Exemplo n.º 1
0
  /**
   * Performs a wildcard search for the specified token.
   *
   * @param token token to look for
   * @return iterator
   */
  private synchronized IndexIterator wc(final byte[] token) {
    final FTIndexIterator it = FTIndexIterator.FTEMPTY;
    final FTWildcard wc = new FTWildcard(token);
    if (!wc.parse()) return it;

    final IntList pr = new IntList();
    final IntList ps = new IntList();
    final byte[] pref = wc.prefix();
    final int pl = pref.length, tl = tp.length;
    final int l = Math.min(tl - 1, wc.max());
    for (int ti = pl; ti <= l; ti++) {
      int i = tp[ti];
      if (i == -1) continue;
      int c = ti + 1;
      int e = -1;
      while (c < tl && e == -1) e = tp[c++];
      i = find(pref, i, e, ti);

      while (i < e) {
        final byte[] t = inY.readBytes(i, ti);
        if (!startsWith(t, pref)) break;
        if (wc.match(t)) {
          inZ.cursor(pointer(i, ti));
          final int s = size(i, ti);
          for (int d = 0; d < s; d++) {
            pr.add(inZ.readNum());
            ps.add(inZ.readNum());
          }
        }
        i += ti + ENTRY;
      }
    }
    return iter(new FTCache(pr, ps), token);
  }
Exemplo n.º 2
0
  /**
   * Performs a fuzzy search for the specified token with a maximum number of errors.
   *
   * @param token token to look for
   * @param k number of errors allowed
   * @return iterator
   */
  private synchronized IndexIterator fuzzy(final byte[] token, final int k) {
    FTIndexIterator it = FTIndexIterator.FTEMPTY;
    final int tokl = token.length, tl = tp.length;
    final int e = Math.min(tl - 1, tokl + k);
    int s = Math.max(1, tokl - k) - 1;

    while (++s <= e) {
      int p = tp[s];
      if (p == -1) continue;
      int t = s + 1, r = -1;
      while (t < tl && r == -1) r = tp[t++];
      while (p < r) {
        if (ls.similar(inY.readBytes(p, s), token, k)) {
          it = FTIndexIterator.union(iter(pointer(p, s), size(p, s), inZ, token), it);
        }
        p += s + ENTRY;
      }
    }
    return it;
  }
Exemplo n.º 3
0
  @Override
  public synchronized int costs(final IndexToken it) {
    final byte[] tok = it.get();
    if (tok.length > data.meta.maxlen) return Integer.MAX_VALUE;

    // estimate costs for queries which stretch over multiple index entries
    final FTOpt opt = ((FTLexer) it).ftOpt();
    if (opt.is(FZ) || opt.is(WC)) return Math.max(1, data.meta.size >> 4);

    return entry(tok).size;
  }