1 /* Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
2
3 This program is free software; you can redistribute it and/or modify
4 it under the terms of the GNU General Public License, version 2.0,
5 as published by the Free Software Foundation.
6
7 This program is also distributed with certain software (including
8 but not limited to OpenSSL) that is licensed under separate terms,
9 as designated in a particular file or component or in included license
10 documentation. The authors of MySQL hereby grant you an additional
11 permission to link the program and your derivative works with the
12 separately licensed software that they have included with MySQL.
13
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License, version 2.0, for more details.
18
19 You should have received a copy of the GNU General Public License
20 along with this program; if not, write to the Free Software
21 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
22
23 /* open a heap-database */
24
25 #include <errno.h>
26 #include <sys/types.h>
27
28 #include "my_dbug.h"
29 #include "my_inttypes.h"
30 #include "my_sys.h"
31 #include "mysql/service_mysql_alloc.h"
32 #include "storage/heap/heapdef.h"
33
34 /*
35 Open heap table based on HP_SHARE structure
36
37 NOTE
38 This doesn't register the table in the open table list.
39 */
40
heap_open_from_share(HP_SHARE * share,int mode)41 HP_INFO *heap_open_from_share(HP_SHARE *share, int mode) {
42 HP_INFO *info;
43 DBUG_TRACE;
44
45 if (!(info = (HP_INFO *)my_malloc(
46 hp_key_memory_HP_INFO,
47 (uint)sizeof(HP_INFO) + 2 * share->max_key_length,
48 MYF(MY_ZEROFILL)))) {
49 return nullptr;
50 }
51 share->open_count++;
52 /*
53 Don't initialize THR_LOCK_DATA for internal temporary tables as it
54 is not used for them anyway (and THR_LOCK is not initialized for them
55 too).
56 */
57 if (share->open_list.data != nullptr)
58 thr_lock_data_init(&share->lock, &info->lock, nullptr);
59 info->s = share;
60 info->lastkey = (uchar *)(info + 1);
61 info->recbuf = (uchar *)(info->lastkey + share->max_key_length);
62 info->mode = mode;
63 info->current_record = (ulong)~0L; /* No current record */
64 info->lastinx = info->errkey = -1;
65 #ifndef DBUG_OFF
66 info->opt_flag = READ_CHECK_USED; /* Check when changing */
67 #endif
68 DBUG_PRINT("exit", ("heap: %p reclength: %d records_in_block: %d", info,
69 share->reclength, share->block.records_in_block));
70 return info;
71 }
72
73 /*
74 Open heap table based on HP_SHARE structure and register it
75 */
76
heap_open_from_share_and_register(HP_SHARE * share,int mode)77 HP_INFO *heap_open_from_share_and_register(HP_SHARE *share, int mode) {
78 HP_INFO *info;
79 DBUG_TRACE;
80
81 mysql_mutex_lock(&THR_LOCK_heap);
82 if ((info = heap_open_from_share(share, mode))) {
83 info->open_list.data = (void *)info;
84 heap_open_list = list_add(heap_open_list, &info->open_list);
85 /* Unpin the share, it is now pinned by the file. */
86 share->open_count--;
87 }
88 mysql_mutex_unlock(&THR_LOCK_heap);
89 return info;
90 }
91
92 /**
93 Dereference a HEAP share and free it if it's not referenced.
94 We needn't check open_count for single instances.
95 */
heap_release_share(HP_SHARE * share,bool single_instance)96 void heap_release_share(HP_SHARE *share, bool single_instance) {
97 /* Couldn't open table; Remove the newly created table */
98 if (single_instance)
99 hp_free(share);
100 else {
101 mysql_mutex_lock(&THR_LOCK_heap);
102 if (--share->open_count == 0) hp_free(share);
103 mysql_mutex_unlock(&THR_LOCK_heap);
104 }
105 }
106
107 /*
108 Open heap table based on name
109
110 NOTE
111 This register the table in the open table list. so that it can be
112 found by future heap_open() calls.
113 */
114
heap_open(const char * name,int mode)115 HP_INFO *heap_open(const char *name, int mode) {
116 HP_INFO *info;
117 HP_SHARE *share;
118 DBUG_TRACE;
119
120 mysql_mutex_lock(&THR_LOCK_heap);
121 if (!(share = hp_find_named_heap(name))) {
122 set_my_errno(ENOENT);
123 mysql_mutex_unlock(&THR_LOCK_heap);
124 return nullptr;
125 }
126 if ((info = heap_open_from_share(share, mode))) {
127 info->open_list.data = (void *)info;
128 heap_open_list = list_add(heap_open_list, &info->open_list);
129 }
130 mysql_mutex_unlock(&THR_LOCK_heap);
131 return info;
132 }
133
134 /* map name to a heap-nr. If name isn't found return 0 */
135
hp_find_named_heap(const char * name)136 HP_SHARE *hp_find_named_heap(const char *name) {
137 LIST *pos;
138 HP_SHARE *info;
139 DBUG_TRACE;
140 DBUG_PRINT("enter", ("name: %s", name));
141
142 for (pos = heap_share_list; pos; pos = pos->next) {
143 info = (HP_SHARE *)pos->data;
144 if (!strcmp(name, info->name)) {
145 DBUG_PRINT("exit", ("Old heap_database: %p", info));
146 return info;
147 }
148 }
149 return (HP_SHARE *)nullptr;
150 }
151