Table definition cache, part 2

The table opening process now works the following way:
- Create common TABLE_SHARE object
- Read the .frm file and unpack it into the TABLE_SHARE object
- Create a TABLE object based on the information in the TABLE_SHARE
  object and open a handler to the table object

Other noteworthy changes:
- In TABLE_SHARE the most common strings are now LEX_STRING's
- Better error message when table is not found
- Variable table_cache is now renamed 'table_open_cache'
- New variable 'table_definition_cache' that is the number of table defintions that will be cached
- strxnmov() calls are now fixed to avoid overflows
- strxnmov() will now always add one end \0 to result
- engine objects are now created with a TABLE_SHARE object instead of a TABLE object.
- After creating a field object one must call field->init(table) before using it

- For a busy system this change will give you:
 - Less memory usage for table object
 - Faster opening of tables (if it's has been in use or is in table definition cache)
 - Allow you to cache many table definitions objects
 - Faster drop of table

1 files changed, 6 insertions, 1 deletions

diff --git a/sql/ha_partition.h b/sql/ha_partition.h
index fb180fdf666..8109fec9323 100644
--- a/sql/ha_partition.h
+++ b/sql/ha_partition.h
@@ -122,6 +122,11 @@ private:
   PARTITION_SHARE *share;               /* Shared lock info */
 
 public:
+  void set_part_info(partition_info *part_info)
+  {
+     m_part_info= part_info;
+     m_is_sub_partitioned= is_sub_partitioned(part_info);
+  }
   /*
     -------------------------------------------------------------------------
     MODULE create/delete handler object
@@ -133,7 +138,7 @@ public:
     partition handler.
     -------------------------------------------------------------------------
   */
-    ha_partition(TABLE * table);
+    ha_partition(TABLE_SHARE * table);
     ha_partition(partition_info * part_info);
    ~ha_partition();
   /*