DIY_GIT_in_Python/how_to/Change_14.md

• commit: Create commit

So far we were able to save versions of a directory (with write-tree), but without any additional context. In reality, when we save a snapshot we would like to attach data such as: + Message describing it + When the snapshot was created + Who created the snapshot + …

We will create a new type of object called a “commit” that will store all this information. A commit will just be a text file stored in the object database with the type of 'commit'.

The first lines in the commit will be key-values, then an empty line will mark the end of the key-values and then the commit message will follow. Like this:

tree 5e550586c91fce59e0006799e0d46b3948f05693
author Nikita Leshenko
time 2019-09-14T09:31:09+00:00

This is the commit message!

For now we’ll just write the “tree” key and the commit message to the commit object.

We will create a new ugit commit command that will accept a commit message, snapshot the current directory using ugit write-tree and save the resulting object.