Drizzled Public API Documentation

heap.h
1 /*
2  Copyright (C) Brian Aker
3  Copyright (C) 2000,2004 MySQL AB
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 02110-1301 USA */
17 
18 /* This file should be included when using heap_database_functions */
19 /* Author: Michael Widenius */
20 
21 #pragma once
22 
23 #include <drizzled/base.h>
24 #include <drizzled/thr_lock.h>
25 
26 #include <plugin/myisam/my_handler.h>
27 
28 #include <vector>
29 
30  /* defines used by heap-funktions */
31 
32 #define HP_MAX_LEVELS 4 /* 128^5 records is enough */
33 #define HP_PTRS_IN_NOD 128
34 
35  /* struct used with heap_funktions */
36 
37 typedef struct st_heapinfo /* Struct from heap_info */
38 {
39  uint32_t records; /* Records in database */
40  uint32_t deleted; /* Deleted records in database */
41  uint32_t max_records;
42  uint64_t data_length;
43  uint64_t index_length;
44  uint32_t reclength; /* Length of one record */
45  int errkey;
46  uint64_t auto_increment;
47 
48  st_heapinfo():
49  records(0),
50  deleted(0),
51  max_records(),
52  data_length(0),
53  index_length(0),
54  reclength(0),
55  errkey(0),
56  auto_increment(0)
57  { }
58 
59 } HEAPINFO;
60 
61 
62  /* Structs used by heap-database-handler */
63 
64 typedef struct st_heap_ptrs
65 {
66  unsigned char *blocks[HP_PTRS_IN_NOD]; /* pointers to HP_PTRS or records */
67 } HP_PTRS;
68 
70 {
71  /* Number of unused slots in *last_blocks HP_PTRS block (0 for 0th level) */
72  uint32_t free_ptrs_in_block;
73 
74  /*
75  Maximum number of records that can be 'contained' inside of each element
76  of last_blocks array. For level 0 - 1, for level 1 - HP_PTRS_IN_NOD, for
77  level 2 - HP_PTRS_IN_NOD^2 and so forth.
78  */
79  uint32_t records_under_level;
80 
81  /*
82  Ptr to last allocated HP_PTRS (or records buffer for level 0) on this
83  level.
84  */
85  HP_PTRS *last_blocks;
86 
87  st_level_info():
88  free_ptrs_in_block(0),
89  records_under_level(0),
90  last_blocks(0)
91  { }
92 };
93 
94 
95 /*
96  Heap table records and hash index entries are stored in HP_BLOCKs.
97  HP_BLOCK is used as a 'growable array' of fixed-size records. Size of record
98  is recbuffer bytes.
99  The internal representation is as follows:
100  HP_BLOCK is a hierarchical structure of 'blocks'.
101  A block at level 0 is an array records_in_block records.
102  A block at higher level is an HP_PTRS structure with pointers to blocks at
103  lower levels.
104  At the highest level there is one top block. It is stored in HP_BLOCK::root.
105 
106  See hp_find_block for a description of how record pointer is obtained from
107  its index.
108  See hp_get_new_block
109 */
110 
111 typedef struct st_heap_block
112 {
113  HP_PTRS *root; /* Top-level block */
114  struct st_level_info level_info[HP_MAX_LEVELS+1];
115  uint32_t levels; /* number of used levels */
116  uint32_t records_in_block; /* Records in one heap-block */
117  uint32_t recbuffer; /* Length of one saved record */
118  uint32_t last_allocated; /* number of records there is allocated space for */
119 
120  st_heap_block() :
121  root(NULL),
122  levels(0),
123  records_in_block(0),
124  recbuffer(0),
125  last_allocated(0)
126  {
127  }
128 } HP_BLOCK;
129 
130 struct st_heap_info; /* For referense */
131 
132 typedef struct st_hp_keydef /* Key definition with open */
133 {
134  uint32_t flag; /* HA_NOSAME | HA_NULL_PART_KEY */
135  uint32_t keysegs; /* Number of key-segment */
136  uint32_t length; /* Length of key (automatic) */
137  HA_KEYSEG *seg;
138  HP_BLOCK block; /* Where keys are saved */
139  /*
140  Number of buckets used in hash table. Used only to provide
141  #records estimates for heap key scans.
