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New MGP API (#219)

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This commit is contained in:
János Benjamin Antal
2021-09-09 10:44:47 +02:00
committed by GitHub
parent 5a8bda2531
commit 2afc1b99f6
29 changed files with 2347 additions and 1598 deletions
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104
query_modules/example.c
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@@ -16,61 +16,101 @@
// CALL example.procedure(1, 2) YIELD args, result;
// CALL example.procedure(1) YIELD args, result;
// Naturally, you may pass in different arguments or yield less fields.
static void procedure(const struct mgp_list *args,
const struct mgp_graph *graph, struct mgp_result *result,
static void procedure(const struct mgp_list *args, const struct mgp_graph *graph, struct mgp_result *result,
struct mgp_memory *memory) {
struct mgp_list *args_copy = mgp_list_make_empty(mgp_list_size(args), memory);
if (args_copy == NULL) goto error_memory;
for (size_t i = 0; i < mgp_list_size(args); ++i) {
int success = mgp_list_append(args_copy, mgp_list_at(args, i));
if (!success) goto error_free_list;
size_t args_size = 0;
if (mgp_list_size(args, &args_size) != MGP_ERROR_NO_ERROR) {
goto error_something_went_wrong;
}
struct mgp_list *args_copy = NULL;
if (mgp_list_make_empty(args_size, memory, &args_copy) != MGP_ERROR_NO_ERROR) {
goto error_something_went_wrong;
}
for (size_t i = 0; i < args_size; ++i) {
const struct mgp_value *value = NULL;
if (mgp_list_at(args, i, &value) != MGP_ERROR_NO_ERROR) {
goto error_free_list;
}
if (mgp_list_append(args_copy, value) != MGP_ERROR_NO_ERROR) {
goto error_free_list;
}
}
struct mgp_result_record *record = NULL;
if (mgp_result_new_record(result, &record) != MGP_ERROR_NO_ERROR) {
goto error_free_list;
}
struct mgp_result_record *record = mgp_result_new_record(result);
if (record == NULL) goto error_free_list;
// Transfer ownership of args_copy to mgp_value.
struct mgp_value *args_value = mgp_value_make_list(args_copy);
if (args_value == NULL) goto error_free_list;
int args_inserted = mgp_result_record_insert(record, "args", args_value);
struct mgp_value *args_value = NULL;
if (mgp_value_make_list(args_copy, &args_value) != MGP_ERROR_NO_ERROR) {
goto error_free_list;
}
// Release `args_value` and contained `args_copy`.
if (mgp_result_record_insert(record, "args", args_value) != MGP_ERROR_NO_ERROR) {
mgp_value_destroy(args_value);
goto error_something_went_wrong;
}
mgp_value_destroy(args_value);
if (!args_inserted) goto error_memory;
struct mgp_value *hello_world_value =
mgp_value_make_string("Hello World!", memory);
if (hello_world_value == NULL) goto error_memory;
int result_inserted =
mgp_result_record_insert(record, "result", hello_world_value);
struct mgp_value *hello_world_value = NULL;
if (mgp_value_make_string("Hello World!", memory, &hello_world_value) != MGP_ERROR_NO_ERROR) {
goto error_something_went_wrong;
}
enum mgp_error insert_result = mgp_result_record_insert(record, "result", hello_world_value);
mgp_value_destroy(hello_world_value);
if (!result_inserted) goto error_memory;
if (insert_result != MGP_ERROR_NO_ERROR) {
goto error_something_went_wrong;
}
// We have successfully finished, so return without error reporting.
return;
error_free_list:
mgp_list_destroy(args_copy);
error_memory:
mgp_result_set_error_msg(result, "Not enough memory!");
error_something_went_wrong:
mgp_result_set_error_msg(result, "Something went wrong!");
return;
}
// Each module needs to define mgp_init_module function.
// Here you can register multiple procedures your module supports.
int mgp_init_module(struct mgp_module *module, struct mgp_memory *memory) {
struct mgp_proc *proc =
mgp_module_add_read_procedure(module, "procedure", procedure);
if (!proc) return 1;
if (!mgp_proc_add_arg(proc, "required_arg",
mgp_type_nullable(mgp_type_any())))
struct mgp_proc *proc = NULL;
if (mgp_module_add_read_procedure(module, "procedure", procedure, &proc) != MGP_ERROR_NO_ERROR) {
return 1;
struct mgp_value *null_value = mgp_value_make_null(memory);
if (!mgp_proc_add_opt_arg(proc, "optional_arg",
mgp_type_nullable(mgp_type_any()), null_value)) {
}
const struct mgp_type *any_type = NULL;
if (mgp_type_any(&any_type) != MGP_ERROR_NO_ERROR) {
return 1;
}
const struct mgp_type *nullable_any_type = NULL;
if (mgp_type_nullable(any_type, &nullable_any_type) != MGP_ERROR_NO_ERROR) {
return 1;
}
if (mgp_proc_add_arg(proc, "required_arg", nullable_any_type) != MGP_ERROR_NO_ERROR) {
return 1;
}
struct mgp_value *null_value = NULL;
if (mgp_value_make_null(memory, &null_value) != MGP_ERROR_NO_ERROR) {
return 1;
}
if (mgp_proc_add_opt_arg(proc, "optional_arg", nullable_any_type, null_value) != MGP_ERROR_NO_ERROR) {
mgp_value_destroy(null_value);
return 1;
}
mgp_value_destroy(null_value);
if (!mgp_proc_add_result(proc, "result", mgp_type_string())) return 1;
if (!mgp_proc_add_result(proc, "args",
mgp_type_list(mgp_type_nullable(mgp_type_any()))))
const struct mgp_type *string = NULL;
if (mgp_type_string(&string) != MGP_ERROR_NO_ERROR) {
return 1;
}
if (mgp_proc_add_result(proc, "result", string) != MGP_ERROR_NO_ERROR) {
return 1;
}
const struct mgp_type *list_of_anything = NULL;
if (mgp_type_list(nullable_any_type, &list_of_anything) != MGP_ERROR_NO_ERROR) {
return 1;
}
if (mgp_proc_add_result(proc, "args", list_of_anything)) {
return 1;
}
return 0;
}