yacy_search_server/source/net/yacy/document/parser/pdfParser.java

//pdfParser.java
//------------------------
//part of YaCy
//(C) by Michael Peter Christen; mc@yacy.net
//first published on http://www.anomic.de
//Frankfurt, Germany, 2005
//
//this file is contributed by Martin Thelian
//
// $LastChangedDate$
// $LastChangedRevision$
// $LastChangedBy$
//
//This program is free software; you can redistribute it and/or modify
//it under the terms of the GNU General Public License as published by
//the Free Software Foundation; either version 2 of the License, or
//(at your option) any later version.
//
//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 General Public License for more details.
//
//You should have received a copy of the GNU General Public License
//along with this program; if not, write to the Free Software
//Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

package net.yacy.document.parser;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Date;
import java.util.HashSet;
import java.util.List;

import org.apache.pdfbox.exceptions.CryptographyException;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDDocumentInformation;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.encryption.AccessPermission;
import org.apache.pdfbox.pdmodel.encryption.BadSecurityHandlerException;
import org.apache.pdfbox.pdmodel.encryption.StandardDecryptionMaterial;
import org.apache.pdfbox.pdmodel.interactive.action.type.PDAction;
import org.apache.pdfbox.pdmodel.interactive.action.type.PDActionURI;
import org.apache.pdfbox.pdmodel.interactive.annotation.PDAnnotation;
import org.apache.pdfbox.pdmodel.interactive.annotation.PDAnnotationLink;
import org.apache.pdfbox.util.PDFTextStripper;

import net.yacy.cora.document.encoding.UTF8;
import net.yacy.cora.document.id.AnchorURL;
import net.yacy.cora.document.id.MultiProtocolURL;
import net.yacy.cora.util.ConcurrentLog;
import net.yacy.document.AbstractParser;
import net.yacy.document.Document;
import net.yacy.document.Parser;
import net.yacy.kelondro.io.CharBuffer;
import net.yacy.kelondro.util.FileUtils;
import net.yacy.kelondro.util.MemoryControl;


public class pdfParser extends AbstractParser implements Parser {

    public static boolean individualPages = false;
    public static String individualPagePropertyname = "page";
    
    public pdfParser() {
        super("Acrobat Portable Document Parser");
        this.SUPPORTED_EXTENSIONS.add("pdf");
        this.SUPPORTED_MIME_TYPES.add("application/pdf");
        this.SUPPORTED_MIME_TYPES.add("application/x-pdf");
        this.SUPPORTED_MIME_TYPES.add("application/acrobat");
        this.SUPPORTED_MIME_TYPES.add("applications/vnd.pdf");
        this.SUPPORTED_MIME_TYPES.add("text/pdf");
        this.SUPPORTED_MIME_TYPES.add("text/x-pdf");
    }

    static {
        clean_up_idiotic_PDFParser_font_cache_which_eats_up_tons_of_megabytes(); // must be called here to get that into the class loader; it will block other threads otherwise;
    }

    @Override
    public Document[] parse(final AnchorURL location, final String mimeType, final String charset, final InputStream source) throws Parser.Failure, InterruptedException {

        // check memory for parser
        if (!MemoryControl.request(200 * 1024 * 1024, false))
            throw new Parser.Failure("Not enough Memory available for pdf parser: " + MemoryControl.available(), location);

        // create a pdf parser
        PDDocument pdfDoc;
        //final PDFParser pdfParser;
        try {
            Thread.currentThread().setPriority(Thread.MIN_PRIORITY); // the pdfparser is a big pain
            pdfDoc = PDDocument.load(source);
            //PDFParser pdfParser = new PDFParser(source);
            //pdfParser.parse();
            //pdfDoc = pdfParser.getPDDocument();
        } catch (final IOException e) {
            throw new Parser.Failure(e.getMessage(), location);
        } finally {
            Thread.currentThread().setPriority(Thread.NORM_PRIORITY);
        }

