lib/ovsdb-data.h

   1 /* Copyright (c) 2009, 2010, 2011, 2012, 2013 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_DATA_H
  17 #define OVSDB_DATA_H 1
  18
  19 #include <stdlib.h>
  20 #include "compiler.h"
  21 #include "ovsdb-types.h"
  22 #include "shash.h"
  23
  24 struct ds;
  25 struct ovsdb_symbol_table;
  26 struct smap;
  27
  28 /* One value of an atomic type (given by enum ovs_atomic_type). */
  29 union ovsdb_atom {
  30     int64_t integer;
  31     double real;
  32     bool boolean;
  33     char *string;
  34     struct uuid uuid;
  35 };
  36
  37 void ovsdb_atom_init_default(union ovsdb_atom *, enum ovsdb_atomic_type);
  38 const union ovsdb_atom *ovsdb_atom_default(enum ovsdb_atomic_type);
  39 bool ovsdb_atom_is_default(const union ovsdb_atom *, enum ovsdb_atomic_type);
  40 void ovsdb_atom_clone(union ovsdb_atom *, const union ovsdb_atom *,
  41                       enum ovsdb_atomic_type);
  42 void ovsdb_atom_swap(union ovsdb_atom *, union ovsdb_atom *);
  43
  44 /* Returns false if ovsdb_atom_destroy() is a no-op when it is applied to an
  45  * initialized atom of the given 'type', true if ovsdb_atom_destroy() actually
  46  * does something.
  47  *
  48  * This can be used to avoid calling ovsdb_atom_destroy() for each element in
  49  * an array of homogeneous atoms.  (It's not worthwhile for a single atom.) */
  50 static inline bool
  51 ovsdb_atom_needs_destruction(enum ovsdb_atomic_type type)
  52 {
  53     return type == OVSDB_TYPE_STRING;
  54 }
  55
  56 /* Frees the contents of 'atom', which must have the specified 'type'.
  57  *
  58  * This does not actually call free(atom).  If necessary, the caller must be
  59  * responsible for that. */
  60 static inline void
  61 ovsdb_atom_destroy(union ovsdb_atom *atom, enum ovsdb_atomic_type type)
  62 {
  63     if (type == OVSDB_TYPE_STRING) {
  64         free(atom->string);
  65     }
  66 }
  67
  68 uint32_t ovsdb_atom_hash(const union ovsdb_atom *, enum ovsdb_atomic_type,
  69                          uint32_t basis);
  70
  71 int ovsdb_atom_compare_3way(const union ovsdb_atom *,
  72                             const union ovsdb_atom *,
  73                             enum ovsdb_atomic_type);
  74
  75 /* Returns true if 'a' and 'b', which are both of type 'type', has the same
  76  * contents, false if their contents differ.  */
  77 static inline bool ovsdb_atom_equals(const union ovsdb_atom *a,
  78                                      const union ovsdb_atom *b,
  79                                      enum ovsdb_atomic_type type)
  80 {
  81     return !ovsdb_atom_compare_3way(a, b, type);
  82 }
  83
  84 struct ovsdb_error *ovsdb_atom_from_json(union ovsdb_atom *,
  85                                          const struct ovsdb_base_type *,
  86                                          const struct json *,
  87                                          struct ovsdb_symbol_table *)
  88     WARN_UNUSED_RESULT;
  89 struct json *ovsdb_atom_to_json(const union ovsdb_atom *,
  90                                 enum ovsdb_atomic_type);
  91 size_t ovsdb_atom_json_length(const union ovsdb_atom *,
  92                               enum ovsdb_atomic_type);
  93
  94 char *ovsdb_atom_from_string(union ovsdb_atom *,
  95                              const struct ovsdb_base_type *, const char *,
  96                              struct ovsdb_symbol_table *)
  97     WARN_UNUSED_RESULT;
  98 void ovsdb_atom_to_string(const union ovsdb_atom *, enum ovsdb_atomic_type,
  99                           struct ds *);
 100 void ovsdb_atom_to_bare(const union ovsdb_atom *, enum ovsdb_atomic_type,
 101                         struct ds *);
 102
 103 struct ovsdb_error *ovsdb_atom_check_constraints(
 104     const union ovsdb_atom *, const struct ovsdb_base_type *)
 105     WARN_UNUSED_RESULT;
 106 \f
 107 /* An instance of an OVSDB type (given by struct ovsdb_type).
