Removed TABLE->sort to make it possible to have multiple active calls to

filesort and init_read_record() for the same table.
This will simplify code for WINDOW FUNCTIONS (MDEV-6115)

- Filesort_info renamed to SORT_INFO and moved to filesort.h
- filesort now returns SORT_INFO
- init_read_record() now takes a SORT_INFO parameter.
- unique declaration is moved to uniques.h
- subselect caching of buffers is now more explicit than before
- filesort_buffer is now reusable even if rec_length has changed.
- filsort_free_buffers() and free_io_cache() calls are removed
- Remove one malloc() when using get_addon_fields()

Other things:
- Added --debug-assert-on-not-freed-memory option to make it easier to
  debug some not-freed-memory issues.

1 files changed, 100 insertions, 0 deletions

diff --git a/sql/uniques.h b/sql/uniques.h
new file mode 100644
index 00000000000..0210e879788
--- /dev/null
+++ b/sql/uniques.h
@@ -0,0 +1,100 @@
+/* Copyright (c) 2016 MariaDB corporation
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA */
+
+#ifndef UNIQUE_INCLUDED
+#define UNIQUE_INCLUDED
+
+#include "filesort.h"
+
+/*
+   Unique -- class for unique (removing of duplicates).
+   Puts all values to the TREE. If the tree becomes too big,
+   it's dumped to the file. User can request sorted values, or
+   just iterate through them. In the last case tree merging is performed in
+   memory simultaneously with iteration, so it should be ~2-3x faster.
+ */
+
+class Unique :public Sql_alloc
+{
+  DYNAMIC_ARRAY file_ptrs;
+  ulong max_elements;
+  ulonglong max_in_memory_size;
+  IO_CACHE file;
+  TREE tree;
+  ulong filtered_out_elems;
+  uint size;
+  uint full_size;
+  uint min_dupl_count;   /* always 0 for unions, > 0 for intersections */
+  bool with_counters;
+
+  bool merge(TABLE *table, uchar *buff, bool without_last_merge);
+  bool flush();
+
+public:
+  ulong elements;
+  SORT_INFO sort;
+  Unique(qsort_cmp2 comp_func, void *comp_func_fixed_arg,
+	 uint size_arg, ulonglong max_in_memory_size_arg,
+         uint min_dupl_count_arg= 0);
+  ~Unique();
+  ulong elements_in_tree() { return tree.elements_in_tree; }
+  inline bool unique_add(void *ptr)
+  {
+    DBUG_ENTER("unique_add");
+    DBUG_PRINT("info", ("tree %u - %lu", tree.elements_in_tree, max_elements));
+    if (!(tree.flag & TREE_ONLY_DUPS) && 
+        tree.elements_in_tree >= max_elements && flush())
+      DBUG_RETURN(1);
+    DBUG_RETURN(!tree_insert(&tree, ptr, 0, tree.custom_arg));
+  }
+
+  bool is_in_memory() { return (my_b_tell(&file) == 0); }
+  void close_for_expansion() { tree.flag= TREE_ONLY_DUPS; }
+
+  bool get(TABLE *table);
+  
+  /* Cost of searching for an element in the tree */
+  inline static double get_search_cost(ulonglong tree_elems, uint compare_factor)
+  {
+    return log((double) tree_elems) / (compare_factor * M_LN2);
+  }  
+
+  static double get_use_cost(uint *buffer, size_t nkeys, uint key_size,
+                             ulonglong max_in_memory_size, uint compare_factor,
+                             bool intersect_fl, bool *in_memory);
+  inline static int get_cost_calc_buff_size(size_t nkeys, uint key_size,
+                                            ulonglong max_in_memory_size)
+  {
+    register ulonglong max_elems_in_tree=
+      max_in_memory_size / ALIGN_SIZE(sizeof(TREE_ELEMENT)+key_size);
+    return (int) (sizeof(uint)*(1 + nkeys/max_elems_in_tree));
+  }
+
+  void reset();
+  bool walk(TABLE *table, tree_walk_action action, void *walk_action_arg);
+
+  uint get_size() const { return size; }
+  ulonglong get_max_in_memory_size() const { return max_in_memory_size; }
+
+  friend int unique_write_to_file(uchar* key, element_count count, Unique *unique);
+  friend int unique_write_to_ptrs(uchar* key, element_count count, Unique *unique);
+
+  friend int unique_write_to_file_with_count(uchar* key, element_count count,
+                                             Unique *unique);
+  friend int unique_intersect_write_to_ptrs(uchar* key, element_count count, 
+				            Unique *unique);
+};
+
+#endif /* UNIQUE_INCLUDED */