ovsdb/column.c

   1 /* Copyright (c) 2009, 2010, 2011, 2016 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 #include <config.h>
  17
  18 #include "ovsdb/column.h"
  19
  20 #include <stdlib.h>
  21
  22 #include "column.h"
  23 #include "openvswitch/dynamic-string.h"
  24 #include "openvswitch/json.h"
  25 #include "ovsdb-error.h"
  26 #include "ovsdb-parser.h"
  27 #include "table.h"
  28 #include "util.h"
  29
  30 struct ovsdb_column *
  31 ovsdb_column_create(const char *name,
  32                     bool mutable, bool persistent,
  33                     const struct ovsdb_type *type)
  34 {
  35     /* Doesn't set the new column's 'index': the caller must do that. */
  36     struct ovsdb_column *column;
  37
  38     column = xzalloc(sizeof *column);
  39     column->name = xstrdup(name);
  40     column->mutable = mutable;
  41     column->persistent = persistent;
  42     ovsdb_type_clone(&column->type, type);
  43
  44     return column;
  45 }
  46
  47 struct ovsdb_column *
  48 ovsdb_column_clone(const struct ovsdb_column *old)
  49 {
  50     /* Doesn't copy the column's 'index': the caller must do that. */
  51     return ovsdb_column_create(old->name,
  52                                old->mutable, old->persistent,
  53                                &old->type);
  54 }
  55
  56 void
  57 ovsdb_column_destroy(struct ovsdb_column *column)
  58 {
  59     ovsdb_type_destroy(&column->type);
  60     free(column->name);
  61     free(column);
  62 }
  63
  64 struct ovsdb_error *
  65 ovsdb_column_from_json(const struct json *json, const char *name,
  66                        struct ovsdb_column **columnp)
  67 {
  68     const struct json *mutable_json, *ephemeral, *type_json;
  69     struct ovsdb_error *error;
  70     struct ovsdb_type type;
  71     struct ovsdb_parser parser;
  72
  73     *columnp = NULL;
  74
  75     ovsdb_parser_init(&parser, json, "schema for column %s", name);
  76     mutable_json = ovsdb_parser_member(&parser, "mutable",
  77                                        OP_TRUE | OP_FALSE | OP_OPTIONAL);
  78     ephemeral = ovsdb_parser_member(&parser, "ephemeral",
  79                                     OP_TRUE | OP_FALSE | OP_OPTIONAL);
  80     type_json = ovsdb_parser_member(&parser, "type", OP_STRING | OP_OBJECT);
  81     error = ovsdb_parser_finish(&parser);
  82     if (error) {
  83         return error;
  84     }
  85
  86     error = ovsdb_type_from_json(&type, type_json);
  87     if (error) {
  88         return error;
  89     }
  90
  91     bool mutable = !mutable_json || json_boolean(mutable_json);
  92     if (!mutable
  93         && (ovsdb_base_type_is_weak_ref(&type.key) ||
  94             ovsdb_base_type_is_weak_ref(&type.value))) {
  95         /* We cannot allow a weak reference to be immutable: if referenced rows
  96          * are deleted, then the weak reference needs to change. */
  97         mutable = true;
  98     }
  99
 100     bool persistent = ephemeral ? !json_boolean(ephemeral) : true;
 101     *columnp = ovsdb_column_create(name, mutable, persistent, &type);
 102
 103     ovsdb_type_destroy(&type);
 104
 105     return NULL;
 106 }
 107
 108 struct json *
 109 ovsdb_column_to_json(const struct ovsdb_column *column)
 110 {
 111     struct json *json = json_object_create();
 112     if (!column->mutable) {
 113         json_object_put(json, "mutable", json_boolean_create(false));
 114     }
 115     if (!column->persistent) {
 116         json_object_put(json, "ephemeral", json_boolean_create(true));
 117     }
 118     json_object_put(json, "type", ovsdb_type_to_json(&column->type));
 119     return json;
 120 }
 121 \f
 122 void
 123 ovsdb_column_set_init(struct ovsdb_column_set *set)
 124 {
 125     set->columns = NULL;
 126     set->n_columns = set->allocated_columns = 0;
 127 }
 128
 129 void
 130 ovsdb_column_set_destroy(struct ovsdb_column_set *set)
 131 {
 132     free(set->columns);
 133 }
 134
 135 void
 136 ovsdb_column_set_clone(struct ovsdb_column_set *new,
 137                        const struct ovsdb_column_set *old)
 138 {
 139     new->columns = xmemdup(old->columns,
 140                            old->n_columns * sizeof *old->columns);
 141     new->n_columns = new->allocated_columns = old->n_columns;
 142 }
 143
 144 struct ovsdb_error *
 145 ovsdb_column_set_from_json(const struct json *json,
 146                            const struct ovsdb_table_schema *schema,
 147                            struct ovsdb_column_set *set)
 148 {
 149     ovsdb_column_set_init(set);
 150     if (!json) {