        if (pdfDoc.isEncrypted()) {
            try {
                pdfDoc.openProtection(new StandardDecryptionMaterial(""));
            } catch (final BadSecurityHandlerException e) {
                try {pdfDoc.close();} catch (final IOException ee) {}
                throw new Parser.Failure("Document is encrypted (1): " + e.getMessage(), location);
            } catch (final IOException e) {
                try {pdfDoc.close();} catch (final IOException ee) {}
                throw new Parser.Failure("Document is encrypted (2): " + e.getMessage(), location);
            } catch (final CryptographyException e) {
                try {pdfDoc.close();} catch (final IOException ee) {}
                throw new Parser.Failure("Document is encrypted (3): " + e.getMessage(), location);
            }
            final AccessPermission perm = pdfDoc.getCurrentAccessPermission();
            if (perm == null || !perm.canExtractContent()) {
                try {pdfDoc.close();} catch (final IOException ee) {}
                throw new Parser.Failure("Document is encrypted and cannot be decrypted", location);
            }
        }

        // extracting some metadata
        PDDocumentInformation info = pdfDoc.getDocumentInformation();
        String docTitle = null, docSubject = null, docAuthor = null, docPublisher = null, docKeywordStr = null;
        Date docDate = new Date();
        if (info != null) {
            docTitle = info.getTitle();
            docSubject = info.getSubject();
            docAuthor = info.getAuthor();
            docPublisher = info.getProducer();
            if (docPublisher == null || docPublisher.isEmpty()) docPublisher = info.getCreator();
            docKeywordStr = info.getKeywords();
            try {if (info.getModificationDate() != null) docDate = info.getModificationDate().getTime();} catch (IOException e) {}
            // unused:
            // info.getTrapped());
        }
        info = null;

        if (docTitle == null || docTitle.isEmpty()) {
            docTitle = MultiProtocolURL.unescape(location.getFileName());
        }
        if (docTitle == null) {
            docTitle = docSubject;
        }
        String[] docKeywords = null;
        if (docKeywordStr != null) {
            docKeywords = docKeywordStr.split(" |,");
        }
        
        Collection<AnchorURL>[] pdflinks = null;
        Document[] result = null;
        try {
            // get the links
            pdflinks = extractPdfLinks(pdfDoc);
            
            // get the fulltext (either per document or for each page)
            final PDFTextStripper stripper = new PDFTextStripper("UTF-8");

            if (individualPages) {
                // this is a hack which stores individual pages of the source pdf into individual index documents
                // the new documents will get a virtual link with a post argument page=X appended to the original url
                
                // collect text
                int pagecount = pdfDoc.getNumberOfPages();
                String[] pages = new String[pagecount];
                for (int page = 1; page <= pagecount; page++) {
                    stripper.setStartPage(page);
                    stripper.setEndPage(page);
                    pages[page - 1] = stripper.getText(pdfDoc);
                    //System.out.println("PAGE " + page + ": " + pages[page - 1]);
                }
                
                // create individual documents for each page
                assert pages.length == pdflinks.length : "pages.length = " + pages.length + ", pdflinks.length = " + pdflinks.length;
                result = new Document[Math.min(pages.length, pdflinks.length)];
                String loc = location.toNormalform(true);
                for (int page = 0; page < result.length; page++) {                    
                    result[page] = new Document(
                            new AnchorURL(loc + (loc.indexOf('?') > 0 ? '&' : '?') + individualPagePropertyname + '=' + (page + 1)), // these are virtual new pages; we cannot combine them with '#' as that would be removed when computing the urlhash
                            mimeType,
                            "UTF-8",
                            this,
                            null,
                            docKeywords,
                            singleList(docTitle),
                            docAuthor,
                            docPublisher,
                            null,
                            null,
                            0.0f, 0.0f,
                            pages == null || page > pages.length ? new byte[0] : UTF8.getBytes(pages[page]),
                            pdflinks == null || page >= pdflinks.length ? null : pdflinks[page],
                            null,
                            null,
                            false,
                            docDate);
                }
            } else {
                // collect the whole text at once
                final CharBuffer writer = new CharBuffer(odtParser.MAX_DOCSIZE);
                byte[] contentBytes = new byte[0];
                stripper.setEndPage(3); // get first 3 pages (always)
                writer.append(stripper.getText(pdfDoc));
                contentBytes = writer.getBytes(); // remember text in case of interrupting thread

