bundles/org.simantics.db.indexing/src/org/simantics/db/indexing/IndexedRelationsSearcherBase.java

   1 /*******************************************************************************
   2  * Copyright (c) 2007, 2015 Association for Decentralized Information Management
   3  * in Industry THTH ry.
   4  * All rights reserved. This program and the accompanying materials
   5  * are made available under the terms of the Eclipse Public License v1.0
   6  * which accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *     VTT Technical Research Centre of Finland - initial API and implementation
  11  *     Semantum Oy - Fix for simantics issue #6053
  12  *******************************************************************************/
  13 package org.simantics.db.indexing;
  14
  15 import java.io.IOException;
  16 import java.nio.file.Files;
  17 import java.nio.file.Path;
  18 import java.util.ArrayList;
  19 import java.util.Collection;
  20 import java.util.Collections;
  21 import java.util.Iterator;
  22 import java.util.List;
  23 import java.util.Map;
  24 import java.util.concurrent.ExecutorService;
  25 import java.util.concurrent.Executors;
  26 import java.util.concurrent.Semaphore;
  27 import java.util.concurrent.ThreadFactory;
  28 import java.util.concurrent.atomic.AtomicReference;
  29
  30 import org.apache.lucene.document.Document;
  31 import org.apache.lucene.document.DocumentStoredFieldVisitor;
  32 import org.apache.lucene.document.Field;
  33 import org.apache.lucene.document.FieldType;
  34 import org.apache.lucene.document.LongField;
  35 import org.apache.lucene.document.TextField;
  36 import org.apache.lucene.index.CorruptIndexException;
  37 import org.apache.lucene.index.DirectoryReader;
  38 import org.apache.lucene.index.FieldInfo;
  39 import org.apache.lucene.index.IndexNotFoundException;
  40 import org.apache.lucene.index.IndexReader;
  41 import org.apache.lucene.index.IndexWriter;
  42 import org.apache.lucene.index.IndexWriterConfig;
  43 import org.apache.lucene.index.IndexWriterConfig.OpenMode;
  44 import org.apache.lucene.index.IndexableField;
  45 import org.apache.lucene.index.StoredFieldVisitor;
  46 import org.apache.lucene.index.Term;
  47 import org.apache.lucene.queryparser.classic.ParseException;
  48 import org.apache.lucene.search.IndexSearcher;
  49 import org.apache.lucene.search.MatchAllDocsQuery;
  50 import org.apache.lucene.search.Query;
  51 import org.apache.lucene.search.ScoreDoc;
  52 import org.apache.lucene.search.TermQuery;
  53 import org.apache.lucene.search.TopDocs;
  54 import org.apache.lucene.store.Directory;
  55 import org.apache.lucene.store.FSDirectory;
  56 import org.apache.lucene.util.Version;
  57 import org.eclipse.core.runtime.IProgressMonitor;
  58 import org.eclipse.core.runtime.SubMonitor;
  59 import org.simantics.databoard.util.ObjectUtils;
  60 import org.simantics.db.ReadGraph;
  61 import org.simantics.db.RequestProcessor;
  62 import org.simantics.db.Resource;
  63 import org.simantics.db.Session;
  64 import org.simantics.db.common.request.SafeName;
  65 import org.simantics.db.common.utils.NameUtils;
  66 import org.simantics.db.exception.DatabaseException;
  67 import org.simantics.db.indexing.internal.IndexingJob;
  68 import org.simantics.db.layer0.adapter.GenericRelation;
  69 import org.simantics.db.request.Read;
  70 import org.simantics.db.service.CollectionSupport;
  71 import org.simantics.db.service.SerialisationSupport;
  72 import org.simantics.utils.FileUtils;
  73 import org.simantics.utils.datastructures.Pair;
  74 import org.slf4j.Logger;
  75
  76 import gnu.trove.map.hash.THashMap;
  77
  78 /**
  79  * @author Tuukka Lehtonen
  80  * @author Antti Villberg
  81  */
  82 abstract public class IndexedRelationsSearcherBase {
  83
  84     protected enum State {
  85         // No index is available
  86         NONE,
  87         // An index is available, but there is a problem with it
  88         PROBLEM,
  89         // An index is available but no reader or writer is ready
  90         READY,
  91         // A reader is ready
  92         READ,
  93         // A writer (and a reader) is ready
  94         WRITE
  95     }
  96
  97     private State state = State.READY;
  98     private Throwable exception;
  99
 100     public Throwable getException() {
 101         return exception;
 102     }
 103
 104     public void setProblem(Throwable t) {
 105         if (t != null)
 106             getLogger().error("Setting problem for {} and previous state {}", this, this.state, t);
 107         this.state = State.PROBLEM;
 108         this.exception = t;
 109     }
 110
 111     public void setNone() {
 112         this.state = State.NONE;
 113     }
 114
 115     public void setReady() {
 116         this.state = State.READY;
 117     }
 118
 119     protected boolean checkState(State state) {
 120         return this.state == state;
 121     }
 122
 123     protected void assertState(State state) throws AssertionError {
 124
 125         if(this.state != state) throw new AssertionError("Illegal state, expected " + state.name() + " but was in " + this.state.name());
 126
 127     }
 128
 129     public void changeState(IProgressMonitor monitor, Session session, State state) {
 130         changeState(monitor, session, state, 0);
 131     }
 132
 133     protected void changeState(IProgressMonitor monitor, Session session, State state, int depth) {
 134
 135         if (this.state == state) {
 136             if (getLogger().isDebugEnabled())
 137                 getLogger().debug("Trying to change state {} to the same as previous state {} in depth {} with {}", state, this.state, depth, this);
 138             return;
 139         }
 140
 141         if (IndexPolicy.TRACE_INDEX_MANAGEMENT)
 142                 System.err.println("Index state " + this.state.name() + " => " + state.name() + " " + this);
 143
 144         // Check transitions
 145
 146         // Try to exit problem state
 147         if (State.PROBLEM == this.state && depth > 0) {
 148             getLogger().info("Try to exit problem state for {} and state {}", this, state);
 149                 Throwable t = bestEffortClear(monitor, session);
 150                 if(t != null) {
 151                     getLogger().error("Best effort clear has failed for state {} and this {}", state, this, t);
 152                                 exception = t;
 153                                 return;
 154                 }
 155                 // Managed to get into initial state
 156                 this.state = State.NONE;
 157                 getLogger().info("Managed to get into initial state {}", this.state);
 158                 return;
 159         }
 160
 161         // Cannot move into read from no index
 162         if (State.NONE ==  this.state && State.READ == state) {
 163             if (getLogger().isDebugEnabled())
 164                 getLogger().debug("Cannot move into read from no index in {} with state {}", this, state);
 165             return;
 166         }
 167         // Cannot move into write from no index
 168         if (State.NONE ==  this.state && State.WRITE == state) {
 169             if (getLogger().isDebugEnabled())
 170                 getLogger().debug("Cannot move into write from no index in {} with state {}", this, state);
 171             return;
 172         }
 173
 174                 boolean success = false;
 175
 176         try {
 177
 178                 if (searcher != null) {
 179                         searcher = null;
 180                 }
 181                 if (reader != null) {
 182                         reader.close();
 183                         reader = null;
 184                 }
 185                         closeWriter(writer);
 186                         directory = null;
 187
 188                         success = true;
 189
 190                 // Enter new state
 191                 if (State.READ == state || State.WRITE == state) {
 192
 193                         success = false;
 194
 195                         boolean forWriting = State.WRITE == state;
 196
 197                         if (directory != null)
 198                                 throw new IllegalStateException(getDescriptor() + "Index already loaded");
 199
 200                         SubMonitor mon = SubMonitor.convert(monitor, 100);
 201
 202                         mon.beginTask("Loading index", 100);
 203
 204                         if (IndexPolicy.TRACE_INDEX_LOAD)
 205                     System.out.println(getDescriptor() + "Loading Lucene index from " + indexPath + " for " + (forWriting ? "writing" : "reading"));
 206
 207                 long start = System.nanoTime();
 208
 209                 directory = getDirectory(session);
 210
 211                 if (forWriting) {
 212                     // Never overwrite an index that is about to be loaded.
 213                     // TODO: could use OpenMode.CREATE_OR_APPEND but must test first
 214                     IndexWriterConfig config = new IndexWriterConfig(Version.LUCENE_4_9, Queries.getAnalyzer()).setOpenMode(OpenMode.APPEND);
 215                     try {
 216                         // FIXME: platform #4676
 217                         writer = new IndexWriter(directory, config);
 218                     } catch (IndexNotFoundException e) {
 219                         // There was no pre-existing index on disk. Create it now.
 220                         writer = new IndexWriter(directory, config.setOpenMode(OpenMode.CREATE));
 221                         writer.commit();
 222                     }
 223                     reader = DirectoryReader.open(directory);
 224                     searcher = new IndexSearcher(reader);
 225                 } else {
 226                     reader = DirectoryReader.open(directory);
 227                     searcher = new IndexSearcher(reader);
 228                 }
 229
 230                 long end = System.nanoTime();
 231
 232                 mon.worked(100);
 233
 234                 if (IndexPolicy.PERF_INDEX_LOAD) {
 235                     double time = (end - start) * 1e-6;
 236                     System.out.println(getDescriptor() + "Loaded Lucene index from " + indexPath + " for " + (forWriting ? "writing" : "reading") + " in " + time + " ms");
 237                 }
 238
 239                 success = true;
 240
 241                 }
 242
 243         } catch (Throwable t) {
 244                 setProblem(t);
 245         } finally {
 246
 247                 if(!success) {
 248                         this.state = State.PROBLEM;
 249                         changeState(monitor, session, State.NONE, depth+1);
 250                         return;
 251                 }
 252
 253         }
 254
 255         this.state = state;
 256
 257     }
 258
 259     public static final FieldType STRING_TYPE = new FieldType();
 260
 261     static {
 262       STRING_TYPE.setIndexed(true);
 263       STRING_TYPE.setStored(true);
 264       STRING_TYPE.setTokenized(true);
 265       STRING_TYPE.freeze();
 266     }
 267
 268     protected static Field makeField(String fieldName, String fieldClass) throws DatabaseException {
 269         switch (fieldClass) {
 270         case "Long":   return new LongField(fieldName, 0L, Field.Store.YES);
 271         case "String": return new Field    (fieldName, "", STRING_TYPE);
 272         case "Text":   return new TextField(fieldName, "", Field.Store.YES);
 273         default:
 274             throw new DatabaseException("Can only index Long, String and Text fields, encountered field type " + fieldClass);
 275         }
