From 491df5f679f0381f529b967df25476ab944406ab Mon Sep 17 00:00:00 2001 From: Victoria Dye Date: Tue, 10 May 2022 23:32:30 +0000 Subject: read-cache: set sparsity when index is new When the index read in 'do_read_index()' does not exist on-disk, mark the index "sparse" if the executing command does not require a full index and sparse index is otherwise enabled. Some commands (such as 'git stash -u') implicitly create a new index (when the 'GIT_INDEX_FILE' variable points to a non-existent file) and perform some operation on it. However, when this index is created, it isn't created with the same sparsity settings as the repo index. As a result, while these indexes may be sparse during the operation, they are always expanded before being written to disk. We can avoid that expansion by defaulting the index to "sparse", in which case it will only be expanded if the full index is needed. Note that the function 'set_new_index_sparsity()' is created despite having only a single caller because additional callers will be added in a subsequent patch. Signed-off-by: Victoria Dye Signed-off-by: Junio C Hamano --- read-cache.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) (limited to 'read-cache.c') diff --git a/read-cache.c b/read-cache.c index 4df97e185e..60355f5ad6 100644 --- a/read-cache.c +++ b/read-cache.c @@ -2260,6 +2260,20 @@ static unsigned long load_cache_entries_threaded(struct index_state *istate, con return consumed; } +static void set_new_index_sparsity(struct index_state *istate) +{ + /* + * If the index's repo exists, mark it sparse according to + * repo settings. + */ + if (istate->repo) { + prepare_repo_settings(istate->repo); + if (!istate->repo->settings.command_requires_full_index && + is_sparse_index_allowed(istate, 0)) + istate->sparse_index = 1; + } +} + /* remember to discard_cache() before reading a different cache! */ int do_read_index(struct index_state *istate, const char *path, int must_exist) { @@ -2281,8 +2295,10 @@ int do_read_index(struct index_state *istate, const char *path, int must_exist) istate->timestamp.nsec = 0; fd = open(path, O_RDONLY); if (fd < 0) { - if (!must_exist && errno == ENOENT) + if (!must_exist && errno == ENOENT) { + set_new_index_sparsity(istate); return 0; + } die_errno(_("%s: index file open failed"), path); } -- cgit v1.2.1