 108  *
 109  * - The 'keys' must be unique and in sorted order.  Most functions that modify
 110  *   an ovsdb_datum maintain these invariants.  Functions that don't maintain
 111  *   the invariants have names that end in "_unsafe".  Use ovsdb_datum_sort()
 112  *   to check and restore these invariants.
 113  *
 114  * - 'n' is constrained by the ovsdb_type's 'n_min' and 'n_max'.
 115  *
 116  *   If 'n' is nonzero, then 'keys' points to an array of 'n' atoms of the type
 117  *   specified by the ovsdb_type's 'key_type'.  (Otherwise, 'keys' should be
 118  *   null.)
 119  *
 120  *   If 'n' is nonzero and the ovsdb_type's 'value_type' is not
 121  *   OVSDB_TYPE_VOID, then 'values' points to an array of 'n' atoms of the type
 122  *   specified by the 'value_type'.  (Otherwise, 'values' should be null.)
 123  *
 124  *   Thus, for 'n' > 0, 'keys' will always be nonnull and 'values' will be
 125  *   nonnull only for "map" types.
 126  */
 127 struct ovsdb_datum {
 128     unsigned int n;             /* Number of 'keys' and 'values'. */
 129     union ovsdb_atom *keys;     /* Each of the ovsdb_type's 'key_type'. */
 130     union ovsdb_atom *values;   /* Each of the ovsdb_type's 'value_type'. */
 131 };
 132
 133 /* Basics. */
 134 void ovsdb_datum_init_empty(struct ovsdb_datum *);
 135 void ovsdb_datum_init_default(struct ovsdb_datum *, const struct ovsdb_type *);
 136 bool ovsdb_datum_is_default(const struct ovsdb_datum *,
 137                             const struct ovsdb_type *);
 138 const struct ovsdb_datum *ovsdb_datum_default(const struct ovsdb_type *);
 139 void ovsdb_datum_clone(struct ovsdb_datum *, const struct ovsdb_datum *,
 140                        const struct ovsdb_type *);
 141 void ovsdb_datum_destroy(struct ovsdb_datum *, const struct ovsdb_type *);
 142 void ovsdb_datum_swap(struct ovsdb_datum *, struct ovsdb_datum *);
 143
 144 /* Checking and maintaining invariants. */
 145 struct ovsdb_error *ovsdb_datum_sort(struct ovsdb_datum *,
 146                                      enum ovsdb_atomic_type key_type)
 147     WARN_UNUSED_RESULT;
 148
 149 void ovsdb_datum_sort_assert(struct ovsdb_datum *,
 150                              enum ovsdb_atomic_type key_type);
 151
 152 size_t ovsdb_datum_sort_unique(struct ovsdb_datum *,
 153                                enum ovsdb_atomic_type key_type,
 154                                enum ovsdb_atomic_type value_type);
 155
 156 struct ovsdb_error *ovsdb_datum_check_constraints(
 157     const struct ovsdb_datum *, const struct ovsdb_type *)
 158     WARN_UNUSED_RESULT;
 159
 160 /* Type conversion. */
 161 struct ovsdb_error *ovsdb_datum_from_json(struct ovsdb_datum *,
 162                                           const struct ovsdb_type *,
 163                                           const struct json *,
 164                                           struct ovsdb_symbol_table *)
 165     WARN_UNUSED_RESULT;
 166 struct json *ovsdb_datum_to_json(const struct ovsdb_datum *,
 167                                  const struct ovsdb_type *);
 168 size_t ovsdb_datum_json_length(const struct ovsdb_datum *,
 169                                const struct ovsdb_type *);
 170
 171 char *ovsdb_datum_from_string(struct ovsdb_datum *,
 172                               const struct ovsdb_type *, const char *,
 173                               struct ovsdb_symbol_table *)
 174     WARN_UNUSED_RESULT;
 175 void ovsdb_datum_to_string(const struct ovsdb_datum *,
 176                            const struct ovsdb_type *, struct ds *);
 177 void ovsdb_datum_to_bare(const struct ovsdb_datum *,
 178                          const struct ovsdb_type *, struct ds *);
 179
 180 void ovsdb_datum_from_smap(struct ovsdb_datum *, struct smap *);
 181
 182 /* Comparison. */
 183 uint32_t ovsdb_datum_hash(const struct ovsdb_datum *,
 184                           const struct ovsdb_type *, uint32_t basis);
 185 int ovsdb_datum_compare_3way(const struct ovsdb_datum *,
 186                              const struct ovsdb_datum *,
