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// Copyright 2018 yuzu emulator team
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#pragma once
#include <map>
#include <memory>
#include <string_view>
#include <boost/container/flat_map.hpp>
#include "core/file_sys/vfs.h"
#include "core/file_sys/vfs_static.h"
namespace FileSys {
// Class that wraps multiple vfs files and concatenates them, making reads seamless. Currently
// read-only.
class ConcatenatedVfsFile : public VfsFile {
friend VirtualFile ConcatenateFiles(std::vector<VirtualFile> files, std::string name);
template <u8 filler_byte>
friend VirtualFile ConcatenateFiles(std::map<u64, VirtualFile> files, std::string name);
ConcatenatedVfsFile(std::vector<VirtualFile> files, std::string name);
ConcatenatedVfsFile(std::map<u64, VirtualFile> files, std::string name);
public:
~ConcatenatedVfsFile() override;
std::string GetName() const override;
std::size_t GetSize() const override;
bool Resize(std::size_t new_size) override;
std::shared_ptr<VfsDirectory> 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 name) override;
private:
// Maps starting offset to file -- more efficient.
std::map<u64, VirtualFile> files;
std::string name;
};
// Wrapper function to allow for more efficient handling of files.size() == 0, 1 cases.
VirtualFile ConcatenateFiles(std::vector<VirtualFile> files, std::string name);
// Convenience function that turns a map of offsets to files into a concatenated file, filling gaps
// with template parameter.
template <u8 filler_byte>
VirtualFile ConcatenateFiles(std::map<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)));
}
} // namespace FileSys
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