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* [PATCH 0/3] git for-each-ref: is-base atom and base branches
@ 2024-08-01 22:10 Derrick Stolee via GitGitGadget
  2024-08-01 22:10 ` [PATCH 1/3] commit-reach: add get_branch_base_for_tip Derrick Stolee via GitGitGadget
                   ` (4 more replies)
  0 siblings, 5 replies; 23+ messages in thread
From: Derrick Stolee via GitGitGadget @ 2024-08-01 22:10 UTC (permalink / raw)
  To: git; +Cc: gitster, vdye, Derrick Stolee

This change introduces a new 'git for-each-ref' atom, 'is-base', in a very
similar way to the 'ahead-behind' atom. As detailed carefully in the first
change, this is motivated by the need to detect the concept of a "base
branch" in a repository with multiple long-lived branches.

This change is motivated by a third-party tool created to make this
detection with the same optimization mechanism, but using a much slower
technique due to the limitations of the Git CLI not presenting this
information. The existing algorithm involves using git rev-list
--first-parent -<N> in batches for the collection of considered references,
comparing those lists, and increasing <N> as needed until finding a
collision. This new use of 'git for-each-ref' will allow determining this
mechanism within a single process and walking a minimal number of commits.

There are benefits to users both on client-side and server-side. In an
internal monorepo, this base branch detection algorithm is used to determine
a long-lived branch based on the HEAD commit, mapping to a group within the
organizational structure of the repository, which determines a set of
projects that the user will likely need to build; this leads to
automatically selecting an initial sparse-checkout definition based on the
build dependencies required. An upcoming feature in Azure Repos will use
this algorithm to automatically create a pull request against the correct
target branch, reducing user pain from needing to select a different branch
after a large commit diff is rendered against the default branch. This atom
unlocks that ability for Git hosting services that use Git in their backend.

Thanks, -Stolee

Derrick Stolee (3):
  commit-reach: add get_branch_base_for_tip
  for-each-ref: add 'is-base' token
  p1500: add is-base performance tests

 commit-reach.c              | 118 ++++++++++++++++++++++++++++++++++++
 commit-reach.h              |  17 ++++++
 ref-filter.c                |  78 +++++++++++++++++++++++-
 ref-filter.h                |  15 +++++
 t/helper/test-reach.c       |   2 +
 t/perf/p1500-graph-walks.sh |  31 ++++++++++
 t/t6600-test-reach.sh       |  94 ++++++++++++++++++++++++++++
 7 files changed, 354 insertions(+), 1 deletion(-)


base-commit: bea9ecd24b0c3bf06cab4a851694fe09e7e51408
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1768%2Fderrickstolee%2Ftarget-ref-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1768/derrickstolee/target-ref-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/1768
-- 
gitgitgadget

^ permalink raw reply	[flat|nested] 23+ messages in thread

end of thread, other threads:[~2024-08-20  1:33 UTC | newest]

Thread overview: 23+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2024-08-01 22:10 [PATCH 0/3] git for-each-ref: is-base atom and base branches Derrick Stolee via GitGitGadget
2024-08-01 22:10 ` [PATCH 1/3] commit-reach: add get_branch_base_for_tip Derrick Stolee via GitGitGadget
2024-08-01 22:10 ` [PATCH 2/3] for-each-ref: add 'is-base' token Derrick Stolee via GitGitGadget
2024-08-01 22:10 ` [PATCH 3/3] p1500: add is-base performance tests Derrick Stolee via GitGitGadget
2024-08-01 23:06 ` [PATCH 0/3] git for-each-ref: is-base atom and base branches Junio C Hamano
2024-08-02 14:32   ` Derrick Stolee
2024-08-02 16:55     ` Junio C Hamano
2024-08-02 17:30       ` Junio C Hamano
2024-08-11 17:34 ` [PATCH v2 " Derrick Stolee via GitGitGadget
2024-08-11 17:34   ` [PATCH v2 1/3] commit-reach: add get_branch_base_for_tip Derrick Stolee via GitGitGadget
2024-08-12 20:30     ` Junio C Hamano
2024-08-13 13:39       ` Derrick Stolee
2024-08-11 17:34   ` [PATCH v2 2/3] for-each-ref: add 'is-base' token Derrick Stolee via GitGitGadget
2024-08-12 21:05     ` Junio C Hamano
2024-08-13 13:44       ` Derrick Stolee
2024-08-11 17:34   ` [PATCH v2 3/3] p1500: add is-base performance tests Derrick Stolee via GitGitGadget
2024-08-14 10:31   ` [PATCH v3 0/4] git for-each-ref: is-base atom and base branches Derrick Stolee via GitGitGadget
2024-08-14 10:31     ` [PATCH v3 1/4] commit-reach: add get_branch_base_for_tip Derrick Stolee via GitGitGadget
2024-08-14 10:31     ` [PATCH v3 2/4] commit: add gentle reference lookup method Derrick Stolee via GitGitGadget
2024-08-14 10:31     ` [PATCH v3 3/4] for-each-ref: add 'is-base' token Derrick Stolee via GitGitGadget
2024-08-14 10:31     ` [PATCH v3 4/4] p1500: add is-base performance tests Derrick Stolee via GitGitGadget
2024-08-19 19:52     ` [PATCH v3 0/4] git for-each-ref: is-base atom and base branches Junio C Hamano
2024-08-20  1:33       ` Derrick Stolee

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