There are several situations where a repository with sparse-checkout
enabled will act differently than a normal repository, and in ways that
are not intentional. The test t1092-sparse-checkout-compatibility.sh
documents some of these deviations, but a casual reader might think
these are intentional behavior changes.
Add comments on these tests that make it clear that these behaviors
should be updated. Using 'NEEDSWORK' helps contributors find that these
are potential areas for improvement.
Helped-by: Elijah Newren <newren@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It is difficult, but possible, to get into a state where we intend to
add a directory that is outside of the sparse-checkout definition. Add a
test to t1092-sparse-checkout-compatibility.sh that demonstrates this
using a combination of 'git reset --mixed' and 'git checkout --orphan'.
This test failed before because the output of 'git status
--porcelain=v2' would not match on the lines for folder1/:
* The sparse-checkout repo (with a full index) would output each path
name that is intended to be added.
* The sparse-index repo would only output that "folder1/" is staged for
addition.
The status should report the full list of files to be added, and so this
sparse-directory entry should be expanded to a full list when reaching
it inside the wt_status_collect_changes_initial() method. Use
read_tree_at() to assist.
Somehow, this loop over the cache entries was not guarded by
ensure_full_index() as intended.
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
By testing 'git -c core.fsmonitor= status -uno', we can check for the
simplest index operations that can be made sparse-aware. The necessary
implementation details are already integrated with sparse-checkout, so
modify command_requires_full_index to be zero for cmd_status().
In refresh_index(), we loop through the index entries to refresh their
stat() information. However, sparse directories have no stat()
information to populate. Ignore these entries.
This allows 'git status' to no longer expand a sparse index to a full
one. This is further tested by dropping the "-uno" option and adding an
untracked file into the worktree.
The performance test p2000-sparse-checkout-operations.sh demonstrates
these improvements:
Test HEAD~1 HEAD
-----------------------------------------------------------------------------
2000.2: git status (full-index-v3) 0.31(0.30+0.05) 0.31(0.29+0.06) +0.0%
2000.3: git status (full-index-v4) 0.31(0.29+0.07) 0.34(0.30+0.08) +9.7%
2000.4: git status (sparse-index-v3) 2.35(2.28+0.10) 0.04(0.04+0.05) -98.3%
2000.5: git status (sparse-index-v4) 2.35(2.24+0.15) 0.05(0.04+0.06) -97.9%
Note that since HEAD~1 was expanding the sparse index by parsing trees,
it was artificially slower than the full index case. Thus, the 98%
improvement is misleading, and instead we should celebrate the 0.34s to
0.05s improvement of 85%. This is more indicative of the peformance
gains we are expecting by using a sparse index.
Note: we are dropping the assignment of core.fsmonitor here. This is not
necessary for the test script as we are not altering the config any
other way. Correct integration with FS Monitor will be validated in
later changes.
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
'git status' began reporting a percentage of populated paths when
sparse-checkout is enabled in 051df3cf (wt-status: show sparse
checkout status as well, 2020-07-18). This percentage is incorrect when
the index has sparse directories. It would also be expensive to
calculate as we would need to parse trees to count the total number of
possible paths.
Avoid the expensive computation by simplifying the output to only report
that a sparse checkout exists, without the percentage.
This change is the reason we use 'git status --porcelain=v2' in
t1092-sparse-checkout-compatibility.sh. We don't want to ensure that
this message is equal across both modes, but instead just the important
information about staged, modified, and untracked files are compared.
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Before moving to update 'git status' and 'git add' to work with sparse
indexes, add an explicit test that ensures the sparse-index works the
same as a normal sparse-checkout when the worktree contains directories
and files outside of the sparse cone.
Specifically, 'folder1/a' is a file in our test repo, but 'folder1' is
not in the sparse cone. When 'folder1/a' is modified, the file is not
shown as modified and adding it will fail. This is new behavior as of
a20f704 (add: warn when asked to update SKIP_WORKTREE entries,
2021-04-08). Before that change, these adds would be silently ignored.
Untracked files are fine: adding new files both with 'git add .' and
'git add folder1/' works just as in a full checkout. This may not be
entirely desirable, but we are not intending to change behavior at the
moment, only document it. A future change could alter the behavior to
be more sensible, and this test could be modified to satisfy the new
expected behavior.
