ENH: Add retrieval and queries to Extern C interface

Summary

See https://gitlab.indiscale.com/caosdb/customers/lfpb/management/-/issues/411. Extends the Extern C interface by retrieving single and multiple entities and executing queries.

Focus

There is a lot of repetitive new code for create, delete, set, and get functions in ccaosdb.cpp. Some aspects of the c++ objects of Entities, Parents, and Propeties had to be changed in order to comply with the C interface, mainly because of memory management.

The most important new parts is that entities, transactions, properties and parents can now be created and deleted via the C interface, and that their properties can be set and gotten.

Test Environment

In principle, unit tests should be sufficient. Check whether you are content with the extent of the tests. Queries and retrievals are checked in the integration tests.

Check List for the Author

Please, prepare your MR for a review. Be sure to write a summary and a focus and create gitlab comments for the reviewer. They should guide the reviewer through the changes, explain your changes and also point out open questions. For further good practices have a look at our review guidelines

• All automated tests pass
• Reference related Issues
• [ ] Up-to-date CHANGELOG.md
• Annotations in code (Gitlab comments)
  • Intent of new code
  • Problems with old code
  • Why this implementation?

Check List for the Reviewer

• I understand the intent of this MR
• All automated tests pass
• [ ] Up-to-date CHANGELOG.md
• The test environment setup works and the intended behavior is reproducible in the test environment
• In-code documentation and comments are up-to-date.
• Check: Are there specifications? Are they satisfied?

For further good practices have a look at our review guidelines.

include/ccaosdb.h

@@ -265,9 +265,17 @@ typedef struct {
   void *wrapped_transaction;
 } caosdb_transaction_transaction;
 
+/**
+ * Create a transaction on an existing connection.
+ *
+ * This transaction has to be deleted manually by
+ * caosdb_transaction_delete_transaction() later on.
+ */
 int caosdb_connection_connection_create_transaction(
   caosdb_connection_connection *connection,
   caosdb_transaction_transaction *out);
+int caosdb_transaction_delete_transaction(
+  caosdb_transaction_transaction *transaction);
 int caosdb_transaction_transaction_retrieve_by_id(
   caosdb_transaction_transaction *transaction, const char *id);
 int caosdb_transaction_transaction_retrieve_by_ids(
@@ -292,42 +300,34 @@ int caosdb_transaction_transaction_get_count_result(
 
 typedef struct {
   void *wrapped_entity;
-  char **id;
-  char **role;
-  char **name;
-  char **description;
-  char **datatype;
-  char **unit;
-  char **value;
-  char **version_id;
 } caosdb_entity_entity;
 
-int caosdb_transaction_result_set_get_entity(
-  caosdb_transaction_result_set *result_set, caosdb_entity_entity *entity,
-  int index);
+int caosdb_transaction_result_set_at(caosdb_transaction_result_set *result_set,
+                                     caosdb_entity_entity *entity, int index);
+int caosdb_transaction_result_set_size(
+  caosdb_transaction_result_set *result_set, int *out);
 
 typedef struct {
   void *wrapped_property;
-  char **id;
-  char **name;
-  char **description;
-  char **datatype;
-  char **unit;
-  char **value;
 } caosdb_entity_property;
 typedef struct {
   void *wrapped_parent;
-  char **id;
-  char **name;
-  char **description;
 } caosdb_entity_parent;
 typedef struct {
   void *wrapped_message;
-  int *code;
-  char **description;
 } caosdb_entity_message;
 
