summaryrefslogtreecommitdiff
path: root/storage/innobase/include/trx0i_s.h
blob: 98b84fe09853b484e19040323518c0cf4a45dea0 (plain)
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
/*****************************************************************************

Copyright (c) 2007, 2015, Oracle and/or its affiliates. All Rights Reserved.
Copyright (c) 2017, 2020, MariaDB Corporation.

This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation; version 2 of the License.

This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA

*****************************************************************************/

/**************************************************//**
@file include/trx0i_s.h
INFORMATION SCHEMA innodb_trx, innodb_locks and
innodb_lock_waits tables cache structures and public
functions.

Created July 17, 2007 Vasil Dimov
*******************************************************/

#ifndef trx0i_s_h
#define trx0i_s_h

#include "trx0types.h"
#include "dict0types.h"
#include "buf0types.h"

/** The maximum amount of memory that can be consumed by innodb_trx,
innodb_locks and innodb_lock_waits information schema tables. */
#define TRX_I_S_MEM_LIMIT		16777216 /* 16 MiB */

/** The maximum length of a string that can be stored in
i_s_locks_row_t::lock_data */
#define TRX_I_S_LOCK_DATA_MAX_LEN	8192

/** The maximum length of a string that can be stored in
i_s_trx_row_t::trx_query */
#define TRX_I_S_TRX_QUERY_MAX_LEN	1024

/** The maximum length of a string that can be stored in
i_s_trx_row_t::trx_foreign_key_error */
#define TRX_I_S_TRX_FK_ERROR_MAX_LEN	256

/** Safely copy strings in to the INNODB_TRX table's
string based columns */
#define TRX_I_S_STRING_COPY(data, field, constraint, tcache)	\
do {								\
	if (strlen(data) > constraint) {			\
		char	buff[constraint + 1];			\
		strncpy(buff, data, constraint);		\
		buff[constraint] = '\0';			\
								\
		field = static_cast<const char*>(		\
			ha_storage_put_memlim(			\
			(tcache)->storage, buff, constraint + 1,\
			MAX_ALLOWED_FOR_STORAGE(tcache)));	\
	} else {						\
		field = static_cast<const char*>(		\
			ha_storage_put_str_memlim(		\
			(tcache)->storage, data,		\
			MAX_ALLOWED_FOR_STORAGE(tcache)));	\
	}							\
} while (0)

/** A row of INFORMATION_SCHEMA.innodb_locks */
struct i_s_locks_row_t;

/** Objects of trx_i_s_cache_t::locks_hash */
struct i_s_hash_chain_t;

/** Objects of this type are added to the hash table
trx_i_s_cache_t::locks_hash */
struct i_s_hash_chain_t {
	i_s_locks_row_t*	value;	/*!< row of
					INFORMATION_SCHEMA.innodb_locks*/
	i_s_hash_chain_t*	next;	/*!< next item in the hash chain */
};

/** This structure represents INFORMATION_SCHEMA.innodb_locks row */
struct i_s_locks_row_t {
	trx_id_t	lock_trx_id;	/*!< transaction identifier */
	const char*	lock_table;	/*!< table name from
					lock_get_table_name() */
	/** index name of a record lock; NULL for table locks */
	const char*	lock_index;
	/** page identifier of the record; (0,0) if !lock_index */
	page_id_t	lock_page;
	/** heap number of the record; 0 if !lock_index */
	uint16_t	lock_rec;
	/** lock mode corresponding to lock_mode_values_typelib */
	uint8_t		lock_mode;
	/** (some) content of the record, if available in the buffer pool;
	NULL if !lock_index */
	const char*	lock_data;

	/** The following are auxiliary and not included in the table */
	/* @{ */
	table_id_t	lock_table_id;
					/*!< table identifier from
					lock_get_table_id */
	i_s_hash_chain_t hash_chain;	/*!< hash table chain node for
					trx_i_s_cache_t::locks_hash */
	/* @} */
};

/** This structure represents INFORMATION_SCHEMA.innodb_trx row */
struct i_s_trx_row_t {
	trx_id_t		trx_id;		/*!< transaction identifier */
	const char*		trx_state;	/*!< transaction state from
						trx_get_que_state_str() */
	time_t			trx_started;	/*!< trx_t::start_time */
	const i_s_locks_row_t*	requested_lock_row;
					/*!< pointer to a row
					in innodb_locks if trx
					is waiting, or NULL */
	time_t		trx_wait_started; /*!< trx_t->lock.wait_started */
	uintmax_t	trx_weight;	/*!< TRX_WEIGHT() */
	ulint		trx_mysql_thread_id; /*!< thd_get_thread_id() */
	const char*	trx_query;	/*!< MySQL statement being
					executed in the transaction */
	CHARSET_INFO*	trx_query_cs;	/*!< the charset of trx_query */
	const char*	trx_operation_state; /*!< trx_t::op_info */
	ulint		trx_tables_in_use;/*!< n_mysql_tables_in_use in
					 trx_t */
	ulint		trx_tables_locked;
					/*!< mysql_n_tables_locked in
					trx_t */
	ulint		trx_lock_structs;/*!< list len of trx_locks in
					trx_t */
	ulint		trx_lock_memory_bytes;
					/*!< mem_heap_get_size(
					trx->lock_heap) */
	ulint		trx_rows_locked;/*!< lock_number_of_rows_locked() */
	uintmax_t	trx_rows_modified;/*!< trx_t::undo_no */
	uint		trx_isolation_level;
					/*!< trx_t::isolation_level */
	bool		trx_unique_checks;
					/*!< check_unique_secondary in trx_t*/
	bool		trx_foreign_key_checks;
					/*!< check_foreigns in trx_t */
	const char*	trx_foreign_key_error;
					/*!< detailed_error in trx_t */
	bool		trx_is_read_only;
					/*!< trx_t::read_only */
	bool		trx_is_autocommit_non_locking;
					/*!< trx_is_autocommit_non_locking(trx)
					*/
};

