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93fe026466
This patch adds support for the creation of multicolumn indexes in the C IDL to enable for efficient search and retrieval of database rows by key. Signed-off-by: Esteban Rodriguez Betancourt <estebarb@hpe.com> Co-authored-by: Lance Richardson <lrichard@redhat.com> Signed-off-by: Lance Richardson <lrichard@redhat.com> Signed-off-by: Ben Pfaff <blp@ovn.org>
413 lines
19 KiB
C
413 lines
19 KiB
C
/* Copyright (c) 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016 Nicira, Inc.
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* Copyright (C) 2016 Hewlett Packard Enterprise Development LP
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at:
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#ifndef OVSDB_IDL_H
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#define OVSDB_IDL_H 1
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/* Open vSwitch Database Interface Definition Language (OVSDB IDL).
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*
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* The OVSDB IDL maintains an in-memory replica of a database. It issues RPC
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* requests to an OVSDB database server and parses the responses, converting
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* raw JSON into data structures that are easier for clients to digest. Most
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* notably, references to rows via UUID become C pointers.
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*
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* The IDL always presents a consistent snapshot of the database to its client,
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* that is, it won't present the effects of some part of a transaction applied
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* at the database server without presenting all of its effects.
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*
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* The IDL also assists with issuing database transactions. The client creates
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* a transaction, manipulates the IDL data structures, and commits or aborts
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* the transaction. The IDL then composes and issues the necessary JSON-RPC
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* requests and reports to the client whether the transaction completed
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* successfully.
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*/
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#include <stdbool.h>
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#include <stdint.h>
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#include "compiler.h"
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#include "ovsdb-types.h"
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#include "ovsdb-data.h"
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#include "openvswitch/list.h"
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#include "ovsdb-condition.h"
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#include "skiplist.h"
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struct json;
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struct ovsdb_datum;
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struct ovsdb_idl_class;
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struct ovsdb_idl_row;
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struct ovsdb_idl_column;
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struct ovsdb_idl_table_class;
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struct uuid;
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struct ovsdb_idl *ovsdb_idl_create(const char *remote,
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const struct ovsdb_idl_class *,
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bool monitor_everything_by_default,
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bool retry);
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void ovsdb_idl_set_remote(struct ovsdb_idl *, const char *, bool);
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void ovsdb_idl_destroy(struct ovsdb_idl *);
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void ovsdb_idl_run(struct ovsdb_idl *);
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void ovsdb_idl_wait(struct ovsdb_idl *);
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void ovsdb_idl_set_lock(struct ovsdb_idl *, const char *lock_name);
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bool ovsdb_idl_has_lock(const struct ovsdb_idl *);
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bool ovsdb_idl_is_lock_contended(const struct ovsdb_idl *);
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const struct uuid * ovsdb_idl_get_monitor_id(const struct ovsdb_idl *);
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unsigned int ovsdb_idl_get_seqno(const struct ovsdb_idl *);
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bool ovsdb_idl_has_ever_connected(const struct ovsdb_idl *);
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void ovsdb_idl_enable_reconnect(struct ovsdb_idl *);
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void ovsdb_idl_force_reconnect(struct ovsdb_idl *);
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void ovsdb_idl_verify_write_only(struct ovsdb_idl *);
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bool ovsdb_idl_is_alive(const struct ovsdb_idl *);
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int ovsdb_idl_get_last_error(const struct ovsdb_idl *);
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void ovsdb_idl_set_probe_interval(const struct ovsdb_idl *, int probe_interval);
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void ovsdb_idl_check_consistency(const struct ovsdb_idl *);
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const struct ovsdb_idl_class *ovsdb_idl_get_class(const struct ovsdb_idl *);
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const struct ovsdb_idl_table_class *ovsdb_idl_table_class_from_column(
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const struct ovsdb_idl_class *, const struct ovsdb_idl_column *);
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/* Choosing columns and tables to replicate. */
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/* Modes with which the IDL can monitor a column.
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*
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* If no bits are set, the column is not monitored at all. Its value will
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* always appear to the client to be the default value for its type.
