Desperate attempt to push part of prepared statements cleanup which was

reviewed in Saint-Petersbourg (including post-review fixes).


include/my_sys.h:
  Added clear_alloc_root (reset alloc root without freeing its memory)
sql/item.h:
  - rename setup_param -> set_parap (function assigns parameter value to item)
sql/mysql_priv.h:
  - all return values are void, because return value is never checked in
      dispatch_command
  - removed unused declaration of setup_param_functions
sql/protocol.h:
  - unused declarations of setup_params_data* removed
sql/sql_class.cc:
  Cleanup:
    - bzero(mem_root) replaced with clear_alloc_root
    - query_id and command members moved back to THD from Statement
  Assignment of mem_root, free_list, query_id and command optimized
  away from set_statement().
sql/sql_class.h:
  - query_id and command moved back to THD from Statement
sql/sql_lex.h:
  - better type for param_list
  - param_count is the same thing as param_list.elements
sql/sql_parse.cc:
  - comments for dispatch_command
sql/sql_prepare.cc:
  Cleanup:
  - added comments to many functions and removed trailing spaces in many 
    lines, some stale comments removed.
  - it's faster to iterate using pointers, than classes
  - Renames: error_in_prepare renamed to get_longdata_error (because it is set
    when there is an error in mysql_send_longdata, rather than in
    mysql_prepare), embedded versions of placeholder assignement functions
    now have prefix emb_, setup_ functions renamed to set_, because they
    perform assignment, not installation, setup_params_data now doesn't
    call insert_params and was renamed to setup_set_param_functions,
  - find_prepared_statement should not send error if called from no-reply
    calls, like mysql_stmt_reset
  - error reporting is checked up, to always report errors and not report
    errors twice. send_prep_stmt can be done mostly in send_prepare_result, 
    rather than in test_* functions.
  - now we don't need to reinit THD->mem_root/free_list in mysql_stmt_execute,
    because it's not reset there.
tests/client_test.c:
  - removed second call to test_subqueries

1 files changed, 2 insertions, 11 deletions

diff --git a/sql/sql_class.cc b/sql/sql_class.cc
index 6fe0521b07a..95374b691c8 100644
--- a/sql/sql_class.cc
+++ b/sql/sql_class.cc
@@ -145,8 +145,7 @@ THD::THD():user_time(0), current_statement(0), is_fatal_error(0),
 
   init();
   /* Initialize sub structures */
-  bzero((char*) &transaction.mem_root,sizeof(transaction.mem_root));
-  bzero((char*) &warn_root,sizeof(warn_root));
+  clear_alloc_root(&transaction.mem_root);
   init_alloc_root(&warn_root, WARN_ALLOC_BLOCK_SIZE, WARN_ALLOC_PREALLOC_SIZE);
   user_connect=(USER_CONN *)0;
   hash_init(&user_vars, &my_charset_bin, USER_VARS_HASH_SIZE, 0, 0,
@@ -331,7 +330,7 @@ THD::~THD()
   dbug_sentry = THD_SENTRY_GONE;
 #endif  
   /* Reset stmt_backup.mem_root to not double-free memory from thd.mem_root */
-  init_alloc_root(&stmt_backup.mem_root, 0, 0);
+  clear_alloc_root(&stmt_backup.mem_root);
   DBUG_VOID_RETURN;
 }
 
@@ -1185,10 +1184,8 @@ int select_dumpvar::prepare(List<Item> &list, SELECT_LEX_UNIT *u)
 
 Statement::Statement(THD *thd)
   :id(++thd->statement_id_counter),
-  query_id(thd->query_id),
   set_query_id(1),
   allow_sum_func(0),
-  command(thd->command),
   lex(&main_lex),
   query(0),
   query_length(0),
@@ -1207,10 +1204,8 @@ Statement::Statement(THD *thd)
 
 Statement::Statement()
   :id(0),
-  query_id(0),                                  /* initialized later */
   set_query_id(1),
   allow_sum_func(0),                            /* initialized later */
-  command(COM_SLEEP),                           /* initialized later */ 
   lex(&main_lex),
   query(0),                                     /* these two are set */ 
   query_length(0),                              /* in alloc_query() */
@@ -1229,15 +1224,11 @@ Statement::Type Statement::type() const
 void Statement::set_statement(Statement *stmt)
 {
   id=             stmt->id;
-  query_id=       stmt->query_id;
   set_query_id=   stmt->set_query_id;
   allow_sum_func= stmt->allow_sum_func;
-  command=        stmt->command;
   lex=            stmt->lex;
   query=          stmt->query;
   query_length=   stmt->query_length;
-  free_list=      stmt->free_list;
-  mem_root=       stmt->mem_root;
 }