Add add-on (DLC) support (#1519)

Add add-on content support

Co-authored-by: nmzik <Nmzik@mail.ru>

src/loader/additionalContent.cpp

@@ -0,0 +1,36 @@
+#include "loader/additionalContent.h"
+
+#include "common/logging/log.h"
+#include "common/stringUtils.h"
+
+#include <algorithm>
+#include <string_view>
+
+namespace Loader {
+
+static std::vector<AddContentEntry> g_add_content;
+
+void AddContentLoad(const std::filesystem::path& dir, const std::string& title_id) {
+	g_add_content = Common::FindAddContent(dir, title_id);
+	for (const auto& entry: g_add_content) {
+		LOGF("AddContent: registered %s -> %s\n", entry.content_id.c_str(),
+		     Common::PathToString(entry.mount_dir).c_str());
+	}
+}
+
+const std::vector<AddContentEntry>& AddContentGetAll() {
+	return g_add_content;
+}
+
+const AddContentEntry* AddContentFind(const char* label, size_t label_size) {
+	if (label == nullptr || label_size == 0) {
+		return nullptr;
+	}
+	const std::string_view value(label, std::find(label, label + label_size, '\0') - label);
+	const auto             it =
+	    std::find_if(g_add_content.begin(), g_add_content.end(),
+	                 [&](const auto& entry) { return entry.entitlement_label == value; });
+	return it == g_add_content.end() ? nullptr : &*it;
+}
+
+} // namespace Loader