ovsdb/row.h

   1 /* Copyright (c) 2009, 2010, 2011, 2012 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_ROW_H
  17 #define OVSDB_ROW_H 1
  18
  19 #include <stddef.h>
  20 #include <stdint.h>
  21 #include "column.h"
  22 #include "openvswitch/hmap.h"
  23 #include "openvswitch/list.h"
  24 #include "ovsdb-data.h"
  25
  26 struct ovsdb_column_set;
  27
  28 /* A weak reference.
  29  *
  30  * When a column in row A contains a weak reference to UUID of a row B this
  31  * constitutes a weak reference from A (the source) to B (the destination).
  32  *
  33  * Rows A and B may be in the same table or different tables.
  34  *
  35  * Weak references from a row to itself are allowed, but no "struct
  36  * ovsdb_weak_ref" structures are created for them.
  37  */
  38 struct ovsdb_weak_ref {
  39     struct ovs_list src_node;      /* In src->src_refs list. */
  40     struct ovs_list dst_node;      /* In destination row's dst_refs list. */
  41     struct ovsdb_row *src;         /* Source row. */
  42     struct ovsdb_table *dst_table; /* Destination table. */
  43     struct uuid dst;               /* Destination row uuid. */
  44 };
  45
  46 /* A row in a database table. */
  47 struct ovsdb_row {
  48     struct hmap_node hmap_node;    /* Element in ovsdb_table's 'rows' hmap. */
  49     struct ovsdb_table *table;     /* Table to which this belongs. */
  50     struct ovsdb_txn_row *txn_row; /* Transaction that row is in, if any. */
  51
  52     /* Weak references.  Updated and checked only at transaction commit. */
  53     struct ovs_list src_refs;   /* Weak references from this row. */
  54     struct ovs_list dst_refs;   /* Weak references to this row. */
  55
  56     /* Number of strong refs to this row from other rows, in this table or
  57      * other tables, through 'uuid' columns that have a 'refTable' constraint
  58      * pointing to this table and a 'refType' of "strong".  A row with nonzero
  59      * 'n_refs' cannot be deleted.  Updated and checked only at transaction
  60      * commit. */
  61     size_t n_refs;
  62
  63     /* One datum for each column (shash_count(&table->schema->columns)
  64      * elements). */
  65     struct ovsdb_datum fields[];
  66
  67     /* Followed by table->schema->n_indexes "struct hmap_node"s.  In rows that
  68      * have have been committed as part of the database, the hmap_node with
  69      * index 'i' is contained in hmap table->indexes[i].  */
  70 };
  71
  72 struct ovsdb_row *ovsdb_row_create(const struct ovsdb_table *);
  73 struct ovsdb_row *ovsdb_row_clone(const struct ovsdb_row *);
  74 void ovsdb_row_destroy(struct ovsdb_row *);
  75
  76 uint32_t ovsdb_row_hash_columns(const struct ovsdb_row *,
  77                                 const struct ovsdb_column_set *,
  78                                 uint32_t basis);
  79 bool ovsdb_row_equal_columns(const struct ovsdb_row *,
  80                              const struct ovsdb_row *,
  81                              const struct ovsdb_column_set *);
  82 int ovsdb_row_compare_columns_3way(const struct ovsdb_row *,
  83                                    const struct ovsdb_row *,
  84                                    const struct ovsdb_column_set *);
  85 void ovsdb_row_update_columns(struct ovsdb_row *, const struct ovsdb_row *,
  86                               const struct ovsdb_column_set *);
  87 void ovsdb_row_columns_to_string(const struct ovsdb_row *,
  88                                  const struct ovsdb_column_set *, struct ds *);
