Function json_get_item

storage/connect/jsonudf.cpp:3460–3518

} // end of json_get_item_init

char *json_get_item(UDF_INIT *initid, UDF_ARGS *args, char *result,
	             unsigned long *res_length, uchar *is_null, uchar *)
{
	char   *path, *str = NULL;
	PJSON   jsp;
	PJVAL   jvp;
	PJSNX   jsx;
	PGLOBAL g = (PGLOBAL)initid->ptr;

	if (g->N) {
		str = (char*)g->Activityp;
		goto fin;
	} else if (initid->const_item)
		g->N = 1;

	if (!g->Xchk) {
		if (CheckMemory(g, initid, args, 1, true, true)) {
			PUSH_WARNING("CheckMemory error");
			goto fin;
		} // endif CheckMemory

		jvp = MakeTypedValue(g, args, 0, TYPE_JSON);
		jsp = jvp->GetJson();

		if (g->Mrr) {			 // First argument is a constant
			g->Xchk = jsp;
			JsonMemSave(g);
			} // endif Mrr

	} else
		jsp = (PJSON)g->Xchk;

	path = MakePSZ(g, args, 1);
	jsx = JsnxNew(g, jsp, TYPE_STRING, initid->max_length);

	if (!jsx || jsx->SetJpath(g, path, true)) {
		PUSH_WARNING(g->Message);
		*is_null = 1;
		return NULL;
	}	// endif SetJpath

	jsx->ReadValue(g);

	if (!jsx->GetValue()->IsNull())
		str = jsx->GetValue()->GetCharValue();

	if (initid->const_item)
		// Keep result of constant function
		g->Activityp = (PACTIVITY)str;

 fin:
	if (!str) {
		*is_null = 1;
		*res_length = 0;
	} else
		*res_length = strlen(str);

	return str;