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*
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* If OVSDB_IDL_MONITOR is set, then the column is replicated. Its value will
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* reflect the value in the database. If OVSDB_IDL_ALERT is also set, then the
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* value returned by ovsdb_idl_get_seqno() will change when the column's value
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* changes.
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*
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* The possible mode combinations are:
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*
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* - 0, for a column that a client doesn't care about.
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*
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* - (OVSDB_IDL_MONITOR | OVSDB_IDL_ALERT), for a column that a client wants
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* to track and possibly update.
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*
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* - OVSDB_IDL_MONITOR, for columns that a client treats as "write-only",
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* that is, it updates them but doesn't want to get alerted about its own
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* updates. It also won't be alerted about other clients' updates, so this
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* is suitable only for use by a client that "owns" a particular column.
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*
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* - OVDSB_IDL_ALERT without OVSDB_IDL_MONITOR is not valid.
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*
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* - (OVSDB_IDL_MONITOR | OVSDB_IDL_ALERT | OVSDB_IDL_TRACK), for a column
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* that a client wants to track using the change tracking
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* ovsdb_idl_track_get_*() functions.
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*/
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#define OVSDB_IDL_MONITOR (1 << 0) /* Monitor this column? */
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#define OVSDB_IDL_ALERT (1 << 1) /* Alert client when column updated? */
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#define OVSDB_IDL_TRACK (1 << 2)
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void ovsdb_idl_add_column(struct ovsdb_idl *, const struct ovsdb_idl_column *);
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void ovsdb_idl_add_table(struct ovsdb_idl *,
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const struct ovsdb_idl_table_class *);
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void ovsdb_idl_omit(struct ovsdb_idl *, const struct ovsdb_idl_column *);
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void ovsdb_idl_omit_alert(struct ovsdb_idl *, const struct ovsdb_idl_column *);
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/* Change tracking.
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*
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* In OVSDB, change tracking is applied at each client in the IDL layer. This
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* means that when a client makes a request to track changes on a particular
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* table, they are essentially requesting information about the incremental
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* changes to that table from the point in time that the request is made. Once
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* the client clears tracked changes, that information will no longer be
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* available.
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*
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* The implication of the above is that if a client requires replaying
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* untracked history, it faces the choice of either trying to remember changes
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* itself (which translates into a memory leak) or of being structured with a
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* path for processing the full untracked table as well as a path that
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* processes incremental changes. */
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enum ovsdb_idl_change {
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OVSDB_IDL_CHANGE_INSERT,
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OVSDB_IDL_CHANGE_MODIFY,
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OVSDB_IDL_CHANGE_DELETE,
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OVSDB_IDL_CHANGE_MAX
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};
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/* Row, table sequence numbers */
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unsigned int ovsdb_idl_table_get_seqno(
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const struct ovsdb_idl *idl,
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const struct ovsdb_idl_table_class *table_class);
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unsigned int ovsdb_idl_row_get_seqno(
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const struct ovsdb_idl_row *row,
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enum ovsdb_idl_change change);
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void ovsdb_idl_track_add_column(struct ovsdb_idl *idl,
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const struct ovsdb_idl_column *column);
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void ovsdb_idl_track_add_all(struct ovsdb_idl *idl);
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const struct ovsdb_idl_row *ovsdb_idl_track_get_first(
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const struct ovsdb_idl *, const struct ovsdb_idl_table_class *);
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const struct ovsdb_idl_row *ovsdb_idl_track_get_next(const struct ovsdb_idl_row *);
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bool ovsdb_idl_track_is_updated(const struct ovsdb_idl_row *row,
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const struct ovsdb_idl_column *column);
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void ovsdb_idl_track_clear(const struct ovsdb_idl *);
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/* Reading the database replica. */
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const struct ovsdb_idl_row *ovsdb_idl_get_row_for_uuid(
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const struct ovsdb_idl *, const struct ovsdb_idl_table_class *,
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const struct uuid *);
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const struct ovsdb_idl_row *ovsdb_idl_first_row(
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const struct ovsdb_idl *, const struct ovsdb_idl_table_class *);
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const struct ovsdb_idl_row *ovsdb_idl_next_row(const struct ovsdb_idl_row *);
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const struct ovsdb_datum *ovsdb_idl_read(const struct ovsdb_idl_row *,
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const struct ovsdb_idl_column *);
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const struct ovsdb_datum *ovsdb_idl_get(const struct ovsdb_idl_row *,
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const struct ovsdb_idl_column *,
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enum ovsdb_atomic_type key_type,
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enum ovsdb_atomic_type value_type);
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bool ovsdb_idl_is_mutable(const struct ovsdb_idl_row *,
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const struct ovsdb_idl_column *);
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bool ovsdb_idl_row_is_synthetic(const struct ovsdb_idl_row *);
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/* Transactions.
