"Derrick Stolee via GitGitGadget" <gitgitgadget@xxxxxxxxx> writes: > From: Derrick Stolee <derrickstolee@xxxxxxxxxx> > > The corrected commit date was first documented in 5a3b130ca (doc: add > corrected commit date info, 2021-01-16) and it used an optional chunk to > augment the commit-graph format without modifying the file format > version. > > One major benefit to this approach is that corrected commit dates could > be written without causing a backwards compatibility issue with Git > versions that do not understand them. The topological level was still > available in the CDAT chunk as it was before. > > However, this causes a different issue: more data needs to be loaded > from disk when parsing commits from the commit-graph. In cases where > there is no significant algorithmic gain from using corrected commit > dates, commit walks take up to 20% longer because of this extra data. > > Create a new file format version for the commit-graph format that > differs only in the CDAT chunk: it now stores corrected commit date > offsets. This brings our data back to normal and will demonstrate > performance gains in almost all cases. OK.
