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// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
#pragma once
#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 {
template <typename EntryType>
Result BucketTree::ScanContinuousReading(ContinuousReadingInfo* out_info,
const ContinuousReadingParam<EntryType>& param) const {
static_assert(std::is_trivial_v<ContinuousReadingParam<EntryType>>);
// Validate our preconditions.
ASSERT(this->IsInitialized());
ASSERT(out_info != nullptr);
ASSERT(m_entry_size == sizeof(EntryType));
// Reset the output.
out_info->Reset();
// If there's nothing to read, we're done.
R_SUCCEED_IF(param.size == 0);
// If we're reading a fragment, we're done.
R_SUCCEED_IF(param.entry.IsFragment());
// Validate the first entry.
auto entry = param.entry;
auto cur_offset = param.offset;
R_UNLESS(entry.GetVirtualOffset() <= cur_offset, ResultOutOfRange);
// Create a pooled buffer for our scan.
PooledBuffer pool(m_node_size, 1);
char* buffer = nullptr;
s64 entry_storage_size = m_entry_storage->GetSize();
// Read the node.
if (m_node_size <= pool.GetSize()) {
buffer = pool.GetBuffer();
const auto ofs = param.entry_set.index * static_cast<s64>(m_node_size);
R_UNLESS(m_node_size + ofs <= static_cast<size_t>(entry_storage_size),
ResultInvalidBucketTreeNodeEntryCount);
m_entry_storage->Read(reinterpret_cast<u8*>(buffer), m_node_size, ofs);
}
// Calculate extents.
const auto end_offset = cur_offset + static_cast<s64>(param.size);
s64 phys_offset = entry.GetPhysicalOffset();
// Start merge tracking.
s64 merge_size = 0;
s64 readable_size = 0;
bool merged = false;
// Iterate.
auto entry_index = param.entry_index;
for (const auto entry_count = param.entry_set.count; entry_index < entry_count; ++entry_index) {
// If we're past the end, we're done.
if (end_offset <= cur_offset) {
break;
}
// Validate the entry offset.
const auto entry_offset = entry.GetVirtualOffset();
R_UNLESS(entry_offset <= cur_offset, ResultInvalidIndirectEntryOffset);
// Get the next entry.
EntryType next_entry = {};
s64 next_entry_offset;
if (entry_index + 1 < entry_count) {
if (buffer != nullptr) {
const auto ofs = impl::GetBucketTreeEntryOffset(0, m_entry_size, entry_index + 1);
std::memcpy(std::addressof(next_entry), buffer + ofs, m_entry_size);
} else {
const auto ofs = impl::GetBucketTreeEntryOffset(param.entry_set.index, m_node_size,
m_entry_size, entry_index + 1);
m_entry_storage->ReadObject(std::addressof(next_entry), ofs);
}
next_entry_offset = next_entry.GetVirtualOffset();
R_UNLESS(param.offsets.IsInclude(next_entry_offset), ResultInvalidIndirectEntryOffset);
} else {
next_entry_offset = param.entry_set.offset;
}
// Validate the next entry offset.
R_UNLESS(cur_offset < next_entry_offset, ResultInvalidIndirectEntryOffset);
// Determine the much data there is.
const auto data_size = next_entry_offset - cur_offset;
ASSERT(data_size > 0);
// Determine how much data we should read.
const auto remaining_size = end_offset - cur_offset;
const size_t read_size = static_cast<size_t>(std::min(data_size, remaining_size));
ASSERT(read_size <= param.size);
// Update our merge tracking.
if (entry.IsFragment()) {
// If we can't merge, stop looping.
if (EntryType::FragmentSizeMax <= read_size || remaining_size <= data_size) {
break;
}
// Otherwise, add the current size to the merge size.
merge_size += read_size;
} else {
// If we can't merge, stop looping.
if (phys_offset != entry.GetPhysicalOffset()) {
break;
}
// Add the size to the readable amount.
readable_size += merge_size + read_size;
ASSERT(readable_size <= static_cast<s64>(param.size));
// Update whether we've merged.
merged |= merge_size > 0;
merge_size = 0;
}
// Advance.
cur_offset += read_size;
ASSERT(cur_offset <= end_offset);
phys_offset += next_entry_offset - entry_offset;
entry = next_entry;
}
// If we merged, set our readable size.
if (merged) {
out_info->SetReadSize(static_cast<size_t>(readable_size));
}
out_info->SetSkipCount(entry_index - param.entry_index);
R_SUCCEED();
}
template <typename EntryType>
Result BucketTree::Visitor::ScanContinuousReading(ContinuousReadingInfo* out_info, s64 offset,
size_t size) const {
static_assert(std::is_trivial_v<EntryType>);
ASSERT(this->IsValid());
// Create our parameters.
ContinuousReadingParam<EntryType> param = {
.offset = offset,
.size = size,
.entry_set = m_entry_set.header,
.entry_index = m_entry_index,
.offsets{},
.entry{},
};
std::memcpy(std::addressof(param.offsets), std::addressof(m_offsets),
sizeof(BucketTree::Offsets));
std::memcpy(std::addressof(param.entry), m_entry, sizeof(EntryType));
// Scan.
R_RETURN(m_tree->ScanContinuousReading<EntryType>(out_info, param));
}
} // namespace FileSys
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