![[tokkee]](http://tokkee.org/images/avatar.png){kind=avatar}
index 580dce06b9a184c17e0c25ce7bc25b75b312be75..c051252f771616ad3df65eba06fbf9fe1bd3f447 100644 (file)
--- a/src/include/core/store.h
+++ b/src/include/core/store.h
#include "core/data.h"
#include "core/time.h"
#include "core/timeseries.h"
+#include "parser/ast.h"
#include "utils/strbuf.h"
+#include <stdbool.h>
#include <stdio.h>
#ifdef __cplusplus
SDB_HOST = 1,
SDB_SERVICE,
SDB_METRIC,
- SDB_ATTRIBUTE,
+
+ SDB_ATTRIBUTE = 1 << 4,
/*
* Queryable fields of a stored object.
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" \
: ((t) == SDB_SERVICE) ? "service" \
: ((t) == SDB_METRIC) ? "metric" \
- : ((t) == SDB_ATTRIBUTE) ? "attribute" : "unknown")
+ : ((t) == SDB_ATTRIBUTE) ? "attribute" \
+ : ((t) == (SDB_ATTRIBUTE | SDB_HOST)) ? "host attribute" \
+ : ((t) == (SDB_ATTRIBUTE | SDB_SERVICE)) ? "service attribute" \
+ : ((t) == (SDB_ATTRIBUTE | SDB_METRIC)) ? "metric attribute" \
+ : "unknown")
#define SDB_FIELD_TO_NAME(f) \
(((f) == SDB_FIELD_NAME) ? "name" \
: ((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 \
: ((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)
/*
struct sdb_store_obj;
typedef struct sdb_store_obj sdb_store_obj_t;
+/*
+ * A metric store describes how to access a metric's data.
+ */
+typedef struct {
+ const char *type;
+ const char *id;
+} sdb_metric_store_t;
+
/*
* Expressions represent arithmetic expressions based on stored objects and
* their various attributes.
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
struct sdb_store_json_formatter;
typedef struct sdb_store_json_formatter sdb_store_json_formatter_t;
+/*
+ * A store writer describes the interface for plugins implementing a store.
+ */
+typedef struct {
+ int (*store_host)(const char *name, sdb_time_t last_update,
+ sdb_object_t *user_data);
+ int (*store_service)(const char *hostname, const char *name,
+ sdb_time_t last_update, sdb_object_t *user_data);
+ int (*store_metric)(const char *hostname, const char *name,
+ sdb_metric_store_t *store, sdb_time_t last_update,
+ sdb_object_t *user_data);
+ int (*store_attribute)(const char *hostname,
+ const char *key, const sdb_data_t *value, sdb_time_t last_update,
+ sdb_object_t *user_data);
+ int (*store_service_attr)(const char *hostname, const char *service,
+ const char *key, const sdb_data_t *value, sdb_time_t last_update,
+ sdb_object_t *user_data);
+ int (*store_metric_attr)(const char *hostname, const char *metric,
+ const char *key, const sdb_data_t *value, sdb_time_t last_update,
+ sdb_object_t *user_data);
+} sdb_store_writer_t;
+
/*
* sdb_store_clear:
* Clear the entire store and remove all stored objects.
* sdb_store_get_host increments the ref count of the host object. The caller
* needs to deref it when no longer using it.
*/
-_Bool
+bool
sdb_store_has_host(const char *name);
sdb_store_obj_t *
sdb_store_service_attr(const char *hostname, const char *service,
const char *key, const sdb_data_t *value, sdb_time_t last_update);
-/*
- * A metric store describes how to access a metric's data.
- */
-typedef struct {
- const char *type;
- const char *id;
-} sdb_metric_store_t;
-
/*
* sdb_store_metric:
* Add/update a metric in the store. If the metric, identified by its name,
sdb_store_get_attr(sdb_store_obj_t *obj, const char *name, sdb_data_t *res,
sdb_store_matcher_t *filter);
+/*
+ * Querying a store:
+ *
+ * - Query interface: A query is a formal description of an interaction with
+ * the store. It can be used, both, for read and write access. The query is
+ * described by its abstract syntax tree (AST). The parser package provides
+ * means to parse a string (SysQL) representation of the query into an AST.
+ *
+ * - Matcher / expression interface: This low-level interface provides direct
+ * control over how to access the store. It is used by the query
+ * implementation internally and can only be used for read access.