 276     }
 277
 278     protected static Field[] makeFieldsForRelation(GenericRelation r, int boundLength, Document document) throws DatabaseException {
 279         Pair<String, String>[] fields = r.getFields();
 280         Field[] fs = new Field[Math.max(0, fields.length - boundLength)];
 281         for (int i = boundLength; i < fields.length; i++) {
 282             Field f = makeField(fields[i].first, fields[i].second);
 283             fs[i - boundLength] = f;
 284             if (document != null)
 285                 document.add(f);
 286         }
 287         return fs;
 288     }
 289
 290     void insertIndex(IProgressMonitor monitor, GenericRelation r, int boundLength, Collection<Object[]> documentsData)
 291     throws CorruptIndexException, IOException, DatabaseException {
 292         assertAccessOpen(true);
 293
 294         if (IndexPolicy.TRACE_INDEX_UPDATE)
 295             System.out.println(getDescriptor() + "Inserting " + documentsData.size() + " documents into index at " + indexPath);
 296
 297         long start = 0, end = 0;
 298         if (IndexPolicy.PERF_INDEX_UPDATE)
 299             start = System.nanoTime();
 300
 301         try {
 302             Document document = new Document();
 303             Field[] fs = makeFieldsForRelation(r, boundLength, document);
 304
 305             for (Object[] documentData : documentsData) {
 306                 if (setFields(fs, documentData) == null)
 307                     continue;
 308
 309                 if (IndexPolicy.TRACE_INDEX_UPDATE)
 310                     System.out.println(getDescriptor() + "Inserting document " + document);
 311
 312                 writer.addDocument(document);
 313             }
 314
 315             if (IndexPolicy.PERF_INDEX_UPDATE) {
 316                 end = System.nanoTime();
 317                 double ms = (end - start) * 1e-6;
 318                 System.out.println(getDescriptor() + "Inserted " + documentsData.size() + " documents into index at " + indexPath + " in " + ms + " ms");
 319             }
 320
 321         } finally {
 322         }
 323     }
 324
 325     void removeIndex(IProgressMonitor monitor, GenericRelation r, RequestProcessor processor, String key, Collection<Object> keyValues) throws DatabaseException, CorruptIndexException, IOException {
 326         assertAccessOpen(true);
 327
 328         if (IndexPolicy.TRACE_INDEX_UPDATE)
 329             System.out.println(getDescriptor() + "Removing " + keyValues.size() + " documents from index at " + indexPath);
 330
 331         long start = 0, end = 0;
 332         if (IndexPolicy.PERF_INDEX_UPDATE)
 333             start = System.nanoTime();
 334
 335         try {
 336             for (Object keyValue : keyValues) {
 337                 Term removedTerm = null;
 338                 if (keyValue instanceof Long) {
 339                     removedTerm = IndexUtils.longTerm(key, (Long) keyValue);
 340                 } else if (keyValue instanceof String) {
 341                     removedTerm = new Term(key, (String) keyValue);
 342                 } else {
 343                     // FIXME: should throw an exception for illegal input data but this would leave the index in an incoherent state
 344                     continue;
 345                 }
 346
 347                 if (IndexPolicy.TRACE_INDEX_UPDATE)
 348                     System.out.println(getDescriptor() + "Removing document with key " + removedTerm);
 349                 writer.deleteDocuments(removedTerm);
 350             }
 351
 352             if (IndexPolicy.PERF_INDEX_UPDATE) {
 353                 end = System.nanoTime();
 354                 double ms = (end - start) * 1e-6;
 355                 System.out.println(getDescriptor() + "Removed " + keyValues.size() + " documents from index at " + indexPath + " in " + ms + " ms");
 356             }
 357
 358         } finally {
 359         }
 360     }
 361
 362     void removeIndex(IProgressMonitor monitor) throws DatabaseException, CorruptIndexException, IOException {
 363         assertAccessOpen(true);
 364
 365         long start = 0, end = 0;
 366         if (IndexPolicy.PERF_INDEX_UPDATE)
 367             start = System.nanoTime();
 368
 369         try {
 370
 371             writer.deleteAll();
 372
 373             if (IndexPolicy.PERF_INDEX_UPDATE) {
 374                 end = System.nanoTime();
 375                 double ms = (end - start) * 1e-6;
 376                 System.out.println(getDescriptor() + "Removed all documents from index at " + indexPath + " in " + ms + " ms");
 377             }
 378
 379         } finally {
 380         }
 381     }
 382
 383     boolean replaceIndex(IProgressMonitor monitor, String key, Collection<Object> keyValues, GenericRelation r, int boundLength, Collection<Object[]> documentsData) throws CorruptIndexException, IOException, DatabaseException {
 384
 385         boolean didReplace = false;
 386
 387         assertAccessOpen(true);
 388         if (keyValues.size() != documentsData.size())
 389             throw new IllegalArgumentException("keyValues size does not match documents data size, " + keyValues.size() + " <> " + documentsData.size());
 390
 391         if (IndexPolicy.TRACE_INDEX_UPDATE)
 392             System.out.println(getDescriptor() + "Replacing " + keyValues.size() + " documents from index at " + indexPath);
 393
 394         long start = 0, end = 0;
 395         if (IndexPolicy.PERF_INDEX_UPDATE)
 396             start = System.nanoTime();
 397
 398         try {
 399             Iterator<Object> keyIt = keyValues.iterator();
 400             Iterator<Object[]> documentDataIt = documentsData.iterator();
 401
 402             Document document = new Document();
 403             Field[] fs = makeFieldsForRelation(r, boundLength, document);
 404
 405             nextDocument:
