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fe19569a | 1 | /* Copyright (c) 2009, 2010, 2011, 2012, 2013 Nicira, Inc. |
c3bb4bd7 BP |
2 | * |
3 | * Licensed under the Apache License, Version 2.0 (the "License"); | |
4 | * you may not use this file except in compliance with the License. | |
5 | * You may obtain a copy of the License at: | |
6 | * | |
7 | * http://www.apache.org/licenses/LICENSE-2.0 | |
8 | * | |
9 | * Unless required by applicable law or agreed to in writing, software | |
10 | * distributed under the License is distributed on an "AS IS" BASIS, | |
11 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
12 | * See the License for the specific language governing permissions and | |
13 | * limitations under the License. | |
14 | */ | |
15 | ||
16 | #ifndef OVSDB_IDL_H | |
17 | #define OVSDB_IDL_H 1 | |
18 | ||
2ce42c88 BP |
19 | /* Open vSwitch Database Interface Definition Language (OVSDB IDL). |
20 | * | |
21 | * The OVSDB IDL maintains an in-memory replica of a database. It issues RPC | |
22 | * requests to an OVSDB database server and parses the responses, converting | |
23 | * raw JSON into data structures that are easier for clients to digest. Most | |
24 | * notably, references to rows via UUID become C pointers. | |
25 | * | |
26 | * The IDL also assists with issuing database transactions. The client creates | |
27 | * a transaction, manipulates the IDL data structures, and commits or aborts | |
28 | * the transaction. The IDL then composes and issues the necessary JSON-RPC | |
29 | * requests and reports to the client whether the transaction completed | |
30 | * successfully. | |
31 | */ | |
32 | ||
f3d64521 | 33 | #include <stdbool.h> |
b54e22e9 | 34 | #include <stdint.h> |
e1c0e2d1 | 35 | #include "compiler.h" |
8c3c2f30 | 36 | #include "ovsdb-types.h" |
b54e22e9 BP |
37 | |
38 | struct json; | |
979821c0 | 39 | struct ovsdb_datum; |
c3bb4bd7 | 40 | struct ovsdb_idl_class; |
979821c0 BP |
41 | struct ovsdb_idl_column; |
42 | struct ovsdb_idl_table_class; | |
43 | struct uuid; | |
c3bb4bd7 BP |
44 | |
45 | struct ovsdb_idl *ovsdb_idl_create(const char *remote, | |
ef73f86c | 46 | const struct ovsdb_idl_class *, |
fba6bd1d BP |
47 | bool monitor_everything_by_default, |
48 | bool retry); | |
c3bb4bd7 BP |
49 | void ovsdb_idl_destroy(struct ovsdb_idl *); |
50 | ||
854a94d9 | 51 | void ovsdb_idl_run(struct ovsdb_idl *); |
c3bb4bd7 BP |
52 | void ovsdb_idl_wait(struct ovsdb_idl *); |
53 | ||
06b6d651 BP |
54 | void ovsdb_idl_set_lock(struct ovsdb_idl *, const char *lock_name); |
55 | bool ovsdb_idl_has_lock(const struct ovsdb_idl *); | |
56 | bool ovsdb_idl_is_lock_contended(const struct ovsdb_idl *); | |
57 | ||
c3bb4bd7 | 58 | unsigned int ovsdb_idl_get_seqno(const struct ovsdb_idl *); |
f3d64521 | 59 | bool ovsdb_idl_has_ever_connected(const struct ovsdb_idl *); |
c3bb4bd7 | 60 | void ovsdb_idl_force_reconnect(struct ovsdb_idl *); |
8cdec725 | 61 | void ovsdb_idl_verify_write_only(struct ovsdb_idl *); |
fba6bd1d BP |
62 | |
63 | bool ovsdb_idl_is_alive(const struct ovsdb_idl *); | |
64 | int ovsdb_idl_get_last_error(const struct ovsdb_idl *); | |
ef73f86c BP |
65 | \f |
66 | /* Choosing columns and tables to replicate. */ | |
67 | ||
68 | /* Modes with which the IDL can monitor a column. | |
69 | * | |
70 | * If no bits are set, the column is not monitored at all. Its value will | |
71 | * always appear to the client to be the default value for its type. | |
72 | * | |
73 | * If OVSDB_IDL_MONITOR is set, then the column is replicated. Its value will | |
854a94d9 BP |
74 | * reflect the value in the database. If OVSDB_IDL_ALERT is also set, then the |
75 | * value returned by ovsdb_idl_get_seqno() will change when the column's value | |
76 | * changes. | |
ef73f86c BP |
77 | * |
78 | * The possible mode combinations are: | |
79 | * | |
80 | * - 0, for a column that a client doesn't care about. | |
81 | * | |
