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, 5 insertions, 5 deletions

diff --git a/sql/key.cc b/sql/key.cc
index 4af88f218ee..e804fb65654 100644
--- a/sql/key.cc
+++ b/sql/key.cc
@@ -28,7 +28,7 @@
 	** Used when calculating key for NEXT_NUMBER
 	*/
 
-int find_ref_key(TABLE *table,Field *field, uint *key_length)
+int find_ref_key(KEY *key, uint key_count, Field *field, uint *key_length)
 {
   reg2 int i;
   reg3 KEY *key_info;
@@ -38,8 +38,8 @@ int find_ref_key(TABLE *table,Field *field, uint *key_length)
 
 	/* Test if some key starts as fieldpos */
 
-  for (i= 0, key_info= table->key_info ;
-       i < (int) table->s->keys ;
+  for (i= 0, key_info= key ;
+       i < (int) key_count ;
        i++, key_info++)
   {
     if (key_info->key_part[0].offset == fieldpos)
@@ -50,8 +50,8 @@ int find_ref_key(TABLE *table,Field *field, uint *key_length)
   }
 	/* Test if some key contains fieldpos */
 
-  for (i= 0, key_info= table->key_info ;
-       i < (int) table->s->keys ;
+  for (i= 0, key_info= key;
+       i < (int) key_count ;
        i++, key_info++)
   {
     uint j;