Calculating major.minor.patch from commit hash

I'd like my releases to have major.minor.patch version number. While increments of major.minor are something one has to do manually, I don't want to do that for patch.

So I was thinking of having a VERSION file in the repo containing major.minor and then calculate patch at the given commit C automatically as the length of the longest path starting at C in the subgraph containing only commits in which VERSION is the same as C's.

I can do that pretty easily right now by

* identifying commits in which VERSION changes with `git log --
VERSION` and then
* walking the graph in topo order with `git log --format=format:"%H %P"`.

The latter step can terminate early, so it doesn't have to walk the entire repo, but the latter walks everything and can be quite slow.

Is there a more efficient way to do this?

If not, would there be an interest in a new builtin (git-depth?) that would calculate the value?

On February 13, 2020 9:41 AM, Martin Vejnár wrote:

You should consider using annotated tags and the git describe command to derive your release number. We do this for all of our products and it works very well. For example:

$ git tag -a 1.6.4 commit-hash

Then, when building your release:

$ git describe --long --first-parent

Good luck, Randall

-- Brief whoami:
 NonStop developer since approximately 211288444200000000
 UNIX developer since approximately 421664400
-- In my real life, I talk too much.

On Thu, Feb 13, 2020 at 3:46 PM Randall S. Becker <rsbecker@nexbridge.com> wrote:

I'd like to avoid tags in this case, because a new tag/deletion of a tag could change the hash->version mapping and I'd like that to be stable.

On 2020-02-13 at 14:54:48, Martin Vejnár wrote:

Tags, usually signed tags, are the traditional way to indicate versions, and with them, git describe is usually used to describe commits. While it is possible to rewrite tags, people usually rely on convention and social sanction to not do that without good cause.

If that isn't enough for you, then you'll probably have to build things yourself. I'm not sure Git provides functionality that finds the longest path between two commits, but you can probably find the commit depth like the following:

git log --format="%H" -- VERSION | head -n1 | xargs -I{} git rev-list {}..HEAD | wc -l