 406                 while (keyIt.hasNext()) {
 407                     Object keyValue = keyIt.next();
 408                     Object[] documentData = documentDataIt.next();
 409
 410                     Term removedTerm = null;
 411                     if (keyValue instanceof Long) {
 412                         removedTerm = IndexUtils.longTerm(key, (Long) keyValue);
 413                     } else if (keyValue instanceof String) {
 414                         removedTerm = new Term(key, (String) keyValue);
 415                     } else {
 416                         // FIXME: should throw an exception for illegal input data but this would leave the index in an incoherent state
 417                         System.err.println("[" + getClass().getSimpleName() + "] Unrecognized document key to remove '" + keyValue + "', only " + String.class + " and " + Resource.class + " are supported.");
 418                         continue nextDocument;
 419                     }
 420
 421                     if (setFields(fs, documentData) == null)
 422                         continue nextDocument;
 423
 424                     if (IndexPolicy.TRACE_INDEX_UPDATE)
 425                         System.out.println(getDescriptor() + "Replacing document with key " + removedTerm + " with " + document);
 426
 427                     boolean done = false;
 428                     if(requireChangeInfoOnReplace()) {
 429                             TopDocs exist = searcher.search(new TermQuery(removedTerm), null, 2);
 430                             if(exist.scoreDocs.length == 1 && requireChangeInfoOnReplace()) {
 431                                 Document doc = reader.document(exist.scoreDocs[0].doc);
 432                                 if(!areSame(doc, document)) {
 433                                     writer.deleteDocuments(removedTerm);
 434                                     writer.addDocument(document);
 435                                     didReplace |= true;
 436                                     if (IndexPolicy.TRACE_INDEX_UPDATE)
 437                                         System.out.println("-replaced single existing");
 438                                 } else {
 439                                     if (IndexPolicy.TRACE_INDEX_UPDATE)
 440                                         System.out.println("-was actually same than single existing");
 441                                 }
 442                                 done = true;
 443                             }
 444                     }
 445                     if(!done) {
 446                         writer.deleteDocuments(removedTerm);
 447                         writer.addDocument(document);
 448                         didReplace |= true;
 449                         if (IndexPolicy.TRACE_INDEX_UPDATE)
 450                                 System.out.println("-had many or none - removed all existing");
 451                     }
 452
 453                 }
 454
 455             if (IndexPolicy.PERF_INDEX_UPDATE) {
 456                 end = System.nanoTime();
 457                 double ms = (end - start) * 1e-6;
 458                 System.out.println(getDescriptor() + "Replaced " + keyValues.size() + " documents from index at " + indexPath + " in " + ms + " ms");
 459             }
 460
 461         } finally {
 462         }
 463
 464         return didReplace;
 465
 466     }
 467
 468     protected boolean requireChangeInfoOnReplace() {
 469         return true;
 470     }
 471
 472     private boolean areSame(Document d1, Document d2) {
 473         List<IndexableField> fs1 = d1.getFields();
 474         List<IndexableField> fs2 = d2.getFields();
 475         if(fs1.size() != fs2.size()) return false;
 476         for(int i=0;i<fs1.size();i++) {
 477                 IndexableField f1 = fs1.get(i);
 478                 IndexableField f2 = fs2.get(i);
 479                 String s1 = f1.stringValue();
 480                 String s2 = f2.stringValue();
 481             if (IndexPolicy.TRACE_INDEX_UPDATE)
 482                 System.err.println("areSame " + s1 + " vs. " + s2 );
 483                 if(!ObjectUtils.objectEquals(s1,s2)) return false;
 484         }
 485         return true;
 486     }
 487
 488     final RequestProcessor session;
 489
 490     final Resource         relation;
 491
 492     /**
 493      * The schema of the index, i.e. the fields that will be indexed per
 494      * document for the specified relation. Since the relation stays the same
 495      * throughout the lifetime of this class, the index schema is also assumed
 496      * to the same. This means that {@link GenericRelation#getFields()} is
 497      * assumed to stay the same.
 498      */
 499     final IndexSchema      schema;
 500
 501     Resource         input;
 502
 503     Path             indexPath;
 504
 505     Directory        directory;
 506
 507     IndexReader      reader;
 508
 509     IndexWriter      writer;
 510
 511     IndexSearcher    searcher;
 512
 513     IndexedRelationsSearcherBase(RequestProcessor session, Resource relation, Resource input) {
 514         this.session = session;
 515         this.relation = relation;
 516         this.input = input;
 517         this.indexPath = getIndexDirectory(session.getSession(), relation, input);
 518         if(isIndexAvailable()) {
 519                 state = State.READY;
 520         } else {
 521                 state = State.NONE;
 522         }
 523         this.schema = IndexSchema.readFromRelation(session, relation);
 524     }
 525
 526     Directory getDirectory(Session session) throws IOException {
 527         return FSDirectory.open(indexPath.toFile());
 528     }
 529
 530     abstract String getDescriptor();
 531
 532     /**
 533      * Ensures that searcher is in read or write state.