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As more features integrate with the sparse-index feature, more and more
special cases arise that require different data shapes within the tree
structure of the repository in order to demonstrate those cases.
Add several interesting special cases all at once instead of sprinkling
them across several commits. The interesting cases being added here are:
* Add sparse-directory entries on both sides of directories within the
sparse-checkout definition.
* Add directories outside the sparse-checkout definition who have only
one entry and are the first entry of a directory with multiple
entries.
* Add filenames adjacent to a sparse directory entry that sort before
and after the trailing slash.
Later tests will take advantage of these shapes, but they also deepen
the tests that already exist.
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This fixes the test data shape to be as expected, allowing rename
detection to work properly now that the 'larger-content' file actually
has meaningful lines.
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The sparse-index format is designed to be compatible with merge
conflicts, even those outside the sparse-checkout definition. The reason
is that when converting a full index to a sparse one, a cache entry with
nonzero stage will not be collapsed into a sparse directory entry.
However, this behavior was not tested, and a different behavior within
convert_to_sparse() fails in this scenario. Specifically,
cache_tree_update() will fail when unmerged entries exist.
convert_to_sparse_rec() uses the cache-tree data to recursively walk the
tree structure, but also to compute the OIDs used in the
sparse-directory entries.
Add an index scan to convert_to_sparse() that will detect if these merge
conflict entries exist and skip the conversion before trying to update
the cache-tree. This is marked as NEEDSWORK because this can be removed
with a suitable update to cache_tree_update() or a similar method that
can construct a cache-tree with invalid nodes, but still allow creating
the nodes necessary for creating sparse directory entries.
It is possible that in the future we will not need to make such an
update, since if we do not expand a sparse-index into a full one, this
conversion does not need to happen. Thus, this can be deferred until the
merge machinery is made to integrate with the sparse-index.
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This looked like a good idea, but it seems to break tests on 32-bit
builds rather badly. Revert to just use "100 thousands must be big
enough" for now.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The t1092-sparse-checkout-compatibility.sh tests compare the stdout and
stderr for several Git commands across both full checkouts, sparse
checkouts with a full index, and sparse checkouts with a sparse index.
Since these are direct comparisons, sometimes a progress indicator can
flush at unpredictable points, especially on slower machines. This
causes the tests to be flaky.
One standard way to avoid this is to add GIT_PROGRESS_DELAY=0 to the Git
commands that are run, as this will force every progress indicator
created with start_progress_delay() to be created immediately. However,
there are some progress indicators that are created in the case of a
full index that are not created with a sparse index. Moreover, their
values may be different as those indexes have a different number of
entries.
Instead, use GIT_PROGRESS_DELAY=-1 (which will turn into UINT_MAX)
to ensure that any reasonable machine running these tests would
never display delayed progress indicators.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The cache_tree_verify() method is run when GIT_TEST_CHECK_CACHE_TREE
is enabled, which it is by default in the test suite. The logic must
be adjusted for the presence of these directory entries.
For now, leave the test as a simple check for whether the directory
entry is sparse. Do not go any further until needed.
This allows us to re-enable GIT_TEST_CHECK_CACHE_TREE in
t1092-sparse-checkout-compatibility.sh. Further,
p2000-sparse-operations.sh uses the test suite and hence this is enabled
for all tests. We need to integrate with it before we run our
performance tests with a sparse-index.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The sparse index extension is used to signal that index writes should be
in sparse mode. This was only updated using GIT_TEST_SPARSE_INDEX=1.
Add a '--[no-]sparse-index' option to 'git sparse-checkout init' that
specifies if the sparse index should be used. It also updates the index
to use the correct format, either way. Add a warning in the
documentation that the use of a repository extension might reduce
compatibility with third-party tools. 'git sparse-checkout init' already
sets extension.worktreeConfig, which places most sparse-checkout users
outside of the scope of most third-party tools.
