示例#1
0
  /**
   * Evaluates the full-text match.
   *
   * @param qc query context
   * @return number of tokens, used for scoring
   * @throws QueryException query exception
   */
  private int contains(final QueryContext qc) throws QueryException {
    first = true;
    final FTLexer lexer = ftt.lexer(qc.ftToken);

    // use faster evaluation for default options
    int num = 0;
    if (fast) {
      for (final byte[] t : tokens) {
        final FTTokens qtok = ftt.cache(t);
        num = Math.max(num, ftt.contains(qtok, lexer) * qtok.length());
      }
      return num;
    }

    // find and count all occurrences
    final boolean all = mode == FTMode.ALL || mode == FTMode.ALL_WORDS;
    int oc = 0;
    for (final byte[] w : unique(tokens(qc))) {
      final FTTokens qtok = ftt.cache(w);
      final int o = ftt.contains(qtok, lexer);
      if (all && o == 0) return 0;
      num = Math.max(num, o * qtok.length());
      oc += o;
    }

    // check if occurrences are in valid range. if yes, return number of tokens
    final long mn = occ != null ? toLong(occ[0], qc) : 1;
    final long mx = occ != null ? toLong(occ[1], qc) : Long.MAX_VALUE;
    if (mn == 0 && oc == 0) matches = FTNot.not(matches);
    return oc >= mn && oc <= mx ? Math.max(1, num) : 0;
  }
示例#2
0
  @Override
  public boolean indexAccessible(final IndexInfo ii) {
    /* If the following conditions yield true, the index is accessed:
     * - all query terms are statically available
     * - no FTTimes option is specified
     * - explicitly set case, diacritics and stemming match options do not
     *   conflict with index options. */
    data = ii.ic.data;
    final MetaData md = data.meta;
    final FTOpt fto = ftt.opt;

    /* Index will be applied if no explicit match options have been set
     * that conflict with the index options. As a consequence, though, index-
     * based querying might yield other results than sequential scanning. */
    if (occ != null
        || fto.cs != null && md.casesens == (fto.cs == FTCase.INSENSITIVE)
        || fto.isSet(DC) && md.diacritics != fto.is(DC)
        || fto.isSet(ST) && md.stemming != fto.is(ST)
        || fto.ln != null && !fto.ln.equals(md.language)) return false;

    // adopt database options to tokenizer
    fto.copy(md);

    // estimate costs if text is not known at compile time
    if (tokens == null) {
      ii.costs = Math.max(2, data.meta.size / 30);
      return true;
    }

    // summarize number of hits; break loop if no hits are expected
    final FTLexer ft = new FTLexer(fto);
    ii.costs = 0;
    for (byte[] t : tokens) {
      ft.init(t);
      while (ft.hasNext()) {
        final byte[] tok = ft.nextToken();
        if (fto.sw != null && fto.sw.contains(tok)) continue;

        if (fto.is(WC)) {
          // don't use index if one of the terms starts with a wildcard
          t = ft.get();
          if (t[0] == '.') return false;
          // don't use index if certain characters or more than 1 dot are found
          int d = 0;
          for (final byte w : t) {
            if (w == '{' || w == '\\' || w == '.' && ++d > 1) return false;
          }
        }
        // favor full-text index requests over exact queries
        final int costs = data.costs(ft);
        if (costs != 0) ii.costs += Math.max(2, costs / 100);
      }
    }
    return true;
  }
示例#3
0
  @Override
  public Value value(final QueryContext qc) throws QueryException {
    final FItem getKey = checkArity(exprs[1], 1, qc);
    final long k = Math.min(toLong(exprs[2], qc), Integer.MAX_VALUE);
    if (k < 1) return Empty.SEQ;

    final Iter iter = exprs[0].iter(qc);
    final MinHeap<Item, Item> heap =
        new MinHeap<>(
            new Comparator<Item>() {
              @Override
              public int compare(final Item it1, final Item it2) {
                try {
                  return OpV.LT.eval(it1, it2, sc.collation, sc, info) ? -1 : 1;
                } catch (final QueryException qe) {
                  throw new QueryRTException(qe);
                }
              }
            });

