A fix and a test case for Bug#6513 "Test Suite: Values inserted by using

cursor is interpreted latin1 character and Bug#9819 "Cursors: Mysql Server
Crash while fetching from table with 5 million records."
A fix for a possible memory leak when fetching into an SP cursor
in a long loop.
The patch uses a common implementation of cursors in the binary protocol and 
in stored procedures and implements materialized cursors.
For implementation details, see comments in sql_cursor.cc


include/my_sys.h:
  - declaration for multi_alloc_root
libmysqld/Makefile.am:
  - drop protocol_cursor.cc, add sql_cursor.cc (replaces the old
  implementation of cursors with a new one)
mysql-test/r/ctype_ujis.result:
  - test results fixed (a test case for Bug#6513)
mysql-test/r/sp-big.result:
  - test results fixed (a test case for Bug#9819)
mysql-test/t/ctype_ujis.test:
  Add a test case for Bug#6513 "Test Suite: Values inserted by using cursor is
   interpreted latin1 character"
mysql-test/t/sp-big.test:
  Add a restricted test case for Bug#9819 "Cursors: Mysql Server Crash
  while fetching from table with 5 million records."
mysys/my_alloc.c:
  - an implementation of multi_alloc_root; this is largely a copy-paste
    from mulalloc.c, but the function is small and there is no easy way
    to reuse the existing C function.
sql/Makefile.am:
  - add sql_cursor.h, sql_cursor.cc (a new implementation of stored procedure
  cursors) and drop protocol_cursor.cc (the old one)
sql/handler.cc:
  - now TABLE object has its mem_root always initialized.
    Adjust the implementation handler::ha_open
sql/item_subselect.cc:
  - adjust to the changed declaration of st_select_lex_unit::prepare
sql/protocol.h:
  - drop Protocol_cursor
sql/sp_head.cc:
  - move juggling with Query_arena::free_list and Item::next to
    sp_eval_func_item, as this is needed in 3 places already.
sql/sp_head.h:
  - declare a no-op implementation for cleanup_stmt in sp_instr_cpush.
    This method is needed for non-materializing cursors, which are yet not 
    used in stored procedures.
  - declaration for sp_eval_func_item
sql/sp_rcontext.cc:
  - reimplement sp_cursor using the new implementation of server side cursors.
  - use sp_eval_func_item to assign values of SP variables from the
    row fetched from a cursor. This should fix a possible memory leak in 
    the old implementation of sp_cursor::fetch
sql/sp_rcontext.h:
  - reimplement sp_cursor using the new implementation of server side cursors.
sql/sql_class.cc:
  - disable the functionality that closes transient cursors at commit/rollback;
    transient cursors are not used in 5.0, instead we use materialized ones.
    To be enabled in a later version.
sql/sql_class.h:
  - adjust to the rename Cursor -> Server_side_cursor
  - additional declarations of select_union used in materialized cursors
sql/sql_derived.cc:
  - reuse bits of tmp table code in UNION, derived tables, and materialized
    cursors
  - cleanup comments
sql/sql_lex.h:
  - declarations of auxiliary methods used by materialized cursors
  - a cleanup in st_select_lex_unit interface
sql/sql_list.h:
  - add an array operator new[] to class Sql_alloc
sql/sql_prepare.cc:
  - split the tight coupling of cursors and prepared statements to reuse 
    the same implementation in stored procedures
  - cleanups of error processing in Prepared_statement::{prepare,execute}
sql/sql_select.cc:
  - move the implementation of sensitive (non-materializing) cursors to 
    sql_cursor.cc
  - make temporary tables self-contained: the table, its record and fields
    are allocated in TABLE::mem_root. This implementation is not clean
    and resets thd->mem_root several times because of the way create_tmp_table 
    works (many additional things are done inside it).
  - adjust to the changed declaration of st_select_lex_unit::prepare
sql/sql_select.h:
  - move the declaration of sensitive (non-materializing) cursors to 
    sql_cursor.cc
sql/sql_union.cc:
  - move pieces of st_select_unit::prepare to select_union and st_table
    methods to be able to reuse code in the implementation of materialized
    cursors
sql/sql_view.cc:
  - adjust to the changed signature of st_select_lex_unit::prepare
sql/table.cc:
  - implement auxiliary st_table methods for use with temporary tables
sql/table.h:
  - add declarations for auxiliary methods of st_table used to work with 
   temporary tables
tests/mysql_client_test.c:
  - if cursors are materialized, a parallel update of the table used
    in the cursor may go through: update the test.
sql/sql_cursor.cc:
  New BitKeeper file ``sql/sql_cursor.cc'' -- implementation of server side
  cursors
sql/sql_cursor.h:
  New BitKeeper file ``sql/sql_cursor.h'' - declarations for
  server side cursors.

1 files changed, 6 insertions, 53 deletions

diff --git a/sql/sql_select.h b/sql/sql_select.h
index 47906c2697e..0dc4be8c104 100644
--- a/sql/sql_select.h
+++ b/sql/sql_select.h
@@ -101,7 +101,7 @@ enum enum_nested_loop_state
 typedef enum_nested_loop_state
 (*Next_select_func)(JOIN *, struct st_join_table *, bool);
 typedef int (*Read_record_func)(struct st_join_table *tab);
-
+Next_select_func setup_end_select_func(JOIN *join);
 
 typedef struct st_join_table {
   TABLE		*table;
@@ -140,6 +140,11 @@ typedef struct st_join_table {
   void cleanup();
 } JOIN_TAB;
 
+enum_nested_loop_state sub_select_cache(JOIN *join, JOIN_TAB *join_tab, bool
+                                        end_of_records);
+enum_nested_loop_state sub_select(JOIN *join,JOIN_TAB *join_tab, bool
+                                  end_of_records);
+
 
 typedef struct st_position			/* Used in find_best */
 {
@@ -372,58 +377,6 @@ class JOIN :public Sql_alloc
 };
 
 
-/*
-  Server-side cursor (now stands only for basic read-only cursor)
-  See class implementation in sql_select.cc
-  A cursor has its own runtime state - list of used items and memory root of
-  used memory - which is different from Prepared statement runtime: it must
-  be different at least for the purpose of reusing the same prepared
-  statement for many cursors.
-*/
-
-class Cursor: public Sql_alloc, public Query_arena
-{
-  MEM_ROOT main_mem_root;
-  JOIN *join;
-  SELECT_LEX_UNIT *unit;
-
-  TABLE *open_tables;
-  MYSQL_LOCK *lock;
-  TABLE *derived_tables;
-  /* List of items created during execution */
-  query_id_t query_id;
-  struct Engine_info
-  {
-    const handlerton *ht;
-    void *read_view;
-  };
-  Engine_info ht_info[MAX_HA];
-public:
-  Protocol_prep protocol;
-  Item_change_list change_list;
-  select_send result;
-  THR_LOCK_OWNER lock_id;
-  my_bool close_at_commit;
-
-  /* Temporary implementation as now we replace THD state by value */
-  /* Save THD state into cursor */
-  void init_from_thd(THD *thd);
-  /* bzero cursor state in THD */
-  void reset_thd(THD *thd);
-
-  int open(JOIN *join);
-  void fetch(ulong num_rows);
-  void reset() { join= 0; }
-  bool is_open() const { return join != 0; }
-
-  void close(bool is_active);
-
-  void set_unit(SELECT_LEX_UNIT *unit_arg) { unit= unit_arg; }
-  Cursor(THD *thd);
-  ~Cursor() {}
-};
-
-
 typedef struct st_select_check {
   uint const_ref,reg_ref;
 } SELECT_CHECK;