// 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_bucket_tree.h"
#include "core/file_sys/fssystem/fssystem_bucket_tree_utils.h"
#include "core/file_sys/fssystem/fssystem_pooled_buffer.h"
namespace FileSys {
namespace {
using Node = impl::BucketTreeNode<const s64*>;
static_assert(sizeof(Node) == sizeof(BucketTree::NodeHeader));
static_assert(std::is_trivial_v<Node>);
constexpr inline s32 NodeHeaderSize = sizeof(BucketTree::NodeHeader);
class StorageNode {
private:
class Offset {
public:
using difference_type = s64;
private:
s64 m_offset;
s32 m_stride;
public:
constexpr Offset(s64 offset, s32 stride) : m_offset(offset), m_stride(stride) {}
constexpr Offset& operator++() {
m_offset += m_stride;
return *this;
}
constexpr Offset operator++(int) {
Offset ret(*this);
m_offset += m_stride;
return ret;
}
constexpr Offset& operator--() {
m_offset -= m_stride;
return *this;
}
constexpr Offset operator--(int) {
Offset ret(*this);
m_offset -= m_stride;
return ret;
}
constexpr difference_type operator-(const Offset& rhs) const {
return (m_offset - rhs.m_offset) / m_stride;
}
constexpr Offset operator+(difference_type ofs) const {
return Offset(m_offset + ofs * m_stride, m_stride);
}
constexpr Offset operator-(difference_type ofs) const {
return Offset(m_offset - ofs * m_stride, m_stride);
}
constexpr Offset& operator+=(difference_type ofs) {
m_offset += ofs * m_stride;
return *this;
}
constexpr Offset& operator-=(difference_type ofs) {
m_offset -= ofs * m_stride;
return *this;
}
constexpr bool operator==(const Offset& rhs) const {
return m_offset == rhs.m_offset;
}
constexpr bool operator!=(const Offset& rhs) const {
return m_offset != rhs.m_offset;
}
constexpr s64 Get() const {
return m_offset;
}
};
private:
const Offset m_start;
const s32 m_count;
s32 m_index;
public:
StorageNode(size_t size, s32 count)
: m_start(NodeHeaderSize, static_cast<s32>(size)), m_count(count), m_index(-1) {}
StorageNode(s64 ofs, size_t size, s32 count)
: m_start(NodeHeaderSize + ofs, static_cast<s32>(size)), m_count(count), m_index(-1) {}
s32 GetIndex() const {
return m_index;
}
void Find(const char* buffer, s64 virtual_address) {
s32 end = m_count;
auto pos = m_start;
while (end > 0) {
auto half = end / 2;
auto mid = pos + half;
s64 offset = 0;
std::memcpy(std::addressof(offset), buffer + mid.Get(), sizeof(s64));
if (offset <= virtual_address) {
pos = mid + 1;
end -= half + 1;
} else {
end = half;
}
}
m_index = static_cast<s32>(pos - m_start) - 1;
}
Result Find(VirtualFile storage, s64 virtual_address) {
s32 end = m_count;
auto pos = m_start;
while (end > 0) {
auto half = end / 2;
auto mid = pos + half;
s64 offset = 0;
storage->ReadObject(std::addressof(offset), mid.Get());
if (offset <= virtual_address) {
pos = mid + 1;
end -= half + 1;
} else {
end = half;
}
}
m_index = static_cast<s32>(pos - m_start) - 1;
R_SUCCEED();
}
};
} // namespace
void BucketTree::Header::Format(s32 entry_count_) {
ASSERT(entry_count_ >= 0);
this->magic = Magic;
this->version = Version;
this->entry_count = entry_count_;
this->reserved = 0;
}
Result BucketTree::Header::Verify() const {
R_UNLESS(this->magic == Magic, ResultInvalidBucketTreeSignature);
R_UNLESS(this->entry_count >= 0, ResultInvalidBucketTreeEntryCount);
R_UNLESS(this->version <= Version, ResultUnsupportedVersion);
R_SUCCEED();
}
Result BucketTree::NodeHeader::Verify(s32 node_index, size_t node_size, size_t entry_size) const {
R_UNLESS(this->index == node_index, ResultInvalidBucketTreeNodeIndex);
R_UNLESS(entry_size != 0 && node_size >= entry_size + NodeHeaderSize, ResultInvalidSize);
const size_t max_entry_count = (node_size - NodeHeaderSize) / entry_size;
R_UNLESS(this->count > 0 && static_cast<size_t>(this->count) <= max_entry_count,
ResultInvalidBucketTreeNodeEntryCount);
R_UNLESS(this->offset >= 0, ResultInvalidBucketTreeNodeOffset);
R_SUCCEED();
}
Result BucketTree::Initialize(VirtualFile node_storage, VirtualFile entry_storage, size_t node_size,
size_t entry_size, s32 entry_count) {
// Validate preconditions.
