1 /* Copyright (c) 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016 Nicira, Inc.
2 * Copyright (C) 2016 Hewlett Packard Enterprise Development LP
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at:
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
20 /* Open vSwitch Database Interface Definition Language (OVSDB IDL).
22 * The OVSDB IDL maintains an in-memory replica of a database. It issues RPC
23 * requests to an OVSDB database server and parses the responses, converting
24 * raw JSON into data structures that are easier for clients to digest. Most
25 * notably, references to rows via UUID become C pointers.
27 * The IDL always presents a consistent snapshot of the database to its client,
28 * that is, it won't present the effects of some part of a transaction applied
29 * at the database server without presenting all of its effects.
31 * The IDL also assists with issuing database transactions. The client creates
32 * a transaction, manipulates the IDL data structures, and commits or aborts
33 * the transaction. The IDL then composes and issues the necessary JSON-RPC
34 * requests and reports to the client whether the transaction completed
41 #include "ovsdb-types.h"
42 #include "ovsdb-data.h"
43 #include "openvswitch/list.h"
44 #include "ovsdb-condition.h"
53 struct ovsdb_idl_class
;
55 struct ovsdb_idl_column
;
56 struct ovsdb_idl_table_class
;
59 struct ovsdb_idl
*ovsdb_idl_create(const char *remote
,
60 const struct ovsdb_idl_class
*,
61 bool monitor_everything_by_default
,
63 void ovsdb_idl_set_remote(struct ovsdb_idl
*, const char *, bool);
64 void ovsdb_idl_destroy(struct ovsdb_idl
*);
66 void ovsdb_idl_run(struct ovsdb_idl
*);
67 void ovsdb_idl_wait(struct ovsdb_idl
*);
69 void ovsdb_idl_set_lock(struct ovsdb_idl
*, const char *lock_name
);
70 bool ovsdb_idl_has_lock(const struct ovsdb_idl
*);
71 bool ovsdb_idl_is_lock_contended(const struct ovsdb_idl
*);
73 const struct uuid
* ovsdb_idl_get_monitor_id(const struct ovsdb_idl
*);
74 unsigned int ovsdb_idl_get_seqno(const struct ovsdb_idl
*);
75 bool ovsdb_idl_has_ever_connected(const struct ovsdb_idl
*);
76 void ovsdb_idl_enable_reconnect(struct ovsdb_idl
*);
77 void ovsdb_idl_force_reconnect(struct ovsdb_idl
*);
78 void ovsdb_idl_verify_write_only(struct ovsdb_idl
*);
80 bool ovsdb_idl_is_alive(const struct ovsdb_idl
*);
81 int ovsdb_idl_get_last_error(const struct ovsdb_idl
*);
83 void ovsdb_idl_set_probe_interval(const struct ovsdb_idl
*, int probe_interval
);
85 void ovsdb_idl_check_consistency(const struct ovsdb_idl
*);
87 const struct ovsdb_idl_class
*ovsdb_idl_get_class(const struct ovsdb_idl
*);
88 const struct ovsdb_idl_table_class
*ovsdb_idl_table_class_from_column(
89 const struct ovsdb_idl_class
*, const struct ovsdb_idl_column
*);
91 /* Choosing columns and tables to replicate. */
93 /* Modes with which the IDL can monitor a column.
95 * If no bits are set, the column is not monitored at all. Its value will
96 * always appear to the client to be the default value for its type.
98 * If OVSDB_IDL_MONITOR is set, then the column is replicated. Its value will
99 * reflect the value in the database. If OVSDB_IDL_ALERT is also set, then the
100 * value returned by ovsdb_idl_get_seqno() will change when the column's value
103 * The possible mode combinations are:
105 * - 0, for a column that a client doesn't care about.
107 * - (OVSDB_IDL_MONITOR | OVSDB_IDL_ALERT), for a column that a client wants
108 * to track and possibly update.
110 * - OVSDB_IDL_MONITOR, for columns that a client treats as "write-only",
111 * that is, it updates them but doesn't want to get alerted about its own
112 * updates. It also won't be alerted about other clients' updates, so this
113 * is suitable only for use by a client that "owns" a particular column.
