Introduce thd->query_cache_tls (thread

local storage for query cache). 
We need more than one pointer in a thread to
represent the query cache and net->query_cache_query can not be used
any more (due to ABI compatibility issues and to different life
time of NET and THD).
This is a backport of the following patch from 6.0:
----------------------------------------------------------
revno: 2476.1157.2
committer: kostja@bodhi.(none)
timestamp: Sat 2007-06-16 13:29:24 +0400


include/mysql.h.pp:
  Update the ABI (NET::query_cache_query is now unused).
include/mysql_com.h:
  NET::query_cache_query is now unused.
sql/mysql_priv.h:
  Update signatures of ex-functios now member functions.
sql/sql_cache.cc:
  Introduce THD::query_cache_tls.
sql/sql_cache.h:
  Introduce THD::query_cache_tls.
sql/sql_class.cc:
  Introduce THD::query_cache_tls.
sql/sql_class.h:
  Introduce THD::query_cache_tls.
sql/sql_parse.cc:
  Use THD::query_cache_tls.
sql/sql_select.cc:
  Use THD::query_cache_tls.

1 files changed, 14 insertions, 13 deletions

diff --git a/sql/sql_cache.h b/sql/sql_cache.h
index 777ddd39280..a1132adfa5a 100644
--- a/sql/sql_cache.h
+++ b/sql/sql_cache.h
@@ -64,6 +64,8 @@ struct Query_cache_table;
 struct Query_cache_query;
 struct Query_cache_result;
 class Query_cache;
+struct Query_cache_tls;
+struct st_lex;
 
 /**
   This class represents a node in the linked chain of queries
@@ -137,7 +139,7 @@ struct Query_cache_query
   ulonglong limit_found_rows;
   rw_lock_t lock;
   Query_cache_block *res;
-  NET *wri;
+  Query_cache_tls *wri;
   ulong len;
   uint8 tbls_type;
   unsigned int last_pkt_nr;
@@ -149,8 +151,8 @@ struct Query_cache_query
   inline void found_rows(ulonglong rows)   { limit_found_rows= rows; }
   inline Query_cache_block *result()	   { return res; }
   inline void result(Query_cache_block *p) { res= p; }
-  inline NET *writer()			   { return wri; }
-  inline void writer(NET *p)		   { wri= p; }
+  inline Query_cache_tls *writer()	   { return wri; }
+  inline void writer(Query_cache_tls *p)   { wri= p; }
   inline uint8 tables_type()               { return tbls_type; }
   inline void tables_type(uint8 type)      { tbls_type= type; }
   inline ulong length()			   { return len; }
@@ -407,7 +409,8 @@ protected:
     If query is cacheable return number tables in query
     (query without tables not cached)
   */
-  TABLE_COUNTER_TYPE is_cacheable(THD *thd, uint32 query_len, char *query,
+  TABLE_COUNTER_TYPE is_cacheable(THD *thd, size_t query_len,
+                                  const char *query,
                                   LEX *lex, TABLE_LIST *tables_used,
                                   uint8 *tables_type);
   TABLE_COUNTER_TYPE process_and_count_tables(THD *thd,
@@ -462,10 +465,13 @@ protected:
 
   void destroy();
 
-  friend void query_cache_init_query(NET *net);
-  friend void query_cache_insert(NET *net, const char *packet, ulong length);
-  friend void query_cache_end_of_result(THD *thd);
-  friend void query_cache_abort(NET *net);
+  void insert(Query_cache_tls *query_cache_tls,
+              const char *packet,
+              ulong length,
+              unsigned pkt_nr);
+
+  void end_of_result(THD *thd);
+  void abort(Query_cache_tls *query_cache_tls);
 
   /*
     The following functions are only used when debugging
@@ -493,9 +499,4 @@ protected:
 
 extern Query_cache query_cache;
 extern TYPELIB query_cache_type_typelib;
-void query_cache_init_query(NET *net);
-void query_cache_insert(NET *net, const char *packet, ulong length);
-void query_cache_end_of_result(THD *thd);
-void query_cache_abort(NET *net);
-
 #endif