📂 Mini Version Control System (VCS) in C++

📖 Overview

This project is a lightweight version control system for text files, implemented entirely in C++ without using STL’s map or priority_queue. It supports:

• File creation and editing
• Versioning with snapshots
• Rollbacks to previous versions
• History tracking of commits
• Listing recent files and biggest version trees
• Compile through shells scripts

Note: User must be able to input commands at runtime, i.e., from stdin has been followed. For that user must run the main.exe after compiling.

The system uses:

• A custom hash map (map.cpp)
• A custom heap/priority queue (Heap.cpp)
• A tree structure to represent file versions (Tree.cpp)

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⚙️ Features

File Operations

• CREATE <filename>

  • Creates a new file with an initial snapshot (version 0).

• READ <filename>

  • Prints the current active version’s ID and content.

• INSERT <filename> <content>

  • Appends content to the active version.
  • If the active version is a snapshot, a new version is created.

• UPDATE <filename> <content>

  • Replaces the file’s content.
  • Creates a new version if the active one is a snapshot.

Version Control

• SNAPSHOT <filename> <message>

  • Commits the current version with a message and timestamp.

• ROLLBACK <filename> [versionID]

  • Rolls back to the parent version (if no ID is provided).
  • Or rolls back to a specific version if versionID is given.

• HISTORY <filename>

  • Shows all snapshots (ID, timestamp, commit message) in chronological order.

File Listings

• RECENT_FILES [num]

  • Lists files in descending order of their last modification time.

• BIGGEST_TREES [num]

  • Lists files in descending order of their total version count.

Exit

• EXIT

  • Ends the program.

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🏧 Project Structure

.
├── main.cpp        # Command interpreter (CLI)
├── map.cpp         # Custom hash map implementation
├── Heap.cpp        # Custom heap/priority queue implementation
├── Tree.cpp        # Version tree (file versioning)

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📦 Data Structures

map<K, V> (in map.cpp)

• Hash-based key-value store.

• Supports:

  • count(key)
  • operator[]
  • insert(key, value)
  • erase(key)
  • items() → returns all key-value pairs as a vector.

Heap<T, C> (in Heap.cpp)

• Binary heap (min/max based on comparator).

• Supports:

  • push(value)
  • pop()
  • top()
  • empty()
  • size()

Tree (in Tree.cpp)

• Represents a file’s version history as a tree of TreeNode.

• TreeNode holds:

  • version_id
  • content
  • message
  • created_timestamp
  • snapshot_timestamp
  • parent and children pointers.

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▶️ Usage

Windows

To compile and run: open the file run.bat

2. Linux

To compile and run: open the file run.sh

🛠️ Error Handling

• Invalid commands → Unknown command
• Missing filename → Please provide a filename
• File does not exist → Error: File does not exist
• Colliding names → File already exists
• No content/message → Error: No content provided
• No num parameter provided in system-wide commands→ Please specify the number of files
• If num more than total files → Terminating early ...
• If rollback to parent of root → Already at root version. Cannot rollback further.