store: Use a separate type for prepared querys.

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

diff --git a/src/include/core/store.h b/src/include/core/store.h
index 0abf0cb467d3d0a66fb3f99008537bce2f8848de..fb59c7c1ba5f8cf7c2d09e56295c74d6512d54e7 100644 (file)
--- a/src/include/core/store.h
+++ b/src/include/core/store.h
@@ -360,17 +360,50 @@ int
 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 matcher on success
+ *  - a store query on success
  *  - NULL else
  */
-sdb_store_matcher_t *
+sdb_store_query_t *
 sdb_store_query_prepare(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