store: Add support for iterable expressions.

[sysdb.git] / src / include / core / store.h

diff --git a/src/include/core/store.h b/src/include/core/store.h
index 68f094b4a9d996a85fb40292656e9fcad4bd8cff..e83ff8486ebcf2a8d21a49a9c8da87ddeceba9ec 100644 (file)
--- a/src/include/core/store.h
+++ b/src/include/core/store.h
@@ -113,6 +113,13 @@ struct sdb_store_expr;
 typedef struct sdb_store_expr sdb_store_expr_t;
 #define SDB_STORE_EXPR(obj) ((sdb_store_expr_t *)(obj))
 
+/*
+ * An expression iterator iterates over the values of an iterable expression
+ * (see sdb_store_expr_iterable).
+ */
+struct sdb_store_expr_iter;
+typedef struct sdb_store_expr_iter sdb_store_expr_iter_t;
+
 /*
  * Store matchers may be used to lookup hosts from the store based on their
  * various attributes. Service and attribute matchers are applied to a host's
@@ -425,6 +432,34 @@ int
 sdb_store_expr_eval(sdb_store_expr_t *expr, sdb_store_obj_t *obj,
                sdb_data_t *res, sdb_store_matcher_t *filter);
 
+/*
+ * sdb_store_expr_iterable:
+ * Check whether an expression, evaluated in the specified context (HOST,
+ * SERVICE, METRIC) is iterable, that is, if it may evaluate to multiple
+ * values.
+ */
+bool
+sdb_store_expr_iterable(sdb_store_expr_t *expr, int context);
+
+/*
+ * sdb_store_expr_iter:
+ * Iterate over the elements of an iterable expression. sdb_store_expr_iter
+ * returns NULL if the expression is not iterable (for the specified object).
+ * See also sdb_store_expr_iterable.
+ *
+ * sdb_store_expr_iter_get_next returns NULL if there is no next element.
+ */
+sdb_store_expr_iter_t *
+sdb_store_expr_iter(sdb_store_expr_t *expr, sdb_store_obj_t *obj,
+               sdb_store_matcher_t *filter);
+void
+sdb_store_expr_iter_destroy(sdb_store_expr_iter_t *iter);
+
+bool
+sdb_store_expr_iter_has_next(sdb_store_expr_iter_t *iter);
+sdb_data_t
+sdb_store_expr_iter_get_next(sdb_store_expr_iter_t *iter);
+
 /*
  * sdb_store_dis_matcher:
  * Creates a matcher matching the disjunction (logical OR) of two matchers.