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index 3722a7262d6aa773d4f3210e12217e7505d449f1..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>
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" \
: ((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)
/*
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_matcher_t *
sdb_store_in_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
-/*
- * sdb_store_nin_matcher:
- * Like sdb_store_in_matcher but matches if the left value is not included in
- * the right value.
- */
-sdb_store_matcher_t *
-sdb_store_nin_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
-
/*
* sdb_store_lt_matcher, sdb_store_le_matcher, sdb_store_eq_matcher,
* sdb_store_ge_matcher, sdb_store_gt_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