+
+/* Returns the most recent IDL change sequence number that caused a
+ * insert, modify or delete update to the table with class 'table_class'.
+ */
+unsigned int
+ovsdb_idl_table_get_seqno(const struct ovsdb_idl *idl,
+ const struct ovsdb_idl_table_class *table_class)
+{
+ struct ovsdb_idl_table *table
+ = ovsdb_idl_table_from_class(idl, table_class);
+ unsigned int max_seqno = table->change_seqno[OVSDB_IDL_CHANGE_INSERT];
+
+ if (max_seqno < table->change_seqno[OVSDB_IDL_CHANGE_MODIFY]) {
+ max_seqno = table->change_seqno[OVSDB_IDL_CHANGE_MODIFY];
+ }
+ if (max_seqno < table->change_seqno[OVSDB_IDL_CHANGE_DELETE]) {
+ max_seqno = table->change_seqno[OVSDB_IDL_CHANGE_DELETE];
+ }
+ return max_seqno;
+}
+
+/* For each row that contains tracked columns, IDL stores the most
+ * recent IDL change sequence numbers associateed with insert, modify
+ * and delete updates to the table.
+ */
+unsigned int
+ovsdb_idl_row_get_seqno(const struct ovsdb_idl_row *row,
+ enum ovsdb_idl_change change)
+{
+ return row->change_seqno[change];
+}
+
+/* Turns on OVSDB_IDL_TRACK for 'column' in 'idl', ensuring that
+ * all rows whose 'column' is modified are traced. Similarly, insert
+ * or delete of rows having 'column' are tracked. Clients are able
+ * to retrive the tracked rows with the ovsdb_idl_track_get_*()
+ * functions.
+ *
+ * This function should be called between ovsdb_idl_create() and
+ * the first call to ovsdb_idl_run(). The column to be tracked
+ * should have OVSDB_IDL_ALERT turned on.
+ */
+void
+ovsdb_idl_track_add_column(struct ovsdb_idl *idl,
+ const struct ovsdb_idl_column *column)
+{
+ if (!(*ovsdb_idl_get_mode(idl, column) & OVSDB_IDL_ALERT)) {
+ ovsdb_idl_add_column(idl, column);
+ }
+ *ovsdb_idl_get_mode(idl, column) |= OVSDB_IDL_TRACK;
+}
+
+void
+ovsdb_idl_track_add_all(struct ovsdb_idl *idl)
+{
+ size_t i, j;
+
+ for (i = 0; i < idl->class->n_tables; i++) {
+ const struct ovsdb_idl_table_class *tc = &idl->class->tables[i];
+
+ for (j = 0; j < tc->n_columns; j++) {
+ const struct ovsdb_idl_column *column = &tc->columns[j];
+ ovsdb_idl_track_add_column(idl, column);
+ }
+ }
+}
+
+/* Returns true if 'table' has any tracked column. */
+static bool
+ovsdb_idl_track_is_set(struct ovsdb_idl_table *table)
+{
+ size_t i;
+
+ for (i = 0; i < table->class->n_columns; i++) {
+ if (table->modes[i] & OVSDB_IDL_TRACK) {
+ return true;
+ }
+ }
+ return false;
+}
+
+/* Returns the first tracked row in table with class 'table_class'
+ * for the specified 'idl'. Returns NULL if there are no tracked rows */
+const struct ovsdb_idl_row *
+ovsdb_idl_track_get_first(const struct ovsdb_idl *idl,
+ const struct ovsdb_idl_table_class *table_class)
+{
+ struct ovsdb_idl_table *table
+ = ovsdb_idl_table_from_class(idl, table_class);
+
+ if (!list_is_empty(&table->track_list)) {
+ return CONTAINER_OF(list_front(&table->track_list), struct ovsdb_idl_row, track_node);
+ }
+ return NULL;
+}
+
+/* Returns the next tracked row in table after the specified 'row'
+ * (in no particular order). Returns NULL if there are no tracked rows */
+const struct ovsdb_idl_row *
+ovsdb_idl_track_get_next(const struct ovsdb_idl_row *row)
+{
+ if (row->track_node.next != &row->table->track_list) {
+ return CONTAINER_OF(row->track_node.next, struct ovsdb_idl_row, track_node);
+ }
+
+ return NULL;
+}
+
+/* Returns true if a tracked 'column' in 'row' was updated by IDL, false
+ * otherwise. The tracking data is cleared by ovsdb_idl_track_clear()
+ *
+ * Function returns false if 'column' is not tracked (see
+ * ovsdb_idl_track_add_column()).
+ */
+bool
+ovsdb_idl_track_is_updated(const struct ovsdb_idl_row *row,
+ const struct ovsdb_idl_column *column)
+{
+ const struct ovsdb_idl_table_class *class;
+ size_t column_idx;
+
+ class = row->table->class;
+ column_idx = column - class->columns;
+
+ if (row->updated && bitmap_is_set(row->updated, column_idx)) {
+ return true;
+ } else {
+ return false;
+ }
+}
+
+/* Flushes the tracked rows. Client calls this function after calling
+ * ovsdb_idl_run() and read all tracked rows with the ovsdb_idl_track_get_*()
+ * functions. This is usually done at the end of the client's processing
+ * loop when it is ready to do ovsdb_idl_run() again.
+ */
+void
+ovsdb_idl_track_clear(const struct ovsdb_idl *idl)
+{
+ size_t i;
+
+ for (i = 0; i < idl->class->n_tables; i++) {
+ struct ovsdb_idl_table *table = &idl->tables[i];
+
+ if (!list_is_empty(&table->track_list)) {
+ struct ovsdb_idl_row *row, *next;
+
+ LIST_FOR_EACH_SAFE(row, next, track_node, &table->track_list) {
+ if (row->updated) {
+ free(row->updated);
+ row->updated = NULL;
+ }
+ list_remove(&row->track_node);
+ list_init(&row->track_node);
+ if (ovsdb_idl_row_is_orphan(row)) {
+ ovsdb_idl_row_clear_old(row);
+ free(row);
+ }
+ }
+ }
+ }
+}
+