store: Add support for unary IS TRUE / IS FALSE matchers.

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

diff --git a/src/include/core/store.h b/src/include/core/store.h
index 179b5d05a470a9f59e13b73c9826edfed9fa184e..8a80852a7a5ba44d64659b1fc10713a67c7b3b18 100644 (file)
--- a/src/include/core/store.h
+++ b/src/include/core/store.h
@@ -360,17 +360,49 @@ 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_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
@@ -381,7 +413,7 @@ sdb_store_query_prepare(sdb_ast_node_t *ast);
  *  - a negative value on error
  */
 int
-sdb_store_query_execute(sdb_store_matcher_t *m,
+sdb_store_query_execute(sdb_store_query_t *m,
                sdb_strbuf_t *buf, sdb_strbuf_t *errbuf);
 
 /*
@@ -593,11 +625,13 @@ sdb_store_matcher_t *
 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: