Backport of:

----------------------------------------------------------
revno: 2630.22.11
committer: Konstantin Osipov <konstantin@mysql.com>
branch nick: mysql-6.0-records
timestamp: Mon 2008-08-11 16:40:09 +0400
message:
  Move read_record related functions to a new header - records.h

sql/Makefile.am:
  Introduce records.h
sql/handler.h:
  Forward-declare class handler (an unnecessary forward declaration
  was removed from mysql_priv.h).
sql/item_subselect.cc:
  Make read_record function naming more consistent.
  Assign read_record function at once, no need to defer till
  read_first_record invocation.
sql/mysql_priv.h:
  Include records.h, previously part of structs.h
sql/records.cc:
  Use records.h
sql/sql_select.h:
  Update to use new declarations.
sql/structs.h:
  Move declarations of READ_RECORD and related functions to records.h

sql/Makefile.am

@@ -110,7 +110,7 @@ noinst_HEADERS =	item.h item_func.h item_sum.h item_cmpfunc.h \
 			sql_plugin.h authors.h event_parse_data.h \
 			event_data_objects.h event_scheduler.h \
 			sql_partition.h partition_info.h partition_element.h \
-			contributors.h sql_servers.h sql_signal.h
+			contributors.h sql_servers.h sql_signal.h records.h
 
 mysqld_SOURCES =	sql_lex.cc sql_handler.cc sql_partition.cc \
 			item.cc item_sum.cc item_buff.cc item_func.cc \

sql/handler.h

@@ -581,6 +581,7 @@ struct handler_iterator {
   void *buffer;
 };
 
+class handler;
 /*
   handlerton is a singleton structure - one instance per storage engine -
   to provide access to storage engine functionality that works on the

sql/item_subselect.cc

@@ -1863,7 +1863,8 @@ void subselect_uniquesubquery_engine::fix_length_and_dec(Item_cache **row)
   DBUG_ASSERT(0);
 }
 
-int  init_read_record_seq(JOIN_TAB *tab);
+int  read_first_record_seq(JOIN_TAB *tab);
+int rr_sequential(READ_RECORD *info);
 int join_read_always_key_or_null(JOIN_TAB *tab);
 int join_read_next_same_or_null(READ_RECORD *info);
 
@@ -1945,7 +1946,8 @@ int subselect_single_select_engine::exec()
               /* Change the access method to full table scan */
               tab->save_read_first_record= tab->read_first_record;
               tab->save_read_record= tab->read_record.read_record;
-              tab->read_first_record= init_read_record_seq;
+              tab->read_record.read_record= rr_sequential;
+              tab->read_first_record= read_first_record_seq;
               tab->read_record.record= tab->table->record[0];
               tab->read_record.thd= join->thd;
               tab->read_record.ref_length= tab->table->file->ref_length;

sql/mysql_priv.h

@@ -878,6 +878,7 @@ bool general_log_write(THD *thd, enum enum_server_command command,
 #include "tztime.h"
 #ifdef MYSQL_SERVER
 #include "sql_servers.h"
+#include "records.h"
 #include "opt_range.h"
 
 #ifdef HAVE_QUERY_CACHE
@@ -2235,12 +2236,6 @@ longlong get_datetime_value(THD *thd, Item ***item_arg, Item **cache_arg,
 
 int test_if_number(char *str,int *res,bool allow_wildcards);
 void change_byte(uchar *,uint,char,char);
-void init_read_record(READ_RECORD *info, THD *thd, TABLE *reg_form,
-		      SQL_SELECT *select, int use_record_cache, 
-                      bool print_errors, bool disable_rr_cache);
-void init_read_record_idx(READ_RECORD *info, THD *thd, TABLE *table, 
-                          bool print_error, uint idx);
-void end_read_record(READ_RECORD *info);
 ha_rows filesort(THD *thd, TABLE *form,struct st_sort_field *sortorder,
 		 uint s_length, SQL_SELECT *select,
 		 ha_rows max_rows, bool sort_positions,

sql/records.cc

@@ -13,6 +13,9 @@
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
 
+#ifdef USE_PRAGMA_INTERFACE
+#pragma implementation /* gcc class implementation */
+#endif
 
 /**
   @file
@@ -21,8 +24,10 @@
   Functions for easy reading of records, possible through a cache
 */
 
+#include "records.h"
 #include "mysql_priv.h"
 
