Commit Graph

6 Commits

Author SHA1 Message Date
Junio C Hamano
8b4701ae4f Merge branch 'ak/corrected-commit-date'
The commit-graph learned to use corrected commit dates instead of
the generation number to help topological revision traversal.

* ak/corrected-commit-date:
  doc: add corrected commit date info
  commit-reach: use corrected commit dates in paint_down_to_common()
  commit-graph: use generation v2 only if entire chain does
  commit-graph: implement generation data chunk
  commit-graph: implement corrected commit date
  commit-graph: return 64-bit generation number
  commit-graph: add a slab to store topological levels
  t6600-test-reach: generalize *_three_modes
  commit-graph: consolidate fill_commit_graph_info
  revision: parse parent in indegree_walk_step()
  commit-graph: fix regression when computing Bloom filters
2021-02-17 17:21:40 -08:00
Abhishek Kumar
8d00d7c3df commit-reach: use corrected commit dates in paint_down_to_common()
091f4cf (commit: don't use generation numbers if not needed,
2018-08-30) changed paint_down_to_common() to use commit dates instead
of generation numbers v1 (topological levels) as the performance
regressed on certain topologies. With generation number v2 (corrected
commit dates) implemented, we no longer have to rely on commit dates and
can use generation numbers.

For example, the command `git merge-base v4.8 v4.9` on the Linux
repository walks 167468 commits, taking 0.135s for committer date and
167496 commits, taking 0.157s for corrected committer date respectively.

While using corrected commit dates, Git walks nearly the same number of
commits as commit date, the process is slower as for each comparision we
have to access a commit-slab (for corrected committer date) instead of
accessing struct member (for committer date).

This change incidentally broke the fragile t6404-recursive-merge test.
t6404-recursive-merge sets up a unique repository where all commits have
the same committer date without a well-defined merge-base.

While running tests with GIT_TEST_COMMIT_GRAPH unset, we use committer
date as a heuristic in paint_down_to_common(). 6404.1 'combined merge
conflicts' merges commits in the order:
- Merge C with B to form an intermediate commit.
- Merge the intermediate commit with A.

With GIT_TEST_COMMIT_GRAPH=1, we write a commit-graph and subsequently
use the corrected committer date, which changes the order in which
commits are merged:
- Merge A with B to form an intermediate commit.
- Merge the intermediate commit with C.

While resulting repositories are equivalent, 6404.4 'virtual trees were
processed' fails with GIT_TEST_COMMIT_GRAPH=1 as we are selecting
different merge-bases and thus have different object ids for the
intermediate commits.

As this has already causes problems (as noted in 859fdc0 (commit-graph:
define GIT_TEST_COMMIT_GRAPH, 2018-08-29)), we disable commit graph
within t6404-recursive-merge.

Signed-off-by: Abhishek Kumar <abhishekkumar8222@gmail.com>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-18 16:21:18 -08:00
Johannes Schindelin
5902f5f460 t6[4-9]*: adjust the references to the default branch name "main"
This trick was performed via

	$ (cd t &&
	   sed -i -e 's/master/main/g' -e 's/MASTER/MAIN/g' \
		-e 's/Master/Main/g' -- t6[4-9]*.sh)

This allows us to define `GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main`
for those tests.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-19 15:44:18 -08:00
Johannes Schindelin
334afbc76f tests: mark tests relying on the current default for init.defaultBranch
In addition to the manual adjustment to let the `linux-gcc` CI job run
the test suite with `master` and then with `main`, this patch makes sure
that GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME is set in all test scripts
that currently rely on the initial branch name being `master by default.

To determine which test scripts to mark up, the first step was to
force-set the default branch name to `master` in

- all test scripts that contain the keyword `master`,

- t4211, which expects `t/t4211/history.export` with a hard-coded ref to
  initialize the default branch,

- t5560 because it sources `t/t556x_common` which uses `master`,

- t8002 and t8012 because both source `t/annotate-tests.sh` which also
  uses `master`)

This trick was performed by this command:

	$ sed -i '/^ *\. \.\/\(test-lib\|lib-\(bash\|cvs\|git-svn\)\|gitweb-lib\)\.sh$/i\
	GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=master\
	export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME\
	' $(git grep -l master t/t[0-9]*.sh) \
	t/t4211*.sh t/t5560*.sh t/t8002*.sh t/t8012*.sh

After that, careful, manual inspection revealed that some of the test
scripts containing the needle `master` do not actually rely on a
specific default branch name: either they mention `master` only in a
comment, or they initialize that branch specificially, or they do not
actually refer to the current default branch. Therefore, the
aforementioned modification was undone in those test scripts thusly:

