git/sparse-index.c, branch v2.40.3

treewide: always have a valid "index_state.repo" member

2023-01-17T22:32:06Z

When the "repo" member was added to "the_index" in [1] the repo_read_index() was made to populate it, but the unpopulated "the_index" variable didn't get the same treatment. Let's do that in initialize_the_repository() when we set it up, and likewise for all of the current callers initialized an empty "struct index_state". This simplifies code that needs to deal with "the_index" or a custom "struct index_state", we no longer need to second-guess this part of the "index_state" deep in the stack. A recent example of such second-guessing is the "istate->repo ? istate->repo : the_repository" code in [2]. We can now simply use "istate->repo". We're doing this by making use of the INDEX_STATE_INIT() macro (and corresponding function) added in [3], which now have mandatory "repo" arguments. Because we now call index_state_init() in repository.c's initialize_the_repository() we don't need to handle the case where we have a "repo->index" whose "repo" member doesn't match the "repo" we're setting up, i.e. the "Complete the double-reference" code in repo_read_index() being altered here. That logic was originally added in [1], and was working around the lack of what we now have in initialize_the_repository(). For "fsmonitor-settings.c" we can remove the initialization of a NULL "r" argument to "the_repository". This was added back in [4], and was needed at the time for callers that would pass us the "r" from an "istate->repo". Before this change such a change to "fsmonitor-settings.c" would segfault all over the test suite (e.g. in t0002-gitfile.sh). This change has wider eventual implications for "fsmonitor-settings.c". The reason the other lazy loading behavior in it is required (starting with "if (!r->settings.fsmonitor) ..." is because of the previously passed "r" being "NULL". I have other local changes on top of this which move its configuration reading to "prepare_repo_settings()" in "repo-settings.c", as we could now start to rely on it being called for our "r". But let's leave all of that for now, and narrowly remove this particular part of the lazy-loading. 1. 1fd9ae517c4 (repository: add repo reference to index_state, 2021-01-23) 2. ee1f0c242ef (read-cache: add index.skipHash config option, 2023-01-06) 3. 2f6b1eb794e (cache API: add a "INDEX_STATE_INIT" macro/function, add release_index(), 2023-01-12) 4. 1e0ea5c4316 (fsmonitor: config settings are repository-specific, 2022-03-25) Signed-off-by: Ævar Arnfjörð Bjarmason Acked-by: Derrick Stolee Signed-off-by: Junio C Hamano

sparse-index API: BUG() out on NULL ensure_full_index()

2023-01-13T18:36:57Z

Make the ensure_full_index() function stricter, and have it only accept a non-NULL "struct index_state". This function (and this behavior) was added in [1]. The only reason it needed to be this lax was due to interaction with repo_index_has_changes(). See the addition of that code in [2]. The other reason for why this was needed dates back to interaction with code added in [3]. In [4] we started calling ensure_full_index() in unpack_trees(), but the caller added in 34110cd4e39 wants to pass us a NULL "dst_index". Let's instead do the NULL check in unpack_trees() itself. 1. 4300f8442a2 (sparse-index: implement ensure_full_index(), 2021-03-30) 2. 0c18c059a15 (read-cache: ensure full index, 2021-04-01) 3. 34110cd4e39 (Make 'unpack_trees()' have a separate source and destination index, 2008-03-06) 4. 6863df35503 (unpack-trees: ensure full index, 2021-03-30) Signed-off-by: Ævar Arnfjörð Bjarmason Acked-by: Derrick Stolee Signed-off-by: Junio C Hamano

sparse-index.c: expand_to_path() can assume non-NULL "istate"

2023-01-13T18:36:57Z

This function added in [1] was subsequently used in [2]. All of the calls to it are in name-hash.c, and come after calls to lazy_init_name_hash(istate). The first thing that function does is: if (istate->name_hash_initialized) return; So we can already assume that we have a non-NULL "istate" here, or we'd be segfaulting. Let's not confuse matters by making it appear that's not the case. 1. 71f82d032f3 (sparse-index: expand_to_path(), 2021-04-12) 2. 4589bca829a (name-hash: use expand_to_path(), 2021-04-12) Signed-off-by: Ævar Arnfjörð Bjarmason Acked-by: Derrick Stolee Signed-off-by: Junio C Hamano

index: raise a bug if the index is materialised more than once

2022-11-05T00:28:28Z

If clear_skip_worktree_from_present_files() encounter a sparse directory, it fully materialise the index which should expand any sparse directories and start going through each entries again. If this happens more than once, raise it with a BUG. Signed-off-by: Anh Le Signed-off-by: Taylor Blau

index: add trace2 region for clear skip worktree

2022-11-05T00:28:28Z

When using sparse checkout, clear_skip_worktree_from_present_files() must enumerate index entries to find ones with the SKIP_WORKTREE bit to determine whether those index entries exist on disk (in which case their SKIP_WORKTREE bit should be removed). In a large repository, this may take considerable time depending on the size of the index. Add a trace2 region to surface this information, keeping a count of how many paths have been checked. Separately, keep counts after a full index is materialized. Signed-off-by: Anh Le Signed-off-by: Taylor Blau

