From 3600d09ab4323098676fa51c869a787fec9d42cc Mon Sep 17 00:00:00 2001
From: unknown <sergefp@mysql.com>
Date: Thu, 13 May 2004 01:38:40 +0400
Subject: This is first cset for WL#1394 "Optimize index merge when all
 involved index ranges include only values with equal keys" The main idea is
 to exploit the fact that key scans for "key=const" return ordered sequences
 of rowids.

include/my_base.h:
  Added HA_EXTRA_KEYREAD_PRESERVE_FIELDS flag
include/my_bitmap.h:
  Added a couple of utility functions
include/my_sys.h:
  Added my_conunt_bits_ushort function
innobase/include/row0mysql.h:
  Added support for HA_EXTRA_KEYREAD_PRESERVE_FIELDS
innobase/row/row0sel.c:
  Added support for HA_EXTRA_KEYREAD_PRESERVE_FIELDS
mysys/my_bit.c:
  Added my_count_bits_ushort function
mysys/my_bitmap.c:
  Added a couple of utility functions
sql/ha_berkeley.cc:
  Added cmp_ref rowid comparison function.
sql/ha_berkeley.h:
  Added cmp_ref rowid comparison function.
sql/ha_heap.h:
  Added cmp_ref rowid comparison function.
sql/ha_innodb.cc:
  Added cmp_ref rowid comparison function and support from HA_EXTRA_KEYREAD_PRESERVE_FIELDS
sql/ha_innodb.h:
  Added cmp_ref rowid comparison function.
sql/handler.h:
  Added cmp_ref rowid comparison function.
sql/opt_range.cc:
  Added QUICK_ROR_{INTERSECT,UNION}_SELECT classes and related optimizer code
sql/opt_range.h:
  Added QUICK_ROR_{INTERSECT,UNION}_SELECT classes
sql/sql_delete.cc:
  Changed to use new ROWID comparison function
  also always call quick->reset() for quick selects
sql/sql_select.cc:
  Account for new quick select types
sql/sql_select.h:
  New, proper rowid ordering/comparison function to be used with Unique class etc.
sql/sql_test.cc:
  Account for new quick select types
sql/sql_update.cc:
  Account for new quick select types
---
 mysys/my_bitmap.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 56 insertions(+)

(limited to 'mysys/my_bitmap.c')

diff --git a/mysys/my_bitmap.c b/mysys/my_bitmap.c
index da16457c299..3c4caa413a9 100644
--- a/mysys/my_bitmap.c
+++ b/mysys/my_bitmap.c
@@ -330,3 +330,59 @@ void bitmap_union(MY_BITMAP *map, const MY_BITMAP *map2)
   bitmap_unlock(map);
 }
 
+
+/*
+  Get number of set bits in the bitmap 
+*/
+uint bitmap_bits_set(const MY_BITMAP *map)
+{  
+  uchar *m= map->bitmap,
+        *end= map->bitmap+map->bitmap_size;
+  uint res= 0;
+
+  DBUG_ASSERT(map->bitmap);
+
+  bitmap_lock((MY_BITMAP *)map);
+  while (m < end)
+  {
+    res+= my_count_bits_ushort(*m++);
+  }
+
+  bitmap_unlock((MY_BITMAP *)map);
+  return res;
+}
+
+
+/* 
+  Return number of first zero bit or MY_BIT_NONE if all bits are set.
+*/
+
+uint bitmap_get_first(const MY_BITMAP *map)
+{
+  uchar *bitmap=map->bitmap;
+  uint bit_found = MY_BIT_NONE;
+  uint bitmap_size=map->bitmap_size*8;
+  uint i;
+
+  DBUG_ASSERT(map->bitmap);
+  bitmap_lock((MY_BITMAP *)map);
+  for (i=0; i < bitmap_size ; i++, bitmap++)
+  {
+    if (*bitmap != 0xff)
+    {						/* Found slot with free bit */
+      uint b;
+      for (b=0; ; b++)
+      {
+	if (!(*bitmap & (1 << b)))
+	{
+	  bit_found = (i*8)+b;
+	  break;
+	}
+      }
+      break;					/* Found bit */
+    }
+  }
+  bitmap_unlock((MY_BITMAP *)map);
+  return bit_found;
+}
+
-- 
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