ASSERT(entry_size >= sizeof(s64));
ASSERT(node_size >= entry_size + sizeof(NodeHeader));
ASSERT(NodeSizeMin <= node_size && node_size <= NodeSizeMax);
ASSERT(Common::IsPowerOfTwo(node_size));
ASSERT(!this->IsInitialized());
// Ensure valid entry count.
R_UNLESS(entry_count > 0, ResultInvalidArgument);
// Allocate node.
R_UNLESS(m_node_l1.Allocate(node_size), ResultBufferAllocationFailed);
ON_RESULT_FAILURE {
m_node_l1.Free(node_size);
};
// Read node.
node_storage->Read(reinterpret_cast<u8*>(m_node_l1.Get()), node_size);
// Verify node.
R_TRY(m_node_l1->Verify(0, node_size, sizeof(s64)));
// Validate offsets.
const auto offset_count = GetOffsetCount(node_size);
const auto entry_set_count = GetEntrySetCount(node_size, entry_size, entry_count);
const auto* const node = m_node_l1.Get<Node>();
s64 start_offset;
if (offset_count < entry_set_count && node->GetCount() < offset_count) {
start_offset = *node->GetEnd();
} else {
start_offset = *node->GetBegin();
}
const auto end_offset = node->GetEndOffset();
R_UNLESS(0 <= start_offset && start_offset <= node->GetBeginOffset(),
ResultInvalidBucketTreeEntryOffset);
R_UNLESS(start_offset < end_offset, ResultInvalidBucketTreeEntryOffset);
// Set member variables.
m_node_storage = node_storage;
m_entry_storage = entry_storage;
m_node_size = node_size;
m_entry_size = entry_size;
m_entry_count = entry_count;
m_offset_count = offset_count;
m_entry_set_count = entry_set_count;
m_offset_cache.offsets.start_offset = start_offset;
m_offset_cache.offsets.end_offset = end_offset;
m_offset_cache.is_initialized = true;
// We succeeded.
R_SUCCEED();
}
void BucketTree::Initialize(size_t node_size, s64 end_offset) {
ASSERT(NodeSizeMin <= node_size && node_size <= NodeSizeMax);
ASSERT(Common::IsPowerOfTwo(node_size));
ASSERT(end_offset > 0);
ASSERT(!this->IsInitialized());
m_node_size = node_size;
m_offset_cache.offsets.start_offset = 0;
m_offset_cache.offsets.end_offset = end_offset;
m_offset_cache.is_initialized = true;
}
void BucketTree::Finalize() {
if (this->IsInitialized()) {
m_node_storage = VirtualFile();
m_entry_storage = VirtualFile();
m_node_l1.Free(m_node_size);
m_node_size = 0;
m_entry_size = 0;
m_entry_count = 0;
m_offset_count = 0;
m_entry_set_count = 0;
m_offset_cache.offsets.start_offset = 0;
m_offset_cache.offsets.end_offset = 0;
m_offset_cache.is_initialized = false;
}
}
Result BucketTree::Find(Visitor* visitor, s64 virtual_address) {
ASSERT(visitor != nullptr);
ASSERT(this->IsInitialized());
R_UNLESS(virtual_address >= 0, ResultInvalidOffset);
R_UNLESS(!this->IsEmpty(), ResultOutOfRange);
BucketTree::Offsets offsets;
R_TRY(this->GetOffsets(std::addressof(offsets)));
R_TRY(visitor->Initialize(this, offsets));
R_RETURN(visitor->Find(virtual_address));
}
Result BucketTree::InvalidateCache() {
// Reset our offsets.
m_offset_cache.is_initialized = false;
R_SUCCEED();
}
Result BucketTree::EnsureOffsetCache() {
// If we already have an offset cache, we're good.