142  */
143  drizzled::ha_rows hash_buckets;
144 } HP_KEYDEF;
145 
146 typedef struct st_heap_dataspace /* control data for data space */
147 {
148  HP_BLOCK block;
149  uint32_t chunk_count; /* Total chunks ever allocated in this dataspace */
150  uint32_t del_chunk_count; /* Deleted chunks count */
151  unsigned char *del_link; /* Link to last deleted chunk */
152  uint32_t chunk_length; /* Total length of one chunk */
153  uint32_t chunk_dataspace_length; /* Length of payload that will be placed into one chunk */
154  uint32_t offset_status; /* Offset of the status flag relative to the chunk start */
155  uint32_t offset_link; /* Offset of the linking pointer relative to the chunk start */
156  uint64_t total_data_length; /* Total size allocated within this data space */
157 
159  chunk_count(0),
160  del_chunk_count(0),
161  del_link(0),
162  chunk_length(0),
163  chunk_dataspace_length(0),
164  offset_status(0),
165  offset_link(0),
166  total_data_length(0)
167  { }
168 
169 } HP_DATASPACE;
170 
171 
172 typedef struct st_heap_share
173 {
174  HP_KEYDEF *keydef;
175  HP_DATASPACE recordspace; /* Describes "block", which contains actual records */
176 
177  uint32_t min_records,max_records; /* Params to open */
178  uint64_t index_length,max_table_size;
179  uint32_t key_stat_version; /* version to indicate insert/delete */
180  uint32_t records; /* Actual record (row) count */
181  uint32_t blength; /* used_chunk_count rounded up to 2^n */
182  uint32_t fixed_data_length; /* Length of record's fixed part, which contains keys and always fits into the first chunk */
183  uint32_t fixed_column_count; /* Number of columns stored in fixed_data_length */
184  uint32_t changed;
185  uint32_t keys,max_key_length;
186  uint32_t column_count;
187  uint32_t currently_disabled_keys; /* saved value from "keys" when disabled */
188  uint32_t open_count;
189 
190 
191  std::string name; /* Name of "memory-file" */
192  bool delete_on_close;
193  uint32_t auto_key;
194  uint32_t auto_key_type; /* real type of the auto key segment */
195  uint64_t auto_increment;
196 
197  st_heap_share() :
198  keydef(0),
199  min_records(0),
200  max_records(0),
201  index_length(0),
202  max_table_size(0),
203  key_stat_version(0),
204  records(0),
205  blength(0),
206  fixed_data_length(0),
207  fixed_column_count(0),
208  changed(0),
209  keys(0),
210  max_key_length(0),
211  column_count(0),
212  currently_disabled_keys(0),
213  open_count(0),
214  delete_on_close(0),
215  auto_key(0),
216  auto_key_type(0),
217  auto_increment(0)
218  { }
219 
220 } HP_SHARE;
221 
222 struct st_hp_hash_info;
223 
224 typedef struct st_heap_info
225 {
226 private:
227  HP_SHARE *s;
228 public:
229 
230  HP_SHARE *getShare()
231  {
232  return s;
233  }
234 
235  void setShare(HP_SHARE *s_arg)
236  {
237  s= s_arg;
238  }
239 
240  unsigned char *current_ptr;
241  struct st_hp_hash_info *current_hash_ptr;
242  uint32_t current_record,next_block;
243  int lastinx,errkey;
244  int mode; /* Mode of file (READONLY..) */
245  uint32_t opt_flag,update;
246  std::vector <unsigned char> lastkey; /* Last used key with rkey */
247  enum drizzled::ha_rkey_function last_find_flag;
248  uint32_t lastkey_len;
250 } HP_INFO;
251 
252 
253 typedef struct st_heap_create_info
254 {
255  uint32_t auto_key; /* keynr [1 - maxkey] for auto key */
256  uint32_t auto_key_type;
257  uint32_t max_chunk_size;
258  uint64_t max_table_size;
259  uint64_t auto_increment;
260  bool with_auto_increment;
261  bool internal_table;
263 
264  /* Prototypes for heap-functions */
265 
266 extern HP_INFO *heap_open(const char *name, int mode);
267 extern HP_INFO *heap_open_from_share(HP_SHARE *share, int mode);
268 extern HP_INFO *heap_open_from_share_and_register(HP_SHARE *share, int mode);
269 extern int heap_close(HP_INFO *info);
270 extern int heap_write(HP_INFO *info,const unsigned char *record);
271 extern int heap_update(HP_INFO *info,const unsigned char *old_record,const unsigned char *new_record);
272 extern int heap_rrnd(HP_INFO *info,unsigned char *buf,unsigned char *pos);
273 extern int heap_scan_init(HP_INFO *info);
274 extern int heap_scan(register HP_INFO *info, unsigned char *record);
275 extern int heap_delete(HP_INFO *info,const unsigned char *buff);
276 extern int heap_info(HP_INFO *info,HEAPINFO *x,int flag);
277 extern int heap_create(const char *name, uint32_t keys, HP_KEYDEF *keydef,
278  uint32_t columns,
279  uint32_t key_part_size,
280  uint32_t reclength, uint32_t keys_memory_size,
281  uint32_t max_records, uint32_t min_records,
282  HP_CREATE_INFO *create_info, HP_SHARE **share);
283 
284 extern int heap_delete_table(const char *name);
285 extern int heap_extra(HP_INFO *info,enum drizzled::ha_extra_function function);
286 extern int heap_reset(HP_INFO *info);
287 extern int heap_rename(const char *old_name,const char *new_name);
288 extern int heap_panic(enum drizzled::ha_panic_function flag);
289 extern int heap_rsame(HP_INFO *info,unsigned char *record,int inx);
290 extern int heap_rnext(HP_INFO *info,unsigned char *record);
291 extern int heap_rprev(HP_INFO *info,unsigned char *record);
292 extern int heap_rfirst(HP_INFO *info,unsigned char *record,int inx);
293 extern int heap_rlast(HP_INFO *info,unsigned char *record,int inx);
294 extern void heap_clear(HP_INFO *info);
295 extern int heap_disable_indexes(HP_INFO *info);
296 extern int heap_enable_indexes(HP_INFO *info);
297 extern int heap_indexes_are_disabled(HP_INFO *info);
298 extern void heap_update_auto_increment(HP_INFO *info, const unsigned char *record);
299 int hp_panic(enum drizzled::ha_panic_function flag);
300 int heap_rkey(HP_INFO *info, unsigned char *record, int inx, const unsigned char *key,
301  drizzled::key_part_map keypart_map,
302  enum drizzled::ha_rkey_function find_flag);
303 extern unsigned char * heap_find(HP_INFO *info,int inx,const unsigned char *key);
304 extern unsigned char *heap_position(HP_INFO *info);