82 | * - (OVSDB_IDL_MONITOR | OVSDB_IDL_ALERT), for a column that a client wants | |
83 | * to track and possibly update. | |
84 | * | |
85 | * - OVSDB_IDL_MONITOR, for columns that a client treats as "write-only", | |
86 | * that is, it updates them but doesn't want to get alerted about its own | |
87 | * updates. It also won't be alerted about other clients' updates, so this | |
88 | * is suitable only for use by a client that "owns" a particular column. | |
89 | * | |
90 | * - OVDSB_IDL_ALERT without OVSDB_IDL_MONITOR is not valid. | |
91 | */ | |
92 | #define OVSDB_IDL_MONITOR (1 << 0) /* Monitor this column? */ | |
93 | #define OVSDB_IDL_ALERT (1 << 1) /* Alert client when column updated? */ | |
94 | ||
95 | void ovsdb_idl_add_column(struct ovsdb_idl *, const struct ovsdb_idl_column *); | |
96 | void ovsdb_idl_add_table(struct ovsdb_idl *, | |
97 | const struct ovsdb_idl_table_class *); | |
c3bb4bd7 | 98 | |
c547535a | 99 | void ovsdb_idl_omit(struct ovsdb_idl *, const struct ovsdb_idl_column *); |
ef73f86c BP |
100 | void ovsdb_idl_omit_alert(struct ovsdb_idl *, const struct ovsdb_idl_column *); |
101 | \f | |
102 | /* Reading the database replica. */ | |
c547535a | 103 | |
979821c0 BP |
104 | const struct ovsdb_idl_row *ovsdb_idl_get_row_for_uuid( |
105 | const struct ovsdb_idl *, const struct ovsdb_idl_table_class *, | |
106 | const struct uuid *); | |
107 | const struct ovsdb_idl_row *ovsdb_idl_first_row( | |
108 | const struct ovsdb_idl *, const struct ovsdb_idl_table_class *); | |
109 | const struct ovsdb_idl_row *ovsdb_idl_next_row(const struct ovsdb_idl_row *); | |
110 | ||
8c3c2f30 BP |
111 | const struct ovsdb_datum *ovsdb_idl_read(const struct ovsdb_idl_row *, |
112 | const struct ovsdb_idl_column *); | |
113 | const struct ovsdb_datum *ovsdb_idl_get(const struct ovsdb_idl_row *, | |
114 | const struct ovsdb_idl_column *, | |
115 | enum ovsdb_atomic_type key_type, | |
116 | enum ovsdb_atomic_type value_type); | |
cfea354b BP |
117 | |
118 | bool ovsdb_idl_row_is_synthetic(const struct ovsdb_idl_row *); | |
ef73f86c | 119 | \f |
2f926787 BP |
120 | /* Transactions. |
121 | * | |
122 | * A transaction may modify the contents of a database by modifying the values | |
123 | * of columns, deleting rows, inserting rows, or adding checks that columns in | |
124 | * the database have not changed ("verify" operations), through | |
125 | * ovsdb_idl_txn_*() functions. (The OVSDB IDL code generator produces helper | |
126 | * functions that internally call the ovsdb_idl_txn_*() functions. These are | |
127 | * likely to be more convenient.) | |
128 | * | |
129 | * Reading and writing columns and inserting and deleting rows are all | |
130 | * straightforward. The reasons to verify columns are less obvious. | |
131 | * Verification is the key to maintaining transactional integrity. Because | |
132 | * OVSDB handles multiple clients, it can happen that between the time that | |
133 | * OVSDB client A reads a column and writes a new value, OVSDB client B has | |
134 | * written that column. Client A's write should not ordinarily overwrite | |
135 | * client B's, especially if the column in question is a "map" column that | |
136 | * contains several more or less independent data items. If client A adds a | |
137 | * "verify" operation before it writes the column, then the transaction fails | |
138 | * in case client B modifies it first. Client A will then see the new value of | |
139 | * the column and compose a new transaction based on the new contents written | |
140 | * by client B. | |
141 | * | |
142 | * When a transaction is complete, which must be before the next call to | |
143 | * ovsdb_idl_run() on 'idl', call ovsdb_idl_txn_commit() or | |
144 | * ovsdb_idl_txn_abort(). | |
145 | * | |
146 | * The life-cycle of a transaction looks like this: | |
147 | * | |
148 | * 1. Create the transaction and record the initial sequence number: | |
149 | * | |
150 | * seqno = ovsdb_idl_get_seqno(idl); | |
