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

4 files changed, 9 insertions, 8 deletions

diff --git a/sql/examples/ha_example.cc b/sql/examples/ha_example.cc
index 68aed7c6483..db7a811df78 100644
--- a/sql/examples/ha_example.cc
+++ b/sql/examples/ha_example.cc
@@ -219,7 +219,7 @@ static handler* example_create_handler(TABLE *table)
 }
 
 
-ha_example::ha_example(TABLE *table_arg)
+ha_example::ha_example(TABLE_SHARE *table_arg)
   :handler(&example_hton, table_arg)
 {}
 
diff --git a/sql/examples/ha_example.h b/sql/examples/ha_example.h
index d2ec83a5837..139a50a3281 100644
--- a/sql/examples/ha_example.h
+++ b/sql/examples/ha_example.h
@@ -45,7 +45,7 @@ class ha_example: public handler
   EXAMPLE_SHARE *share;    /* Shared lock info */
 
 public:
-  ha_example(TABLE *table_arg);
+  ha_example(TABLE_SHARE *table_arg);
   ~ha_example()
   {
   }
diff --git a/sql/examples/ha_tina.cc b/sql/examples/ha_tina.cc
index 6bb883f91e0..1312577e126 100644
--- a/sql/examples/ha_tina.cc
+++ b/sql/examples/ha_tina.cc
@@ -55,7 +55,7 @@ TODO:
 pthread_mutex_t tina_mutex;
 static HASH tina_open_tables;
 static int tina_init= 0;
-static handler* tina_create_handler(TABLE *table);
+static handler *tina_create_handler(TABLE_SHARE *table);
 
 handlerton tina_hton= {
   "CSV",
@@ -285,17 +285,17 @@ byte * find_eoln(byte *data, off_t begin, off_t end)
 }
 
 
-static handler* tina_create_handler(TABLE *table)
+static handler *tina_create_handler(TABLE_SHARE *table)
 {
   return new ha_tina(table);
 }
 
 
-ha_tina::ha_tina(TABLE *table_arg)
+ha_tina::ha_tina(TABLE_SHARE *table_arg)
   :handler(&tina_hton, table_arg),
   /*
-    These definitions are found in hanler.h
-    These are not probably completely right.
+    These definitions are found in handler.h
+    They are not probably completely right.
   */
   current_position(0), next_position(0), chain_alloced(0),
   chain_size(DEFAULT_CHAIN_LENGTH)
@@ -308,6 +308,7 @@ ha_tina::ha_tina(TABLE *table_arg)
 /*
   Encode a buffer into the quoted format.
 */
+
 int ha_tina::encode_quote(byte *buf)
 {
   char attribute_buffer[1024];
diff --git a/sql/examples/ha_tina.h b/sql/examples/ha_tina.h
index 2de6d8c8257..eecdeeb5826 100644
--- a/sql/examples/ha_tina.h
+++ b/sql/examples/ha_tina.h
@@ -55,7 +55,7 @@ class ha_tina: public handler
   uint32 chain_size;
 
 public:
-  ha_tina(TABLE *table_arg);
+  ha_tina(TABLE_SHARE *table_arg);
   ~ha_tina() 
   {
     if (chain_alloced)