Commit Graph

54 Commits

Author SHA1 Message Date
9ce6000cb7 object-name.c: don't have GET_OID_ONLY_TO_DIE imply *_QUIETLY
Stop having GET_OID_ONLY_TO_DIE imply GET_OID_QUIETLY in
get_oid_with_context_1().

The *_DIE flag was added in 33bd598c39 (sha1_name.c: teach lookup
context to get_sha1_with_context(), 2012-07-02), and then later
tweaked in 7243ffdd78 (get_sha1: avoid repeating ourselves via
ONLY_TO_DIE, 2016-09-26).

Everything in that commit makes sense, but only for callers that
expect to fail in an initial call to get_oid_with_context_1(), e.g. as
"git show 0017" does via handle_revision_arg(), and then would like to
call get_oid_with_context_1() again via this
maybe_die_on_misspelt_object_name() function.

In the subsequent commit we'll add a new caller that expects to call
this only once, but who would still like to have all the error
messaging that GET_OID_ONLY_TO_DIE gives it, in addition to any
regular errors.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-30 13:05:29 -08:00
ed9bff0817 advice: remove read uses of most global advice_ variables
In c4a09cc9cc (Merge branch 'hw/advise-ng', 2020-03-25), a new API for
accessing advice variables was introduced and deprecated `advice_config`
in favor of a new array, `advice_setting`.

This patch ports all but two uses which read the status of the global
`advice_` variables over to the new `advice_enabled` API. We'll deal
with advice_add_embedded_repo and advice_graft_file_deprecated
separately.

Signed-off-by: Ben Boeckel <mathstuf@gmail.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-25 12:07:52 -07:00
92d8ed8ac1 oidtree: a crit-bit tree for odb_loose_cache
This saves 8K per `struct object_directory', meaning it saves
around 800MB in my case involving 100K alternates (half or more
of those alternates are unlikely to hold loose objects).

This is implemented in two parts: a generic, allocation-free
`cbtree' and the `oidtree' wrapper on top of it.  The latter
provides allocation using alloc_state as a memory pool to
improve locality and reduce free(3) overhead.

Unlike oid-array, the crit-bit tree does not require sorting.
Performance is bound by the key length, for oidtree that is
fixed at sizeof(struct object_id).  There's no need to have
256 oidtrees to mitigate the O(n log n) overhead like we did
with oid-array.

Being a prefix trie, it is natively suited for expanding short
object IDs via prefix-limited iteration in
`find_short_object_filename'.

On my busy workstation, p4205 performance seems to be roughly
unchanged (+/-8%).  Startup with 100K total alternates with no
loose objects seems around 10-20% faster on a hot cache.
(800MB in memory savings means more memory for the kernel FS
cache).

The generic cbtree implementation does impose some extra
overhead for oidtree in that it uses memcmp(3) on
"struct object_id" so it wastes cycles comparing 12 extra bytes
on SHA-1 repositories.  I've not yet explored reducing this
overhead, but I expect there are many places in our code base
where we'd want to investigate this.

More information on crit-bit trees: https://cr.yp.to/critbit.html

Signed-off-by: Eric Wong <e@80x24.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-07 21:28:04 -07:00
1e6771e504 object-name.c: rename from sha1-name.c
Generalize the last remnants of "sha" and "sha1" in this file and rename
it to reflect that we're not just able to handle SHA-1 these days.

We need to update one test to check for an updated error string.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-04 13:01:55 -08:00