1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
|
/******************************************************
Transaction undo log
(c) 1996 Innobase Oy
Created 3/26/1996 Heikki Tuuri
*******************************************************/
#include "data0type.h"
/***************************************************************************
Builds a roll pointer dulint. */
UNIV_INLINE
dulint
trx_undo_build_roll_ptr(
/*====================*/
/* out: roll pointer */
ibool is_insert, /* in: TRUE if insert undo log */
ulint rseg_id, /* in: rollback segment id */
ulint page_no, /* in: page number */
ulint offset) /* in: offset of the undo entry within page */
{
#if DATA_ROLL_PTR_LEN != 7
# error "DATA_ROLL_PTR_LEN != 7"
#endif
ut_ad(rseg_id < 128);
return(ut_dulint_create(is_insert * 128 * 256 * 256
+ rseg_id * 256 * 256
+ (page_no / 256) / 256,
(page_no % (256 * 256)) * 256 * 256
+ offset));
}
/***************************************************************************
Decodes a roll pointer dulint. */
UNIV_INLINE
void
trx_undo_decode_roll_ptr(
/*=====================*/
dulint roll_ptr, /* in: roll pointer */
ibool* is_insert, /* out: TRUE if insert undo log */
ulint* rseg_id, /* out: rollback segment id */
ulint* page_no, /* out: page number */
ulint* offset) /* out: offset of the undo entry within page */
{
ulint low;
ulint high;
#if DATA_ROLL_PTR_LEN != 7
# error "DATA_ROLL_PTR_LEN != 7"
#endif
#if TRUE != 1
# error "TRUE != 1"
#endif
high = ut_dulint_get_high(roll_ptr);
low = ut_dulint_get_low(roll_ptr);
*offset = low % (256 * 256);
*is_insert = high / (256 * 256 * 128); /* TRUE == 1 */
*rseg_id = (high / (256 * 256)) % 128;
*page_no = (high % (256 * 256)) * 256 * 256
+ (low / 256) / 256;
}
/***************************************************************************
Returns TRUE if the roll pointer is of the insert type. */
UNIV_INLINE
ibool
trx_undo_roll_ptr_is_insert(
/*========================*/
/* out: TRUE if insert undo log */
dulint roll_ptr) /* in: roll pointer */
{
ulint high;
#if DATA_ROLL_PTR_LEN != 7
# error "DATA_ROLL_PTR_LEN != 7"
#endif
#if TRUE != 1
# error "TRUE != 1"
#endif
high = ut_dulint_get_high(roll_ptr);
return(high / (256 * 256 * 128));
}
/*********************************************************************
Writes a roll ptr to an index page. In case that the size changes in
some future version, this function should be used instead of
mach_write_... */
UNIV_INLINE
void
trx_write_roll_ptr(
/*===============*/
byte* ptr, /* in: pointer to memory where written */
dulint roll_ptr) /* in: roll ptr */
{
ut_ad(DATA_ROLL_PTR_LEN == 7);
mach_write_to_7(ptr, roll_ptr);
}
/*********************************************************************
Reads a roll ptr from an index page. In case that the roll ptr size
changes in some future version, this function should be used instead of
mach_read_... */
UNIV_INLINE
dulint
trx_read_roll_ptr(
/*==============*/
/* out: roll ptr */
byte* ptr) /* in: pointer to memory from where to read */
{
#if DATA_ROLL_PTR_LEN != 7
# error "DATA_ROLL_PTR_LEN != 7"
#endif
return(mach_read_from_7(ptr));
}
/**********************************************************************
Gets an undo log page and x-latches it. */
UNIV_INLINE
page_t*
trx_undo_page_get(
/*==============*/
/* out: pointer to page x-latched */
ulint space, /* in: space where placed */
ulint page_no, /* in: page number */
mtr_t* mtr) /* in: mtr */
{
page_t* page;
page = buf_page_get(space, page_no, RW_X_LATCH, mtr);
#ifdef UNIV_SYNC_DEBUG
buf_page_dbg_add_level(page, SYNC_TRX_UNDO_PAGE);
#endif /* UNIV_SYNC_DEBUG */
return(page);
}
/**********************************************************************
Gets an undo log page and s-latches it. */
UNIV_INLINE
page_t*
trx_undo_page_get_s_latched(
/*========================*/
/* out: pointer to page s-latched */
ulint space, /* in: space where placed */
ulint page_no, /* in: page number */
mtr_t* mtr) /* in: mtr */
{
page_t* page;
page = buf_page_get(space, page_no, RW_S_LATCH, mtr);
#ifdef UNIV_SYNC_DEBUG
buf_page_dbg_add_level(page, SYNC_TRX_UNDO_PAGE);
#endif /* UNIV_SYNC_DEBUG */