Merge branch 'ds/sparse-sparse-checkout'

2022-06-03T21:30:35Z

"sparse-checkout" learns to work well with the sparse-index feature. * ds/sparse-sparse-checkout: sparse-checkout: integrate with sparse index p2000: add test for 'git sparse-checkout [add|set]' sparse-index: complete partial expansion sparse-index: partially expand directories sparse-checkout: --no-sparse-index needs a full index cache-tree: implement cache_tree_find_path() sparse-index: introduce partially-sparse indexes sparse-index: create expand_index() t1092: stress test 'git sparse-checkout set' t1092: refactor 'sparse-index contents' test

sparse-index: complete partial expansion

2022-05-23T18:08:21Z

To complete the implementation of expand_to_pattern_list(), we need to detect when a sparse directory entry should remain sparse. This avoids a full expansion, so we now need to use the PARTIALLY_SPARSE mode to indicate this state. There still are no callers to this method, but we will add one in the next change. Signed-off-by: Derrick Stolee Signed-off-by: Junio C Hamano

sparse-index: partially expand directories

2022-05-23T18:08:21Z

The expand_to_pattern_list() method expands sparse directory entries to their list of contained files when either the pattern list is NULL or the directory is contained in the new pattern list's cone mode patterns. It is possible that the pattern list has a recursive match with a directory 'A/B/C/' and so an existing sparse directory 'A/B/' would need to be expanded. If there exists a directory 'A/B/D/', then that directory should not be expanded and instead we can create a sparse directory. To implement this, we plug into the add_path_to_index() callback for the call to read_tree_at(). Since we now need access to both the index we are writing and the pattern list we are comparing, create a 'struct modify_index_context' to use as a data transfer object. It is important that we use the given pattern list since we will use this pattern list to change the sparse-checkout patterns and cannot use istate->sparse_checkout_patterns. Signed-off-by: Derrick Stolee Signed-off-by: Junio C Hamano

sparse-index: introduce partially-sparse indexes

2022-05-23T18:08:21Z

A future change will present a temporary, in-memory mode where the index can both contain sparse directory entries but also not be completely collapsed to the smallest possible sparse directories. This will be necessary for modifying the sparse-checkout definition while using a sparse index. For now, convert the single-bit member 'sparse_index' in 'struct index_state' to be a an 'enum sparse_index_mode' with three modes: * INDEX_EXPANDED (0): No sparse directories exist. This is always the case for repositories that do not use cone-mode sparse-checkout. * INDEX_COLLAPSED: Sparse directories may exist. Files outside the sparse-checkout cone are reduced to sparse directory entries whenever possible. * INDEX_PARTIALLY_SPARSE: Sparse directories may exist. Some file entries outside the sparse-checkout cone may exist. Running convert_to_sparse() may further reduce those files to sparse directory entries. The main reason to store this extra information is to allow convert_to_sparse() to short-circuit when the index is already in INDEX_EXPANDED mode but to actually do the necessary work when in INDEX_PARTIALLY_SPARSE mode. The INDEX_PARTIALLY_SPARSE mode will be used in an upcoming change. Signed-off-by: Derrick Stolee Signed-off-by: Junio C Hamano

sparse-index: create expand_index()

2022-05-23T18:08:21Z

This is the first change in a series to allow modifying the sparse-checkout pattern set without expanding a sparse index to a full one in the process. Here, we focus on the problem of expanding the pattern set through a command like 'git sparse-checkout add ' which needs to create new index entries for the paths now being written to the worktree. To achieve this, we need to be able to replace sparse directory entries with their contained files and subdirectories. Once this is complete, other code paths can discover those cache entries and write the corresponding files to disk before committing the index. We already have logic in ensure_full_index() that expands the index entries, so we will use that as our base. Create a new method, expand_index(), which takes a pattern list, but for now mostly ignores it. The current implementation is only correct when the pattern list is NULL as that does the same as ensure_full_index(). In fact, ensure_full_index() is converted to a shim over expand_index(). A future update will actually implement expand_index() to its full capabilities. For now, it is created and documented. Signed-off-by: Derrick Stolee Signed-off-by: Junio C Hamano