How to efficiently generating the diffstat?

Hi,

I need some help to efficiently generating the diffstat. I would like to get the number of lines added and deleted from one commit to another, like the following command does:

git log --stat

I wrote the following code, but it is pretty slow.

for raw_parent in self.__raw_commit.parents:
    diff = self.__raw_commit.tree.diff_to_tree(raw_parent.tree)
    self._stats.insertions += diff.stats.insertions
    self._stats.deletions += diff.stats.deletions
    self._stats.files_changed += diff.stats.files_changed

Do you know a better way to capture this information?

Best regards,

Start with the Python loop over self.__raw_commit.parents and the tree.diff_to_tree and diff.stats entry points, then compare its goal with git log --stat. Determine whether pygit2 or libgit2 exposes a more efficient way to obtain insertions, deletions, and files changed; done means the approach is identified and produces equivalent diffstat values.