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*
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* A transaction may modify the contents of a database by modifying the values
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* of columns, deleting rows, inserting rows, or adding checks that columns in
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* the database have not changed ("verify" operations), through
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* ovsdb_idl_txn_*() functions. (The OVSDB IDL code generator produces helper
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* functions that internally call the ovsdb_idl_txn_*() functions. These are
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* likely to be more convenient.)
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*
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* Reading and writing columns and inserting and deleting rows are all
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* straightforward. The reasons to verify columns are less obvious.
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* Verification is the key to maintaining transactional integrity. Because
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* OVSDB handles multiple clients, it can happen that between the time that
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* OVSDB client A reads a column and writes a new value, OVSDB client B has
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* written that column. Client A's write should not ordinarily overwrite
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* client B's, especially if the column in question is a "map" column that
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* contains several more or less independent data items. If client A adds a
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* "verify" operation before it writes the column, then the transaction fails
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* in case client B modifies it first. Client A will then see the new value of
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* the column and compose a new transaction based on the new contents written
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* by client B.
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*
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* When a transaction is complete, which must be before the next call to
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* ovsdb_idl_run() on 'idl', call ovsdb_idl_txn_commit() or
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* ovsdb_idl_txn_abort().
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*
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* The life-cycle of a transaction looks like this:
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*
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* 1. Create the transaction and record the initial sequence number:
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*
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* seqno = ovsdb_idl_get_seqno(idl);
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* txn = ovsdb_idl_txn_create(idl);
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*
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* 2. Modify the database with ovsdb_idl_txn_*() functions directly or
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* indirectly.
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*
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* 3. Commit the transaction by calling ovsdb_idl_txn_commit(). The first call
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* to this function probably returns TXN_INCOMPLETE. The client must keep
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* calling again along as this remains true, calling ovsdb_idl_run() in
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* between to let the IDL do protocol processing. (If the client doesn't
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* have anything else to do in the meantime, it can use
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* ovsdb_idl_txn_commit_block() to avoid having to loop itself.)
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*
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* 4. If the final status is TXN_TRY_AGAIN, wait for ovsdb_idl_get_seqno() to
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* change from the saved 'seqno' (it's possible that it's already changed,
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* in which case the client should not wait at all), then start over from
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* step 1. Only a call to ovsdb_idl_run() will change the return value of
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* ovsdb_idl_get_seqno(). (ovsdb_idl_txn_commit_block() calls
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* ovsdb_idl_run().)
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*/
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enum ovsdb_idl_txn_status {
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TXN_UNCOMMITTED, /* Not yet committed or aborted. */
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TXN_UNCHANGED, /* Transaction didn't include any changes. */
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TXN_INCOMPLETE, /* Commit in progress, please wait. */
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TXN_ABORTED, /* ovsdb_idl_txn_abort() called. */
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TXN_SUCCESS, /* Commit successful. */
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TXN_TRY_AGAIN, /* Commit failed because a "verify" operation
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* reported an inconsistency, due to a network
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* problem, or other transient failure. Wait
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* for a change, then try again. */
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TXN_NOT_LOCKED, /* Server hasn't given us the lock yet. */
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TXN_ERROR /* Commit failed due to a hard error. */
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};
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const char *ovsdb_idl_txn_status_to_string(enum ovsdb_idl_txn_status);
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struct ovsdb_idl_txn *ovsdb_idl_txn_create(struct ovsdb_idl *);
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void ovsdb_idl_txn_add_comment(struct ovsdb_idl_txn *, const char *, ...)
