Ejemplo n.º 1
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();
  }
Ejemplo n.º 2
0
  @Override
  FItem evalFunc(final QueryContext ctx) throws QueryException {
    final int ar = expr.length - 1;
    final Item it = checkItem(expr[ar], ctx);
    if (!(it instanceof FItem)) throw INVFUNCITEM.get(info, it.type);
    final FItem fit = (FItem) it;
    if (fit.arity() != ar) throw INVARITY.get(info, fit, ar);
    if (!sc.mixUpdates && updating != fit.annotations().contains(Ann.Q_UPDATING))
      throw (updating ? UPFUNCNOTUP : UPFUNCUP).get(info);

    return fit;
  }
Ejemplo n.º 3
0
  /**
   * Performs the test function.
   *
   * @param ctx query context
   * @return resulting value
   * @throws QueryException query exception
   */
  private Item test(final QueryContext ctx) throws QueryException {
    final Unit unit = new Unit(ctx, info);
    if (expr.length == 0) return unit.test(sc);

    final ArrayList<StaticFunc> funcs = new ArrayList<>();
    final Iter ir = ctx.iter(expr[0]);
    for (Item it; (it = ir.next()) != null; ) {
      final FItem fi = checkFunc(it, ctx);
      if (fi.funcName() != null) {
        final StaticFunc sf = ctx.funcs.get(fi.funcName(), fi.arity(), null, true);
        if (sf != null) funcs.add(sf);
      }
    }
    return unit.test(sc, funcs);
  }