2 * Copyright (c) 2015 Nicira, Inc.
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.
18 #define DB_CTL_BASE_H 1
21 #include "dynamic-string.h"
29 struct ovsdb_symbol_table;
32 /* This library module contains the common parts for ovsdb manipulation
33 * (structs, commands and functions). To utilize this module, user must
34 * define the following:
36 * - the 'the_idl' and 'the_idl_txn'.
38 * - the command syntaxes for each command. (See 'struct ctl_command_syntax'
39 * for more info) and regiters them using ctl_register_commands().
41 * - the *ctl command context by inheriting the 'struct ctl_context' for
42 * additional commands implemented by user. (See 'struct ctl_context' for
45 * - the 'tables[]' for each table in the schema.
49 /* ctl_fatal() also logs the error, so it is preferred in this file. */
50 #define ovs_fatal please_use_ctl_fatal_instead_of_ovs_fatal
52 /* idl and idl transaction to be used for the *ctl command execution.
53 * User must provide them. */
54 extern struct ovsdb_idl *the_idl;
55 extern struct ovsdb_idl_txn *the_idl_txn;
58 char *ctl_default_db(void);
59 OVS_NO_RETURN void ctl_exit(int status);
60 OVS_NO_RETURN void ctl_fatal(const char *, ...) OVS_PRINTF_FORMAT(1, 2);
62 /* *clt command syntax structure, to be defined by each command implementation.
67 * Three stylized functions accompany each of these data structures:
69 * "pre-run" "run" "post-run"
70 * --------------- ------------ -----------------
71 * *ctl ->prerequisites ->run ->postprocess
73 * Any *clt command implementation should go through the following execution
76 * 1. parses user command-line input and finds the corresponding syntax
79 * 2. calls prerequisites() for getting the columns or tables used by each
82 * 3. calls run() to execute each command and to generate output.
84 * 4. calls postprocess() after output has been committed. (Only needed
85 * by 'create' command sofar)
90 * Each of the stylized functions requires the 'struct ctl_context' as input
91 * to provide context e.g. command-line arguments, table to be modified. User
92 * may define more specific context (by inheriting 'struct ctl_context') and
93 * write stylized functions that use it. In that case, CONTAINER_OF() can
94 * be used to cast the generic context to the specific one.
97 struct ctl_command_syntax {
98 const char *name; /* e.g. "add-br" */
99 int min_args; /* Min number of arguments following name. */
100 int max_args; /* Max number of arguments following name. */
102 /* Names that roughly describe the arguments that the command
103 * uses. These should be similar to the names displayed in the
104 * man page or in the help output. */
105 const char *arguments;
107 /* If nonnull, calls ovsdb_idl_add_column() or ovsdb_idl_add_table() for
108 * each column or table in ctx->idl that it uses. */
109 void (*prerequisites)(struct ctl_context *ctx);
111 /* Does the actual work of the command and puts the command's output, if
112 * any, in ctx->output or ctx->table.
114 * Alternatively, if some prerequisite of the command is not met and the
115 * caller should wait for something to change and then retry, it may set
116 * ctx->try_again to true. (Only the "wait-until" command currently does
118 void (*run)(struct ctl_context *ctx);
120 /* If nonnull, called after the transaction has been successfully
121 * committed. ctx->output is the output from the "run" function, which
122 * this function may modify and otherwise postprocess as needed. (Only the
123 * "create" command currently does any postprocessing.) */
124 void (*postprocess)(struct ctl_context *ctx);
126 /* A comma-separated list of supported options, e.g. "--a,--b", or the
127 * empty string if the command does not support any options. */
130 enum { RO, RW } mode; /* Does this command modify the database? */
133 /* A command extracted from command-line input plus the structs for
134 * output generation. */
136 /* Data that remains constant after initialization. */
137 const struct ctl_command_syntax *syntax;
140 struct shash options;
142 /* Data modified by commands. */
147 bool ctl_might_write_to_db(char **argv);
148 const char *ctl_get_db_cmd_usage(void);
149 void ctl_print_commands(void);
150 void ctl_print_options(const struct option *);
151 void ctl_add_cmd_options(struct option **, size_t *n_options_p,
152 size_t *allocated_options_p, int opt_val);
153 void ctl_register_commands(const struct ctl_command_syntax *);
154 const struct shash *ctl_get_all_commands(void);
155 struct ctl_command *ctl_parse_commands(int argc, char *argv[],
156 struct shash *local_options,
157 size_t *n_commandsp);
159 /* The base context struct for conducting the common database
160 * operations (commands listed in 'db_ctl_commands'). User should
161 * define the per-schema context by inheriting this struct as base.
166 * User may implement caches for contents of the database to facilitate
167 * specific commands. In that case, the common commands defined in
168 * 'db_ctl_commands' that may invalidate the cache must call the
169 * invalidate_cache().
176 struct shash options;
178 /* Modifiable state. */
181 struct ovsdb_idl *idl;
182 struct ovsdb_idl_txn *txn;
183 struct ovsdb_symbol_table *symtab;
185 /* For implementation with a cache of the contents of the database,
186 * this function will be called when the database is changed and the
187 * change makes the cache no longer valid. */
188 void (*invalidate_cache)(struct ctl_context *);
190 /* A command may set this member to true if some prerequisite is not met
191 * and the caller should wait for something to change and then retry. */
195 void ctl_context_init_command(struct ctl_context *, struct ctl_command *);
196 void ctl_context_init(struct ctl_context *, struct ctl_command *,
197 struct ovsdb_idl *, struct ovsdb_idl_txn *,
198 struct ovsdb_symbol_table *,
199 void (*invalidate_cache)(struct ctl_context *));
200 void ctl_context_done_command(struct ctl_context *, struct ctl_command *);
201 void ctl_context_done(struct ctl_context *, struct ctl_command *);
204 const struct ovsdb_idl_table_class *table;
205 const struct ovsdb_idl_column *name_column;
206 const struct ovsdb_idl_column *uuid_column;
209 struct ctl_table_class {
210 struct ovsdb_idl_table_class *class;
211 struct ctl_row_id row_ids[2];
214 /* Represents all tables in the schema. User must define 'tables'
215 * in implementation. And the definition must end with an all-NULL
217 extern const struct ctl_table_class tables[];
219 const struct ctl_table_class * get_table(const char *table_name);
220 void set_column(const struct ctl_table_class *,
221 const struct ovsdb_idl_row *, const char *arg,
222 struct ovsdb_symbol_table *);
224 #endif /* db-ctl-base.h */