Drizzled Public API Documentation

sel_imerge.cc
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19 
20 #include <config.h>
21 
22 #include <drizzled/sql_base.h>
23 #include <drizzled/sql_select.h>
24 #include <drizzled/memory/sql_alloc.h>
25 #include <drizzled/optimizer/range.h>
26 #include <drizzled/optimizer/range_param.h>
27 #include <drizzled/optimizer/sel_arg.h>
28 #include <drizzled/optimizer/sel_tree.h>
29 #include <drizzled/optimizer/sel_imerge.h>
30 
31 using namespace std;
32 using namespace drizzled;
33 
34 optimizer::SEL_IMERGE::SEL_IMERGE()
35  :
36  trees(&trees_prealloced[0]),
37  trees_next(trees),
38  trees_end(trees + PREALLOCED_TREES)
39 {}
40 
41 
42 void optimizer::SEL_IMERGE::or_sel_tree(optimizer::RangeParameter *param, optimizer::SEL_TREE *tree)
43 {
44  if (trees_next == trees_end)
45  {
46  uint32_t old_elements= trees_end - trees;
47  optimizer::SEL_TREE** new_trees= new (*param->mem_root) optimizer::SEL_TREE*[2 * old_elements];
48  memcpy(new_trees, trees, sizeof(optimizer::SEL_TREE**) * old_elements);
49  trees= new_trees;
50  trees_next= trees + old_elements;
51  trees_end= trees + 2 * old_elements;
52  }
53  *(trees_next++)= tree;
54 }
55 
56 
57 int optimizer::SEL_IMERGE::or_sel_tree_with_checks(optimizer::RangeParameter& param, optimizer::SEL_TREE& new_tree)
58 {
59  for (optimizer::SEL_TREE** tree = trees; tree != trees_next; tree++)
60  {
61  if (sel_trees_can_be_ored(**tree, new_tree, param))
62  {
63  *tree = tree_or(&param, *tree, &new_tree);
64  if (!*tree)
65  return 1;
66  if (((*tree)->type == SEL_TREE::MAYBE) ||
67  ((*tree)->type == SEL_TREE::ALWAYS))
68  return 1;
69  /* optimizer::SEL_TREE::IMPOSSIBLE is impossible here */
70  return 0;
71  }
72  }
73 
74  /* New tree cannot be combined with any of existing trees. */
75  or_sel_tree(&param, &new_tree);
76  return 0;
77 }
78 
79 
80 int optimizer::SEL_IMERGE::or_sel_imerge_with_checks(RangeParameter& param, SEL_IMERGE& imerge)
81 {
82  for (SEL_TREE** tree= imerge.trees; tree != imerge.trees_next; tree++)
83  {
84  if (or_sel_tree_with_checks(param, **tree))
85  return 1;
86  }
87  return 0;
88 }
89