--- /dev/null
+/*
+ * $Id$
+ * ============================================================================
+ * The Apache Software License, Version 1.1
+ * ============================================================================
+ *
+ * Copyright (C) 1999-2003 The Apache Software Foundation. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modifica-
+ * tion, 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. The end-user documentation included with the redistribution, if any, must
+ * include the following acknowledgment: "This product includes software
+ * developed by the Apache Software Foundation (http://www.apache.org/)."
+ * Alternately, this acknowledgment may appear in the software itself, if
+ * and wherever such third-party acknowledgments normally appear.
+ *
+ * 4. The names "FOP" and "Apache Software Foundation" must not be used to
+ * endorse or promote products derived from this software without prior
+ * written permission. For written permission, please contact
+ * apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache", nor may
+ * "Apache" appear in their name, without prior written permission of the
+ * Apache Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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
+ * APACHE SOFTWARE FOUNDATION OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLU-
+ * DING, 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.
+ * ============================================================================
+ *
+ * This software consists of voluntary contributions made by many individuals
+ * on behalf of the Apache Software Foundation and was originally created by
+ * James Tauber <jtauber@jtauber.com>. For more information on the Apache
+ * Software Foundation, please see <http://www.apache.org/>.
+ */
+package org.apache.fop.pdf;
+
+import java.io.IOException;
+import java.io.OutputStream;
+
+import org.apache.commons.io.output.CountingOutputStream;
+import org.apache.fop.util.CloseBlockerOutputStream;
+
+/**
+ * This is an abstract base class for PDF streams.
+ */
+public abstract class AbstractPDFStream extends PDFObject {
+
+ /** The filters that should be applied */
+ private PDFFilterList filters;
+
+ /**
+ * Constructor for AbstractPDFStream.
+ */
+ public AbstractPDFStream() {
+ super();
+ }
+
+ /**
+ * Sets up the default filters for this stream if they haven't been set
+ * from outside.
+ */
+ protected void setupFilterList() {
+ if (!getFilterList().isInitialized()) {
+ getFilterList().addDefaultFilters(
+ getDocumentSafely().getFilterMap(),
+ PDFFilterList.DEFAULT_FILTER);
+ }
+ prepareImplicitFilters();
+ getDocument().applyEncryption(this);
+ }
+
+ /**
+ * Returns the associated filter list.
+ * @return the filter list
+ */
+ public PDFFilterList getFilterList() {
+ if (this.filters == null) {
+ if (getDocument() == null) {
+ this.filters = new PDFFilterList();
+ } else {
+ this.filters = new PDFFilterList(getDocument().isEncryptionActive());
+ //this.filters = new PDFFilterList(false);
+ }
+ }
+ return this.filters;
+ }
+
+ /**
+ * Returns a value that hints at the size of the encoded stream. This is
+ * used to optimize buffer allocation so fewer buffer reallocations are
+ * necessary.
+ * @return an estimated size (0 if no hint can be given)
+ * @throws IOException in case of an I/O problem
+ */
+ protected abstract int getSizeHint() throws IOException;
+
+ /**
+ * Sends the raw stream data to the target OutputStream.
+ * @param out OutputStream to write to
+ * @throws IOException In case of an I/O problem
+ */
+ protected abstract void outputRawStreamData(OutputStream out)
+ throws IOException;
+
+ /**
+ * Output just the stream data enclosed by stream/endstream markers
+ * @param encodedStream already encoded/filtered stream to write
+ * @param out OutputStream to write to
+ * @return int number of bytes written
+ * @throws IOException in case of an I/O problem
+ */
+ protected int outputStreamData(StreamCache encodedStream, OutputStream out) throws IOException {
+ int length = 0;
+ byte[] p = encode("stream\n");
+ out.write(p);
+ length += p.length;
+
+ encodedStream.outputContents(out);
+ length += encodedStream.getSize();
+
+ p = encode("\nendstream");
+ out.write(p);
+ length += p.length;
+ return length;
+ }
+
+ /**
+ * Encodes the raw data stream for output to a PDF file.
