Using Git prune (with examples)
Git is a powerful version control system that allows developers to track changes in their codebase. One of the important tasks in Git is to manage the object database, which stores all the objects (commits, trees, blobs, etc.) in a repository. Over time, the object database can become cluttered with unreachable objects that are no longer needed. Git provides the git prune command to remove these unreachable objects and optimize the storage.
In this article, we will explore different use cases of the git prune command along with code examples and their motivations.
Use Case 1: Reporting what would be removed by Git prune without removing it
It is often useful to know what objects would be removed by Git prune before actually removing them. This can help to ensure that no important objects are deleted unintentionally. To perform a dry run of Git prune, we can use the --dry-run option.
git prune --dry-run
Motivation: The --dry-run option allows us to see a preview of what objects would be removed by Git prune without actually removing them. This is useful when we want to evaluate the impact of running Git prune or when we want to include the output in a script.
Explanation: The --dry-run option instructs Git prune to simulate the removal of unreachable objects without actually deleting them. It scans the object database and reports the list of objects that would be pruned.
Example Output:
Checking object database... done
Pruning: 15b71ef, ed3b7ae, 80a2079
Use Case 2: Pruning unreachable objects and displaying what has been pruned
To perform the actual pruning of unreachable objects and see the list of objects that have been pruned, we can use the --verbose option with the git prune command.
git prune --verbose
Motivation: The --verbose option is helpful when we want to see the detailed information about the objects that are being pruned. It provides transparency and helps in understanding the impact and effectiveness of the pruning operation.
Explanation: The --verbose option instructs Git prune to display a detailed output while pruning the unreachable objects. It shows the list of objects that have been pruned along with additional information such as the type of object and its hash.
Example Output:
Pruning objects: 100% (3/3), done.
Deleted blob object: 15b71ef
Deleted commit object: ed3b7ae
Deleted tree object: 80a2079
Use Case 3: Pruning unreachable objects while showing progress
When pruning a large repository with a lot of unreachable objects, it can be beneficial to have a progress indication to gauge the pruning operation’s completion. Git provides the --progress option to show the progress bar during the pruning process.
git prune --progress
Motivation: The --progress option is particularly useful when dealing with large repositories where the pruning operation can take a significant amount of time. The progress bar helps in estimating the remaining time and ensures that the process is ongoing.
Explanation: The --progress option shows a progress bar while Git prune is performing the pruning operation. It indicates the completion percentage and gives a visual representation of the ongoing process.
Example Output:
Cleaning repository...
Pruning objects: 50% (3/6), done.
Conclusion
In this article, we explored different use cases of the git prune command with code examples and their motivations. We saw how to report what would be removed by Git prune, perform the pruning operation while displaying the list of pruned objects, and show progress during the pruning process. These use cases provide developers with the flexibility to manage and optimize the object database effectively using the Git prune command.
