示例#1
0
文件: FTIndex.java 项目: fpapai/basex
  @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;
  }
示例#2
0
文件: FTIndex.java 项目: fpapai/basex
  /**
   * 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;
  }