filesystem: Implement basic IStorage functionality.

src/core/hle/service/filesystem/filesystem.cpp

@@ -0,0 +1,54 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <boost/container/flat_map.hpp>
+#include "core/file_sys/filesystem.h"
+#include "core/hle/service/filesystem/filesystem.h"
+#include "core/hle/service/filesystem/fsp_srv.h"
+
+namespace Service {
+namespace FileSystem {
+
+/**
+ * Map of registered file systems, identified by type. Once an file system is registered here, it
+ * is never removed until UnregisterFileSystems is called.
+ */
+static boost::container::flat_map<Type, std::unique_ptr<FileSys::FileSystemFactory>> filesystem_map;
+
+ResultCode RegisterFileSystem(std::unique_ptr<FileSys::FileSystemFactory>&& factory, Type type) {
+    auto result = filesystem_map.emplace(type, std::move(factory));
+
+    bool inserted = result.second;
+    ASSERT_MSG(inserted, "Tried to register more than one system with same id code");
+
+    auto& filesystem = result.first->second;
+    LOG_DEBUG(Service_FS, "Registered file system %s with id code 0x%08X",
+              filesystem->GetName().c_str(), static_cast<u32>(type));
+    return RESULT_SUCCESS;
+}
+
+ResultVal<std::unique_ptr<FileSys::FileSystemBackend>> OpenFileSystem(Type type,
+                                                                      FileSys::Path& path) {
+    LOG_TRACE(Service_FS, "Opening FileSystem with type=%d", type);
+
+    auto itr = filesystem_map.find(type);
+    if (itr == filesystem_map.end()) {
+        // TODO(bunnei): Find a better error code for this
+        return ResultCode(-1);
+    }
+
+    return itr->second->Open(path);
+}
+
+void UnregisterFileSystems() {
+    filesystem_map.clear();
+}
+
+void InstallInterfaces(SM::ServiceManager& service_manager) {
+    UnregisterFileSystems();
+    std::make_shared<FSP_SRV>()->InstallAsService(service_manager);
+}
+
+} // namespace FileSystem
+} // namespace Service