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, 29 insertions, 14 deletions

diff --git a/sql/sp_rcontext.h b/sql/sp_rcontext.h
index 36380952e5d..9c0fa88fe34 100644
--- a/sql/sp_rcontext.h
+++ b/sql/sp_rcontext.h
@@ -216,6 +216,27 @@ private:
 }; // class sp_rcontext : public Sql_alloc
 
 
+/*
+  An interceptor of cursor result set used to implement
+  FETCH <cname> INTO <varlist>.
+*/
+
+class Select_fetch_into_spvars: public select_result_interceptor
+{
+  List<struct sp_pvar> *spvar_list;
+  uint field_count;
+public:
+  uint get_field_count() { return field_count; }
+  void set_spvar_list(List<struct sp_pvar> *vars) { spvar_list= vars; }
+
+  virtual bool send_eof() { return FALSE; }
+  virtual bool send_data(List<Item> &items);
+  virtual int prepare(List<Item> &list, SELECT_LEX_UNIT *u);
+};
+
+
+/* A mediator between stored procedures and server side cursors */
+
 class sp_cursor : public Sql_alloc
 {
 public:
@@ -227,12 +248,11 @@ public:
     destroy();
   }
 
-  // We have split this in two to make it easy for sp_instr_copen
-  // to reuse the sp_instr::exec_stmt() code.
   sp_lex_keeper *
-  pre_open(THD *thd);
-  void
-  post_open(THD *thd, my_bool was_opened);
+  get_lex_keeper() { return m_lex_keeper; }
+
+  int
+  open(THD *thd);
 
   int
   close(THD *thd);
@@ -240,7 +260,7 @@ public:
   inline my_bool
   is_open()
   {
-    return m_isopen;
+    return test(server_side_cursor);
   }
 
   int
@@ -251,18 +271,13 @@ public:
   {
     return m_i;
   }
-  
+
 private:
 
-  MEM_ROOT m_mem_root;		// My own mem_root
+  Select_fetch_into_spvars result;
   sp_lex_keeper *m_lex_keeper;
-  Protocol_cursor *m_prot;
-  my_bool m_isopen;
-  my_bool m_nseof;		// Original no_send_eof
-  Protocol *m_oprot;		// Original protcol
-  MYSQL_ROWS *m_current_row;
+  Server_side_cursor *server_side_cursor;
   sp_instr_cpush *m_i;		// My push instruction
-  
   void
   destroy();