 534      *
 535      * @param forWriting <code>true</code> to open index for writing,
 536      *        <code>false</code> for reading
 537      * @return true is required state was reached
 538      *
 539      */
 540     boolean startAccess(IProgressMonitor monitor, Session session, boolean forWriting) {
 541         if(forWriting) {
 542                 changeState(monitor, session, State.WRITE);
 543                 return checkState(State.WRITE);
 544         } else {
 545                 changeState(monitor, session, State.READ);
 546                 return checkState(State.READ);
 547         }
 548     }
 549
 550     boolean hasAccess(boolean forWriting) {
 551
 552         if (forWriting)
 553                 return checkState(State.WRITE);
 554         else
 555                 return checkState(State.WRITE) || checkState(State.READ);
 556
 557     }
 558
 559     void assertAccessOpen(boolean forWriting) {
 560         if (forWriting)
 561                 if(!checkState(State.WRITE))
 562                 throw new IllegalStateException("index not opened for writing (directory=" + directory + ", reader=" + reader + ")");
 563         else
 564                 if(!(checkState(State.WRITE) || checkState(State.READ)))
 565                 throw new IllegalStateException("index not opened for reading (directory=" + directory + ", writer=" + writer + ")");
 566     }
 567
 568     void closeWriter(IndexWriter writer) throws CorruptIndexException, IOException {
 569         if (writer == null)
 570             return;
 571
 572         try {
 573             // May throw OOME, see IndexWriter javadoc for the correct actions.
 574             writer.close(false);
 575         } catch (OutOfMemoryError e) {
 576             writer.close();
 577             throw e;
 578         }
 579     }
 580
 581     private static String getPattern(GenericRelation relation, int boundCount) {
 582         String result = "";
 583         for (int i = 0; i < boundCount; i++)
 584             result += "b";
 585         for (int i = 0; i < relation.getFields().length - boundCount; i++)
 586             result += "f";
 587         return result;
 588     }
 589
 590     private static final int INDEXING_THREAD_COUNT = 2;
 591
 592     private static final ExecutorService executor = Executors.newFixedThreadPool(INDEXING_THREAD_COUNT, new ThreadFactory() {
 593         @Override
 594         public Thread newThread(Runnable r) {
 595             Thread t = new Thread(r, "Lucene Index Creator");
 596             if (!t.isDaemon())
 597                 t.setDaemon(true);
 598             if (t.getPriority() != Thread.NORM_PRIORITY)
 599                 t.setPriority(Thread.NORM_PRIORITY);
 600             return t;
 601         }
 602     });
 603
 604     void initializeIndex(IProgressMonitor monitor, ReadGraph graph, Object[] bound, boolean overwrite)
 605             throws IOException, DatabaseException
 606     {
 607         IndexingJob.jobifyIfPossible(
 608                 monitor,
 609                 "Reindexing " + NameUtils.getSafeLabel(graph, input),
 610                 mon -> {
 611                     try {
 612                         initializeIndexImpl(mon, graph, bound, overwrite);
 613                     } catch (IOException e) {
 614                         getLogger().error("Index is in problematic state! {}", this, e);
 615                         throw new DatabaseException(e);
 616                     }
 617                 });
 618     }
 619
 620     void initializeIndexImpl(IProgressMonitor monitor, ReadGraph graph, final Object[] bound, boolean overwrite) throws IOException,
 621     DatabaseException {
 622
 623         final SubMonitor mon = SubMonitor.convert(monitor, 100);
 624
 625         if (IndexPolicy.TRACE_INDEX_INIT)
 626             System.out.println(getDescriptor() + "Initializing index at " + indexPath + " (overwrite = " + overwrite + ")");
 627         mon.beginTask("Initializing Index", 100);
 628
 629         if (overwrite) {
 630             if (Files.exists(indexPath)) {
 631                 mon.subTask("Erasing previous index");
 632                 if (getLogger().isDebugEnabled())
 633                     getLogger().debug("Erasing previous index {}", indexPath.toAbsolutePath());
 634                 FileUtils.delete(indexPath);
 635             }
 636         }
 637
 638         final AtomicReference<FSDirectory> directory = new AtomicReference<FSDirectory>();
 639         final AtomicReference<IndexWriter> writer = new AtomicReference<IndexWriter>();
 640
 641         try {
 642             mon.subTask("Start index write");
 643             createDirectory(indexPath);
 644
 645             directory.set(FSDirectory.open(indexPath.toFile()));
 646             IndexWriterConfig conf = new IndexWriterConfig(Version.LUCENE_4_9, Queries.getAnalyzer()).setOpenMode(OpenMode.CREATE);
 647             writer.set(new IndexWriter(directory.get(), conf));
 648
 649             mon.worked(5);
 650
 651             final GenericRelation r = graph.adapt(relation, GenericRelation.class);
 652             if (r == null)
 653                 throw new DatabaseException("Given resource " + graph.syncRequest(new SafeName(relation))
 654                 + "could not be adapted to GenericRelation.");
 655
 656             long realizeStart = 0;
 657             if (IndexPolicy.PERF_INDEX_INIT)
 658                 realizeStart = System.nanoTime();
 659
 660             mon.subTask("Calculating indexed content");