+ * @return the encoded stream
+ * @throws IOException in case of an I/O problem
+ */
+ protected StreamCache encodeStream() throws IOException {
+ //Allocate a temporary buffer to find out the size of the encoded stream
+ final StreamCache encodedStream = StreamCacheFactory.getInstance().
+ createStreamCache(getSizeHint());
+ OutputStream filteredOutput =
+ getFilterList().applyFilters(encodedStream.getOutputStream());
+ outputRawStreamData(filteredOutput);
+ filteredOutput.flush();
+ filteredOutput.close();
+ return encodedStream;
+ }
+
+ /**
+ * Encodes and writes a stream directly to an OutputStream. The length of
+ * the stream, in this case, is set on a PDFNumber object that has to be
+ * prepared beforehand.
+ * @param out OutputStream to write to
+ * @param refLength PDFNumber object to receive the stream length
+ * @return number of bytes written (header and trailer included)
+ * @throws IOException in case of an I/O problem
+ */
+ protected int encodeAndWriteStream(OutputStream out, PDFNumber refLength)
+ throws IOException {
+ int bytesWritten = 0;
+ //Stream header
+ byte[] buf = encode("stream\n");
+ out.write(buf);
+ bytesWritten += buf.length;
+
+ //Stream contents
+ CloseBlockerOutputStream cbout = new CloseBlockerOutputStream(out);
+ CountingOutputStream cout = new CountingOutputStream(cbout);
+ OutputStream filteredOutput =
+ getFilterList().applyFilters(cout);
+ outputRawStreamData(filteredOutput);
+ filteredOutput.close();
+ refLength.setNumber(new Integer(cout.getCount()));
+ bytesWritten += cout.getCount();
+
+ //Stream trailer
+ buf = encode("\nendstream");
+ out.write(buf);
+ bytesWritten += buf.length;
+
+ return bytesWritten;
+ }
+
+ /**
+ * Overload the base object method so we don't have to copy
+ * byte arrays around so much
+ * @see org.apache.fop.pdf.PDFObject#output(OutputStream)
+ */
+ protected int output(OutputStream stream) throws IOException {
+ int length = 0;
+ setupFilterList();
+
+ StreamCache encodedStream = null;
+ PDFNumber refLength = null;
+ final String lengthEntry;
+ if (getDocument().isEncodingOnTheFly()) {
+ refLength = new PDFNumber();
+ getDocumentSafely().registerObject(refLength);
+ lengthEntry = refLength.referencePDF();
+ } else {
+ encodedStream = encodeStream();
+ lengthEntry = Integer.toString(encodedStream.getSize() + 1);
+ }
+
+ String filterEntry = getFilterList().buildFilterDictEntries();
+ byte[] p = encode(buildStreamDict(lengthEntry));
+
+ stream.write(p);
+ length += p.length;
+
+ //Send encoded stream to target OutputStream
+ if (encodedStream == null) {
+ int bytesWritten = encodeAndWriteStream(stream, refLength);
+ length += bytesWritten;
+ } else {
+ length += outputStreamData(encodedStream, stream);
+ encodedStream.clear(); //Encoded stream can now be discarded
+ }
+
+ p = encode("\nendobj\n");
+ stream.write(p);
+ length += p.length;
+ return length;
+ }
+
+ /**
+ * Constructs the dictionary for the stream. Override this method if you
+ * need additional entries.
+ * @param lengthEntry value for the /Length entry
+ * @return the newly constructed dictionary
+ */
+ protected String buildStreamDict(String lengthEntry) {
+ final String filterEntry = getFilterList().buildFilterDictEntries();
+ return (getObjectID()
+ + "<< /Length " + lengthEntry + "\n"
+ + filterEntry
+ + "\n>>\n");
+ }
+
+ /**
+ * Prepares implicit filters (such as the DCTFilter for JPEG images). You
+ * must make sure that the appropriate filters are in the filter list at
+ * the right places.
+ */
+ protected void prepareImplicitFilters() {
+ //nop: No default implicit filters
+ }
+
+}
projects / xmlgraphics-fop.git / commitdiff