MySQL 5.6.14 Source Code Document
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ha_heap.h
1 /*
2  Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
3 
4  This program is free software; you can redistribute it and/or modify
5  it under the terms of the GNU General Public License as published by
6  the Free Software Foundation; version 2 of the License.
7 
8  This program is distributed in the hope that it will be useful,
9  but WITHOUT ANY WARRANTY; without even the implied warranty of
10  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11  GNU General Public License for more details.
12 
13  You should have received a copy of the GNU General Public License
14  along with this program; if not, write to the Free Software
15  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
16 
17 
18 /* class for the the heap handler */
19 
20 #include <heap.h>
21 #include "sql_class.h" /* THD */
22 
23 class ha_heap: public handler
24 {
25  HP_INFO *file;
26  HP_SHARE *internal_share;
27  key_map btree_keys;
28  /* number of records changed since last statistics update */
29  uint records_changed;
30  uint key_stat_version;
31  my_bool internal_table;
32 public:
33  ha_heap(handlerton *hton, TABLE_SHARE *table);
34  ~ha_heap() {}
35  handler *clone(const char *name, MEM_ROOT *mem_root);
36  const char *table_type() const
37  {
38  return (table->in_use->variables.sql_mode & MODE_MYSQL323) ?
39  "HEAP" : "MEMORY";
40  }
41  const char *index_type(uint inx)
42  {
43  return ((table_share->key_info[inx].algorithm == HA_KEY_ALG_BTREE) ?
44  "BTREE" : "HASH");
45  }
46  /* Rows also use a fixed-size format */
47  enum row_type get_row_type() const { return ROW_TYPE_FIXED; }
48  const char **bas_ext() const;
49  ulonglong table_flags() const
50  {
51  return (HA_FAST_KEY_READ | HA_NO_BLOBS | HA_NULL_IN_KEY |
52  HA_BINLOG_ROW_CAPABLE | HA_BINLOG_STMT_CAPABLE |
53  HA_REC_NOT_IN_SEQ | HA_CAN_INSERT_DELAYED | HA_NO_TRANSACTIONS |
54  HA_HAS_RECORDS | HA_STATS_RECORDS_IS_EXACT);
55  }
56  ulong index_flags(uint inx, uint part, bool all_parts) const
57  {
58  return ((table_share->key_info[inx].algorithm == HA_KEY_ALG_BTREE) ?
59  HA_READ_NEXT | HA_READ_PREV | HA_READ_ORDER | HA_READ_RANGE :
60  HA_ONLY_WHOLE_INDEX | HA_KEY_SCAN_NOT_ROR);
61  }
62  const key_map *keys_to_use_for_scanning() { return &btree_keys; }
63  uint max_supported_keys() const { return MAX_KEY; }
64  uint max_supported_key_part_length() const { return MAX_KEY_LENGTH; }
65  double scan_time()
66  { return (double) (stats.records+stats.deleted) / 20.0+10; }
67  double read_time(uint index, uint ranges, ha_rows rows)
68  { return (double) rows / 20.0+1; }
69 
70  int open(const char *name, int mode, uint test_if_locked);
71  int close(void);
72  void set_keys_for_scanning(void);
73  int write_row(uchar * buf);
74  int update_row(const uchar * old_data, uchar * new_data);
75  int delete_row(const uchar * buf);
76  virtual void get_auto_increment(ulonglong offset, ulonglong increment,
77  ulonglong nb_desired_values,
78  ulonglong *first_value,
79  ulonglong *nb_reserved_values);
80  int index_read_map(uchar * buf, const uchar * key, key_part_map keypart_map,
81  enum ha_rkey_function find_flag);
82  int index_read_last_map(uchar *buf, const uchar *key, key_part_map keypart_map);
83  int index_read_idx_map(uchar * buf, uint index, const uchar * key,
84  key_part_map keypart_map,
85  enum ha_rkey_function find_flag);
86  int index_next(uchar * buf);
87  int index_prev(uchar * buf);
88  int index_first(uchar * buf);
89  int index_last(uchar * buf);
90  int rnd_init(bool scan);
91  int rnd_next(uchar *buf);
92  int rnd_pos(uchar * buf, uchar *pos);
93  void position(const uchar *record);
94  int info(uint);
95  int extra(enum ha_extra_function operation);
96  int reset();
97  int external_lock(THD *thd, int lock_type);
98  int delete_all_rows(void);
99  int truncate();
100  int reset_auto_increment(ulonglong value);
101  int disable_indexes(uint mode);
102  int enable_indexes(uint mode);
103  int indexes_are_disabled(void);
104  ha_rows records_in_range(uint inx, key_range *min_key, key_range *max_key);
105  int delete_table(const char *from);
106  void drop_table(const char *name);
107  int rename_table(const char * from, const char * to);
108  int create(const char *name, TABLE *form, HA_CREATE_INFO *create_info);
109  void update_create_info(HA_CREATE_INFO *create_info);
110 
111  THR_LOCK_DATA **store_lock(THD *thd, THR_LOCK_DATA **to,
112  enum thr_lock_type lock_type);
113  int cmp_ref(const uchar *ref1, const uchar *ref2)
114  {
115  return memcmp(ref1, ref2, sizeof(HEAP_PTR));
116  }
117  bool check_if_incompatible_data(HA_CREATE_INFO *info, uint table_changes);
118 private:
119  void update_key_stats();
120 };