    try {
      for (Item it; (it = iter.next()) != null; ) {
        heap.insert(checkNoEmpty(getKey.invokeItem(qc, info, it)), it);
        if (heap.size() > k) heap.removeMin();
      }
    } catch (final QueryRTException ex) {
      throw ex.getCause();
    }

    final ValueBuilder vb = new ValueBuilder();
    while (!heap.isEmpty()) vb.addFront(heap.removeMin());
    return vb.value();
  }
示例#4
0
文件: FTAnd.java 项目: BaseXdb/basex
 /**
  * Merges two matches.
  *
  * @param i1 first item
  * @param i2 second item
  */
 private static void and(final FTNode i1, final FTNode i2) {
   final FTMatches all = new FTMatches((byte) Math.max(i1.matches().pos, i2.matches().pos));
   for (final FTMatch s1 : i1.matches()) {
     for (final FTMatch s2 : i2.matches()) {
       all.add(new FTMatch(s1.size() + s2.size()).add(s1).add(s2));
     }
   }
   i1.score(Scoring.avg(i1.score() + i2.score(), 2));
   i1.matches(all);
 }
示例#5
0
文件: Num.java 项目: fpapai/basex
 /**
  * Rounds values.
  *
  * @param qc query context
  * @param even half-to-even flag
  * @return number
  * @throws QueryException query exception
  */
 ANum round(final QueryContext qc, final boolean even) throws QueryException {
   final ANum num = toNumber(exprs[0], qc);
   final long p = exprs.length == 1 ? 0 : Math.max(Integer.MIN_VALUE, toLong(exprs[1], qc));
   return num == null ? null : p > Integer.MAX_VALUE ? num : num.round((int) p, even);
 }
示例#6
0
  /**
   * Evaluates the specified query.
   *
   * @param query query
   * @return success flag
   */
  final boolean query(final String query) {
    final Performance p = new Performance();
    String error;
    if (exception != null) {
      error = Util.message(exception);
    } else {
      try {
        long hits = 0;
        final boolean run = options.get(MainOptions.RUNQUERY);
        final boolean serial = options.get(MainOptions.SERIALIZE);
        final int runs = Math.max(1, options.get(MainOptions.RUNS));
        for (int r = 0; r < runs; ++r) {
          // reuse existing processor instance
          if (r != 0) qp = null;
          qp(query, context);
          parse(p);
          if (r == 0) plan(false);

          qp.compile();
          info.compiling += p.time();
          if (r == 0) plan(true);
          if (!run) continue;

          final PrintOutput po = r == 0 && serial ? out : new NullOutput();
          try (final Serializer ser = qp.getSerializer(po)) {
            if (maxResults >= 0) {
              result = qp.cache(maxResults);
              info.evaluating += p.time();
              result.serialize(ser);
              hits = result.size();
            } else {
              hits = 0;
              final Iter ir = qp.iter();
              info.evaluating += p.time();
              for (Item it; (it = ir.next()) != null; ) {
                ser.serialize(it);
                ++hits;
                checkStop();
              }
            }
          }
          qp.close();
          info.serializing += p.time();
        }
        // dump some query info
        // out.flush();

        // remove string list if global locking is used and if query is updating
        if (soptions.get(StaticOptions.GLOBALLOCK) && qp.updating) {
          info.readLocked = null;
          info.writeLocked = null;
        }
        return info(info.toString(qp, out.size(), hits, options.get(MainOptions.QUERYINFO)));

      } catch (final QueryException | IOException ex) {
        exception = ex;
        error = Util.message(ex);
      } catch (final ProcException ex) {
        error = INTERRUPTED;
      } catch (final StackOverflowError ex) {
        Util.debug(ex);
        error = BASX_STACKOVERFLOW.desc;
      } catch (final RuntimeException ex) {
        extError("");
        Util.debug(info());
        throw ex;
      } finally {
        // close processor after exceptions
        if (qp != null) qp.close();
      }
    }
    return extError(error);
  }