+ */
+
+/*
+ * sdb_store_query_t:
+ * A parsed query readily prepared for execution.
+ */
+struct sdb_store_query;
+typedef struct sdb_store_query sdb_store_query_t;
+
+/*
+ * sdb_store_query_prepare:
+ * Prepare the query described by 'ast' for execution in a store.
+ *
+ * Returns:
+ * - a store query on success
+ * - NULL else
+ */
+sdb_store_query_t *
+sdb_store_query_prepare(sdb_ast_node_t *ast);
+
+/*
+ * sdb_store_query_prepare_matcher:
+ * Prepare the logical expression described by 'ast' for execution as a store
+ * matcher.
+ *
+ * Returns:
+ * - a matcher on success
+ * - NULL else
+ */
+sdb_store_matcher_t *
+sdb_store_query_prepare_matcher(sdb_ast_node_t *ast);
+
+/*
+ * sdb_store_query_execute:
+ * Execute a previously prepared query. The query result will be written to
+ * 'buf' and any errors to 'errbuf'.
+ *
+ * Returns:
+ * - the result type (to be used by the server reply)
+ * - a negative value on error
+ */
+int
+sdb_store_query_execute(sdb_store_query_t *m,
+ sdb_strbuf_t *buf, sdb_strbuf_t *errbuf);
+
/*
* sdb_store_expr_create:
* Creates an arithmetic expression implementing the specified operator on the
sdb_store_expr_t *
sdb_store_expr_create(int op, sdb_store_expr_t *left, sdb_store_expr_t *right);
+/*
+ * sdb_store_expr_typed:
+ * Creates an expression which evaluates in the context of an object's sibling
+ * as specified by the given type.
+ *
+ * Returns:
+ * - an expression object on success
+ * - NULL else
+ */
+sdb_store_expr_t *
+sdb_store_expr_typed(int typ, sdb_store_expr_t *expr);
+
/*
* sdb_store_expr_fieldvalue:
* Creates an expression which evaluates to the value of the specified
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.
sdb_store_con_matcher(sdb_store_matcher_t *left, sdb_store_matcher_t *right);
/*
- * sdb_store_con_matcher::
+ * sdb_store_inv_matcher::
* Creates a matcher matching the inverse (logical NOT) of a matcher.
*/
sdb_store_matcher_t *
/*
* 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:
sdb_store_isnull_matcher(sdb_store_expr_t *expr);
/*
- * sdb_store_isnnull_matcher:
- * Creates a matcher matching non-NULL values.
+ * sdb_store_istrue_matcher, sdb_store_isfalse_matcher:
+ * Creates a matcher matching boolean values.
*/
sdb_store_matcher_t *
-sdb_store_isnnull_matcher(sdb_store_expr_t *expr);
+sdb_store_istrue_matcher(sdb_store_expr_t *expr);
+sdb_store_matcher_t *
+sdb_store_isfalse_matcher(sdb_store_expr_t *expr);
/*
* sdb_store_matcher_matches:
typedef sdb_store_matcher_t *(*sdb_store_matcher_op_cb)
(sdb_store_expr_t *, sdb_store_expr_t *);
-/*
- * sdb_store_parse_matcher_op:
- * Parse a matcher operator and return a constructor for the respective
- * matcher.
- *
- * Returns:
- * - matcher operator constructor on success
- * - NULL else
- */
-sdb_store_matcher_op_cb
-sdb_store_parse_matcher_op(const char *op);
-
-/*
- * sdb_store_parse_object_type:
- * Parse the type name of a stored object.
- *
- * Returns:
- * - the object type on success
- * - a negative value else
- */
-int
-sdb_store_parse_object_type(const char *name);
-
-/*
- * sdb_store_parse_object_type_plural:
- * Parse the type name (plural) of a stored object.
- *
- * Returns:
- * - the object type on success
- * - a negative value else
- */
-int
-sdb_store_parse_object_type_plural(const char *name);
-
-/*
- * sdb_store_parse_field_name:
- * Parse the name of a stored object's queryable field.
- *
- * Returns:
- * - the field id on success
- * - a negative value else
- */
-int
-sdb_store_parse_field_name(const char *name);
-
/*
* sdb_store_lookup_cb:
* Lookup callback. It is called for each matching object when looking up data