	$ git checkout HEAD -- \
		t/t0027-auto-crlf.sh t/t0060-path-utils.sh \
		t/t1011-read-tree-sparse-checkout.sh \
		t/t1305-config-include.sh t/t1309-early-config.sh \
		t/t1402-check-ref-format.sh t/t1450-fsck.sh \
		t/t2024-checkout-dwim.sh \
		t/t2106-update-index-assume-unchanged.sh \
		t/t3040-subprojects-basic.sh t/t3301-notes.sh \
		t/t3308-notes-merge.sh t/t3423-rebase-reword.sh \
		t/t3436-rebase-more-options.sh \
		t/t4015-diff-whitespace.sh t/t4257-am-interactive.sh \
		t/t5323-pack-redundant.sh t/t5401-update-hooks.sh \
		t/t5511-refspec.sh t/t5526-fetch-submodules.sh \
		t/t5529-push-errors.sh t/t5530-upload-pack-error.sh \
		t/t5548-push-porcelain.sh \
		t/t5552-skipping-fetch-negotiator.sh \
		t/t5572-pull-submodule.sh t/t5608-clone-2gb.sh \
		t/t5614-clone-submodules-shallow.sh \
		t/t7508-status.sh t/t7606-merge-custom.sh \
		t/t9302-fast-import-unpack-limit.sh

We excluded one set of test scripts in these commands, though: the range
of `git p4` tests. The reason? `git p4` stores the (foreign) remote
branch in the branch called `p4/master`, which is obviously not the
default branch. Manual analysis revealed that only five of these tests
actually require a specific default branch name to pass; They were
modified thusly:

	$ sed -i '/^ *\. \.\/lib-git-p4\.sh$/i\
	GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=master\
	export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME\
	' t/t980[0167]*.sh t/t9811*.sh

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-19 15:44:17 -08:00
Elijah Newren
727c75b23f t6404, t6423: expect improved rename/delete handling in ort backend
When a file is renamed and has content conflicts, merge-recursive does
not have some stages for the old filename and some stages for the new
filename in the index; instead it copies all the stages corresponding to
the old filename over to the corresponding locations for the new
filename, so that there are three higher order stages all corresponding
to the new filename.  Doing things this way makes it easier for the user
to access the different versions and to resolve the conflict (no need to
manually 'git rm' the old version as well as 'git add' the new one).

rename/deletes should be handled similarly -- there should be two stages
for the renamed file rather than just one.  We do not want to
destabilize merge-recursive right now, so instead update relevant tests
to have different expectations depending on whether the "recursive" or
"ort" merge strategies are in use.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-26 12:31:24 -07:00
Elijah Newren
919df31955 Collect merge-related tests to t64xx
The tests for the merge machinery are spread over several places.
Collect them into t64xx for simplicity.  Some notes:

t60[234]*.sh:
  Merge tests started in t602*, overgrew bisect and remote tracking
  tests in t6030, t6040, and t6041, and nearly overtook replace tests
  in t6050.  This made picking out relevant tests that I wanted to run
  in a tighter loop slightly more annoying for years.

t303*.sh:
  These started out as tests for the 'merge-recursive' toplevel command,
  but did not restrict to that and had lots of overlap with the
  underlying merge machinery.
t7405, t7613:
  submodule-specific merge logic started out in submodule.c but was
  moved to merge-recursive.c in commit 18cfc08866 ("submodule.c: move
  submodule merging to merge-recursive.c", 2018-05-15).  Since these
  tests are about the logic found in the merge machinery, moving these
  tests to be with the merge tests makes sense.

t7607, t7609:
  Having tests spread all over the place makes it more likely that
  additional tests related to a certain piece of logic grow in all those
  other places.  Much like t303*.sh, these two tests were about the
  underlying merge machinery rather than outer levels.

Tests that were NOT moved:

t76[01]*.sh:
  Other than the four tests mentioned above, the remaining tests in
  t76[01]*.sh are related to non-recursive merge strategies, parameter
  parsing, and other stuff associated with the highlevel builtin/merge.c
  rather than the recursive merge machinery.

t3[45]*.sh:
  The rebase testcases in t34*.sh also test the merge logic pretty
  heavily; sometimes changes I make only trigger failures in the rebase
  tests.  The rebase tests are already nicely coupled together, though,
  and I didn't want to mess that up.  Similar comments apply for the
  cherry-pick tests in t35*.sh.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-10 15:59:00 -07:00