There Are 4 Parts For The Project; The Question May Be Long

There Are 4 Parts For The Project The Question May Be Long To Read Bu

There are four parts to this project, each involving different functionalities related to disk simulation, file system management, shell implementation, and database creation. The first part requires implementing a class to simulate a disk drive with functionalities to create, read, and write blocks within a file representing the disk. The second part involves developing a simplified file system with a File Allocation Table (FAT) and root directory, including functions for file management such as creation, deletion, block addition, and retrieval. The third part entails designing a shell interface to interact with the file system, providing commands like list directory contents, add, delete, and copy files. The final part focuses on constructing a database system that manages records related to Art History, using the previous file system to store data efficiently, generate an index, and support search capabilities.

Paper For Above instruction

Introduction

In modern computing, the simulation of disk drives, file systems, shell environments, and database systems form the backbone of data management and interaction. Implementing these components from scratch provides invaluable insights into how data storage, retrieval, and management work at a low level. This paper discusses a comprehensive approach to developing such systems in a modular and systematic manner, addressing each part outlined in the project brief.

Part 1: Disk Drive Simulation

The first component involves creating a class named Sdisk that simulates a physical disk using a file. The class manages a disk with a specified number of blocks, each of a uniform size. The constructor of Sdisk checks whether the disk file exists; if it does, it opens the file, otherwise, it creates a new file initialized with empty data. This process involves dividing the file into logically contiguous blocks, enabling easy retrieval and storage of data blocks.

The key member functions include getblock and putblock, which facilitate reading and writing blocks at specified block numbers, respectively. These functions operate directly on the file, ensuring data persistence and consistency. Additional accessor functions provide information about disk characteristics, such as total block count and block size. Proper exception handling and error checking are vital to prevent data corruption or runtime failures during disk operations.

Part 2: File System Management

The second part involves designing a class named Filesys that extends Sdisk. This class manages a file system structure, including a FAT and a root directory, both stored on the disk. The constructor reads existing file system information or initializes a new one with an empty FAT and ROOT. The FAT is an array where each entry points to the next block in a file, or zero if free, with special handling for the end of file indicator.

Functions such as newfile and rmfile manage the directory entries, creating or deleting files. Block-level operations like addblock, delblock, readblock, and writeblock control data storage within files, utilizing the FAT to track sequences of blocks. Synchronization functions ensure updates to the FAT and ROOT are written to disk immediately, preserving integrity.

The significant challenge in this part is calculating the FAT_size based on disk parameters, ensuring the FAT fits within the allocated storage blocks. Maintaining synchronization between in-memory data and on-disk data is critical for consistent recovery and operation.

Part 3: Shell Interface

The third component introduces a shell interface through the Shell class. It provides commands for listing directory contents, adding new files, deleting files, displaying file contents, and copying files. The class inherits from Filesys and interacts with the file management functions to perform user commands seamlessly.

The shell logic handles user input, validates file names, and invokes appropriate member functions of Filesys. For example, the dir command displays all files present in the root directory, while add prompts the user for content and stores it in the file system with proper block allocation. The del command removes files if they are empty, and the type command displays file contents while considering block sequences.

Implementing this shell provides an interactive environment to test the lower-level system functionalities, demonstrating the practical usability of the file system constructed.

Part 4: Art History Database System

The final part pertains to building a database system that manages records related to Art History. Using the Filesys class, this system creates and maintains two files: a flat file storing raw records and an index file that maintains key-value pairs (date and block number). Data records are delimited by asterisks and contain variable-length descriptions, with an overall record length limit ensuring efficient block storage.

The Table class extends Filesys and manages data building, indexing, and searching. The Build_Table function reads data from a text file, structures it, and stores it in the flat file, simultaneously creating index records. The Search function utilizes IndexSearch to find the record matching a specified date key, then retrieves and displays it.

This system demonstrates how indexing enhances retrieval speed in large datasets, facilitating efficient lookup operations, a critical feature in database design.

Conclusion

Designing and implementing a disk simulation, file system, shell interface, and database from the ground up offers comprehensive insights into core computer system principles. Each component plays a vital role in data management and interaction, emphasizing the importance of structured storage, efficient retrieval, and user-friendly interfaces. Through modular development and careful synchronization, these systems can be made robust and scalable, providing a foundation for more advanced applications.

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