115 * - OVDSB_IDL_ALERT without OVSDB_IDL_MONITOR is not valid.
117 * - (OVSDB_IDL_MONITOR | OVSDB_IDL_ALERT | OVSDB_IDL_TRACK), for a column
118 * that a client wants to track using the change tracking
119 * ovsdb_idl_track_get_*() functions.
121 #define OVSDB_IDL_MONITOR (1 << 0) /* Monitor this column? */
122 #define OVSDB_IDL_ALERT (1 << 1) /* Alert client when column updated? */
123 #define OVSDB_IDL_TRACK (1 << 2)
125 void ovsdb_idl_add_column(struct ovsdb_idl
*, const struct ovsdb_idl_column
*);
126 void ovsdb_idl_add_table(struct ovsdb_idl
*,
127 const struct ovsdb_idl_table_class
*);
129 void ovsdb_idl_omit(struct ovsdb_idl
*, const struct ovsdb_idl_column
*);
130 void ovsdb_idl_omit_alert(struct ovsdb_idl
*, const struct ovsdb_idl_column
*);
134 * In OVSDB, change tracking is applied at each client in the IDL layer. This
135 * means that when a client makes a request to track changes on a particular
136 * table, they are essentially requesting information about the incremental
137 * changes to that table from the point in time that the request is made. Once
138 * the client clears tracked changes, that information will no longer be
141 * The implication of the above is that if a client requires replaying
142 * untracked history, it faces the choice of either trying to remember changes
143 * itself (which translates into a memory leak) or of being structured with a
144 * path for processing the full untracked table as well as a path that
145 * processes incremental changes. */
146 enum ovsdb_idl_change
{
147 OVSDB_IDL_CHANGE_INSERT
,
148 OVSDB_IDL_CHANGE_MODIFY
,
149 OVSDB_IDL_CHANGE_DELETE
,
153 /* Row, table sequence numbers */
154 unsigned int ovsdb_idl_table_get_seqno(
155 const struct ovsdb_idl
*idl
,
156 const struct ovsdb_idl_table_class
*table_class
);
157 unsigned int ovsdb_idl_row_get_seqno(
158 const struct ovsdb_idl_row
*row
,
159 enum ovsdb_idl_change change
);
161 void ovsdb_idl_track_add_column(struct ovsdb_idl
*idl
,
162 const struct ovsdb_idl_column
*column
);
163 void ovsdb_idl_track_add_all(struct ovsdb_idl
*idl
);
164 const struct ovsdb_idl_row
*ovsdb_idl_track_get_first(
165 const struct ovsdb_idl
*, const struct ovsdb_idl_table_class
*);
166 const struct ovsdb_idl_row
*ovsdb_idl_track_get_next(const struct ovsdb_idl_row
*);
167 bool ovsdb_idl_track_is_updated(const struct ovsdb_idl_row
*row
,
168 const struct ovsdb_idl_column
*column
);
169 void ovsdb_idl_track_clear(struct ovsdb_idl
*);
172 /* Reading the database replica. */
174 const struct ovsdb_idl_row
*ovsdb_idl_get_row_for_uuid(
175 const struct ovsdb_idl
*, const struct ovsdb_idl_table_class
*,
176 const struct uuid
*);
177 const struct ovsdb_idl_row
*ovsdb_idl_first_row(
178 const struct ovsdb_idl
*, const struct ovsdb_idl_table_class
*);
179 const struct ovsdb_idl_row
*ovsdb_idl_next_row(const struct ovsdb_idl_row
*);
181 const struct ovsdb_datum
*ovsdb_idl_read(const struct ovsdb_idl_row
*,
182 const struct ovsdb_idl_column
*);
183 const struct ovsdb_datum
*ovsdb_idl_get(const struct ovsdb_idl_row
*,
184 const struct ovsdb_idl_column
*,
185 enum ovsdb_atomic_type key_type
,
186 enum ovsdb_atomic_type value_type
);
187 bool ovsdb_idl_is_mutable(const struct ovsdb_idl_row
*,
188 const struct ovsdb_idl_column
*);
190 bool ovsdb_idl_row_is_synthetic(const struct ovsdb_idl_row
*);
194 * A transaction may modify the contents of a database by modifying the values
195 * of columns, deleting rows, inserting rows, or adding checks that columns in
196 * the database have not changed ("verify" operations), through
197 * ovsdb_idl_txn_*() functions. (The OVSDB IDL code generator produces helper
198 * functions that internally call the ovsdb_idl_txn_*() functions. These are
199 * likely to be more convenient.)