 661             GenericRelation selection = r.select(getPattern(r, bound.length), bound);
 662             mon.worked(5);
 663             List<Object[]> results = selection.realize(graph);
 664             mon.worked(40);
 665
 666             if (IndexPolicy.PERF_INDEX_INIT)
 667                 System.out.println(getDescriptor() + "Realized index with " + results.size() + " entries at " + indexPath + " in " + (1e-9 * (System.nanoTime()-realizeStart)) + " seconds.");
 668             if (IndexPolicy.TRACE_INDEX_INIT)
 669                 System.out.println(getDescriptor() + "Indexed relation " + r + " produced " + results.size() + " results");
 670
 671             long start = IndexPolicy.PERF_INDEX_INIT ? System.nanoTime() : 0;
 672
 673             mon.subTask("Indexing content");
 674             final Semaphore s = new Semaphore(0);
 675             mon.setWorkRemaining(results.size());
 676
 677             for (int i = 0; i < INDEXING_THREAD_COUNT; i++) {
 678                 final int startIndex = i;
 679                 executor.submit(() -> {
 680                     try {
 681                         Document document = new Document();
 682                         Field[] fs = makeFieldsForRelation(r, bound.length, document);
 683
 684                         for (int index = startIndex; index < results.size(); index += INDEXING_THREAD_COUNT) {
 685                             if (setFields(fs, results.get(index)) == null)
 686                                 continue;
 687                             try {
 688                                 writer.get().addDocument(document);
 689                             } catch (CorruptIndexException e) {
 690                                 getLogger().error("Index is corrupted! {}", this, e);
 691                                 throw new IllegalStateException(e);
 692                             } catch (IOException e) {
 693                                 getLogger().error("Index is in problematic state! {}", this, e);
 694                                 throw new IllegalStateException(e);
 695                             } finally {
 696                                 synchronized (mon) {
 697                                     mon.worked(1);
 698                                 }
 699                             }
 700                         }
 701
 702                         s.release();
 703                     } catch (DatabaseException e) {
 704                         throw new IllegalStateException(e);
 705                     }
 706                 });
 707             }
 708
 709             try {
 710                 s.acquire(INDEXING_THREAD_COUNT);
 711             } catch (InterruptedException e) {
 712                 getLogger().error("Could not initialize index {}", this, e);
 713             }
 714
 715             // http://www.gossamer-threads.com/lists/lucene/java-dev/47895
 716             // and http://lucene.apache.org/java/docs/index.html#27+November+2011+-+Lucene+Core+3.5.0
 717             // advise against calling optimize at all. So let's not do it anymore.
 718             //writer.get().optimize();
 719             //writer.get().commit();
 720
 721             mon.subTask("Flushing");
 722
 723             if (IndexPolicy.PERF_INDEX_INIT)
 724                 System.out.println(getDescriptor() + "Wrote index at " + indexPath + " in " + (1e-9 * (System.nanoTime()-start)) + " seconds.");
 725
 726         } catch (DatabaseException e) {
 727             getLogger().error("Could not initialize index due to db {}", this, e);
 728         } finally {
 729             try {
 730                 closeWriter(writer.getAndSet(null));
 731             } finally {
 732                 FileUtils.uncheckedClose(directory.getAndSet(null));
 733             }
 734         }
 735     }
 736
 737
 738     public List<Object[]> debugDocs(IProgressMonitor monitor) throws ParseException, IOException, DatabaseException {
 739
 740             Query query = new MatchAllDocsQuery();
 741
 742             TopDocs td = searcher.search(query, Integer.MAX_VALUE);
 743
 744             ScoreDoc[ ] scoreDocs = td.scoreDocs;
 745             List<Object[]> result = new ArrayList<Object[]>(scoreDocs.length);
 746
 747             for(ScoreDoc scoreDoc:scoreDocs) {
 748
 749                 try {
 750
 751                     Document doc = reader.document(scoreDoc.doc);
 752                     List<IndexableField> fs = doc.getFields();
 753                     Object[] o = new Object[fs.size()];
 754                     int index = 0;
 755                     for (IndexableField f : fs) {
 756                     o[index++] = f.stringValue();
 757                     }
 758                     result.add(o);
 759
 760             } catch (CorruptIndexException e) {
 761                 getLogger().error("Index is corrupted! {}", this, e);
 762                 throw new DatabaseException(e);
 763             } catch (IOException e) {
 764                 getLogger().error("Index is in problematic state! {}", this, e);
 765                 throw new DatabaseException(e);
 766             }
 767
 768             }
 769
 770             return result;
 771
 772     }
 773
 774
 775     List<Map<String, Object>> doSearch(IProgressMonitor monitor, RequestProcessor processor, String search, int maxResultCount) throws ParseException, IOException,
 776     DatabaseException {
 777
 778         // An empty search string will crash QueryParser
 779         // Just return no results for empty queries.
