lib/ovsdb-data.h

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