R_SUCCEED_IF(m_offset_cache.is_initialized);
// Acquire exclusive right to edit the offset cache.
std::scoped_lock lk(m_offset_cache.mutex);
// Check again, to be sure.
R_SUCCEED_IF(m_offset_cache.is_initialized);
// Read/verify L1.
m_node_storage->Read(reinterpret_cast<u8*>(m_node_l1.Get()), m_node_size);
R_TRY(m_node_l1->Verify(0, m_node_size, sizeof(s64)));
// Get the node.
auto* const node = m_node_l1.Get<Node>();
s64 start_offset;
if (m_offset_count < m_entry_set_count && node->GetCount() < m_offset_count) {
start_offset = *node->GetEnd();
} else {
start_offset = *node->GetBegin();
}
const auto end_offset = node->GetEndOffset();
R_UNLESS(0 <= start_offset && start_offset <= node->GetBeginOffset(),
ResultInvalidBucketTreeEntryOffset);
R_UNLESS(start_offset < end_offset, ResultInvalidBucketTreeEntryOffset);
m_offset_cache.offsets.start_offset = start_offset;
m_offset_cache.offsets.end_offset = end_offset;
m_offset_cache.is_initialized = true;
R_SUCCEED();
}
Result BucketTree::Visitor::Initialize(const BucketTree* tree, const BucketTree::Offsets& offsets) {
ASSERT(tree != nullptr);
ASSERT(m_tree == nullptr || m_tree == tree);
if (m_entry == nullptr) {
m_entry = ::operator new(tree->m_entry_size);
R_UNLESS(m_entry != nullptr, ResultBufferAllocationFailed);
m_tree = tree;
m_offsets = offsets;
}
R_SUCCEED();
}
Result BucketTree::Visitor::MoveNext() {
R_UNLESS(this->IsValid(), ResultOutOfRange);
// Invalidate our index, and read the header for the next index.
auto entry_index = m_entry_index + 1;
if (entry_index == m_entry_set.info.count) {
const auto entry_set_index = m_entry_set.info.index + 1;
R_UNLESS(entry_set_index < m_entry_set_count, ResultOutOfRange);
m_entry_index = -1;
const auto end = m_entry_set.info.end;
const auto entry_set_size = m_tree->m_node_size;
const auto entry_set_offset = entry_set_index * static_cast<s64>(entry_set_size);
m_tree->m_entry_storage->ReadObject(std::addressof(m_entry_set), entry_set_offset);
R_TRY(m_entry_set.header.Verify(entry_set_index, entry_set_size, m_tree->m_entry_size));
R_UNLESS(m_entry_set.info.start == end && m_entry_set.info.start < m_entry_set.info.end,
ResultInvalidBucketTreeEntrySetOffset);
entry_index = 0;
} else {
m_entry_index = -1;
}
// Read the new entry.
const auto entry_size = m_tree->m_entry_size;
const auto entry_offset = impl::GetBucketTreeEntryOffset(
m_entry_set.info.index, m_tree->m_node_size, entry_size, entry_index);
m_tree->m_entry_storage->Read(reinterpret_cast<u8*>(m_entry), entry_size, entry_offset);
// Note that we changed index.
m_entry_index = entry_index;
R_SUCCEED();
}
Result BucketTree::Visitor::MovePrevious() {
R_UNLESS(this->IsValid(), ResultOutOfRange);
// Invalidate our index, and read the header for the previous index.