 780         //System.out.println("search: '" + search + "'");
 781         if (search.isEmpty())
 782             return Collections.emptyList();
 783
 784         assertAccessOpen(false);
 785
 786         Query query = Queries.parse(search, schema);
 787
 788         long start = System.nanoTime();
 789
 790         maxResultCount = Math.min(maxResultCount, searcher.getIndexReader().numDocs());
 791         if (maxResultCount == 0)
 792             return Collections.emptyList();
 793
 794         final TopDocs docs = searcher.search(query, null, maxResultCount);
 795
 796 //        for(Object[] o : debugDocs(monitor)) {
 797 //            System.err.println("-" + Arrays.toString(o));
 798 //        }
 799
 800         if (IndexPolicy.PERF_INDEX_QUERY) {
 801             long end = System.nanoTime();
 802             System.out.println(getDescriptor() + "search(" + search + ", " + maxResultCount + ") into index at " + indexPath + " took " + (1e-9 * (end-start)) + " seconds.");
 803         }
 804
 805         if (docs.totalHits == 0) {
 806             return Collections.emptyList();
 807         }
 808
 809         return processor.syncRequest(new Read<List<Map<String, Object>>>() {
 810
 811             @Override
 812             public List<Map<String, Object>> perform(ReadGraph graph) throws DatabaseException {
 813
 814                 GenericRelation r = graph.adapt(relation, GenericRelation.class);
 815                 if (r == null)
 816                     throw new DatabaseException("Given resource " + graph.syncRequest(new SafeName(relation))
 817                             + "could not be adapted to GenericRelation.");
 818
 819                 SerialisationSupport support = graph.getService(SerialisationSupport.class);
 820
 821                 List<Map<String, Object>> result = new ArrayList<Map<String, Object>>(docs.scoreDocs.length);
 822
 823                 final DocumentStoredFieldVisitor visitor = new DocumentStoredFieldVisitor();
 824
 825                 for (ScoreDoc scoreDoc : docs.scoreDocs) {
 826
 827                     try {
 828
 829                         reader.document(scoreDoc.doc, visitor);
 830
 831                         Document doc = visitor.getDocument();
 832
 833                         List<IndexableField> fs = doc.getFields();
 834                         Map<String, Object> entry = new THashMap<String, Object>(fs.size());
 835                         for (IndexableField f : fs) {
 836                             IndexSchema.Type type = schema.typeMap.get(f.name());
 837                             if (type == IndexSchema.Type.LONG) {
 838                                 entry.put(f.name(), support.getResource(f.numericValue().longValue()));
 839                             } else {
 840                                 entry.put(f.name(), f.stringValue());
 841                             }
 842                         }
 843
 844                         result.add(entry);
 845
 846                     } catch (CorruptIndexException e) {
 847                         getLogger().error("Index is corrupted! {}", this, e);
 848                         throw new DatabaseException(e);
 849                     } catch (IOException e) {
 850                         getLogger().error("Index is in problematic state! {}", this, e);
 851                         throw new DatabaseException(e);
 852                     }
 853                 }
 854                 return result;
 855             }
 856         });
 857     }
 858
 859     static class ResourceVisitor extends StoredFieldVisitor {
 860
 861         public long id;
 862
 863                 @Override
 864                 public Status needsField(FieldInfo fieldInfo) throws IOException {
 865                         if("Resource".equals(fieldInfo.name)) return Status.YES;
 866                         return Status.NO;
 867                 }
 868
 869                 @Override
 870                 public void longField(FieldInfo fieldInfo, long value) throws IOException {
 871                         id = value;
 872                 }
 873
 874     };
 875
 876     static class DumpVisitor extends StoredFieldVisitor {
 877
 878         public List<Object> values;
 879
 880         DumpVisitor(List<Object> values) {
 881                 this.values = values;
 882         }
 883
 884                 @Override
 885                 public Status needsField(FieldInfo fieldInfo) throws IOException {
 886                         return Status.YES;
 887                 }
 888
 889                 @Override
 890                 public void longField(FieldInfo fieldInfo, long value) throws IOException {
 891                         values.add(value);
 892                 }
 893
 894                 @Override
 895                 public void stringField(FieldInfo fieldInfo, String value) throws IOException {
 896                         values.add(value);
 897                 }
 898
 899     }
 900
 901     List<Resource> doSearchResources(IProgressMonitor monitor, RequestProcessor processor, String search, int maxResultCount) throws ParseException, IOException,
 902     DatabaseException {
 903
 904         // An empty search string will crash QueryParser
 905         // Just return no results for empty queries.