201 * Reading and writing columns and inserting and deleting rows are all
202 * straightforward. The reasons to verify columns are less obvious.
203 * Verification is the key to maintaining transactional integrity. Because
204 * OVSDB handles multiple clients, it can happen that between the time that
205 * OVSDB client A reads a column and writes a new value, OVSDB client B has
206 * written that column. Client A's write should not ordinarily overwrite
207 * client B's, especially if the column in question is a "map" column that
208 * contains several more or less independent data items. If client A adds a
209 * "verify" operation before it writes the column, then the transaction fails
210 * in case client B modifies it first. Client A will then see the new value of
211 * the column and compose a new transaction based on the new contents written
214 * When a transaction is complete, which must be before the next call to
215 * ovsdb_idl_run() on 'idl', call ovsdb_idl_txn_commit() or
216 * ovsdb_idl_txn_abort().
218 * The life-cycle of a transaction looks like this:
220 * 1. Create the transaction and record the initial sequence number:
222 * seqno = ovsdb_idl_get_seqno(idl);
223 * txn = ovsdb_idl_txn_create(idl);
225 * 2. Modify the database with ovsdb_idl_txn_*() functions directly or
228 * 3. Commit the transaction by calling ovsdb_idl_txn_commit(). The first call
229 * to this function probably returns TXN_INCOMPLETE. The client must keep
230 * calling again along as this remains true, calling ovsdb_idl_run() in
231 * between to let the IDL do protocol processing. (If the client doesn't
232 * have anything else to do in the meantime, it can use
233 * ovsdb_idl_txn_commit_block() to avoid having to loop itself.)
235 * 4. If the final status is TXN_TRY_AGAIN, wait for ovsdb_idl_get_seqno() to
236 * change from the saved 'seqno' (it's possible that it's already changed,
237 * in which case the client should not wait at all), then start over from
238 * step 1. Only a call to ovsdb_idl_run() will change the return value of
239 * ovsdb_idl_get_seqno(). (ovsdb_idl_txn_commit_block() calls
243 enum ovsdb_idl_txn_status
{
244 TXN_UNCOMMITTED
, /* Not yet committed or aborted. */
245 TXN_UNCHANGED
, /* Transaction didn't include any changes. */
246 TXN_INCOMPLETE
, /* Commit in progress, please wait. */
247 TXN_ABORTED
, /* ovsdb_idl_txn_abort() called. */
248 TXN_SUCCESS
, /* Commit successful. */
249 TXN_TRY_AGAIN
, /* Commit failed because a "verify" operation
250 * reported an inconsistency, due to a network
251 * problem, or other transient failure. Wait
252 * for a change, then try again. */
253 TXN_NOT_LOCKED
, /* Server hasn't given us the lock yet. */
254 TXN_ERROR
/* Commit failed due to a hard error. */
257 const char *ovsdb_idl_txn_status_to_string(enum ovsdb_idl_txn_status
);
259 struct ovsdb_idl_txn
*ovsdb_idl_txn_create(struct ovsdb_idl
*);
260 void ovsdb_idl_txn_add_comment(struct ovsdb_idl_txn
*, const char *, ...)