  89 struct ovsdb_error *ovsdb_row_from_json(struct ovsdb_row *,
  90                                         const struct json *,
  91                                         struct ovsdb_symbol_table *,
  92                                         struct ovsdb_column_set *included)
  93     OVS_WARN_UNUSED_RESULT;
  94 struct json *ovsdb_row_to_json(const struct ovsdb_row *,
  95                                const struct ovsdb_column_set *include);
  96
  97 static inline const struct uuid *
  98 ovsdb_row_get_uuid(const struct ovsdb_row *row)
  99 {
 100     return &row->fields[OVSDB_COL_UUID].keys[0].uuid;
 101 }
 102
 103 static inline struct uuid *
 104 ovsdb_row_get_uuid_rw(struct ovsdb_row *row)
 105 {
 106     return &row->fields[OVSDB_COL_UUID].keys[0].uuid;
 107 }
 108
 109 static inline const struct uuid *
 110 ovsdb_row_get_version(const struct ovsdb_row *row)
 111 {
 112     return &row->fields[OVSDB_COL_VERSION].keys[0].uuid;
 113 }
 114
 115 static inline struct uuid *
 116 ovsdb_row_get_version_rw(struct ovsdb_row *row)
 117 {
 118     return &row->fields[OVSDB_COL_VERSION].keys[0].uuid;
 119 }
 120
 121 static inline uint32_t
 122 ovsdb_row_hash(const struct ovsdb_row *row)
 123 {
 124     return uuid_hash(ovsdb_row_get_uuid(row));
 125 }
 126 \f
 127 /* An unordered collection of rows. */
 128 struct ovsdb_row_set {
 129     const struct ovsdb_row **rows;
 130     size_t n_rows, allocated_rows;
 131 };
 132
 133 #define OVSDB_ROW_SET_INITIALIZER { NULL, 0, 0 }
 134
 135 void ovsdb_row_set_init(struct ovsdb_row_set *);
 136 void ovsdb_row_set_destroy(struct ovsdb_row_set *);
 137 void ovsdb_row_set_add_row(struct ovsdb_row_set *, const struct ovsdb_row *);
 138
 139 struct json *ovsdb_row_set_to_json(const struct ovsdb_row_set *,
 140                                    const struct ovsdb_column_set *);
 141
 142 void ovsdb_row_set_sort(struct ovsdb_row_set *,
 143                         const struct ovsdb_column_set *);
 144 \f
 145 /* A hash table of rows.  A specified set of columns is used for hashing and
 146  * comparing rows.
 147  *
 148  * The row hash doesn't necessarily own its rows.  They may be owned by, for
 149  * example, an ovsdb_table. */
 150 struct ovsdb_row_hash {
 151     struct hmap rows;
 152     struct ovsdb_column_set columns;
 153 };
 154
 155 #define OVSDB_ROW_HASH_INITIALIZER(RH) \
 156     { HMAP_INITIALIZER(&(RH).rows), OVSDB_COLUMN_SET_INITIALIZER }
 157
 158 struct ovsdb_row_hash_node {
 159     struct hmap_node hmap_node;
 160     const struct ovsdb_row *row;
 161 };
 162
 163 void ovsdb_row_hash_init(struct ovsdb_row_hash *,
 164                          const struct ovsdb_column_set *);
 165 void ovsdb_row_hash_destroy(struct ovsdb_row_hash *, bool destroy_rows);
 166 size_t ovsdb_row_hash_count(const struct ovsdb_row_hash *);
 167 bool ovsdb_row_hash_contains(const struct ovsdb_row_hash *,
 168                              const struct ovsdb_row *);
 169 bool ovsdb_row_hash_contains_all(const struct ovsdb_row_hash *,
 170                                  const struct ovsdb_row_hash *);
 171 bool ovsdb_row_hash_insert(struct ovsdb_row_hash *, const struct ovsdb_row *);
 172 bool ovsdb_row_hash_contains__(const struct ovsdb_row_hash *,
 173                                const struct ovsdb_row *, size_t hash);
 174 bool ovsdb_row_hash_insert__(struct ovsdb_row_hash *,
 175                              const struct ovsdb_row *, size_t hash);
 176
 177 #endif /* ovsdb/row.h */