1 #ifndef SQL_RECORDS_H
2 #define SQL_RECORDS_H
3 /* Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
4 
5    This program is free software; you can redistribute it and/or modify
6    it under the terms of the GNU General Public License as published by
7    the Free Software Foundation; version 2 of the License.
8 
9    This program is distributed in the hope that it will be useful,
10    but WITHOUT ANY WARRANTY; without even the implied warranty of
11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12    GNU General Public License for more details.
13 
14    You should have received a copy of the GNU General Public License
15    along with this program; if not, write to the Free Software
16    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335  USA */
17 
18 #ifdef USE_PRAGMA_INTERFACE
19 #pragma interface                      /* gcc class implementation */
20 #endif
21 
22 #include "table.h"
23 
24 struct st_join_table;
25 class handler;
26 class THD;
27 class SQL_SELECT;
28 class Copy_field;
29 class SORT_INFO;
30 
31 struct READ_RECORD;
32 
33 void end_read_record(READ_RECORD *info);
34 void free_cache(READ_RECORD *info);
35 
36 /**
37   A context for reading through a single table using a chosen access method:
38   index read, scan, etc, use of cache, etc.
39 
40   Use by:
41   READ_RECORD read_record;
42   init_read_record(&read_record, ...);
43   while (read_record.read_record())
44   {
45     ...
46   }
47   end_read_record();
48 */
49 
50 struct READ_RECORD
51 {
52   typedef int (*Read_func)(READ_RECORD*);
53   typedef void (*Unlock_row_func)(st_join_table *);
54   typedef int (*Setup_func)(struct st_join_table*);
55 
56   TABLE *table;                                 /* Head-form */
57   Unlock_row_func unlock_row;
58   Read_func read_record_func;
59   THD *thd;
60   SQL_SELECT *select;
61   uint ref_length, reclength, rec_cache_size, error_offset;
62 
63   /**
64     Counting records when reading result from filesort().
65     Used when filesort leaves the result in the filesort buffer.
66    */
67   ha_rows unpack_counter;
68 
69   uchar *ref_pos;				/* pointer to form->refpos */
70   uchar *rec_buf;                /* to read field values  after filesort */
71   uchar	*cache,*cache_pos,*cache_end,*read_positions;
72 
73   /*
74     Structure storing information about sorting
75   */
76   SORT_INFO *sort_info;
77   struct st_io_cache *io_cache;
78   bool print_error;
79 
read_recordREAD_RECORD80   int read_record() { return read_record_func(this); }
recordREAD_RECORD81   uchar *record() const { return table->record[0]; }
82 
83   /*
84     SJ-Materialization runtime may need to read fields from the materialized
85     table and unpack them into original table fields:
86   */
87   Copy_field *copy_field;
88   Copy_field *copy_field_end;
89 public:
READ_RECORDREAD_RECORD90   READ_RECORD() : table(NULL), cache(NULL) {}
~READ_RECORDREAD_RECORD91   ~READ_RECORD() { end_read_record(this); }
92 };
93 
94 bool init_read_record(READ_RECORD *info, THD *thd, TABLE *reg_form,
95 		      SQL_SELECT *select, SORT_INFO *sort,
96                       int use_record_cache,
97                       bool print_errors, bool disable_rr_cache);
98 bool init_read_record_idx(READ_RECORD *info, THD *thd, TABLE *table,
99                           bool print_error, uint idx, bool reverse);
100 
101 void rr_unlock_row(st_join_table *tab);
102 
103 #endif /* SQL_RECORDS_H */
104