Making Git Clone

This week was spent in learning by building and I made a prototype of Git using Javascript.

Here is the summary of it.

Github Link

Overview

The script provides basic Git-like operations, such as:

1. Initializing a Git-like repository with a .git directory.


2. Handling file hashing and object storage in a way similar to Git’s object storage.


3. Building and committing trees to model directory structures.

Commands Implemented

• init: Sets up a .git directory structure with objects and refs folders and creates a HEAD file pointing to the main branch.


• cat-file: Reads and decompresses a Git object given its SHA-1 hash, displaying its contents.


• hash-object: Hashes a file, creates a compressed version, and stores it in the .git/objects folder.


• ls-tree: Lists the contents of a tree object, similar to the git ls-tree command.


• write-tree: Writes the current directory structure into a tree object and stores it.


• commit-tree: Creates a new commit object, linking it to a tree object and a parent commit, and stores it in the Git object storage.

Functionality Breakdown

1. Git Directory Initialization (init):

• Creates .git, .git/objects, and .git/refs directories.


• Sets HEAD to reference the main branch.

2. File Hashing and Object Storage (hash-object):

• Reads a file, hashes its contents using SHA-1, and compresses it using zlib.


• Stores the compressed object in .git/objects using the first two characters of the SHA-1 hash to create a subdirectory.

3. Viewing Object Content (cat-file):

• Decompresses a stored object from .git/objects and prints its content.

4. Tree Management (ls-tree and write-tree):

• ls-tree: Lists the files and directories in a tree object.


• write-tree: Recursively traverses the current directory, hashing files and building a tree object. Stores the tree object in .git/objects.

5. Commit Creation (commit-tree):

• Constructs a commit object containing metadata (author, committer, timestamp) and a reference to the tree object and parent commit.


• Compresses and stores the commit object in .git/objects.

That's all for this week folks.

Stay tuned for more.