return(page);
}
/**********************************************************************
Returns the start offset of the undo log records of the specified undo
log on the page. */
UNIV_INLINE
ulint
trx_undo_page_get_start(
/*====================*/
/* out: start offset */
page_t* undo_page,/* in: undo log page */
ulint page_no,/* in: undo log header page number */
ulint offset) /* in: undo log header offset on page */
{
ulint start;
if (page_no == buf_frame_get_page_no(undo_page)) {
start = mach_read_from_2(offset + undo_page
+ TRX_UNDO_LOG_START);
} else {
start = TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_HDR_SIZE;
}
return(start);
}
/**********************************************************************
Returns the end offset of the undo log records of the specified undo
log on the page. */
UNIV_INLINE
ulint
trx_undo_page_get_end(
/*==================*/
/* out: end offset */
page_t* undo_page,/* in: undo log page */
ulint page_no,/* in: undo log header page number */
ulint offset) /* in: undo log header offset on page */
{
trx_ulogf_t* log_hdr;
ulint end;
if (page_no == buf_frame_get_page_no(undo_page)) {
log_hdr = undo_page + offset;
end = mach_read_from_2(log_hdr + TRX_UNDO_NEXT_LOG);
if (end == 0) {
end = mach_read_from_2(undo_page + TRX_UNDO_PAGE_HDR
+ TRX_UNDO_PAGE_FREE);
}
} else {
end = mach_read_from_2(undo_page + TRX_UNDO_PAGE_HDR
+ TRX_UNDO_PAGE_FREE);
}
return(end);
}
/**********************************************************************
Returns the previous undo record on the page in the specified log, or
NULL if none exists. */
UNIV_INLINE
trx_undo_rec_t*
trx_undo_page_get_prev_rec(
/*=======================*/
/* out: pointer to record, NULL if none */
trx_undo_rec_t* rec, /* in: undo log record */
ulint page_no,/* in: undo log header page number */
ulint offset) /* in: undo log header offset on page */
{
page_t* undo_page;
ulint start;
undo_page = buf_frame_align(rec);
start = trx_undo_page_get_start(undo_page, page_no, offset);
if (start + undo_page == rec) {
return(NULL);
}
return(undo_page + mach_read_from_2(rec - 2));
}
/**********************************************************************
Returns the next undo log record on the page in the specified log, or
NULL if none exists. */
UNIV_INLINE
trx_undo_rec_t*
trx_undo_page_get_next_rec(
/*=======================*/
/* out: pointer to record, NULL if none */
trx_undo_rec_t* rec, /* in: undo log record */
ulint page_no,/* in: undo log header page number */
ulint offset) /* in: undo log header offset on page */
{
page_t* undo_page;
ulint end;
ulint next;
undo_page = buf_frame_align(rec);
end = trx_undo_page_get_end(undo_page, page_no, offset);
next = mach_read_from_2(rec);
if (next == end) {
return(NULL);
}
return(undo_page + next);
}
/**********************************************************************
Returns the last undo record on the page in the specified undo log, or
NULL if none exists. */
UNIV_INLINE
trx_undo_rec_t*
trx_undo_page_get_last_rec(
/*=======================*/
/* out: pointer to record, NULL if none */
page_t* undo_page,/* in: undo log page */
ulint page_no,/* in: undo log header page number */
ulint offset) /* in: undo log header offset on page */
{
ulint start;
ulint end;
start = trx_undo_page_get_start(undo_page, page_no, offset);
end = trx_undo_page_get_end(undo_page, page_no, offset);
if (start == end) {
return(NULL);
}
return(undo_page + mach_read_from_2(undo_page + end - 2));
}
/**********************************************************************
Returns the first undo record on the page in the specified undo log, or
NULL if none exists. */
UNIV_INLINE
trx_undo_rec_t*
trx_undo_page_get_first_rec(
/*========================*/
/* out: pointer to record, NULL if none */
page_t* undo_page,/* in: undo log page */
ulint page_no,/* in: undo log header page number */
ulint offset) /* in: undo log header offset on page */
{
ulint start;
ulint end;
start = trx_undo_page_get_start(undo_page, page_no, offset);
end = trx_undo_page_get_end(undo_page, page_no, offset);
if (start == end) {
return(NULL);
}
return(undo_page + start);
}
|