                if (pdfDoc.getNumberOfPages() > 3) { // spare creating/starting thread if all pages read
                    stripper.setStartPage(4); // continue with page 4 (terminated, resulting in no text)
                    stripper.setEndPage(Integer.MAX_VALUE); // set to default
                    // we start the pdf parsing in a separate thread to ensure that it can be terminated
                    final PDDocument pdfDocC = pdfDoc;
                    final Thread t = new Thread() {
                        @Override
                        public void run() {
                            Thread.currentThread().setName("pdfParser.getText:" + location);
                            try {
                                writer.append(stripper.getText(pdfDocC));
                            } catch (final Throwable e) {}
                        }
                    };
                    t.start();
                    t.join(3000); // pdfbox likes to forget to terminate ... (quite often)
                    if (t.isAlive()) t.interrupt();
                }
                contentBytes = writer.getBytes(); // get final text before closing writer

                Collection<AnchorURL> pdflinksCombined = new HashSet<AnchorURL>();
                for (Collection<AnchorURL> pdflinksx: pdflinks) if (pdflinksx != null) pdflinksCombined.addAll(pdflinksx);
                result = new Document[]{new Document(
                        location,
                        mimeType,
                        "UTF-8",
                        this,
                        null,
                        docKeywords,
                        singleList(docTitle),
                        docAuthor,
                        docPublisher,
                        null,
                        null,
                        0.0f, 0.0f,
                        contentBytes,
                        pdflinksCombined,
                        null,
                        null,
                        false,
                        docDate)};
            }         
        } catch (final Throwable e) {
            //close the writer (in finally)
            //throw new Parser.Failure(e.getMessage(), location);
        } finally {
            try {pdfDoc.close();} catch (final Throwable e) {}
        }

        // clear resources in pdfbox. they say that is resolved but it's not. see:
        // https://issues.apache.org/jira/browse/PDFBOX-313
        // https://issues.apache.org/jira/browse/PDFBOX-351
        // https://issues.apache.org/jira/browse/PDFBOX-441
        // the pdfbox still generates enormeous number of object allocations and don't delete these
        // the following Object are statically stored and never flushed:
        // COSFloat, COSArray, COSInteger, COSObjectKey, COSObject, COSDictionary,
        // COSStream, COSString, COSName, COSDocument, COSInteger[], COSNull
        // the great number of these objects can easily be seen in Java Visual VM
        // we try to get this shit out of the memory here by forced clear calls, hope the best the rubbish gets out.
        pdfDoc = null;
        clean_up_idiotic_PDFParser_font_cache_which_eats_up_tons_of_megabytes();
        
        return result;
    }

    /**
     * extract clickable links from pdf
     * @param pdf the document to parse
     * @return all detected links
     */
    private Collection<AnchorURL>[] extractPdfLinks(final PDDocument pdf) {
        @SuppressWarnings("unchecked")
        List<PDPage> allPages = pdf.getDocumentCatalog().getAllPages();
        @SuppressWarnings("unchecked")
        Collection<AnchorURL>[] linkCollections = (Collection<AnchorURL>[]) new Collection<?>[allPages.size()];
        int pagecount = 0;
        for (PDPage page : allPages) {
            final Collection<AnchorURL> pdflinks = new ArrayList<AnchorURL>();
            try {
                List<PDAnnotation> annotations = page.getAnnotations();
                if (annotations != null) {
                    for (PDAnnotation pdfannotation : annotations) {
                        if (pdfannotation instanceof PDAnnotationLink) {
                            PDAction link = ((PDAnnotationLink)pdfannotation).getAction();
                            if (link != null && link instanceof PDActionURI) {
                                PDActionURI pdflinkuri = (PDActionURI) link;
                                String uristr = pdflinkuri.getURI();
                                AnchorURL url = new AnchorURL(uristr);
                                pdflinks.add(url);
                            }
                        }
                    }
                }
            } catch (IOException ex) {}
            linkCollections[pagecount++] = pdflinks;
        }
        return linkCollections;
    }