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OVS_PRINTF_FORMAT (2, 3);
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void ovsdb_idl_txn_set_dry_run(struct ovsdb_idl_txn *);
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void ovsdb_idl_txn_increment(struct ovsdb_idl_txn *,
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const struct ovsdb_idl_row *,
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const struct ovsdb_idl_column *,
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bool force);
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void ovsdb_idl_txn_destroy(struct ovsdb_idl_txn *);
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void ovsdb_idl_txn_wait(const struct ovsdb_idl_txn *);
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enum ovsdb_idl_txn_status ovsdb_idl_txn_commit(struct ovsdb_idl_txn *);
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enum ovsdb_idl_txn_status ovsdb_idl_txn_commit_block(struct ovsdb_idl_txn *);
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void ovsdb_idl_txn_abort(struct ovsdb_idl_txn *);
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const char *ovsdb_idl_txn_get_error(const struct ovsdb_idl_txn *);
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int64_t ovsdb_idl_txn_get_increment_new_value(const struct ovsdb_idl_txn *);
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const struct uuid *ovsdb_idl_txn_get_insert_uuid(const struct ovsdb_idl_txn *,
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const struct uuid *);
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void ovsdb_idl_txn_write(const struct ovsdb_idl_row *,
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const struct ovsdb_idl_column *,
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struct ovsdb_datum *);
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void ovsdb_idl_txn_write_clone(const struct ovsdb_idl_row *,
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const struct ovsdb_idl_column *,
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const struct ovsdb_datum *);
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void ovsdb_idl_txn_write_partial_map(const struct ovsdb_idl_row *,
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const struct ovsdb_idl_column *,
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struct ovsdb_datum *);
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void ovsdb_idl_txn_delete_partial_map(const struct ovsdb_idl_row *,
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const struct ovsdb_idl_column *,
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struct ovsdb_datum *);
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void ovsdb_idl_txn_write_partial_set(const struct ovsdb_idl_row *,
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const struct ovsdb_idl_column *,
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struct ovsdb_datum *);
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void ovsdb_idl_txn_delete_partial_set(const struct ovsdb_idl_row *,
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const struct ovsdb_idl_column *,
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struct ovsdb_datum *);
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void ovsdb_idl_txn_delete(const struct ovsdb_idl_row *);
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const struct ovsdb_idl_row *ovsdb_idl_txn_insert(
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struct ovsdb_idl_txn *, const struct ovsdb_idl_table_class *,
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const struct uuid *);
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struct ovsdb_idl *ovsdb_idl_txn_get_idl (struct ovsdb_idl_txn *);
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void ovsdb_idl_get_initial_snapshot(struct ovsdb_idl *);
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/* ovsdb_idl_loop provides an easy way to manage the transactions related
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* to 'idl' and to cope with different status during transaction. */
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struct ovsdb_idl_loop {
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struct ovsdb_idl *idl;
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unsigned int skip_seqno;
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struct ovsdb_idl_txn *committing_txn;
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unsigned int precommit_seqno;
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struct ovsdb_idl_txn *open_txn;
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/* These members allow a client a simple, stateless way to keep track of
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* transactions that commit: when a transaction commits successfully,
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* ovsdb_idl_loop_commit_and_wait() copies 'next_cfg' to 'cur_cfg'. Thus,
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* the client can set 'next_cfg' to a value that indicates a successful
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* commit and check 'cur_cfg' on each iteration. */
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int64_t cur_cfg;
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int64_t next_cfg;
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};
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#define OVSDB_IDL_LOOP_INITIALIZER(IDL) { .idl = (IDL) }
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void ovsdb_idl_loop_destroy(struct ovsdb_idl_loop *);
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struct ovsdb_idl_txn *ovsdb_idl_loop_run(struct ovsdb_idl_loop *);
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int ovsdb_idl_loop_commit_and_wait(struct ovsdb_idl_loop *);
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/* Conditional Replication
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* =======================
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*
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* By default, when the IDL replicates a particular table in the database, it
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* replicates every row in the table. These functions allow the client to
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* specify that only selected rows should be replicated, by constructing a
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* per-table condition that specifies the rows to replicate.
