On Fri, Mar 5, 2021 at 12:18 AM Bryan Turner <bturner@xxxxxxxxxxxxx> wrote: > > The documentation for --use-bitmap-index notes that if used with > --objects trees and blobs they won't have their paths printed, but it > appears to change a whole lot more than that. In my testing, it > appears to mean --date-order, --format. --parents, and maybe more are > effectively ignored. > > It appears this changed in 2.26.0. The release notes for that version > include this blurb, which seems like it might be relevant, but I'm not > sure: > * The object reachability bitmap machinery and the partial cloning > machinery were not prepared to work well together, because some > object-filtering criteria that partial clones use inherently rely > on object traversal, but the bitmap machinery is an optimization > to bypass that object traversal. There however are some cases > where they can work together, and they were taught about them. > > I have a repository with a bitmap: > $ git repack -abdfln --keep-unreachable > Marked 2 islands, done. > Enumerating objects: 3603142, done. > Propagating island marks: 100% (2576295/2576295), done. > Counting objects: 100% (3603142/3603142), done. > Delta compression using up to 20 threads > Compressing objects: 100% (2898179/2898179), done. > Writing objects: 100% (3603142/3603142), done. > Reusing bitmaps: 291, done. > Selecting bitmap commits: 293052, done. > Building bitmaps: 100% (363/363), done. > > Here's some output from Git 2.25.1: > $ /opt/git/2.25.1/bin/git rev-list --boundary --ignore-missing > --date-order --parents --use-bitmap-index > c6abb83d2798415fa9fe0ebd683623620076b412 > 1c55e675a66cb98955232e1bd230119fd97a5467 > 634396036782682e7cd8c955070dfb30546ed58c -- | head > c6abb83d2798415fa9fe0ebd683623620076b412 > 2c7281b151d0079acc3f9b2c67d4667e1c9bf6d9 > 634396036782682e7cd8c955070dfb30546ed58c > 1c55e675a66cb98955232e1bd230119fd97a5467 > 2c7281b151d0079acc3f9b2c67d4667e1c9bf6d9 > d672894d3b2413b62034cb3cdb3470e5dee0001c > 76250ec85aadff2ff451ec13efdadb8ccfd6b239 > d672894d3b2413b62034cb3cdb3470e5dee0001c > 013343e1900330429bcd1e31bb2ae7261fc1e3af > 3e1e27621aa5f1d49286e23d77199004a835699e > 3e1e27621aa5f1d49286e23d77199004a835699e > b944291d204cb7f3d5eb7678360b16435c53b2f3 > b745a7b9bd9434eefb411d5f2a80a7187e3e8b93 > 1c55e675a66cb98955232e1bd230119fd97a5467 > 7f2c871e0d239e87bef7a1505ae928ae3a09a402 > 76250ec85aadff2ff451ec13efdadb8ccfd6b239 > 04f561866a9c015c14c69a0294b753ced5e084f2 > 013343e1900330429bcd1e31bb2ae7261fc1e3af > d907528818d010a360113790e227ebbcd8a61395 > b745a7b9bd9434eefb411d5f2a80a7187e3e8b93 > b944291d204cb7f3d5eb7678360b16435c53b2f3 > 7f2c871e0d239e87bef7a1505ae928ae3a09a402 > c2ec4d3d76d865a9b701eb8be822d31252278a76 Apologies, it looks like Gmail helpfully jumped in and ruined my output for me. Let me try this with shorter hashes: c6abb83 2c7281b 6343960 1c55e67 2c7281b d672894 76250ec d672894 013343e 3e1e276 3e1e276 b944291 b745a7b 1c55e67 7f2c871 76250ec 04f5618 013343e d907528 b745a7b b944291 7f2c871 c2ec4d3d > > Changing to Git 2.26.0, I see this: > $ /opt/git/2.26.0/bin/git rev-list --boundary --ignore-missing > --date-order --parents --use-bitmap-index > c6abb83d2798415fa9fe0ebd683623620076b412 > 1c55e675a66cb98955232e1bd230119fd97a5467 > 634396036782682e7cd8c955070dfb30546ed58c -- | head > 634396036782682e7cd8c955070dfb30546ed58c > 1c55e675a66cb98955232e1bd230119fd97a5467 > 7f2c871e0d239e87bef7a1505ae928ae3a09a402 > c2ec4d3d76d865a9b701eb8be822d31252278a76 > 899053a9043045fcfeb7f9254f2700d286c60a63 > f1adcf64a8c06cb12f4e3e876040ee596fb3c0ca > 16792db59ffdbbefe4a27a11a9831eac39be69a0 > b844c3d11d09c2aec3428ce61bef02fdd097b9f9 > 802918fb139ef96cae5259822d22a36478c5e7b1 > 3a6105686ab302093648733dbf5fada3b44db72b All of these are on their own lines, as shown. > > No parents now, and the commits aren't in the same order. I've tested > with 2.30.1 and it produces the same output as 2.26.0. If I remove the > bitmap, all versions produce the same output as 2.25.1 does, with > parents and in the expected order. (I should note, the bitmap is > perfectly up-to-date; I did the repack right before running these > rev-list commands. I've also tried the rev-list without several of the > options in place, like --boundary, and it behaves the same. This > command line is assembled automatically, so I'm just including it here > how the system produced it.) > > Is this expected? If so, perhaps the --use-bitmap-index documentation > should be updated to indicate that it has unexpected interactions with > a whole lot more than just --objects? Or perhaps I'm doing something > wrong/unexpected here? What sorts of traversals are --use-bitmap-index > expected to be used for? > > Best regards, > Bryan Turner
