cache-tree: integrate with sparse directory entries

The cache-tree extension was previously disabled with sparse indexes.
However, the cache-tree is an important performance feature for commands
like 'git status' and 'git add'. Integrate it with sparse directory
entries.

When writing a sparse index, completely clear and recalculate the cache
tree. By starting from scratch, the only integration necessary is to
check if we hit a sparse directory entry and create a leaf of the
cache-tree that has an entry_count of one and no subtrees.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Derrick Stolee 2021-03-30 13:11:02 +00:00 committed by Junio C Hamano
parent dcc5fd5fd2
commit 2de37c536d
2 changed files with 27 additions and 1 deletions

View file

@ -256,6 +256,24 @@ static int update_one(struct cache_tree *it,
*skip_count = 0;
/*
* If the first entry of this region is a sparse directory
* entry corresponding exactly to 'base', then this cache_tree
* struct is a "leaf" in the data structure, pointing to the
* tree OID specified in the entry.
*/
if (entries > 0) {
const struct cache_entry *ce = cache[0];
if (S_ISSPARSEDIR(ce->ce_mode) &&
ce->ce_namelen == baselen &&
!strncmp(ce->name, base, baselen)) {
it->entry_count = 1;
oidcpy(&it->oid, &ce->oid);
return 1;
}
}
if (0 <= it->entry_count && has_object_file(&it->oid))
return it->entry_count;

View file

@ -172,7 +172,11 @@ int convert_to_sparse(struct index_state *istate)
istate->cache_nr = convert_to_sparse_rec(istate,
0, 0, istate->cache_nr,
"", 0, istate->cache_tree);
istate->drop_cache_tree = 1;
/* Clear and recompute the cache-tree */
cache_tree_free(&istate->cache_tree);
cache_tree_update(istate, 0);
istate->sparse_index = 1;
trace2_region_leave("index", "convert_to_sparse", istate->repo);
return 0;
@ -273,5 +277,9 @@ void ensure_full_index(struct index_state *istate)
strbuf_release(&base);
free(full);
/* Clear and recompute the cache-tree */
cache_tree_free(&istate->cache_tree);
cache_tree_update(istate, 0);
trace2_region_leave("index", "ensure_full_index", istate->repo);
}