auto entry_index = m_entry_index;
if (entry_index == 0) {
R_UNLESS(m_entry_set.info.index > 0, ResultOutOfRange);
m_entry_index = -1;
const auto start = m_entry_set.info.start;
const auto entry_set_size = m_tree->m_node_size;
const auto entry_set_index = m_entry_set.info.index - 1;
const auto entry_set_offset = entry_set_index * static_cast<s64>(entry_set_size);
m_tree->m_entry_storage->ReadObject(std::addressof(m_entry_set), entry_set_offset);
R_TRY(m_entry_set.header.Verify(entry_set_index, entry_set_size, m_tree->m_entry_size));
R_UNLESS(m_entry_set.info.end == start && m_entry_set.info.start < m_entry_set.info.end,
ResultInvalidBucketTreeEntrySetOffset);
entry_index = m_entry_set.info.count;
} else {
m_entry_index = -1;
}
--entry_index;
// Read the new entry.
const auto entry_size = m_tree->m_entry_size;
const auto entry_offset = impl::GetBucketTreeEntryOffset(
m_entry_set.info.index, m_tree->m_node_size, entry_size, entry_index);
m_tree->m_entry_storage->Read(reinterpret_cast<u8*>(m_entry), entry_size, entry_offset);
// Note that we changed index.
m_entry_index = entry_index;
R_SUCCEED();
}
Result BucketTree::Visitor::Find(s64 virtual_address) {
ASSERT(m_tree != nullptr);
// Get the node.
const auto* const node = m_tree->m_node_l1.Get<Node>();
R_UNLESS(virtual_address < node->GetEndOffset(), ResultOutOfRange);
// Get the entry set index.
s32 entry_set_index = -1;
if (m_tree->IsExistOffsetL2OnL1() && virtual_address < node->GetBeginOffset()) {
const auto start = node->GetEnd();
const auto end = node->GetBegin() + m_tree->m_offset_count;
auto pos = std::upper_bound(start, end, virtual_address);
R_UNLESS(start < pos, ResultOutOfRange);
--pos;
entry_set_index = static_cast<s32>(pos - start);
} else {
const auto start = node->GetBegin();
const auto end = node->GetEnd();
auto pos = std::upper_bound(start, end, virtual_address);
R_UNLESS(start < pos, ResultOutOfRange);
--pos;
if (m_tree->IsExistL2()) {
const auto node_index = static_cast<s32>(pos - start);
R_UNLESS(0 <= node_index && node_index < m_tree->m_offset_count,
ResultInvalidBucketTreeNodeOffset);
R_TRY(this->FindEntrySet(std::addressof(entry_set_index), virtual_address, node_index));
} else {
entry_set_index = static_cast<s32>(pos - start);
}
}
// Validate the entry set index.
R_UNLESS(0 <= entry_set_index && entry_set_index < m_tree->m_entry_set_count,
ResultInvalidBucketTreeNodeOffset);
// Find the entry.
R_TRY(this->FindEntry(virtual_address, entry_set_index));
// Set count.
m_entry_set_count = m_tree->m_entry_set_count;
R_SUCCEED();
}
Result BucketTree::Visitor::FindEntrySet(s32* out_index, s64 virtual_address, s32 node_index) {
const auto node_size = m_tree->m_node_size;
PooledBuffer pool(node_size, 1);
if (node_size <= pool.GetSize()) {
R_RETURN(
this->FindEntrySetWithBuffer(out_index, virtual_address, node_index, pool.GetBuffer()));
} else {
pool.Deallocate();
R_RETURN(this->FindEntrySetWithoutBuffer(out_index, virtual_address, node_index));
}
}
Result BucketTree::Visitor::FindEntrySetWithBuffer(s32* out_index, s64 virtual_address,
s32 node_index, char* buffer) {
// Calculate node extents.
const auto node_size = m_tree->m_node_size;
const auto node_offset = (node_index + 1) * static_cast<s64>(node_size);
VirtualFile storage = m_tree->m_node_storage;
// Read the node.
storage->Read(reinterpret_cast<u8*>(buffer), node_size, node_offset);
// Validate the header.
NodeHeader header;
std::memcpy(std::addressof(header), buffer, NodeHeaderSize);
R_TRY(header.Verify(node_index, node_size, sizeof(s64)));
// Create the node, and find.
StorageNode node(sizeof(s64), header.count);
node.Find(buffer, virtual_address);
R_UNLESS(node.GetIndex() >= 0, ResultInvalidBucketTreeVirtualOffset);
// Return the index.