151 | * txn = ovsdb_idl_txn_create(idl); | |
152 | * | |
153 | * 2. Modify the database with ovsdb_idl_txn_*() functions directly or | |
154 | * indirectly. | |
155 | * | |
156 | * 3. Commit the transaction by calling ovsdb_idl_txn_commit(). The first call | |
157 | * to this function probably returns TXN_INCOMPLETE. The client must keep | |
158 | * calling again along as this remains true, calling ovsdb_idl_run() in | |
159 | * between to let the IDL do protocol processing. (If the client doesn't | |
160 | * have anything else to do in the meantime, it can use | |
161 | * ovsdb_idl_txn_commit_block() to avoid having to loop itself.) | |
162 | * | |
163 | * 4. If the final status is TXN_TRY_AGAIN, wait for ovsdb_idl_get_seqno() to | |
164 | * change from the saved 'seqno' (it's possible that it's already changed, | |
165 | * in which case the client should not wait at all), then start over from | |
166 | * step 1. Only a call to ovsdb_idl_run() will change the return value of | |
167 | * ovsdb_idl_get_seqno(). (ovsdb_idl_txn_commit_block() calls | |
168 | * ovsdb_idl_run().) | |
169 | */ | |
8c3c2f30 | 170 | |
475281c0 | 171 | enum ovsdb_idl_txn_status { |
2096903b | 172 | TXN_UNCOMMITTED, /* Not yet committed or aborted. */ |
b54e22e9 | 173 | TXN_UNCHANGED, /* Transaction didn't include any changes. */ |
475281c0 BP |
174 | TXN_INCOMPLETE, /* Commit in progress, please wait. */ |
175 | TXN_ABORTED, /* ovsdb_idl_txn_abort() called. */ | |
176 | TXN_SUCCESS, /* Commit successful. */ | |
854a94d9 | 177 | TXN_TRY_AGAIN, /* Commit failed because a "verify" operation |
475281c0 | 178 | * reported an inconsistency, due to a network |
4fdfe5cc BP |
179 | * problem, or other transient failure. Wait |
180 | * for a change, then try again. */ | |
06b6d651 | 181 | TXN_NOT_LOCKED, /* Server hasn't given us the lock yet. */ |
475281c0 BP |
182 | TXN_ERROR /* Commit failed due to a hard error. */ |
183 | }; | |
184 | ||
185 | const char *ovsdb_idl_txn_status_to_string(enum ovsdb_idl_txn_status); | |
186 | ||
187 | struct ovsdb_idl_txn *ovsdb_idl_txn_create(struct ovsdb_idl *); | |
e1c0e2d1 BP |
188 | void ovsdb_idl_txn_add_comment(struct ovsdb_idl_txn *, const char *, ...) |
189 | PRINTF_FORMAT (2, 3); | |
577aebdf | 190 | void ovsdb_idl_txn_set_dry_run(struct ovsdb_idl_txn *); |
94fbe1aa BP |
191 | void ovsdb_idl_txn_increment(struct ovsdb_idl_txn *, |
192 | const struct ovsdb_idl_row *, | |
193 | const struct ovsdb_idl_column *); | |
475281c0 | 194 | void ovsdb_idl_txn_destroy(struct ovsdb_idl_txn *); |
586bb84a | 195 | void ovsdb_idl_txn_wait(const struct ovsdb_idl_txn *); |
475281c0 | 196 | enum ovsdb_idl_txn_status ovsdb_idl_txn_commit(struct ovsdb_idl_txn *); |
af96ccd2 | 197 | enum ovsdb_idl_txn_status ovsdb_idl_txn_commit_block(struct ovsdb_idl_txn *); |
475281c0 BP |
198 | void ovsdb_idl_txn_abort(struct ovsdb_idl_txn *); |
199 | ||
91e310a5 BP |
200 | const char *ovsdb_idl_txn_get_error(const struct ovsdb_idl_txn *); |
201 | ||
69490970 BP |
202 | int64_t ovsdb_idl_txn_get_increment_new_value(const struct ovsdb_idl_txn *); |
203 | const struct uuid *ovsdb_idl_txn_get_insert_uuid(const struct ovsdb_idl_txn *, | |
204 | const struct uuid *); | |
205 | ||
979821c0 BP |
206 | void ovsdb_idl_txn_write(const struct ovsdb_idl_row *, |
207 | const struct ovsdb_idl_column *, | |
208 | struct ovsdb_datum *); | |
fe19569a BP |
209 | void ovsdb_idl_txn_write_clone(const struct ovsdb_idl_row *, |
210 | const struct ovsdb_idl_column *, | |
211 | const struct ovsdb_datum *); | |
9e336f49 BP |
212 | void ovsdb_idl_txn_delete(const struct ovsdb_idl_row *); |
213 | const struct ovsdb_idl_row *ovsdb_idl_txn_insert( | |
ce5a3e38 BP |
214 | struct ovsdb_idl_txn *, const struct ovsdb_idl_table_class *, |
215 | const struct uuid *); | |
979821c0 | 216 | |
1e86ae6f BP |
217 | struct ovsdb_idl *ovsdb_idl_txn_get_idl (struct ovsdb_idl_txn *); |
218 | ||
c3bb4bd7 | 219 | #endif /* ovsdb-idl.h */ |