store: Add sdb_store_query_prepare().

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

diff --git a/src/include/core/store.h b/src/include/core/store.h
index 68f094b4a9d996a85fb40292656e9fcad4bd8cff..0abf0cb467d3d0a66fb3f99008537bce2f8848de 100644 (file)
--- a/src/include/core/store.h
+++ b/src/include/core/store.h
@@ -33,6 +33,7 @@
 #include "core/data.h"
 #include "core/time.h"
 #include "core/timeseries.h"
+#include "parser/ast.h"
 #include "utils/strbuf.h"
 
 #include <stdbool.h>
@@ -60,6 +61,7 @@ enum {
        SDB_FIELD_AGE,           /* type: datetime */
        SDB_FIELD_INTERVAL,      /* type: datetime */
        SDB_FIELD_BACKEND,       /* type: array of strings */
+       SDB_FIELD_VALUE,         /* attributes only;  type: type of the value */
 };
 #define SDB_STORE_TYPE_TO_NAME(t) \
        (((t) == SDB_HOST) ? "host" \
@@ -76,7 +78,9 @@ enum {
                : ((f) == SDB_FIELD_LAST_UPDATE) ? "last-update" \
                : ((f) == SDB_FIELD_AGE) ? "age" \
                : ((f) == SDB_FIELD_INTERVAL) ? "interval" \
-               : ((f) == SDB_FIELD_BACKEND) ? "backend" : "unknown")
+               : ((f) == SDB_FIELD_BACKEND) ? "backend" \
+               : ((f) == SDB_FIELD_VALUE) ? "value" \
+               : "unknown")
 
 #define SDB_FIELD_TYPE(f) \
        (((f) == SDB_FIELD_NAME) ? SDB_TYPE_STRING \
@@ -84,6 +88,7 @@ enum {
                : ((f) == SDB_FIELD_AGE) ? SDB_TYPE_DATETIME \
                : ((f) == SDB_FIELD_INTERVAL) ? SDB_TYPE_DATETIME \
                : ((f) == SDB_FIELD_BACKEND) ? (SDB_TYPE_ARRAY | SDB_TYPE_STRING) \
+               : ((f) == SDB_FIELD_VALUE) ? -1 /* unknown */ \
                : -1)
 
 /*
@@ -113,6 +118,13 @@ 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
@@ -348,6 +360,17 @@ int
 sdb_store_get_attr(sdb_store_obj_t *obj, const char *name, sdb_data_t *res,
                sdb_store_matcher_t *filter);
 
+/*
+ * sdb_store_query_prepare:
+ * Prepare the query described by 'ast' for execution in a store.
+ *
+ * Returns:
+ *  - a store matcher on success
+ *  - NULL else
+ */
+sdb_store_matcher_t *
+sdb_store_query_prepare(sdb_ast_node_t *ast);
+
 /*
  * sdb_store_expr_create:
  * Creates an arithmetic expression implementing the specified operator on the
@@ -425,6 +448,34 @@ 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.
@@ -448,19 +499,21 @@ sdb_store_inv_matcher(sdb_store_matcher_t *m);
 
 /*
  * sdb_store_any_matcher:
- * Creates a matcher iterating over objects of the specified type. It matches
- * if *any* of those objects match 'm'.
+ * Creates a matcher iterating over values of the first expression (which has
+ * to be iterable). It matches if *any* of those elements match 'm'. 'm' has
+ * to be an ary operation with the left operand unset.
  */
 sdb_store_matcher_t *
-sdb_store_any_matcher(int type, sdb_store_matcher_t *m);
+sdb_store_any_matcher(sdb_store_expr_t *iter, sdb_store_matcher_t *m);
 
 /*
  * sdb_store_all_matcher:
- * Creates a matcher iterating over objects of the specified type. It matches
- * if *all* of those objects match 'm'.
+ * Creates a matcher iterating over values of the first expression (which has
+ * to be iterable). It matches if *all* of those elements match 'm'. 'm' has
+ * to be an ary operation with the left operand unset.
  */
 sdb_store_matcher_t *
-sdb_store_all_matcher(int type, sdb_store_matcher_t *m);
+sdb_store_all_matcher(sdb_store_expr_t *iter, sdb_store_matcher_t *m);
 
 /*
  * sdb_store_in_matcher: