Azure DevOps recently rolled out comprehensive Git Partial Clone support, a feature that streamlines cloning processes with specified command line arguments. These partial clones, proven to significantly slash cloning times by an average of 88.6%, particularly benefit larger repositories.
Michael Carlson, principal software engineer at Microsoft, delved into this advancement in a blog post. Unlike conventional clones, partial clones delay downloading historical repository objects until the checkout of a branch or specific Git scenarios necessitate them.
Developed to manage hefty repositories efficiently, Partial Clone aims to alleviate the burdensome nature of handling mammoth-sized repositories. Often spanning hours or days and hogging over 100 gigabytes of disk space, traditional cloning processes are notorious for retrieving unnecessary blobs and trees. Partial clones evade this by deferring the download of non-essential objects, minimizing download times and disk usage. Missing objects are retrieved on demand from a designated promisor remote committed to delivering these objects upon request.
The impact of Git Partial Clone extends to specific Git clones/fetches with defined arguments:
Blobless clones: git clone –filter=blob:none <url>
Treeless clones: git clone –filter=tree:0 <url>
While similar in appearance to the Shallow Clone feature in Azure DevOps (git clone –depth=1 <url>), Partial Clone serves distinct purposes. Shallow clones suit specific scenarios, like building pipelines void of historical context, leading to a truncated commit history without prior historical data.
The tech community actively engaged in response to this announcement, discussing and posing queries in blog post comments and Reddit threads. Queries about Git Partial Clone’s compatibility with Azure DevOps Server 2022 garnered attention. Carlson confirmed its upcoming availability in a future Azure DevOps Server release. In a Reddit post, a feature request for treeless/blobless clones within the standard checkout task received acknowledgement from a Microsoft representative, hinting at potential future inclusion.