65X-DOS/include/kernel/file.h

// SPDX-License-Identifier: MIT
//
// kernel/file.h
//      File related declarations
//
// Copyright © 2024 Kyle J Cardoza <Kyle.Cardoza@icloud.com>

#pragma once

#include <stdbool.h>
#include <stdint.h>

#include "kernel/device.h"

enum file_type {
        FILE_TYPE_NORMAL,
        FILE_TYPE_DIRECTORY,
		FILE_TYPE_DEVICE
};

struct file {
        // The full path of the file, including its volume and basename.
        char *pathname;

        // The basename of the file. This usually points to
        // the begining of the basename of the file in the
        // pathname string.
        char *basename;

        // The type of the file.
        enum file_type type;

		bool open;
        
        // Generic driver-specific data pointer
		void *userdata;
		
		// The major number identifies the device driver responsible for
		// the file.
		uint8_t major_number;

		// The minor number identifies the device, among those the driver
		// controls, which this file represents or is associated with.
		uint8_t minor_number;
};

// Using the pathname in the provided file stucture, identify the device which manages
// the file and have that device populate the file structure.
int file_init(char *pathname, struct file *file);

int file_open(struct file *file);

int file_ioctl(struct file *file,
               unsigned short operation,
               void *arg);

// Closes an open file, given a unique ID.
int file_close(struct file *file);

// Seeks within an open file, given a unique ID and a length.
int file_seek(struct file *file, int32_t length);

// Reads data from the specified file.
int file_read(struct file *file, void *dest, size_t length);

// Writes data to the specified file.
int file_write(struct file *file, void *src, size_t length);

// Creates the specified file given a pathname.
int file_create(struct file *file);

// Copies the specified file using the specified names.
int file_copy(struct file *src, struct file *dest);

// Moves the specified file using the specified names.
int file_move(struct file *src, struct file *dest);

// Gets the size of the file.
int file_get_file_size(struct file *file, size_t *size);