Update t1092-sparse-checkout-compatibility.sh to use this CLI instead of
GIT_TEST_SPARSE_INDEX=1.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a test case that uses test_region to ensure that we are truly
expanding a sparse index to a full one, then converting back to sparse
when writing the index. As we integrate more Git commands with the
sparse index, we will convert these commands to check that we do _not_
convert the sparse index to a full index and instead stay sparse the
entire time.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A submodule is stored as a "Git link" that actually points to a commit
within a submodule. Submodules are populated or not depending on
submodule configuration, not sparse-checkout. To ensure that the
sparse-index feature integrates correctly with submodules, we should not
collapse a directory if there is a Git link within its range.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If we have a full index, then we can convert it to a sparse index by
replacing directories outside of the sparse cone with sparse directory
entries. The convert_to_sparse() method does this, when the situation is
appropriate.
For now, we avoid converting the index to a sparse index if:
1. the index is split.
2. the index is already sparse.
3. sparse-checkout is disabled.
4. sparse-checkout does not use cone mode.
Finally, we currently limit the conversion to when the
GIT_TEST_SPARSE_INDEX environment variable is enabled. A mode using Git
config will be added in a later change.
The trickiest thing about this conversion is that we might not be able
to mark a directory as a sparse directory just because it is outside the
sparse cone. There might be unmerged files within that directory, so we
need to look for those. Also, if there is some strange reason why a file
is not marked with CE_SKIP_WORKTREE, then we should give up on
converting that directory. There is still hope that some of its
subdirectories might be able to convert to sparse, so we keep looking
deeper.
The conversion process is assisted by the cache-tree extension. This is
calculated from the full index if it does not already exist. We then
abandon the cache-tree as it no longer applies to the newly-sparse
index. Thus, this cache-tree will be recalculated in every
sparse-full-sparse round-trip until we integrate the cache-tree
extension with the sparse index.
Some Git commands use the index after writing it. For example, 'git add'
will update the index, then write it to disk, then read its entries to
report information. To keep the in-memory index in a full state after
writing, we re-expand it to a full one after the write. This is wasteful
for commands that only write the index and do not read from it again,
but that is only the case until we make those commands "sparse aware."
We can compare the behavior of the sparse-index in
t1092-sparse-checkout-compability.sh by using GIT_TEST_SPARSE_INDEX=1
when operating on the 'sparse-index' repo. We can also compare the two
sparse repos directly, such as comparing their indexes (when expanded to
full in the case of the 'sparse-index' repo). We also verify that the
index is actually populated with sparse directory entries.
The 'checkout and reset (mixed)' test is marked for failure when
comparing a sparse repo to a full repo, but we can compare the two
sparse-checkout cases directly to ensure that we are not changing the
behavior when using a sparse index.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We will use 'test-tool read-cache --table' to check that a sparse
index is written as part of init_repos. Since we will no longer always
expand a sparse index into a full index, add an '--expand' parameter
that adds a call to ensure_full_index() so we can compare a sparse index
directly against a full index, or at least what the in-memory index
looks like when expanded in this way.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a new 'sparse-index' repo alongside the 'full-checkout' and
'sparse-checkout' repos in t1092-sparse-checkout-compatibility.sh. Also
add run_on_sparse and test_sparse_match helpers. These helpers will be
used when the sparse index is implemented.
Add the GIT_TEST_SPARSE_INDEX environment variable to enable the
sparse-index by default. This can be enabled across all tests, but that
will only affect cases where the sparse-checkout feature is enabled.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This test was introduced in 19a0acc83e (t1092: test interesting
sparse-checkout scenarios, 2021-01-23), but it contains issues with quoting
that were not noticed until starting this follow-up series. The old
mechanism would drop quoting such as in
test_all_match git commit -m "touch README.md"
The above happened to work because README.md is a file in the
repository, so 'git commit -m touch REAMDE.md' would succeed by
accident.
Other cases included quoting for no good reason, so clean that up now.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
These also document some behaviors that differ from a full checkout, and
possibly in a way that is not intended.
The test is designed to be run with "--run=1,X" where 'X' is an
interesting test case. Each test uses 'init_repos' to reset the full and
sparse copies of the initial-repo that is created by the first test
case. This also makes it possible to have test cases leave the working
directory or index in unusual states without disturbing later cases.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