 906         //System.out.println("search: '" + search + "'");
 907         if (search.isEmpty())
 908             return Collections.emptyList();
 909
 910         assertAccessOpen(false);
 911
 912         Query query = Queries.parse(search, schema);
 913
 914         long start = System.nanoTime();
 915
 916         maxResultCount = Math.min(maxResultCount, searcher.getIndexReader().numDocs());
 917         if (maxResultCount == 0)
 918             return Collections.emptyList();
 919
 920         final TopDocs docs = searcher.search(query, null, maxResultCount);
 921
 922 //        for(Object[] o : debugDocs(monitor)) {
 923 //            System.err.println("-" + Arrays.toString(o));
 924 //        }
 925
 926         if (IndexPolicy.PERF_INDEX_QUERY) {
 927             long end = System.nanoTime();
 928             System.out.println(getDescriptor() + "search(" + search + ", " + maxResultCount + ") into index at " + indexPath + " took " + (1e-9 * (end-start)) + " seconds.");
 929         }
 930
 931         if (docs.totalHits == 0) {
 932             return Collections.emptyList();
 933         }
 934
 935         return processor.syncRequest(new Read<List<Resource>>() {
 936
 937             @Override
 938             public List<Resource> perform(ReadGraph graph) throws DatabaseException {
 939
 940                 CollectionSupport cs = graph.getService(CollectionSupport.class);
 941                 SerialisationSupport support = graph.getService(SerialisationSupport.class);
 942
 943                 List<Resource> result = cs.createList();
 944
 945                 ResourceVisitor visitor = new ResourceVisitor();
 946
 947                 for (ScoreDoc scoreDoc : docs.scoreDocs) {
 948                     try {
 949                         reader.document(scoreDoc.doc, visitor);
 950                         result.add(support.getResource(visitor.id));
 951                     } catch (CorruptIndexException e) {
 952                         getLogger().error("Index is corrupted! {}", this, e);
 953                         throw new DatabaseException(e);
 954                     } catch (IOException e) {
 955                         getLogger().error("Index is in problematic state! {}", this, e);
 956                         throw new DatabaseException(e);
 957                     }
 958                 }
 959                 return result;
 960             }
 961         });
 962     }
 963
 964     List<Object> doList(IProgressMonitor monitor, RequestProcessor processor) throws ParseException, IOException,
 965     DatabaseException {
 966
 967         assertAccessOpen(false);
 968
 969         Query query = new MatchAllDocsQuery();
 970
 971         final TopDocs docs = searcher.search(query, Integer.MAX_VALUE);
 972
 973         ArrayList<Object> result = new ArrayList<Object>();
 974
 975         DumpVisitor visitor = new DumpVisitor(result);
 976
 977         for (ScoreDoc scoreDoc : docs.scoreDocs) {
 978
 979                 try {
 980
 981                         reader.document(scoreDoc.doc, visitor);
 982
 983                 } catch (CorruptIndexException e) {
 984                     getLogger().error("Index is corrupted! {}", this, e);
 985                         throw new DatabaseException(e);
 986                 } catch (IOException e) {
 987                     getLogger().error("Index is in problematic state! {}", this, e);
 988                         throw new DatabaseException(e);
 989                 }
 990
 991         }
 992
 993         return result;
 994
 995     }
 996
 997     protected static Path getIndexDirectory(Session session, Resource relation, Resource input) {
 998         Path path = DatabaseIndexing.getIndexLocation(session, relation, input);
 999 //        System.out.println("getIndexDirectory = " + path);
1000         return path;
1001     }
1002
1003     private static void createDirectory(Path path) throws IOException {
1004         if (Files.exists(path) && !Files.isDirectory(path))
1005             throw new IOException("Could not create index directory " + path + ", a file by that name already exists");
1006         Files.createDirectories(path);
1007     }
1008
1009     Path getIndexPath() {
1010         return indexPath;
1011     }
1012
1013     boolean isIndexAvailable() {
1014         return (Files.exists(indexPath) && Files.isDirectory(indexPath));
1015     }
1016
1017     abstract Throwable bestEffortClear(IProgressMonitor monitor, Session session);
1018
1019     /*
1020      * Start from scratch. Clear all caches and rebuild the index.
1021      */
1022     Throwable clearDirectory(IProgressMonitor monitor, Session session) {
1023
1024                 Path file = getIndexPath();
1025
1026         try {
1027                         FileUtils.delete(file);
1028         } catch (Throwable t) {
1029                 getLogger().error("Could not delete directory {}", file.toAbsolutePath(), t);
1030                 return t;
1031         }
1032         if (Files.exists(file))
1033             return new IllegalStateException("Failed to delete directory " + file.toAbsolutePath());
1034         return null;
1035     }
1036
1037     private Field[] setFields(Field[] fs, Object[] result) {
1038         for (int i = 0; i < result.length; i++) {
1039             Object value = result[i];
1040             if (value instanceof String) {
1041                 if (IndexPolicy.DEBUG_INDEX_INIT)
1042                     System.out.println(getDescriptor() + "index " + fs[i].name() + " = " + value + " : String");
1043                 fs[i].setStringValue((String) value);
1044             } else if (value instanceof Long) {
1045                 if (IndexPolicy.DEBUG_INDEX_INIT)
1046                     System.out.println(getDescriptor() + "index " + fs[i].name() + " = " + value + " : Long");
1047                 fs[i].setLongValue((Long) value);
1048             } else {
1049                 getLogger().error("Can only index Long and String fields, encountered " + value);
1050                 return null;
1051             }
1052         }
1053         return fs;
1054     }
1055
1056     protected abstract Logger getLogger();
1057
1058     @Override
1059     public String toString() {
1060         return getClass().getSimpleName() + " [" + String.valueOf(schema) + ", " + String.valueOf(relation) + ", " + String.valueOf(input) + ", " + String.valueOf(indexPath) + ", " + String.valueOf(directory) + ", " + String.valueOf(state) + "]";
1061     }
1062 }