ovsdb/trigger.h

   1 /* Copyright (c) 2009, 2011, 2012 Nicira, Inc.
   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_TRIGGER_H
  17 #define OVSDB_TRIGGER_H 1
  18
  19 #include "openvswitch/list.h"
  20
  21 struct ovsdb;
  22
  23 /* Triggers have the following states:
  24  *
  25  *    - Initialized (reply == NULL, progress == NULL): Executing the trigger
  26  *      can keep it in the initialized state, if it has a "wait" condition that
  27  *      isn't met.  Executing the trigger can also yield an error, in which
  28  *      case it transitions to "complete".  Otherwise, execution yields a
  29  *      transaction, which the database attempts to commit.  If the transaction
  30  *      completes immediately and synchronously, then the trigger transitions
  31  *      to the "complete" state.  If the transaction requires some time to
  32  *      complete, it transitions to the "committing" state.
  33  *
  34  *    - Committing (reply != NULL, progress != NULL): The transaction is
  35  *      committing.  If it succeeds, or if it fails permanently, then the
  36  *      trigger transitions to "complete".  If it fails temporarily
  37  *      (e.g. because someone else committed to cluster-based storage before we
  38  *      did), then we transition back to "initialized" to try again.
  39  *
  40  *    - Complete (reply != NULL, progress == NULL): The transaction is done
  41  *      and either succeeded or failed.
  42  */
  43 struct ovsdb_trigger {
  44     /* In "initialized" or "committing" state, in db->triggers.
  45      * In "complete", in session->completions. */
  46     struct ovs_list node;
  47     struct ovsdb_session *session; /* Session that owns this trigger. */
  48     struct ovsdb *db;           /* Database on which trigger acts. */
  49     struct jsonrpc_msg *request; /* Database request. */
  50     struct jsonrpc_msg *reply;   /* Result (null if none yet). */
  51     struct ovsdb_txn_progress *progress;
  52     long long int created;      /* Time created. */
  53     long long int timeout_msec; /* Max wait duration. */
  54     bool read_only;             /* Database is in read only mode. */
  55     char *role;                 /* Role, for role-based access controls. */
  56     char *id;                   /* ID, for role-based access controls. */
  57 };
  58
  59 bool ovsdb_trigger_init(struct ovsdb_session *, struct ovsdb *,
  60                         struct ovsdb_trigger *,
  61                         struct jsonrpc_msg *request, long long int now,
  62                         bool read_only, const char *role, const char *id);
  63 void ovsdb_trigger_destroy(struct ovsdb_trigger *);
  64
  65 bool ovsdb_trigger_is_complete(const struct ovsdb_trigger *);
  66 struct jsonrpc_msg *ovsdb_trigger_steal_reply(struct ovsdb_trigger *);
  67 void ovsdb_trigger_cancel(struct ovsdb_trigger *, const char *reason);
  68
  69 void ovsdb_trigger_prereplace_db(struct ovsdb_trigger *);
  70
  71 bool ovsdb_trigger_run(struct ovsdb *, long long int now);
  72 void ovsdb_trigger_wait(struct ovsdb *, long long int now);
  73
  74 #endif /* ovsdb/trigger.h */