store_expr: Added support to include field values in an expression.

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

diff --git a/src/include/core/store.h b/src/include/core/store.h
index 578fb51e7087e72b634cb60f4b44cc32738a5b9d..760c23d9fa89f7151b0e33267ebcaff0e37936c1 100644 (file)
--- a/src/include/core/store.h
+++ b/src/include/core/store.h
@@ -53,7 +53,6 @@ enum {
                : ((t) == SDB_SERVICE) ? "service" \
                : ((t) == SDB_ATTRIBUTE) ? "attribute" : "unknown")
 
-
 /*
  * sdb_store_obj_t represents the super-class of any object stored in the
  * database. It inherits from sdb_object_t and may safely be cast to a generic
@@ -62,6 +61,22 @@ enum {
 struct sdb_store_obj;
 typedef struct sdb_store_obj sdb_store_obj_t;
 
+/*
+ * Queryable fields of a stored object.
+ */
+enum {
+       SDB_FIELD_LAST_UPDATE = 1, /* datetime */
+       SDB_FIELD_AGE,             /* datetime */
+       SDB_FIELD_INTERVAL,        /* datetime */
+       SDB_FIELD_BACKEND,         /* string */
+};
+
+#define SDB_FIELD_TO_NAME(f) \
+       (((f) == SDB_FIELD_LAST_UPDATE) ? "last-update" \
+               : ((f) == SDB_FIELD_AGE) ? "age" \
+               : ((f) == SDB_FIELD_INTERVAL) ? "interval" \
+               : ((f) == SDB_FIELD_BACKEND) ? "backend" : "unknown")
+
 /*
  * sdb_store_clear:
  * Clear the entire store and remove all stored objects.
@@ -158,6 +173,21 @@ int
 sdb_store_service_attr(const char *hostname, const char *service,
                const char *key, const sdb_data_t *value, sdb_time_t last_update);
 
+/*
+ * sdb_store_get_field:
+ * Get the value of a stored object's queryable field. The caller is
+ * responsible for freeing any dynamically allocated memory possibly stored in
+ * the returned value.
+ *
+ * Note: Retrieving the backend this way is not currently supported.
+ *
+ * Returns:
+ *  - 0 on success
+ *  - a negative value else
+ */
+int
+sdb_store_get_field(sdb_store_obj_t *obj, int field, sdb_data_t *res);
+
 /*
  * Expressions specify arithmetic expressions.
  *
@@ -180,6 +210,18 @@ typedef struct sdb_store_expr sdb_store_expr_t;
 sdb_store_expr_t *
 sdb_store_expr_create(int op, sdb_store_expr_t *left, sdb_store_expr_t *right);
 
+/*
+ * sdb_store_expr_fieldvalue:
+ * Creates an expression which evaluates to the value of the specified
+ * queryable field of a stored object.
+ *
+ * Returns:
+ *  - an expression object on success
+ *  - NULL else
+ */
+sdb_store_expr_t *
+sdb_store_expr_fieldvalue(int field);
+
 /*
  * sdb_store_expr_constvalue:
  * Creates an expression which evaluates to the specified constant value.
@@ -193,16 +235,19 @@ sdb_store_expr_constvalue(const sdb_data_t *value);
 
 /*
  * sdb_store_expr_eval:
- * Evaluate an expression and stores the result in 'res'. The result's value
- * will be allocated dynamically if necessary and, thus, should be free'd by
- * the caller (e.g. using sdb_data_free_datum);
+ * Evaluate an expression for the specified stored object and stores the
+ * result in 'res'. The result's value will be allocated dynamically if
+ * necessary and, thus, should be free'd by the caller (e.g. using
+ * sdb_data_free_datum). The object may be NULL, in which case the expression
+ * needs to evaluate to a constant value.
  *
  * Returns:
  *  - 0 on success
  *  - a negative value else
  */
 int
-sdb_store_expr_eval(sdb_store_expr_t *expr, sdb_data_t *res);
+sdb_store_expr_eval(sdb_store_expr_t *expr, sdb_store_obj_t *obj,
+               sdb_data_t *res);
 
 /*
  * Conditionals may be used to lookup hosts from the store based on a
@@ -224,6 +269,15 @@ typedef struct sdb_store_cond sdb_store_cond_t;
 sdb_store_cond_t *
 sdb_store_attr_cond(const char *name, sdb_store_expr_t *expr);
 
+/*
+ * sdb_store_obj_cond:
+ * Creates a conditional based on queryable object fields. The respective
+ * field of *any* object type is compared against the value the expression
+ * evaluates to.
+ */
+sdb_store_cond_t *
+sdb_store_obj_cond(int field, sdb_store_expr_t *expr);
+
 /*
  * 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
@@ -293,6 +347,19 @@ sdb_store_matcher_t *
 sdb_store_matcher_parse_cmp(const char *obj_type, const char *attr,
                const char *op, sdb_store_expr_t *expr);
 
+/*
+ * sdb_store_matcher_parse_field_cmp:
+ * Parse a simple compare expression for queryable object fields (<field> <op>
+ * <expression>).
+ *
+ * Returns:
+ *  - a matcher object on success
+ *  - NULL else
+ */
+sdb_store_matcher_t *
+sdb_store_matcher_parse_field_cmp(const char *name, const char *op,
+               sdb_store_expr_t *expr);
+
 /*
  * sdb_store_dis_matcher:
  * Creates a matcher matching the disjunction (logical OR) of two matchers.
@@ -381,26 +448,32 @@ enum {
 /*
  * sdb_store_tojson:
  * Serialize the entire store to JSON and append the result to the specified
- * buffer.
+ * buffer. If specified, only objects matching the filter will be included in
+ * the result (see sdb_store_host_tojson for details).
  *
  * Returns:
  *  - 0 on success
  *  - a negative value on error
  */
 int
-sdb_store_tojson(sdb_strbuf_t *buf, int flags);
+sdb_store_tojson(sdb_strbuf_t *buf, sdb_store_matcher_t *filter, int flags);
 
 /*
  * sdb_store_host_tojson:
  * Serialize a host object to JSON and append the result to the specified
- * buffer.
+ * buffer. If specified, only objects matching the filter will be included in
+ * the result. The filter is applied to each object individually and, thus,
+ * should not be of any object-type specific kind. The filter is never applied
+ * to the specified host object; the caller is responsible for this and for
+ * correctly handling skipped hosts.
  *
  * Returns:
  *  - 0 on success
  *  - a negative value on error
  */
 int
-sdb_store_host_tojson(sdb_store_obj_t *host, sdb_strbuf_t *buf, int flags);
+sdb_store_host_tojson(sdb_store_obj_t *host, sdb_strbuf_t *buf,
+               sdb_store_matcher_t *filter, int flags);
 
 /*
  * sdb_store_iter_cb: