sparse-index: introduce partially-sparse indexes
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 <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/sparse-index.c b/sparse-index.c
index a11b5cf..7848910 100644
--- a/sparse-index.c
+++ b/sparse-index.c
@@ -173,7 +173,7 @@ int convert_to_sparse(struct index_state *istate, int flags)
* If the index is already sparse, empty, or otherwise
* cannot be converted to sparse, do not convert.
*/
- if (istate->sparse_index || !istate->cache_nr ||
+ if (istate->sparse_index == INDEX_COLLAPSED || !istate->cache_nr ||
!is_sparse_index_allowed(istate, flags))
return 0;
@@ -214,7 +214,7 @@ int convert_to_sparse(struct index_state *istate, int flags)
FREE_AND_NULL(istate->fsmonitor_dirty);
FREE_AND_NULL(istate->fsmonitor_last_update);
- istate->sparse_index = 1;
+ istate->sparse_index = INDEX_COLLAPSED;
trace2_region_leave("index", "convert_to_sparse", istate->repo);
return 0;
}
@@ -259,7 +259,7 @@ void expand_index(struct index_state *istate, struct pattern_list *pl)
* If the index is already full, then keep it full. We will convert
* it to a sparse index on write, if possible.
*/
- if (!istate || !istate->sparse_index)
+ if (!istate || istate->sparse_index == INDEX_EXPANDED)
return;
/*