+
 static int rr_quick(READ_RECORD *info);
 int rr_sequential(READ_RECORD *info);
 static int rr_from_tempfile(READ_RECORD *info);

sql/records.h

+#ifndef SQL_RECORDS_H
+#define SQL_RECORDS_H 
+/* Copyright (C) 2008 Sun/MySQL
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+
+#ifdef USE_PRAGMA_INTERFACE
+#pragma interface                      /* gcc class implementation */
+#endif
+#include <my_global.h>                /* for uint typedefs */
+
+struct st_join_table;
+class handler;
+struct TABLE;
+class THD;
+class SQL_SELECT;
+
+/**
+  A context for reading through a single table using a chosen access method:
+  index read, scan, etc, use of cache, etc.
+
+  Use by:
+  READ_RECORD read_record;
+  init_read_record(&read_record, ...);
+  while (read_record.read_record())
+  {
+    ...
+  }
+  end_read_record();
+*/
+
+struct READ_RECORD
+{
+  typedef int (*Read_func)(READ_RECORD*);
+  typedef int (*Setup_func)(struct st_join_table*);
+
+  TABLE *table;                                 /* Head-form */
+  handler *file;
+  TABLE **forms;                                /* head and ref forms */
+  Read_func read_record;
+  THD *thd;
+  SQL_SELECT *select;
+  uint cache_records;
+  uint ref_length,struct_length,reclength,rec_cache_size,error_offset;
+  uint index;
+  uchar *ref_pos;				/* pointer to form->refpos */
+  uchar *record;
+  uchar *rec_buf;                /* to read field values  after filesort */
+  uchar	*cache,*cache_pos,*cache_end,*read_positions;
+  struct st_io_cache *io_cache;
+  bool print_error, ignore_not_found_rows;
+
+public:
+  READ_RECORD() {}
+};
+
+void init_read_record(READ_RECORD *info, THD *thd, TABLE *reg_form,
+		      SQL_SELECT *select, int use_record_cache,
+                      bool print_errors, bool disable_rr_cache);
+void init_read_record_idx(READ_RECORD *info, THD *thd, TABLE *table,
+                          bool print_error, uint idx);
+void end_read_record(READ_RECORD *info);
+
+#endif /* SQL_RECORDS_H */

sql/sql_select.cc

@@ -11881,10 +11881,8 @@ join_init_quick_read_record(JOIN_TAB *tab)
 }
 
 
-int rr_sequential(READ_RECORD *info);
-int init_read_record_seq(JOIN_TAB *tab)
+int read_first_record_seq(JOIN_TAB *tab)
 {
-  tab->read_record.read_record= rr_sequential;
   if (tab->read_record.file->ha_rnd_init(1))
     return 1;
   return (*tab->read_record.read_record)(&tab->read_record);

sql/sql_select.h

@@ -134,7 +134,6 @@ 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);
 
 
@@ -162,7 +161,7 @@ typedef struct st_join_table {
   */
   uint          packed_info;
 
-  Read_record_func read_first_record;
+  READ_RECORD::Setup_func read_first_record;
   Next_select_func next_select;
   READ_RECORD	read_record;
   /* 
@@ -170,8 +169,8 @@ typedef struct st_join_table {
     if it is executed by an alternative full table scan when the left operand of
     the subquery predicate is evaluated to NULL.
   */  
-  Read_record_func save_read_first_record;/* to save read_first_record */ 
-  int (*save_read_record) (READ_RECORD *);/* to save read_record.read_record */
+  READ_RECORD::Setup_func save_read_first_record;/* to save read_first_record */
+  READ_RECORD::Read_func save_read_record;/* to save read_record.read_record */
   double	worst_seeks;
   key_map	const_keys;			/**< Keys with constant part */
   key_map	checked_keys;			/**< Keys checked in find_best */

sql/structs.h

@@ -18,6 +18,7 @@
 
 struct TABLE;
 class Field;
+class THD;
 
 typedef struct st_date_time_format {
   uchar positions[8];
@@ -115,30 +116,6 @@ typedef struct st_reginfo {		/* Extra info about reg */
 } REGINFO;
 
 
-struct st_read_record;				/* For referense later */
-class SQL_SELECT;
-class THD;
-class handler;
-
-typedef struct st_read_record {			/* Parameter to read_record */
-  TABLE *table;                                 /* Head-form */
-  handler *file;
-  TABLE **forms;                                /* head and ref forms */
-  int (*read_record)(struct st_read_record *);
-  THD *thd;
-  SQL_SELECT *select;
-  uint cache_records;
-  uint ref_length,struct_length,reclength,rec_cache_size,error_offset;
-  uint index;
-  uchar *ref_pos;				/* pointer to form->refpos */
-  uchar *record;
-  uchar *rec_buf;                /* to read field values  after filesort */
-  uchar	*cache,*cache_pos,*cache_end,*read_positions;
-  IO_CACHE *io_cache;
-  bool print_error, ignore_not_found_rows;
-} READ_RECORD;
-
-
 /*
   Originally MySQL used MYSQL_TIME structure inside server only, but since
   4.1 it's exported to user in the new client API. Define aliases for