Virtual file system

📙 Summary

This project is simulation of the allocation and de-allocation of files and folders using different allocation techniques with protection level.

The techniques which simulated in this project:

Contiguous allocation:

In this technique, each file occupies a contiguous set of blocks on the disk. For example, if a file requires n blocks and is given a block b as the starting location, then the blocks assigned to the file will be: b, b+1, b+2,……b+n-1. This means that given the starting block address and the length of the file (in terms of blocks required), we can determine the blocks occupied by the file.
Indexed allocation:

In this scheme, a special block known as the Index block contains the pointers to all the blocks occupied by a file. Each file has its own index block. The ith entry in the index block contains the disk address of the ith file block.
Linked allocation:

In this scheme, each file is a linked list of disk blocks which need not be contiguous. The disk blocks can be scattered anywhere on the disk. The directory entry contains a pointer to the starting and the ending file block. Each block contains a pointer to the next block occupied by the file.

In this program we are not creating actual files and folder, we will just simulate having a series of blocks and these blocks will be allocated to files when created and will be de-allocated when these files are deleted, our virtual file system information like (the files information, the folders information, the allocated blocks and so on) will be saved on files like contiguousAllocation.txt, indexedAllocation.txt and linkedAllocation.txt to be loaded the next time you run the application.

We store the information of the user in user.txt and their capabilities in capabilities.txt.

💻 Running

Open the terminal or the command line in the directory of our repository and type the following commands:

cd ./src

javac *

java Main

💡 Commands

After running the application the user will interact with your virtual file system through the following commands:

CreateFile : This command used to create a file and it takes 2 parameters (path of the file which will be created and the size of this file).

ex: CreateFile root/file.txt 100

In the previous example a file named file.txt will be created with 100 KB size under the path root.
CreateFolder : This command used to create a folder and it takes 1 parameter (path of the folder which will be created).

ex: CreateFolder root/folder1

In the previous example a folder named folder1 will be created under the path root.
DeleteFile : This command used to delete a file and it takes 1 parameter (path of the file which will be deleted) but it requires existing this file under the path specified.

ex: DeleteFile root/folder1/file.txt

In the previous example a file named folder1 under the path root will be deleted.
DeleteFolder : This command used to delete a folder and it takes 1 parameter (path of the folder which will be deleted) but it requires existing this file under the path specified.

ex: DeleteFolder root/folder1

In the previous example a folder named folder1 under the path root will be deleted.
DisplayDiskStatus : This command used to display the status of your driver and this status should contain empty space, allocated space, empty blocks in the disk and allocated blocks in the disk . It takes no parameters.
DisplayDiskStructure : This command will display the files and folders in your system file in a tree structure. It takes no parameters.

🎯 Clone the project

$ git clone https://github.com/MarwanGalal746/Virtual-file-system

👥 Contributers

Eyad Youssef, Abdelrahman Ali, Abdelrahman Ammar and Marwan Galal.