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MontaukOS/kernel/src/Fs/Vfs.hpp
T
2026-07-21 14:23:06 +02:00

79 lines
3.2 KiB
C++

/*
* Vfs.hpp
* Virtual File System with numerical logical drive identifiers
* Copyright (c) 2025 Daniel Hammer
*/
#pragma once
#include <cstdint>
#include <cstddef>
namespace Fs::Vfs {
static constexpr int MaxDrives = 16;
struct BackendFile {
int driveNumber;
int localHandle;
uint32_t generation;
};
// Metadata for a single path, filled by FsDriver::Stat. Timestamps are UTC
// unix seconds; a filesystem that does not record a given time leaves it 0.
struct StatInfo {
uint64_t size; // file size in bytes
int64_t mtime; // last data modification time
int64_t ctime; // last inode (metadata) change time
int64_t atime; // last access time
uint32_t mode; // ext2/POSIX i_mode bits (type + permissions)
bool isDir; // true if the entry is a directory
};
struct FsDriver {
int (*Open)(const char* path);
int (*Read)(int handle, uint8_t* buffer, uint64_t offset, uint64_t size);
uint64_t (*GetSize)(int handle);
void (*Close)(int handle);
int (*ReadDir)(const char* path, const char** outNames, int maxEntries);
int (*Write)(int handle, const uint8_t* buffer, uint64_t offset, uint64_t size);
int (*Create)(const char* path);
int (*Delete)(const char* path);
int (*Mkdir)(const char* path);
int (*Rename)(const char* oldPath, const char* newPath);
const char* (*GetLabel)();
// Optional: paginated directory read returning entries [startIndex, startIndex+maxEntries).
// Drivers that leave this null are read via ReadDir at startIndex 0 only.
int (*ReadDirAt)(const char* path, const char** outNames, int maxEntries, int startIndex);
// Optional: fill metadata for a path. Drivers that leave this null do
// not support stat and VfsStat returns -1 for their paths.
int (*Stat)(const char* path, StatInfo* out);
};
void Initialize();
bool IsInitialized();
int RegisterDrive(int driveNumber, FsDriver* driver);
int UnregisterDrive(int driveNumber);
bool IsDriveRegistered(int driveNumber);
int FindLowestAvailableDrive(int firstDrive = 0);
int OpenBackendFile(const char* path, BackendFile& outFile);
int CreateBackendFile(const char* path, BackendFile& outFile);
int ReadBackendFile(const BackendFile& file, uint8_t* buffer, uint64_t offset, uint64_t size);
int WriteBackendFile(const BackendFile& file, const uint8_t* buffer, uint64_t offset, uint64_t size);
uint64_t GetBackendFileSize(const BackendFile& file);
bool BackendFileCanWrite(const BackendFile& file);
void CloseBackendFile(BackendFile& file);
int VfsDelete(const char* path);
int VfsStat(const char* path, StatInfo& out);
int VfsReadDir(const char* path, const char** outNames, int maxEntries);
int VfsReadDirAt(const char* path, const char** outNames, int maxEntries, int startIndex);
int VfsMkdir(const char* path);
int VfsRename(const char* oldPath, const char* newPath);
// Returns number of registered drives, fills outDrives[] with their indices
int VfsDriveList(int* outDrives, int maxEntries);
int VfsDriveLabel(int driveNumber, char* outLabel, int maxLen);
}