Understanding Git Internals: How Git Works Under the Hood

Understanding Git Internals: How Git Works Under the Hood

While most developers use Git as a high-level tool for version control, understanding its internals can provide deeper insights into how it manages data and operations. In this advanced blog, we’ll explore Git’s underlying architecture, storage mechanisms, and internal commands.

Table of Contents

• Git Objects: Blobs, Trees, Commits, and Tags
• The Three Stages of Git Workflow
• References and Refs
• Packs and Compression
• Exercise: Inspecting Git Objects

Git Objects: Blobs, Trees, Commits, and Tags

Git stores all data as objects in the .git/objects directory. There are four types of objects:

• Blob: Represents file content.
• Tree: Represents a directory structure.
• Commit: Represents a snapshot of the repository at a specific point in time.
• Tag: Represents a reference to a specific commit.

The Three Stages of Git Workflow

Git operates through three stages:

• Working Directory: Files you are actively editing.
• Staging Area: Files that are prepared for the next commit.
• Repository: The final snapshot stored in .git.

References and Refs

References (refs) are pointers to commits or other references. Common types include:

• Branches: Pointers to the latest commit in a branch.
• Tags: Immutable pointers to specific commits.
• HEAD: Points to the current branch or commit.

Packs and Compression

To optimize storage, Git periodically compresses loose objects into pack files using git gc (garbage collection). Pack files store deltas (differences) between objects to save space.

Exercise: Inspecting Git Objects

Practice inspecting Git objects:

• Create a new file, stage it, and commit it.
• Use git hash-object to find the blob hash and inspect its content with git cat-file.
• Explore trees using git ls-tree.
• Analyze pack files using git verify-pack.

Coming Up Next

In the next part of this series, we’ll explore Git submodules and hidden features for managing dependencies and modularizing large projects.