261 OVS_PRINTF_FORMAT (2, 3);
262 void ovsdb_idl_txn_set_dry_run(struct ovsdb_idl_txn
*);
263 void ovsdb_idl_txn_increment(struct ovsdb_idl_txn
*,
264 const struct ovsdb_idl_row
*,
265 const struct ovsdb_idl_column
*,
267 void ovsdb_idl_txn_destroy(struct ovsdb_idl_txn
*);
268 void ovsdb_idl_txn_wait(const struct ovsdb_idl_txn
*);
269 enum ovsdb_idl_txn_status
ovsdb_idl_txn_commit(struct ovsdb_idl_txn
*);
270 enum ovsdb_idl_txn_status
ovsdb_idl_txn_commit_block(struct ovsdb_idl_txn
*);
271 void ovsdb_idl_txn_abort(struct ovsdb_idl_txn
*);
273 const char *ovsdb_idl_txn_get_error(const struct ovsdb_idl_txn
*);
275 int64_t ovsdb_idl_txn_get_increment_new_value(const struct ovsdb_idl_txn
*);
276 const struct uuid
*ovsdb_idl_txn_get_insert_uuid(const struct ovsdb_idl_txn
*,
277 const struct uuid
*);
279 void ovsdb_idl_txn_write(const struct ovsdb_idl_row
*,
280 const struct ovsdb_idl_column
*,
281 struct ovsdb_datum
*);
282 void ovsdb_idl_txn_write_clone(const struct ovsdb_idl_row
*,
283 const struct ovsdb_idl_column
*,
284 const struct ovsdb_datum
*);
285 void ovsdb_idl_txn_write_partial_map(const struct ovsdb_idl_row
*,
286 const struct ovsdb_idl_column
*,
287 struct ovsdb_datum
*);
288 void ovsdb_idl_txn_delete_partial_map(const struct ovsdb_idl_row
*,
289 const struct ovsdb_idl_column
*,
290 struct ovsdb_datum
*);
291 void ovsdb_idl_txn_write_partial_set(const struct ovsdb_idl_row
*,
292 const struct ovsdb_idl_column
*,
293 struct ovsdb_datum
*);
294 void ovsdb_idl_txn_delete_partial_set(const struct ovsdb_idl_row
*,
295 const struct ovsdb_idl_column
*,
296 struct ovsdb_datum
*);
297 void ovsdb_idl_txn_delete(const struct ovsdb_idl_row
*);
298 const struct ovsdb_idl_row
*ovsdb_idl_txn_insert(
299 struct ovsdb_idl_txn
*, const struct ovsdb_idl_table_class
*,
300 const struct uuid
*);
302 struct ovsdb_idl
*ovsdb_idl_txn_get_idl (struct ovsdb_idl_txn
*);
303 void ovsdb_idl_get_initial_snapshot(struct ovsdb_idl
*);
306 /* ovsdb_idl_loop provides an easy way to manage the transactions related
307 * to 'idl' and to cope with different status during transaction. */
308 struct ovsdb_idl_loop
{
309 struct ovsdb_idl
*idl
;
310 unsigned int skip_seqno
;
312 struct ovsdb_idl_txn
*committing_txn
;
313 unsigned int precommit_seqno
;
315 struct ovsdb_idl_txn
*open_txn
;
317 /* These members allow a client a simple, stateless way to keep track of
318 * transactions that commit: when a transaction commits successfully,
319 * ovsdb_idl_loop_commit_and_wait() copies 'next_cfg' to 'cur_cfg'. Thus,
320 * the client can set 'next_cfg' to a value that indicates a successful
321 * commit and check 'cur_cfg' on each iteration. */
326 #define OVSDB_IDL_LOOP_INITIALIZER(IDL) { .idl = (IDL) }
328 void ovsdb_idl_loop_destroy(struct ovsdb_idl_loop
*);
329 struct ovsdb_idl_txn
*ovsdb_idl_loop_run(struct ovsdb_idl_loop
*);
330 int ovsdb_idl_loop_commit_and_wait(struct ovsdb_idl_loop
*);
332 /* Conditional Replication
333 * =======================
335 * By default, when the IDL replicates a particular table in the database, it
336 * replicates every row in the table. These functions allow the client to
337 * specify that only selected rows should be replicated, by constructing a
338 * per-table condition that specifies the rows to replicate.
340 * A condition is a disjunction of clauses. The condition is true, and thus a
341 * row is replicated, if any of the clauses evaluates to true for a given row.
342 * (Thus, a condition with no clauses is always false.)
