citra/src/core/file_sys/vfs_concat.h

60 lines
2.0 KiB
C++

// SPDX-FileCopyrightText: Copyright 2018 yuzu Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
#pragma once
#include <compare>
#include <map>
#include <memory>
#include "core/file_sys/vfs.h"
namespace FileSys {
// Class that wraps multiple vfs files and concatenates them, making reads seamless. Currently
// read-only.
class ConcatenatedVfsFile : public VfsFile {
private:
struct ConcatenationEntry {
u64 offset;
VirtualFile file;
auto operator<=>(const ConcatenationEntry& other) const {
return this->offset <=> other.offset;
}
};
using ConcatenationMap = std::vector<ConcatenationEntry>;
explicit ConcatenatedVfsFile(std::vector<ConcatenationEntry>&& concatenation_map,
std::string&& name);
bool VerifyContinuity() const;
public:
~ConcatenatedVfsFile() override;
/// Wrapper function to allow for more efficient handling of files.size() == 0, 1 cases.
static VirtualFile MakeConcatenatedFile(const std::vector<VirtualFile>& files,
std::string&& name);
/// Convenience function that turns a map of offsets to files into a concatenated file, filling
/// gaps with a given filler byte.
static VirtualFile MakeConcatenatedFile(u8 filler_byte,
const std::multimap<u64, VirtualFile>& files,
std::string&& name);
std::string GetName() const override;
std::size_t GetSize() const override;
bool Resize(std::size_t new_size) override;
VirtualDir GetContainingDirectory() const override;
bool IsWritable() const override;
bool IsReadable() const override;
std::size_t Read(u8* data, std::size_t length, std::size_t offset) const override;
std::size_t Write(const u8* data, std::size_t length, std::size_t offset) override;
bool Rename(std::string_view new_name) override;
private:
ConcatenationMap concatenation_map;
std::string name;
};
} // namespace FileSys