c4_JoinViewer::c4_JoinViewer(c4_Sequence &seq_, const c4_View &keys_, const
  c4_View &view_, bool outer_): _parent(&seq_), _argView(view_.SortOn(keys_)) {
  // why not in GetTemplate, since we don't need to know this...
  _template = _parent.Clone();
  for (int l = 0; l < _argView.NumProperties(); ++l)
    _template.AddProperty(_argView.NthProperty(l));

  c4_View sorted = _parent.SortOn(keys_).Project(keys_);
  c4_View temp = _argView.Project(keys_);

  _base.SetSize(0, 5);
  _offset.SetSize(0, 5);

  int j = 0, n = 0;

  for (int i = 0; i < sorted.GetSize(); ++i) {
    int orig = _parent.GetIndexOf(sorted[i]);
    d4_assert(orig >= 0);

    if (i > 0 && sorted[i] == sorted[i - 1]) {
      // if last key was same, repeat the same join
      int last = _offset.GetSize() - n;
      for (int k = 0; k < n; ++k) {
        _base.Add(orig);
        _offset.Add(_offset.GetAt(last + k));
      }
    } else
     { // no, this is a new combination
      bool match = false;

      // advance until the temp view entry is >= this sorted entry
      while (j < temp.GetSize())
      if (sorted[i] <= temp[j]) {
        match = sorted[i] == temp[j];
        break;
      } else
        ++j;

      n = 0;

      if (match) {
        do {
          _base.Add(orig);
          _offset.Add(j);
          ++n;
        } while (++j < temp.GetSize() && temp[j] == temp[j - 1]);
      } else if (outer_) {
        // no match, add an entry anyway if this is an outer join
        _base.Add(orig);
        _offset.Add(~(t4_i32)0); // special null entry
        ++n;
      }
    }
  }
}
Exemplo n.º 2
0
 v1.Add(p1[345] + p2["four"]);
 v1.Add(p1[234] + p2["five"]);
 v1.Add(p1[123] + p2["six"]);
 c4_View v2 = v1.Sort();
 A(v2.GetSize() == 6);
 A(p1(v2[0]) == 111);
 A(p1(v2[1]) == 123);
 A(p1(v2[2]) == 222);
 A(p1(v2[3]) == 234);
 A(p1(v2[4]) == 333);
 A(p1(v2[5]) == 345);
 A(v2.Search(p1[123]) == 1);
 A(v2.Search(p1[100]) == 0);
 A(v2.Search(p1[200]) == 2);
 A(v2.Search(p1[400]) == 6);
 c4_View v3 = v1.SortOn(p2);
 A(v3.GetSize() == 6);
 A(p1(v3[0]) == 234);
 A(p1(v3[1]) == 345);
 A(p1(v3[2]) == 111);
 A(p1(v3[3]) == 123);
 A(p1(v3[4]) == 333);
 A(p1(v3[5]) == 222);
 A(v3.Search(p2["six"]) == 3);
 A(v3.Search(p2["aha"]) == 0);
 A(v3.Search(p2["gee"]) == 2);
 A(v3.Search(p2["wow"]) == 6);
 c4_View v4 = v1.SortOnReverse(p2, p2);
 A(v4.GetSize() == 6);
 A(p1(v4[0]) == 222);
 A(p1(v4[1]) == 333);