suyu/src/core/file_sys/vfs_concat.cpp
Morph fd1c3aa14e fs: Fix RomFS building when zero byte files are present
When zero byte files are present, the key (offset) for that file is identical to the file right after. A std::map isn't able to fit key-value pairs with identical keys (offsets), therefore, the solution is to use std::multimap which permits multiple entries with the same key.

This most prominently fixes Pokemon Sword and Shield weather with any RomFS mod applied.
2020-07-12 04:33:35 -04:00

140 lines
4.4 KiB
C++

// Copyright 2018 yuzu emulator team
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include <algorithm>
#include <utility>
#include "common/assert.h"
#include "core/file_sys/vfs_concat.h"
#include "core/file_sys/vfs_static.h"
namespace FileSys {
static bool VerifyConcatenationMapContinuity(const std::multimap<u64, VirtualFile>& map) {
const auto last_valid = --map.end();
for (auto iter = map.begin(); iter != last_valid;) {
const auto old = iter++;
if (old->first + old->second->GetSize() != iter->first) {
return false;
}
}
return map.begin()->first == 0;
}
ConcatenatedVfsFile::ConcatenatedVfsFile(std::vector<VirtualFile> files_, std::string name)
: name(std::move(name)) {
std::size_t next_offset = 0;
for (const auto& file : files_) {
files.emplace(next_offset, file);
next_offset += file->GetSize();
}
}
ConcatenatedVfsFile::ConcatenatedVfsFile(std::multimap<u64, VirtualFile> files_, std::string name)
: files(std::move(files_)), name(std::move(name)) {
ASSERT(VerifyConcatenationMapContinuity(files));
}
ConcatenatedVfsFile::~ConcatenatedVfsFile() = default;
VirtualFile ConcatenatedVfsFile::MakeConcatenatedFile(std::vector<VirtualFile> files,
std::string name) {
if (files.empty())
return nullptr;
if (files.size() == 1)
return files[0];
return std::shared_ptr<VfsFile>(new ConcatenatedVfsFile(std::move(files), std::move(name)));
}
VirtualFile ConcatenatedVfsFile::MakeConcatenatedFile(u8 filler_byte,
std::multimap<u64, VirtualFile> files,
std::string name) {
if (files.empty())
return nullptr;
if (files.size() == 1)
return files.begin()->second;
const auto last_valid = --files.end();
for (auto iter = files.begin(); iter != last_valid;) {
const auto old = iter++;
if (old->first + old->second->GetSize() != iter->first) {
files.emplace(old->first + old->second->GetSize(),
std::make_shared<StaticVfsFile>(filler_byte, iter->first - old->first -
old->second->GetSize()));
}
}
// Ensure the map starts at offset 0 (start of file), otherwise pad to fill.
if (files.begin()->first != 0)
files.emplace(0, std::make_shared<StaticVfsFile>(filler_byte, files.begin()->first));
return std::shared_ptr<VfsFile>(new ConcatenatedVfsFile(std::move(files), std::move(name)));
}
std::string ConcatenatedVfsFile::GetName() const {
if (files.empty())
return "";
if (!name.empty())
return name;
return files.begin()->second->GetName();
}
std::size_t ConcatenatedVfsFile::GetSize() const {
if (files.empty())
return 0;
return files.rbegin()->first + files.rbegin()->second->GetSize();
}
bool ConcatenatedVfsFile::Resize(std::size_t new_size) {
return false;
}
std::shared_ptr<VfsDirectory> ConcatenatedVfsFile::GetContainingDirectory() const {
if (files.empty())
return nullptr;
return files.begin()->second->GetContainingDirectory();
}
bool ConcatenatedVfsFile::IsWritable() const {
return false;
}
bool ConcatenatedVfsFile::IsReadable() const {
return true;
}
std::size_t ConcatenatedVfsFile::Read(u8* data, std::size_t length, std::size_t offset) const {
auto entry = --files.end();
for (auto iter = files.begin(); iter != files.end(); ++iter) {
if (iter->first > offset) {
entry = --iter;
break;
}
}
if (entry->first + entry->second->GetSize() <= offset)
return 0;
const auto read_in =
std::min<u64>(entry->first + entry->second->GetSize() - offset, entry->second->GetSize());
if (length > read_in) {
return entry->second->Read(data, read_in, offset - entry->first) +
Read(data + read_in, length - read_in, offset + read_in);
}
return entry->second->Read(data, std::min<u64>(read_in, length), offset - entry->first);
}
std::size_t ConcatenatedVfsFile::Write(const u8* data, std::size_t length, std::size_t offset) {
return 0;
}
bool ConcatenatedVfsFile::Rename(std::string_view name) {
return false;
}
} // namespace FileSys