diff options
Diffstat (limited to 'sql/sql_cache.cc')
| -rw-r--r-- | sql/sql_cache.cc | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/sql/sql_cache.cc b/sql/sql_cache.cc index 63a5af5e666..5ff5e596f63 100644 --- a/sql/sql_cache.cc +++ b/sql/sql_cache.cc @@ -418,6 +418,43 @@ TYPELIB query_cache_type_typelib= array_elements(query_cache_type_names)-1,"", query_cache_type_names, NULL }; + +/** + Helper function for determine if a SELECT statement has a SQL_NO_CACHE + directive. + + @param sql A pointer to the first white space character after SELECT + + @return + @retval TRUE The character string contains SQL_NO_CACHE + @retval FALSE No directive found. +*/ + +static bool has_no_cache_directive(char *sql) +{ + int i=0; + while (sql[i] == ' ') + ++i; + + if (my_toupper(system_charset_info, sql[i]) == 'S' && + my_toupper(system_charset_info, sql[i+1]) == 'Q' && + my_toupper(system_charset_info, sql[i+2]) == 'L' && + my_toupper(system_charset_info, sql[i+3]) == '_' && + my_toupper(system_charset_info, sql[i+4]) == 'N' && + my_toupper(system_charset_info, sql[i+5]) == 'O' && + my_toupper(system_charset_info, sql[i+6]) == '_' && + my_toupper(system_charset_info, sql[i+7]) == 'C' && + my_toupper(system_charset_info, sql[i+8]) == 'A' && + my_toupper(system_charset_info, sql[i+9]) == 'C' && + my_toupper(system_charset_info, sql[i+10]) == 'H' && + my_toupper(system_charset_info, sql[i+11]) == 'E' && + my_toupper(system_charset_info, sql[i+12]) == ' ') + return TRUE; + + return FALSE; +} + + /***************************************************************************** Query_cache_block_table method(s) *****************************************************************************/ @@ -1236,6 +1273,16 @@ Query_cache::send_result_to_client(THD *thd, char *sql, uint query_length) DBUG_PRINT("qcache", ("The statement is not a SELECT; Not cached")); goto err; } + + if (query_length > 20 && has_no_cache_directive(&sql[i+6])) + { + /* + We do not increase 'refused' statistics here since it will be done + later when the query is parsed. + */ + DBUG_PRINT("qcache", ("The statement has a SQL_NO_CACHE directive")); + goto err; + } } STRUCT_LOCK(&structure_guard_mutex); @@ -1524,6 +1571,9 @@ void Query_cache::invalidate(THD *thd, TABLE_LIST *tables_used, invalidate_table(thd, tables_used); } + DBUG_EXECUTE_IF("wait_after_query_cache_invalidate", + debug_wait_for_kill("wait_after_query_cache_invalidate");); + DBUG_VOID_RETURN; } |