|
|
|
|
/**
|
|
* Constructs a <CODE>PdfStream</CODE>-object.
|
|
*/
|
|
|
|
protected PdfStream() : base() {
|
|
type = STREAM;
|
|
}
|
|
|
|
// methods overriding some methods of PdfObject
|
|
|
|
/**
|
|
* Writes the stream length to the <CODE>PdfWriter</CODE>.
|
|
* <p>
|
|
* This method must be called and can only be called if the contructor {@link #PdfStream(InputStream,PdfWriter)}
|
|
* is used to create the stream.
|
|
* @throws IOException on error
|
|
* @see #PdfStream(InputStream,PdfWriter)
|
|
*/
|
|
public void WriteLength() {
|
|
if (inputStream == null)
|
|
throw new PdfException("WriteLength() can only be called in a contructed PdfStream(InputStream,PdfWriter).");
|
|
if (inputStreamLength == -1)
|
|
throw new PdfException("WriteLength() can only be called after output of the stream body.");
|
|
writer.AddToBody(new PdfNumber(inputStreamLength), iref, false);
|
|
}
|
|
|
|
public int RawLength {
|
|
get {
|
|
return rawLength;
|
|
}
|
|
}
|
|
|
|
// methods
|
|
|
|
/**
|
|
* Compresses the stream.
|
|
*/
|
|
public void FlateCompress() {
|
|
FlateCompress(DEFAULT_COMPRESSION);
|
|
}
|
|
|
|
/**
|
|
* Compresses the stream.
|
|
* @param compressionLevel the compression level (0 = best speed, 9 = best compression, -1 is default)
|
|
* @since 2.1.3
|
|
*/
|
|
public void FlateCompress(int compressionLevel) {
|
|
if (!Document.Compress)
|
|
return;
|
|
// check if the flateCompress-method has allready been
|
|
if (compressed) {
|
|
return;
|
|
}
|
|
this.compressionLevel = compressionLevel;
|
|
if (inputStream != null) {
|
|
compressed = true;
|
|
return;
|
|
}
|
|
// check if a filter allready exists
|
|
PdfObject filter = PdfReader.GetPdfObject(Get(PdfName.FILTER));
|
|
if (filter != null) {
|
|
if (filter.IsName()) {
|
|
if (PdfName.FLATEDECODE.Equals(filter))
|
|
return;
|
|
}
|
|
else if (filter.IsArray()) {
|
|
if (((PdfArray) filter).Contains(PdfName.FLATEDECODE))
|
|
return;
|
|
}
|
|
else {
|
|
throw new PdfException("Stream could not be compressed: filter is not a name or array.");
|
|
}
|
|
}
|
|
// compress
|
|
MemoryStream stream = new MemoryStream();
|
|
ZDeflaterOutputStream zip = new ZDeflaterOutputStream(stream, compressionLevel);
|
|
if (streamBytes != null)
|
|
streamBytes.WriteTo(zip);
|
|
else
|
|
zip.Write(bytes, 0, bytes.Length);
|
|
//zip.Close();
|
|
zip.Finish();
|
|
// update the object
|
|
streamBytes = stream;
|
|
bytes = null;
|
|
Put(PdfName.LENGTH, new PdfNumber(streamBytes.Length));
|
|
if (filter == null) {
|
|
Put(PdfName.FILTER, PdfName.FLATEDECODE);
|
|
}
|
|
else {
|
|
PdfArray filters = new PdfArray(filter);
|
|
filters.Add(PdfName.FLATEDECODE);
|
|
Put(PdfName.FILTER, filters);
|
|
}
|
|
compressed = true;
|
|
}
|
|
|
|
protected virtual void SuperToPdf(PdfWriter writer, Stream os) {
|
|
base.ToPdf(writer, os);
|
|
}
|
|
|
|
public override void ToPdf(PdfWriter writer, Stream os) {
|
|
if (inputStream != null && compressed)
|
|
Put(PdfName.FILTER, PdfName.FLATEDECODE);
|
|
PdfEncryption crypto = null;
|
|
if (writer != null)
|
|
crypto = writer.Encryption;
|
|
if (crypto != null) {
|
|
PdfObject filter = Get(PdfName.FILTER);
|
|
if (filter != null) {
|
|
if (PdfName.CRYPT.Equals(filter))
|
|
crypto = null;
|
|
else if (filter.IsArray()) {
|
|
PdfArray a = ((PdfArray)filter);
|
|
if (a.Size > 0 && PdfName.CRYPT.Equals(a[0]))
|
|
crypto = null;
|
|
}
|
|
}
|
|
}
|
|
PdfObject nn = Get(PdfName.LENGTH);
|
|
if (crypto != null && nn != null && nn.IsNumber()) {
|
|
int sz = ((PdfNumber)nn).IntValue;
|
|
Put(PdfName.LENGTH, new PdfNumber(crypto.CalculateStreamSize(sz)));
|
|
SuperToPdf(writer, os);
|
|
Put(PdfName.LENGTH, nn);
|
|
}
|
|
else
|
|
SuperToPdf(writer, os);
|
|
os.Write(STARTSTREAM, 0, STARTSTREAM.Length);
|
|
if (inputStream != null) {
|
|
rawLength = 0;
|
|
ZDeflaterOutputStream def = null;
|
|
OutputStreamCounter osc = new OutputStreamCounter(os);
|
|
OutputStreamEncryption ose = null;
|
|
Stream fout = osc;
|
|
if (crypto != null && !crypto.IsEmbeddedFilesOnly())
|
|
fout = ose = crypto.GetEncryptionStream(fout);
|
|
if (compressed)
|
|
fout = def = new ZDeflaterOutputStream(fout, compressionLevel);
|
|
|
|
byte[] buf = new byte[4192];
|
|
while (true) {
|
|
int n = inputStream.Read(buf, 0, buf.Length);
|
|
if (n <= 0)
|
|
break;
|
|
fout.Write(buf, 0, n);
|
|
rawLength += n;
|
|
}
|
|
if (def != null)
|
|
def.Finish();
|
|
if (ose != null)
|
|
ose.Finish();
|
|
inputStreamLength = osc.Counter;
|
|
}
|
|
else {
|
|
if (crypto != null && !crypto.IsEmbeddedFilesOnly()) {
|
|
byte[] b;
|
|
if (streamBytes != null) {
|
|
b = crypto.EncryptByteArray(streamBytes.ToArray());
|
|
}
|
|
else {
|
|
b = crypto.EncryptByteArray(bytes);
|
|
}
|
|
os.Write(b, 0, b.Length);
|
|
}
|
|
else {
|
|
if (streamBytes != null)
|
|
streamBytes.WriteTo(os);
|
|
else
|
|
os.Write(bytes, 0, bytes.Length);
|
|
}
|
|
}
|
|
os.Write(ENDSTREAM, 0, ENDSTREAM.Length);
|
|
}
|
|
|
|
/**
|
|
* Writes the data content to an <CODE>Stream</CODE>.
|
|
* @param os the destination to write to
|
|
* @throws IOException on error
|
|
*/
|
|
public void WriteContent(Stream os) {
|
|
if (streamBytes != null)
|
|
streamBytes.WriteTo(os);
|
|
else if (bytes != null)
|
|
os.Write(bytes, 0, bytes.Length);
|
|
}
|
|
|
|
/**
|
|
* @see com.lowagie.text.pdf.PdfObject#toString()
|
|
*/
|
|
public override String ToString() {
|
|
if (Get(PdfName.TYPE) == null) return "Stream";
|
|
return "Stream of type: " + Get(PdfName.TYPE);
|
|
}
|
|
}
|
|
}
|