    public static void clean_up_idiotic_PDFParser_font_cache_which_eats_up_tons_of_megabytes() {
        // thank you very much, PDFParser hackers, this font cache will occupy >80MB RAM for a single pdf and then stays forever
        // AND I DO NOT EVEN NEED A FONT HERE TO PARSE THE TEXT!
        // Don't be so ignorant, just google once "PDFParser OutOfMemoryError" to feel the pain.
        ResourceCleaner cl = new ResourceCleaner();
        cl.clearClassResources("org.apache.pdfbox.cos.COSName");
        cl.clearClassResources("org.apache.pdfbox.pdmodel.font.PDFont");
        cl.clearClassResources("org.apache.pdfbox.pdmodel.font.PDType1Font");
        cl.clearClassResources("org.apache.pdfbox.pdmodel.font.PDTrueTypeFont");
        cl.clearClassResources("org.apache.pdfbox.pdmodel.font.PDType0Font");
        cl.clearClassResources("org.apache.pdfbox.pdmodel.font.PDType1AfmPfbFont");
        cl.clearClassResources("org.apache.pdfbox.pdmodel.font.PDType3Font");
        cl.clearClassResources("org.apache.pdfbox.pdmodel.font.PDType1CFont");
        cl.clearClassResources("org.apache.pdfbox.pdmodel.font.PDCIDFont");
        cl.clearClassResources("org.apache.pdfbox.pdmodel.font.PDCIDFontType0Font");
        cl.clearClassResources("org.apache.pdfbox.pdmodel.font.PDCIDFontType2Font");
        cl.clearClassResources("org.apache.pdfbox.pdmodel.font.PDMMType1Font");
        cl.clearClassResources("org.apache.pdfbox.pdmodel.font.PDSimpleFont");
    }

    @SuppressWarnings({ "unchecked", "rawtypes" })
    private static class ResourceCleaner {
        Method findLoadedClass;
        private ClassLoader sys;
        public ResourceCleaner() {
            try {
                this.findLoadedClass = ClassLoader.class.getDeclaredMethod("findLoadedClass", new Class[] { String.class });
                this.findLoadedClass.setAccessible(true);
                this.sys = ClassLoader.getSystemClassLoader();
            } catch (Throwable e) {
                e.printStackTrace();
                this.findLoadedClass = null;
                this.sys = null;
            }
        }
        public void clearClassResources(String name) {
            if (this.findLoadedClass == null) return;
            try {
                Object pdfparserpainclass = this.findLoadedClass.invoke(this.sys, name);
                if (pdfparserpainclass != null) {
                    Method clearResources = ((Class) pdfparserpainclass).getDeclaredMethod("clearResources", new Class[] {});
                    if (clearResources != null) clearResources.invoke(null);
                }
            } catch (Throwable e) {
                //e.printStackTrace();
            }
        }
    }
    
    /**
     * test
     * @param args
     */
    public static void main(final String[] args) {
        if (args.length > 0 && args[0].length() > 0) {
            // file
            final File pdfFile = new File(args[0]);
            if(pdfFile.canRead()) {

                System.out.println(pdfFile.getAbsolutePath());
                final long startTime = System.currentTimeMillis();

                // parse
                final AbstractParser parser = new pdfParser();
                Document document = null;
                try {
                    document = Document.mergeDocuments(null, "application/pdf", parser.parse(null, "application/pdf", null, new FileInputStream(pdfFile)));
                } catch (final Parser.Failure e) {
                    System.err.println("Cannot parse file " + pdfFile.getAbsolutePath());
                    ConcurrentLog.logException(e);
                } catch (final InterruptedException e) {
                    System.err.println("Interrupted while parsing!");
                    ConcurrentLog.logException(e);
                } catch (final NoClassDefFoundError e) {
                    System.err.println("class not found: " + e.getMessage());
                } catch (final FileNotFoundException e) {
                    ConcurrentLog.logException(e);
                }

                // statistics
                System.out.println("\ttime elapsed: " + (System.currentTimeMillis() - startTime) + " ms");

                // output
                if (document == null) {
                    System.out.println("\t!!!Parsing without result!!!");
                } else {
                    System.out.println("\tParsed text with " + document.getTextLength() + " chars of text and " + document.getAnchors().size() + " anchors");
                    try {
                        // write file
                        FileUtils.copy(document.getTextStream(), new File("parsedPdf.txt"));
                    } catch (final IOException e) {
                        System.err.println("error saving parsed document");
                        ConcurrentLog.logException(e);
                    }
                }
            } else {
                System.err.println("Cannot read file "+ pdfFile.getAbsolutePath());
            }
        } else {
            System.out.println("Please give a filename as first argument.");
        }
    }

}