| commit | 95acf11a3dc3d18ec999f4913ec6c6a54545c6b7 | [log] [tgz] |
|---|---|---|
| author | Jonathan Tan <jonathantanmy@google.com> | Tue Apr 07 15:11:43 2020 -0700 |
| committer | Junio C Hamano <gitster@pobox.com> | Tue Apr 07 16:09:29 2020 -0700 |
| tree | 3448ee7b27c3a42dfc07931e7eee15441b1b57c8 | |
| parent | c14b6f83ec7453d2a93bba04f45caf26905f2bff [diff] |
diff: restrict when prefetching occurs
Commit 7fbbcb21b1 ("diff: batch fetching of missing blobs", 2019-04-08)
optimized "diff" by prefetching blobs in a partial clone, but there are
some cases wherein blobs do not need to be prefetched. In these cases,
any command that uses the diff machinery will unnecessarily fetch blobs.
diffcore_std() may read blobs when it calls the following functions:
(1) diffcore_skip_stat_unmatch() (controlled by the config variable
diff.autorefreshindex)
(2) diffcore_break() and diffcore_merge_broken() (for break-rewrite
detection)
(3) diffcore_rename() (for rename detection)
(4) diffcore_pickaxe() (for detecting addition/deletion of specified
string)
Instead of always prefetching blobs, teach diffcore_skip_stat_unmatch(),
diffcore_break(), and diffcore_rename() to prefetch blobs upon the first
read of a missing object. This covers (1), (2), and (3): to cover the
rest, teach diffcore_std() to prefetch if the output type is one that
includes blob data (and hence blob data will be required later anyway),
or if it knows that (4) will be run.
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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