1 files changed, 73 insertions, 0 deletions
diff --git a/src/core/file_sys/fssystem/fssystem_sparse_storage.h b/src/core/file_sys/fssystem/fssystem_sparse_storage.h
new file mode 100644
index 000000000..c1ade7195
--- /dev/null
+++ b/src/core/file_sys/fssystem/fssystem_sparse_storage.h
@@ -0,0 +1,73 @@
+// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include "core/file_sys/fssystem/fssystem_indirect_storage.h"
+
+namespace FileSys {
+
+class SparseStorage : public IndirectStorage {
+    YUZU_NON_COPYABLE(SparseStorage);
+    YUZU_NON_MOVEABLE(SparseStorage);
+
+private:
+    class ZeroStorage : public IReadOnlyStorage {
+    public:
+        ZeroStorage() {}
+        virtual ~ZeroStorage() {}
+
+        virtual size_t GetSize() const override {
+            return std::numeric_limits<size_t>::max();
+        }
+
+        virtual size_t Read(u8* buffer, size_t size, size_t offset) const override {
+            ASSERT(offset >= 0);
+            ASSERT(buffer != nullptr || size == 0);
+
+            if (size > 0) {
+                std::memset(buffer, 0, size);
+            }
+
+            return size;
+        }
+    };
+
+private:
+    VirtualFile m_zero_storage;
+
+public:
+    SparseStorage() : IndirectStorage(), m_zero_storage(std::make_shared<ZeroStorage>()) {}
+    virtual ~SparseStorage() {}
+
+    using IndirectStorage::Initialize;
+
+    void Initialize(s64 end_offset) {
+        this->GetEntryTable().Initialize(NodeSize, end_offset);
+        this->SetZeroStorage();
+    }
+
+    void SetDataStorage(VirtualFile storage) {
+        ASSERT(this->IsInitialized());
+
+        this->SetStorage(0, storage);
+        this->SetZeroStorage();
+    }
+
+    template <typename T>
+    void SetDataStorage(T storage, s64 offset, s64 size) {
+        ASSERT(this->IsInitialized());
+
+        this->SetStorage(0, storage, offset, size);
+        this->SetZeroStorage();
+    }
+
+    virtual size_t Read(u8* buffer, size_t size, size_t offset) const override;
+
+private:
+    void SetZeroStorage() {
+        return this->SetStorage(1, m_zero_storage, 0, std::numeric_limits<s64>::max());
+    }
+};
+
+} // namespace FileSys