yuzu/src/core/file_sys/vfs_concat.cpp

97 lines
2.6 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 "core/file_sys/vfs_concat.h"
namespace FileSys {
VirtualFile ConcatenateFiles(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)));
}
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[next_offset] = file;
next_offset += file->GetSize();
}
}
ConcatenatedVfsFile::~ConcatenatedVfsFile() = default;
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;
}
}
// Check if the entry should be the last one. The loop above will make it end().
if (entry == files.end() && offset < files.rbegin()->first + files.rbegin()->second->GetSize())
--entry;
if (entry == files.end())
return 0;
const auto remaining = entry->second->GetSize() + offset - entry->first;
if (length > remaining) {
return entry->second->Read(data, remaining, offset - entry->first) +
Read(data + remaining, length - remaining, offset + remaining);
}
return entry->second->Read(data, 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