/** This structure represents INFORMATION_SCHEMA.innodb_lock_waits row */
struct i_s_lock_waits_row_t {
	const i_s_locks_row_t*	requested_lock_row;	/*!< requested lock */
	const i_s_locks_row_t*	blocking_lock_row;	/*!< blocking lock */
};

/** Cache of INFORMATION_SCHEMA table data */
struct trx_i_s_cache_t;

/** Auxiliary enum used by functions that need to select one of the
INFORMATION_SCHEMA tables */
enum i_s_table {
	I_S_INNODB_TRX,		/*!< INFORMATION_SCHEMA.innodb_trx */
	I_S_INNODB_LOCKS,	/*!< INFORMATION_SCHEMA.innodb_locks */
	I_S_INNODB_LOCK_WAITS	/*!< INFORMATION_SCHEMA.innodb_lock_waits */
};

/** This is the intermediate buffer where data needed to fill the
INFORMATION SCHEMA tables is fetched and later retrieved by the C++
code in handler/i_s.cc. */
extern trx_i_s_cache_t*	trx_i_s_cache;

/*******************************************************************//**
Initialize INFORMATION SCHEMA trx related cache. */
void
trx_i_s_cache_init(
/*===============*/
	trx_i_s_cache_t*	cache);	/*!< out: cache to init */
/*******************************************************************//**
Free the INFORMATION SCHEMA trx related cache. */
void
trx_i_s_cache_free(
/*===============*/
	trx_i_s_cache_t*	cache);	/*!< in/out: cache to free */

/*******************************************************************//**
Issue a shared/read lock on the tables cache. */
void
trx_i_s_cache_start_read(
/*=====================*/
	trx_i_s_cache_t*	cache);	/*!< in: cache */

/*******************************************************************//**
Release a shared/read lock on the tables cache. */
void
trx_i_s_cache_end_read(
/*===================*/
	trx_i_s_cache_t*	cache);	/*!< in: cache */

/*******************************************************************//**
Issue an exclusive/write lock on the tables cache. */
void
trx_i_s_cache_start_write(
/*======================*/
	trx_i_s_cache_t*	cache);	/*!< in: cache */

/*******************************************************************//**
Release an exclusive/write lock on the tables cache. */
void
trx_i_s_cache_end_write(
/*====================*/
	trx_i_s_cache_t*	cache);	/*!< in: cache */


/*******************************************************************//**
Retrieves the number of used rows in the cache for a given
INFORMATION SCHEMA table.
@return number of rows */
ulint
trx_i_s_cache_get_rows_used(
/*========================*/
	trx_i_s_cache_t*	cache,	/*!< in: cache */
	enum i_s_table		table);	/*!< in: which table */

/*******************************************************************//**
Retrieves the nth row in the cache for a given INFORMATION SCHEMA
table.
@return row */
void*
trx_i_s_cache_get_nth_row(
/*======================*/
	trx_i_s_cache_t*	cache,	/*!< in: cache */
	enum i_s_table		table,	/*!< in: which table */
	ulint			n);	/*!< in: row number */

/*******************************************************************//**
Update the transactions cache if it has not been read for some time.
@return 0 - fetched, 1 - not */
int
trx_i_s_possibly_fetch_data_into_cache(
/*===================================*/
	trx_i_s_cache_t*	cache);	/*!< in/out: cache */

/*******************************************************************//**
Returns true, if the data in the cache is truncated due to the memory
limit posed by TRX_I_S_MEM_LIMIT.
@return TRUE if truncated */
bool
trx_i_s_cache_is_truncated(
/*=======================*/
	trx_i_s_cache_t*	cache);	/*!< in: cache */
/** The maximum length of a resulting lock_id_size in
trx_i_s_create_lock_id(), not including the terminating NUL.
":%lu:%lu:%lu" -> 63 chars */
#define TRX_I_S_LOCK_ID_MAX_LEN	(TRX_ID_MAX_LEN + 63)

/*******************************************************************//**
Crafts a lock id string from a i_s_locks_row_t object. Returns its
second argument. This function aborts if there is not enough space in
lock_id. Be sure to provide at least TRX_I_S_LOCK_ID_MAX_LEN + 1 if you
want to be 100% sure that it will not abort.
@return resulting lock id */
char*
trx_i_s_create_lock_id(
/*===================*/
	const i_s_locks_row_t*	row,	/*!< in: innodb_locks row */
	char*			lock_id,/*!< out: resulting lock_id */
	ulint			lock_id_size);/*!< in: size of the lock id
					buffer */

#endif /* trx0i_s_h */