345 struct ovsdb_idl_condition
{
346 struct hmap clauses
; /* Contains "struct ovsdb_idl_clause"s. */
347 bool is_true
; /* Is the condition unconditionally true? */
349 #define OVSDB_IDL_CONDITION_INIT(CONDITION) \
350 { HMAP_INITIALIZER(&(CONDITION)->clauses), false }
352 void ovsdb_idl_condition_init(struct ovsdb_idl_condition
*);
353 void ovsdb_idl_condition_clear(struct ovsdb_idl_condition
*);
354 void ovsdb_idl_condition_destroy(struct ovsdb_idl_condition
*);
355 void ovsdb_idl_condition_add_clause(struct ovsdb_idl_condition
*,
356 enum ovsdb_function function
,
357 const struct ovsdb_idl_column
*column
,
358 const struct ovsdb_datum
*arg
);
359 void ovsdb_idl_condition_add_clause_true(struct ovsdb_idl_condition
*);
360 bool ovsdb_idl_condition_is_true(const struct ovsdb_idl_condition
*);
362 unsigned int ovsdb_idl_set_condition(struct ovsdb_idl
*,
363 const struct ovsdb_idl_table_class
*,
364 const struct ovsdb_idl_condition
*);
366 unsigned int ovsdb_idl_get_condition_seqno(const struct ovsdb_idl
*);
368 /* The OVSDB-IDL Compound Indexes feature allows for the creation of custom
369 * table indexes over one or more columns in the IDL. These indexes provide
370 * the ability to retrieve rows matching a particular search criteria and to
371 * iterate over a subset of rows in a defined order.
374 #define OVSDB_INDEX_DESC -1
375 #define OVSDB_INDEX_ASC 1
378 * Skiplist comparison function. Allows to store sorted data.
380 typedef int (column_comparator
)(const void *a
, const void *b
);
382 struct ovsdb_idl_index_cursor
{
383 struct ovsdb_idl_index
*index
; /* Index used by this cursor */
384 struct skiplist_node
*position
; /* Current position in the index */
387 struct ovsdb_idl_index
*ovsdb_idl_create_index(struct ovsdb_idl
*idl
,
388 const struct ovsdb_idl_table_class
*tc
,
389 const char *index_name
);
390 void ovsdb_idl_index_add_column(struct ovsdb_idl_index
*,
391 const struct ovsdb_idl_column
*,
393 column_comparator
*custom_comparer
);
394 bool ovsdb_idl_initialize_cursor(struct ovsdb_idl
*,
395 const struct ovsdb_idl_table_class
*tc
,
396 const char *index_name
,
397 struct ovsdb_idl_index_cursor
*cursor
);
398 void ovsdb_idl_index_write_(struct ovsdb_idl_row
*,
399 const struct ovsdb_idl_column
*,
400 struct ovsdb_datum
*,
401 const struct ovsdb_idl_table_class
*);
402 struct ovsdb_idl_row
*ovsdb_idl_index_init_row(struct ovsdb_idl
*,
403 const struct ovsdb_idl_table_class
*);
404 void ovsdb_idl_index_destroy_row__(const struct ovsdb_idl_row
*);
405 struct ovsdb_idl_row
*ovsdb_idl_index_first(struct ovsdb_idl_index_cursor
*);
406 struct ovsdb_idl_row
*ovsdb_idl_index_next(struct ovsdb_idl_index_cursor
*);
407 struct ovsdb_idl_row
*ovsdb_idl_index_data(struct ovsdb_idl_index_cursor
*);
408 struct ovsdb_idl_row
*ovsdb_idl_index_find(struct ovsdb_idl_index_cursor
*,
409 struct ovsdb_idl_row
*);
410 struct ovsdb_idl_row
*ovsdb_idl_index_forward_to(
411 struct ovsdb_idl_index_cursor
*,
412 struct ovsdb_idl_row
*);
413 int ovsdb_idl_index_compare(struct ovsdb_idl_index_cursor
*,
414 struct ovsdb_idl_row
*a
,
415 struct ovsdb_idl_row
*b
);
421 #endif /* ovsdb-idl.h */