 151         struct shash_node *node;
 152
 153         SHASH_FOR_EACH (node, &schema->columns) {
 154             const struct ovsdb_column *column = node->data;
 155             ovsdb_column_set_add(set, column);
 156         }
 157
 158         return NULL;
 159     } else {
 160         struct ovsdb_error *error = NULL;
 161         size_t i;
 162
 163         if (json->type != JSON_ARRAY) {
 164             goto error;
 165         }
 166
 167         /* XXX this is O(n**2) */
 168         for (i = 0; i < json->u.array.n; i++) {
 169             const struct ovsdb_column *column;
 170             const char *s;
 171
 172             if (json->u.array.elems[i]->type != JSON_STRING) {
 173                 goto error;
 174             }
 175
 176             s = json->u.array.elems[i]->u.string;
 177             column = shash_find_data(&schema->columns, s);
 178             if (!column) {
 179                 error = ovsdb_syntax_error(json, NULL, "%s is not a valid "
 180                                            "column name", s);
 181                 goto error;
 182             } else if (ovsdb_column_set_contains(set, column->index)) {
 183                 goto error;
 184             }
 185             ovsdb_column_set_add(set, column);
 186         }
 187         return NULL;
 188
 189     error:
 190         ovsdb_column_set_destroy(set);
 191         ovsdb_column_set_init(set);
 192         if (!error) {
 193             error = ovsdb_syntax_error(json, NULL, "array of distinct column "
 194                                        "names expected");
 195         }
 196         return error;
 197     }
 198 }
 199
 200 struct json *
 201 ovsdb_column_set_to_json(const struct ovsdb_column_set *set)
 202 {
 203     struct json *json;
 204     size_t i;
 205
 206     json = json_array_create_empty();
 207     for (i = 0; i < set->n_columns; i++) {
 208         json_array_add(json, json_string_create(set->columns[i]->name));
 209     }
 210     return json;
 211 }
 212
 213 /* Returns an English string listing the contents of 'set', e.g. "columns
 214  * \"a\", \"b\", and \"c\"".  The caller must free the string. */
 215 char *
 216 ovsdb_column_set_to_string(const struct ovsdb_column_set *set)
 217 {
 218     if (!set->n_columns) {
 219         return xstrdup("no columns");
 220     } else {
 221         struct ds s;
 222         size_t i;
 223
 224         ds_init(&s);
 225         ds_put_format(&s, "column%s ", set->n_columns > 1 ? "s" : "");
 226         for (i = 0; i < set->n_columns; i++) {
 227             const char *delimiter = english_list_delimiter(i, set->n_columns);
 228             ds_put_format(&s, "%s\"%s\"", delimiter, set->columns[i]->name);
 229         }
 230         return ds_steal_cstr(&s);
 231     }
 232 }
 233
 234 void
 235 ovsdb_column_set_add(struct ovsdb_column_set *set,
 236                      const struct ovsdb_column *column)
 237 {
 238     if (set->n_columns >= set->allocated_columns) {
 239         set->columns = x2nrealloc(set->columns, &set->allocated_columns,
 240                                   sizeof *set->columns);
 241     }
 242     set->columns[set->n_columns++] = column;
 243 }
 244
 245 void
 246 ovsdb_column_set_add_all(struct ovsdb_column_set *set,
 247                          const struct ovsdb_table *table)
 248 {
 249     struct shash_node *node;
 250
 251     SHASH_FOR_EACH (node, &table->schema->columns) {
 252         const struct ovsdb_column *column = node->data;
 253         ovsdb_column_set_add(set, column);
 254     }
 255 }
 256
 257 bool
 258 ovsdb_column_set_contains(const struct ovsdb_column_set *set,
 259                           unsigned int column_index)
 260 {
 261     size_t i;
 262
 263     for (i = 0; i < set->n_columns; i++) {
 264         if (set->columns[i]->index == column_index) {
 265             return true;
 266         }
 267     }
 268     return false;
 269 }
 270
 271 /* This comparison is sensitive to ordering of columns within a set, but that's
 272  * good: the only existing caller wants to make sure that hash values are
 273  * comparable, which is only true if column ordering is the same. */
 274 bool
 275 ovsdb_column_set_equals(const struct ovsdb_column_set *a,
 276                         const struct ovsdb_column_set *b)
 277 {
 278     size_t i;
 279
 280     if (a->n_columns != b->n_columns) {
 281         return false;
 282     }
 283     for (i = 0; i < a->n_columns; i++) {
 284         if (a->columns[i] != b->columns[i]) {
 285             return false;
 286         }
 287     }
 288     return true;
 289 }