serenity/Kernel/FileSystem/SysFSComponent.h
Liav A 478f543899 Kernel/SysFS: Prevent allocation for component name during construction
Instead, allocate before constructing the object and pass NonnullOwnPtr
of KString to the object if needed. Some classes can determine their
names as they have a known attribute to look for or have a static name.
2021-12-14 09:01:33 +01:00

65 lines
2.2 KiB
C++

/*
* Copyright (c) 2021, Liav A. <liavalb@hotmail.co.il>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Error.h>
#include <AK/Function.h>
#include <AK/RefCounted.h>
#include <AK/RefPtr.h>
#include <AK/StringView.h>
#include <AK/Types.h>
#include <Kernel/FileSystem/File.h>
#include <Kernel/FileSystem/FileSystem.h>
#include <Kernel/FileSystem/OpenFileDescription.h>
#include <Kernel/Forward.h>
namespace Kernel {
struct SysFSInodeData : public OpenFileDescriptionData {
OwnPtr<KBuffer> buffer;
};
class SysFSComponent : public RefCounted<SysFSComponent> {
public:
virtual StringView name() const = 0;
virtual ErrorOr<size_t> read_bytes(off_t, size_t, UserOrKernelBuffer&, OpenFileDescription*) const { return Error::from_errno(ENOTIMPL); }
virtual ErrorOr<void> traverse_as_directory(FileSystemID, Function<ErrorOr<void>(FileSystem::DirectoryEntryView const&)>) const { VERIFY_NOT_REACHED(); }
virtual RefPtr<SysFSComponent> lookup(StringView) { VERIFY_NOT_REACHED(); };
virtual mode_t permissions() const;
virtual ErrorOr<void> truncate(u64) { return EPERM; }
virtual ErrorOr<void> set_mtime(time_t) { return ENOTIMPL; }
virtual ErrorOr<size_t> write_bytes(off_t, size_t, UserOrKernelBuffer const&, OpenFileDescription*) { return EROFS; }
virtual ErrorOr<void> refresh_data(OpenFileDescription&) const { return {}; }
virtual ErrorOr<NonnullRefPtr<SysFSInode>> to_inode(SysFS const&) const;
InodeIndex component_index() const { return m_component_index; };
virtual ~SysFSComponent() = default;
protected:
SysFSComponent();
private:
InodeIndex m_component_index {};
};
class SysFSDirectory : public SysFSComponent {
public:
virtual ErrorOr<void> traverse_as_directory(FileSystemID, Function<ErrorOr<void>(FileSystem::DirectoryEntryView const&)>) const override;
virtual RefPtr<SysFSComponent> lookup(StringView name) override;
virtual ErrorOr<NonnullRefPtr<SysFSInode>> to_inode(SysFS const& sysfs_instance) const override final;
protected:
SysFSDirectory() = default;
explicit SysFSDirectory(SysFSDirectory const& parent_directory);
NonnullRefPtrVector<SysFSComponent> m_components;
RefPtr<SysFSDirectory> m_parent_directory;
};
}