1 /* Copyright (C) 2006 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
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 as published by
5 the Free Software Foundation; version 2 of the License.
6
7 This program is distributed in the hope that it will be useful,
8 but WITHOUT ANY WARRANTY; without even the implied warranty of
9 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 GNU General Public License for more details.
11
12 You should have received a copy of the GNU General Public License
13 along with this program; if not, write to the Free Software
14 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */
15
16 /* Remove all rows from a MARIA table */
17 /* This clears the status information and truncates files */
18
19 #include "maria_def.h"
20 #include "trnman.h"
21
22 /**
23 @brief deletes all rows from a table
24
25 @param info Maria handler
26
27 @note It is important that this function does not rely on the state
28 information, as it may be called by ma_apply_undo_bulk_insert() on an
29 inconsistent table left by a crash.
30
31 @return Operation status
32 @retval 0 ok
33 @retval 1 error
34 */
35
maria_delete_all_rows(MARIA_HA * info)36 int maria_delete_all_rows(MARIA_HA *info)
37 {
38 MARIA_SHARE *share= info->s;
39 my_bool log_record;
40 LSN lsn;
41 #ifdef HAVE_MMAP
42 my_bool mmap_file= share->file_map != 0;
43 #endif
44 DBUG_ENTER("maria_delete_all_rows");
45
46 if (share->options & HA_OPTION_READ_ONLY_DATA)
47 {
48 DBUG_RETURN(my_errno=EACCES);
49 }
50 /**
51 @todo LOCK take X-lock on table here.
52 When we have versioning, if some other thread is looking at this table,
53 we cannot shrink the file like this.
54 */
55 if (_ma_readinfo(info,F_WRLCK,1))
56 DBUG_RETURN(my_errno);
57 log_record= share->now_transactional && !share->temporary;
58
59 if (log_record)
60 {
61 /*
62 This record will be used by Recovery to finish the deletion if it
63 crashed. We force it to have a complete history in the log.
64 */
65 LEX_CUSTRING log_array[TRANSLOG_INTERNAL_PARTS + 1];
66 uchar log_data[FILEID_STORE_SIZE];
67 log_array[TRANSLOG_INTERNAL_PARTS + 0].str= log_data;
68 log_array[TRANSLOG_INTERNAL_PARTS + 0].length= sizeof(log_data);
69 if (unlikely(translog_write_record(&lsn, LOGREC_REDO_DELETE_ALL,
70 info->trn, info, 0,
71 sizeof(log_array)/sizeof(log_array[0]),
72 log_array, log_data, NULL) ||
73 translog_flush(lsn)))
74 goto err;
75 /*
76 If we fail in this function after this point, log and table will be
77 inconsistent.
78 */
79 if (_ma_mark_file_changed(share))
80 goto err;
81 }
82 else
83 {
84 if (_ma_mark_file_changed(share))
85 goto err;
86 /* Other branch called function below when writing log record, in hook */
87 _ma_reset_status(info);
88 }
89 /* Remove old history as the table is now empty for everyone */
90 _ma_reset_state(info);
91 share->state.changed= 0;
92
93 /*
94 If we are using delayed keys or if the user has done changes to the tables
95 since it was locked then there may be key blocks in the page cache. Or
96 there may be data blocks there. We need to throw them away or they may
97 re-enter the emptied table or another table later.
98 */
99
100 #ifdef HAVE_MMAP
101 if (mmap_file)
102 _ma_unmap_file(info);
103 #endif
104
105 if (_ma_flush_table_files(info, MARIA_FLUSH_DATA|MARIA_FLUSH_INDEX,
106 FLUSH_IGNORE_CHANGED, FLUSH_IGNORE_CHANGED) ||
107 mysql_file_chsize(info->dfile.file, 0, 0, MYF(MY_WME)) ||
108 mysql_file_chsize(share->kfile.file, share->base.keystart, 0, MYF(MY_WME)))
109 goto err;
110
111 if (_ma_initialize_data_file(share, info->dfile.file))
112 goto err;
113
114 if (log_record)
115 {
116 /*
117 Because LOGREC_REDO_DELETE_ALL does not operate on pages, it has the
118 following problem:
119 delete_all; inserts (redo_insert); all pages get flushed; checkpoint:
120 the dirty pages list will be empty. In recovery, delete_all is executed,
121 but redo_insert are skipped (dirty pages list is empty).
122 To avoid this, we need to set skip_redo_lsn now, and thus need to sync
123 files.
124 Also fixes the problem of:
125 bulk insert; insert; delete_all; crash:
126 "bulk insert" is skipped (no REDOs), so if "insert" would not be skipped
127 (if we didn't update skip_redo_lsn below) then "insert" would be tried
128 and fail, saying that it sees that the first page has to be created
129 though the inserted row has rownr>0.
130 */
131 my_bool error= _ma_state_info_write(share,
132 MA_STATE_INFO_WRITE_DONT_MOVE_OFFSET |
133 MA_STATE_INFO_WRITE_LOCK) ||
134 _ma_update_state_lsns(share, lsn, trnman_get_min_trid(), FALSE, FALSE) ||
135 _ma_sync_table_files(info);
136 info->trn->rec_lsn= LSN_IMPOSSIBLE;
137 if (error)
138 goto err;
139 }
140
141 if (info->opt_flag & WRITE_CACHE_USED)
142 reinit_io_cache(&info->rec_cache, WRITE_CACHE, 0, 1, 1);
143
144 _ma_writeinfo(info, WRITEINFO_UPDATE_KEYFILE);
145 #ifdef HAVE_MMAP
146 /* Map again */
147 if (mmap_file)
148 _ma_dynmap_file(info, (my_off_t) 0);
149 #endif
150 DBUG_RETURN(0);
151
152 err:
153 {
154 int save_errno=my_errno;
155 _ma_writeinfo(info, WRITEINFO_UPDATE_KEYFILE);
156 info->update|=HA_STATE_WRITTEN; /* Buffer changed */
157 DBUG_RETURN(my_errno=save_errno);
158 }
159 } /* maria_delete_all_rows */
160
161
162 /*
163 Reset status information
164
165 SYNOPSIS
166 _ma_reset_status()
167 maria Maria handler
168
169 DESCRIPTION
170 Resets data and index file information as if the file would be empty
171 Files are not touched.
172 */
173
_ma_reset_status(MARIA_HA * info)174 void _ma_reset_status(MARIA_HA *info)
175 {
176 MARIA_SHARE *share= info->s;
177 MARIA_STATE_INFO *state= &share->state;
178 uint i;
179 DBUG_ENTER("_ma_reset_status");
180
181 state->split= 0;
182 state->state.records= state->state.del= 0;
183 state->changed= 0; /* File is optimized */
184 state->dellink= HA_OFFSET_ERROR;
185 state->sortkey= (ushort) ~0;
186 state->state.key_file_length= share->base.keystart;
187 state->state.data_file_length= 0;
188 state->state.empty= state->state.key_empty= 0;
189 state->state.checksum= 0;
190 share->state.open_count= 0;
191 share->global_changed= 0;
192
193 share->changed= 1; /* We must write state */
194
195 *info->state= state->state;
196
197 /* Drop the delete key chain. */
198 state->key_del= HA_OFFSET_ERROR;
199 /* Clear all keys */
200 for (i=0 ; i < share->base.keys ; i++)
201 state->key_root[i]= HA_OFFSET_ERROR;
202 DBUG_VOID_RETURN;
203 }
204