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, 3 insertions, 3 deletions

diff --git a/sql/ha_archive.cc b/sql/ha_archive.cc
index 488343c5402..b5c2f2a6555 100644
--- a/sql/ha_archive.cc
+++ b/sql/ha_archive.cc
@@ -135,7 +135,7 @@ static HASH archive_open_tables;
 #define ARCHIVE_CHECK_HEADER 254 // The number we use to determine corruption
 
 /* Static declarations for handerton */
-static handler *archive_create_handler(TABLE *table);
+static handler *archive_create_handler(TABLE_SHARE *table);
 
 
 /* dummy handlerton - only to have something to return from archive_db_init */
@@ -172,7 +172,7 @@ handlerton archive_hton = {
   HTON_NO_FLAGS
 };
 
-static handler *archive_create_handler(TABLE *table)
+static handler *archive_create_handler(TABLE_SHARE *table)
 {
   return new ha_archive(table);
 }
@@ -242,7 +242,7 @@ int archive_db_end(ha_panic_function type)
   return 0;
 }
 
-ha_archive::ha_archive(TABLE *table_arg)
+ha_archive::ha_archive(TABLE_SHARE *table_arg)
   :handler(&archive_hton, table_arg), delayed_insert(0), bulk_insert(0)
 {
   /* Set our original buffer from pre-allocated memory */