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*
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* A condition is a disjunction of clauses. The condition is true, and thus a
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* row is replicated, if any of the clauses evaluates to true for a given row.
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* (Thus, a condition with no clauses is always false.)
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*/
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struct ovsdb_idl_condition {
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struct hmap clauses; /* Contains "struct ovsdb_idl_clause"s. */
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bool is_true; /* Is the condition unconditionally true? */
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};
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#define OVSDB_IDL_CONDITION_INIT(CONDITION) \
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{ HMAP_INITIALIZER(&(CONDITION)->clauses), false }
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void ovsdb_idl_condition_init(struct ovsdb_idl_condition *);
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void ovsdb_idl_condition_clear(struct ovsdb_idl_condition *);
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void ovsdb_idl_condition_destroy(struct ovsdb_idl_condition *);
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void ovsdb_idl_condition_add_clause(struct ovsdb_idl_condition *,
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enum ovsdb_function function,
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const struct ovsdb_idl_column *column,
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const struct ovsdb_datum *arg);
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void ovsdb_idl_condition_add_clause_true(struct ovsdb_idl_condition *);
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bool ovsdb_idl_condition_is_true(const struct ovsdb_idl_condition *);
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unsigned int ovsdb_idl_set_condition(struct ovsdb_idl *,
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const struct ovsdb_idl_table_class *,
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const struct ovsdb_idl_condition *);
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unsigned int ovsdb_idl_get_condition_seqno(const struct ovsdb_idl *);
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/* The OVSDB-IDL Compound Indexes feature allows for the creation of custom
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* table indexes over one or more columns in the IDL. These indexes provide
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* the ability to retrieve rows matching a particular search criteria and to
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* iterate over a subset of rows in a defined order.
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*/
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#define OVSDB_INDEX_DESC -1
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#define OVSDB_INDEX_ASC 1
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/*
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* Skiplist comparison function. Allows to store sorted data.
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*/
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typedef int (column_comparator)(const void *a, const void *b);
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struct ovsdb_idl_index_cursor {
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struct ovsdb_idl_index *index; /* Index used by this cursor */
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struct skiplist_node *position; /* Current position in the index */
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};
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struct ovsdb_idl_index *ovsdb_idl_create_index(struct ovsdb_idl *idl,
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const struct ovsdb_idl_table_class *tc,
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const char *index_name);
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void ovsdb_idl_index_add_column(struct ovsdb_idl_index *,
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const struct ovsdb_idl_column *,
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int order,
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column_comparator *custom_comparer);
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bool ovsdb_idl_initialize_cursor(struct ovsdb_idl *,
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const struct ovsdb_idl_table_class *tc,
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const char *index_name,
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struct ovsdb_idl_index_cursor *cursor);
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void ovsdb_idl_index_write_(struct ovsdb_idl_row *,
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const struct ovsdb_idl_column *,
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struct ovsdb_datum *,
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const struct ovsdb_idl_table_class *);
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struct ovsdb_idl_row *ovsdb_idl_index_init_row(struct ovsdb_idl *,
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const struct ovsdb_idl_table_class *);
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void ovsdb_idl_index_destroy_row__(const struct ovsdb_idl_row *);
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struct ovsdb_idl_row *ovsdb_idl_index_first(struct ovsdb_idl_index_cursor *);
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struct ovsdb_idl_row *ovsdb_idl_index_next(struct ovsdb_idl_index_cursor *);
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struct ovsdb_idl_row *ovsdb_idl_index_data(struct ovsdb_idl_index_cursor *);
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struct ovsdb_idl_row *ovsdb_idl_index_find(struct ovsdb_idl_index_cursor *,
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struct ovsdb_idl_row *);
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struct ovsdb_idl_row *ovsdb_idl_index_forward_to(
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struct ovsdb_idl_index_cursor *,
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||
struct ovsdb_idl_row *);
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int ovsdb_idl_index_compare(struct ovsdb_idl_index_cursor *,
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struct ovsdb_idl_row *a,
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struct ovsdb_idl_row *b);
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#endif /* ovsdb-idl.h */
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