1 files changed, 119 insertions, 0 deletions
diff --git a/src/core/file_sys/fssystem/fssystem_indirect_storage.cpp b/src/core/file_sys/fssystem/fssystem_indirect_storage.cpp
new file mode 100644
index 000000000..7544e70b2
--- /dev/null
+++ b/src/core/file_sys/fssystem/fssystem_indirect_storage.cpp
@@ -0,0 +1,119 @@
+// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "core/file_sys/errors.h"
+#include "core/file_sys/fssystem/fssystem_indirect_storage.h"
+
+namespace FileSys {
+
+Result IndirectStorage::Initialize(VirtualFile table_storage) {
+    // Read and verify the bucket tree header.
+    BucketTree::Header header;
+    table_storage->ReadObject(std::addressof(header));
+    R_TRY(header.Verify());
+
+    // Determine extents.
+    const auto node_storage_size = QueryNodeStorageSize(header.entry_count);
+    const auto entry_storage_size = QueryEntryStorageSize(header.entry_count);
+    const auto node_storage_offset = QueryHeaderStorageSize();
+    const auto entry_storage_offset = node_storage_offset + node_storage_size;
+
+    // Initialize.
+    R_RETURN(this->Initialize(
+        std::make_shared<OffsetVfsFile>(table_storage, node_storage_size, node_storage_offset),
+        std::make_shared<OffsetVfsFile>(table_storage, entry_storage_size, entry_storage_offset),
+        header.entry_count));
+}
+
+void IndirectStorage::Finalize() {
+    if (this->IsInitialized()) {
+        m_table.Finalize();
+        for (auto i = 0; i < StorageCount; i++) {
+            m_data_storage[i] = VirtualFile();
+        }
+    }
+}
+
+Result IndirectStorage::GetEntryList(Entry* out_entries, s32* out_entry_count, s32 entry_count,
+                                     s64 offset, s64 size) {
+    // Validate pre-conditions.
+    ASSERT(offset >= 0);
+    ASSERT(size >= 0);
+    ASSERT(this->IsInitialized());
+
+    // Clear the out count.
+    R_UNLESS(out_entry_count != nullptr, ResultNullptrArgument);
+    *out_entry_count = 0;
+
+    // Succeed if there's no range.
+    R_SUCCEED_IF(size == 0);
+
+    // If we have an output array, we need it to be non-null.
+    R_UNLESS(out_entries != nullptr || entry_count == 0, ResultNullptrArgument);
+
+    // Check that our range is valid.
+    BucketTree::Offsets table_offsets;
+    R_TRY(m_table.GetOffsets(std::addressof(table_offsets)));
+
+    R_UNLESS(table_offsets.IsInclude(offset, size), ResultOutOfRange);
+
+    // Find the offset in our tree.
+    BucketTree::Visitor visitor;
+    R_TRY(m_table.Find(std::addressof(visitor), offset));
+    {
+        const auto entry_offset = visitor.Get<Entry>()->GetVirtualOffset();
+        R_UNLESS(0 <= entry_offset && table_offsets.IsInclude(entry_offset),
+                 ResultInvalidIndirectEntryOffset);
+    }
+
+    // Prepare to loop over entries.
+    const auto end_offset = offset + static_cast<s64>(size);
+    s32 count = 0;
+
+    auto cur_entry = *visitor.Get<Entry>();
+    while (cur_entry.GetVirtualOffset() < end_offset) {
+        // Try to write the entry to the out list.
+        if (entry_count != 0) {
+            if (count >= entry_count) {
+                break;
+            }
+            std::memcpy(out_entries + count, std::addressof(cur_entry), sizeof(Entry));
+        }
+
+        count++;
+
+        // Advance.
+        if (visitor.CanMoveNext()) {
+            R_TRY(visitor.MoveNext());
+            cur_entry = *visitor.Get<Entry>();
+        } else {
+            break;
+        }
+    }
+
+    // Write the output count.
+    *out_entry_count = count;
+    R_SUCCEED();
+}
+
+size_t IndirectStorage::Read(u8* buffer, size_t size, size_t offset) const {
+    // Validate pre-conditions.
+    ASSERT(this->IsInitialized());
+    ASSERT(buffer != nullptr);
+
+    // Succeed if there's nothing to read.
+    if (size == 0) {
+        return 0;
+    }
+
+    const_cast<IndirectStorage*>(this)->OperatePerEntry<true, true>(
+        offset, size,
+        [=](VirtualFile storage, s64 data_offset, s64 cur_offset, s64 cur_size) -> Result {
+            storage->Read(reinterpret_cast<u8*>(buffer) + (cur_offset - offset),
+                          static_cast<size_t>(cur_size), data_offset);
+            R_SUCCEED();
+        });
+
+    return size;
+}
+} // namespace FileSys