*out_index = static_cast<s32>(m_tree->GetEntrySetIndex(header.index, node.GetIndex()));
R_SUCCEED();
}
Result BucketTree::Visitor::FindEntrySetWithoutBuffer(s32* out_index, s64 virtual_address,
s32 node_index) {
// Calculate node extents.
const auto node_size = m_tree->m_node_size;
const auto node_offset = (node_index + 1) * static_cast<s64>(node_size);
VirtualFile storage = m_tree->m_node_storage;
// Read and validate the header.
NodeHeader header;
storage->ReadObject(std::addressof(header), node_offset);
R_TRY(header.Verify(node_index, node_size, sizeof(s64)));
// Create the node, and find.
StorageNode node(node_offset, sizeof(s64), header.count);
R_TRY(node.Find(storage, virtual_address));
R_UNLESS(node.GetIndex() >= 0, ResultOutOfRange);
// Return the index.
*out_index = static_cast<s32>(m_tree->GetEntrySetIndex(header.index, node.GetIndex()));
R_SUCCEED();
}
Result BucketTree::Visitor::FindEntry(s64 virtual_address, s32 entry_set_index) {
const auto entry_set_size = m_tree->m_node_size;
PooledBuffer pool(entry_set_size, 1);
if (entry_set_size <= pool.GetSize()) {
R_RETURN(this->FindEntryWithBuffer(virtual_address, entry_set_index, pool.GetBuffer()));
} else {
pool.Deallocate();
R_RETURN(this->FindEntryWithoutBuffer(virtual_address, entry_set_index));
}
}
Result BucketTree::Visitor::FindEntryWithBuffer(s64 virtual_address, s32 entry_set_index,
char* buffer) {
// Calculate entry set extents.
const auto entry_size = m_tree->m_entry_size;
const auto entry_set_size = m_tree->m_node_size;
const auto entry_set_offset = entry_set_index * static_cast<s64>(entry_set_size);
VirtualFile storage = m_tree->m_entry_storage;
// Read the entry set.
storage->Read(reinterpret_cast<u8*>(buffer), entry_set_size, entry_set_offset);
// Validate the entry_set.
EntrySetHeader entry_set;
std::memcpy(std::addressof(entry_set), buffer, sizeof(EntrySetHeader));
R_TRY(entry_set.header.Verify(entry_set_index, entry_set_size, entry_size));
// Create the node, and find.
StorageNode node(entry_size, entry_set.info.count);
node.Find(buffer, virtual_address);
R_UNLESS(node.GetIndex() >= 0, ResultOutOfRange);
// Copy the data into entry.
const auto entry_index = node.GetIndex();
const auto entry_offset = impl::GetBucketTreeEntryOffset(0, entry_size, entry_index);
std::memcpy(m_entry, buffer + entry_offset, entry_size);
// Set our entry set/index.
m_entry_set = entry_set;
m_entry_index = entry_index;
R_SUCCEED();
}
Result BucketTree::Visitor::FindEntryWithoutBuffer(s64 virtual_address, s32 entry_set_index) {
// Calculate entry set extents.
const auto entry_size = m_tree->m_entry_size;
const auto entry_set_size = m_tree->m_node_size;
const auto entry_set_offset = entry_set_index * static_cast<s64>(entry_set_size);
VirtualFile storage = m_tree->m_entry_storage;
// Read and validate the entry_set.
EntrySetHeader entry_set;
storage->ReadObject(std::addressof(entry_set), entry_set_offset);
R_TRY(entry_set.header.Verify(entry_set_index, entry_set_size, entry_size));
// Create the node, and find.
StorageNode node(entry_set_offset, entry_size, entry_set.info.count);
R_TRY(node.Find(storage, virtual_address));
R_UNLESS(node.GetIndex() >= 0, ResultOutOfRange);
// Copy the data into entry.
const auto entry_index = node.GetIndex();
const auto entry_offset =
impl::GetBucketTreeEntryOffset(entry_set_offset, entry_size, entry_index);
storage->Read(reinterpret_cast<u8*>(m_entry), entry_size, entry_offset);
// Set our entry set/index.
m_entry_set = entry_set;
m_entry_index = entry_index;
R_SUCCEED();
}
} // namespace FileSys