 187                              const struct ovsdb_type *);
 188 bool ovsdb_datum_equals(const struct ovsdb_datum *,
 189                         const struct ovsdb_datum *,
 190                         const struct ovsdb_type *);
 191
 192 /* Search. */
 193 unsigned int ovsdb_datum_find_key(const struct ovsdb_datum *,
 194                                   const union ovsdb_atom *key,
 195                                   enum ovsdb_atomic_type key_type);
 196 unsigned int ovsdb_datum_find_key_value(const struct ovsdb_datum *,
 197                                         const union ovsdb_atom *key,
 198                                         enum ovsdb_atomic_type key_type,
 199                                         const union ovsdb_atom *value,
 200                                         enum ovsdb_atomic_type value_type);
 201
 202 /* Set operations. */
 203 bool ovsdb_datum_includes_all(const struct ovsdb_datum *,
 204                               const struct ovsdb_datum *,
 205                               const struct ovsdb_type *);
 206 bool ovsdb_datum_excludes_all(const struct ovsdb_datum *,
 207                               const struct ovsdb_datum *,
 208                               const struct ovsdb_type *);
 209 void ovsdb_datum_union(struct ovsdb_datum *,
 210                        const struct ovsdb_datum *,
 211                        const struct ovsdb_type *,
 212                        bool replace);
 213 void ovsdb_datum_subtract(struct ovsdb_datum *a,
 214                           const struct ovsdb_type *a_type,
 215                           const struct ovsdb_datum *b,
 216                           const struct ovsdb_type *b_type);
 217
 218 /* Raw operations that may not maintain the invariants. */
 219 void ovsdb_datum_remove_unsafe(struct ovsdb_datum *, size_t idx,
 220                                const struct ovsdb_type *);
 221 void ovsdb_datum_add_unsafe(struct ovsdb_datum *,
 222                             const union ovsdb_atom *key,
 223                             const union ovsdb_atom *value,
 224                             const struct ovsdb_type *);
 225
 226 /* Type checking. */
 227 static inline bool
 228 ovsdb_datum_conforms_to_type(const struct ovsdb_datum *datum,
 229                              const struct ovsdb_type *type)
 230 {
 231     return datum->n >= type->n_min && datum->n <= type->n_max;
 232 }
 233 \f
 234 /* A table mapping from names to data items.  Currently the data items are
 235  * always UUIDs; perhaps this will be expanded in the future. */
 236
 237 struct ovsdb_symbol_table {
 238     struct shash sh;            /* Maps from name to struct ovsdb_symbol *. */
 239 };
 240
 241 struct ovsdb_symbol {
 242     struct uuid uuid;           /* The UUID that the symbol represents. */
 243     bool created;               /* Already used to create row? */
 244     bool strong_ref;            /* Parsed a strong reference to this row? */
 245     bool weak_ref;              /* Parsed a weak reference to this row? */
 246 };
 247
 248 struct ovsdb_symbol_table *ovsdb_symbol_table_create(void);
 249 void ovsdb_symbol_table_destroy(struct ovsdb_symbol_table *);
 250 struct ovsdb_symbol *ovsdb_symbol_table_get(const struct ovsdb_symbol_table *,
 251                                             const char *name);
 252 struct ovsdb_symbol *ovsdb_symbol_table_put(struct ovsdb_symbol_table *,
 253                                             const char *name,
 254                                             const struct uuid *, bool used);
 255 struct ovsdb_symbol *ovsdb_symbol_table_insert(struct ovsdb_symbol_table *,
 256                                                const char *name);
 257 \f
 258 /* Tokenization
 259  *
 260  * Used by ovsdb_atom_from_string() and ovsdb_datum_from_string(). */
 261
 262 char *ovsdb_token_parse(const char **, char **outp) WARN_UNUSED_RESULT;
 263 bool ovsdb_token_is_delim(unsigned char);
 264
 265 #endif /* ovsdb-data.h */