On 5/14/2021 1:37 PM, Elijah Newren wrote: > On Mon, May 3, 2021 at 7:12 PM Elijah Newren via GitGitGadget > <gitgitgadget@xxxxxxxxx> wrote: >> >> This series avoids repeatedly detecting the same renames in a sequence of >> merges such as a rebase or cherry-pick of several commits. It's >> unfortunately become a bit lengthy, but much of the length (the first five >> patches) is owed to special testcases and documentation. > > Since this obviously hasn't inspired much review, let me note that you > can cut out 90% of the review size by skipping patches 2 & 5. > > Patch 2 is essentially written as something approaching a formal > proof, so yes it's dense and lengthy, but it's not at all required; > there's no code there. Think of it as insurance for if someone wants > to introduce some new tricky optimizations or radically different > features to the merge machinery, because the remember-renames > optimization by its nature tends to interact with other optimizations. > I figured because of that interaction that documenting why and how the > remember renames optimization works at a much deeper level than is > typical for optimizations or code in git in general that it might help > with future maintenance...and it happened to help me catch two minor > bugs. > > Patch 5 is very much related to patch 2; it's testcases inspired by > that document. Most of those tests were just "what could possibly go > wrong in a new from-scratch implementation of this optimization?" > based on what's written in this proof-like document. Most of the > tests didn't turn up anything, but a couple found some small issues in > my implementation. I decided to just include all of them; it's nice > to be thorough. > > You can get 95% of the whole idea behind this optimization skipping > those patches and reading Junio's great two-paragraph summary at > https://lore.kernel.org/git/xmqqzgyrukic.fsf@gitster.g/, and then just > read the other patches in this series. Sorry, yes. I've been reading this a bit but haven't commented yet. Patch 2 was enlightening and I appreciate the attention to detail there. The overall argument made sense to me. I can promise a completed review on Monday. -Stolee