-// GETTERS FOR COMPLEX OBJECTS
+// GETTERS FOR EVERYTHING
+int caosdb_entity_entity_get_id(caosdb_entity_entity *entity, char *out);
+int caosdb_entity_entity_get_role(caosdb_entity_entity *entity, char *out);
+int caosdb_entity_entity_get_name(caosdb_entity_entity *entity, char *out);
+int caosdb_entity_entity_get_description(caosdb_entity_entity *entity,
+                                         char *out);
+int caosdb_entity_entity_get_datatype(caosdb_entity_entity *entity, char *out);
+int caosdb_entity_entity_get_unit(caosdb_entity_entity *entity, char *out);
+int caosdb_entity_entity_get_value(caosdb_entity_entity *entity, char *out);
+int caosdb_entity_entity_get_version_id(caosdb_entity_entity *entity,
+                                        char *out);
 int caosdb_entity_entity_get_errors_size(caosdb_entity_entity *entity,
                                          int *out);
 int caosdb_entity_entity_get_error(caosdb_entity_entity *entity,
@@ -348,6 +348,29 @@ int caosdb_entity_entity_get_parents_size(caosdb_entity_entity *entity,
 int caosdb_entity_entity_get_parent(caosdb_entity_entity *entity,
                                     caosdb_entity_parent *out, int index);
 
+int caosdb_entity_property_get_id(caosdb_entity_property *property, char *out);
+int caosdb_entity_property_get_name(caosdb_entity_property *property,
+                                    char *out);
+int caosdb_entity_property_get_description(caosdb_entity_property *property,
+                                           char *out);
+int caosdb_entity_property_get_importance(caosdb_entity_property *property,
+                                          char *out);
+int caosdb_entity_property_get_datatype(caosdb_entity_property *property,
+                                        char *out);
+int caosdb_entity_property_get_unit(caosdb_entity_property *property,
+                                    char *out);
+int caosdb_entity_property_get_value(caosdb_entity_property *property,
+                                     char *out);
+
+int caosdb_entity_parent_get_id(caosdb_entity_parent *parent, char *out);
+int caosdb_entity_parent_get_name(caosdb_entity_parent *parent, char *out);
+int caosdb_entity_parent_get_description(caosdb_entity_parent *parent,
+                                         char *out);
+
+int caosdb_entity_message_get_code(caosdb_entity_message *message, int *out);
+int caosdb_entity_message_get_description(caosdb_entity_message *message,
+                                          char *out);
+
 // CONSTRUCTORS AND DESTRUCTORS
 int caosdb_entity_create_entity(caosdb_entity_entity *out);
 int caosdb_entity_delete_entity(caosdb_entity_entity *out);
@@ -356,12 +379,37 @@ int caosdb_entity_delete_property(caosdb_entity_property *out);
 int caosdb_entity_create_parent(caosdb_entity_parent *out);
 int caosdb_entity_delete_parent(caosdb_entity_parent *out);
 
-// SETTERS FOR COMPLEX OBJECTS
+// SETTERS FOR EVERYTHING THAT MAY BE SET
+int caosdb_entity_entity_set_role(caosdb_entity_entity *entity,
+                                  const char *role);
+int caosdb_entity_entity_set_name(caosdb_entity_entity *entity,
+                                  const char *name);
+int caosdb_entity_entity_set_description(caosdb_entity_entity *entity,
+                                         const char *description);
+int caosdb_entity_entity_set_datatype(caosdb_entity_entity *entity,
+                                      const char *datatype);
+int caosdb_entity_entity_set_unit(caosdb_entity_entity *entity,
+                                  const char *unit);
+int caosdb_entity_entity_set_value(caosdb_entity_entity *entity,
+                                   const char *value);
 int caosdb_entity_entity_append_parent(caosdb_entity_entity *entity,
                                        caosdb_entity_parent *parent);
 int caosdb_entity_entity_append_property(caosdb_entity_entity *entity,
                                          caosdb_entity_property *property);
 
+int caosdb_entity_property_set_id(caosdb_entity_property *property,
+                                  const char *id);
+int caosdb_entity_property_set_name(caosdb_entity_property *property,
+                                    const char *name);
+int caosdb_entity_property_set_datatype(caosdb_entity_property *property,
+                                        const char *datatype);
+int caosdb_entity_property_set_importance(caosdb_entity_property *property,
+                                          const char *importance);
+int caosdb_entity_property_set_unit(caosdb_entity_property *property,
+                                    const char *unit);
+int caosdb_entity_property_set_value(caosdb_entity_property *property,
+                                     const char *value);
+
 #ifdef __cplusplus
 }
 #endif