@matheusbsbs / matheus-bagliano / commits / 6620f9134c

reftable/record: reuse refname when copying

Do the same optimization as in the preceding commit, but this time for `reftable_record_copy()`. While not as noticeable, it still results in a small speedup when iterating over 1 million refs: Benchmark 1: show-ref: single matching ref (revision = HEAD~) Time (mean ± σ): 114.0 ms ± 3.8 ms [User: 111.1 ms, System: 2.7 ms] Range (min … max): 110.9 ms … 144.3 ms 1000 runs Benchmark 2: show-ref: single matching ref (revision = HEAD) Time (mean ± σ): 112.5 ms ± 3.7 ms [User: 109.5 ms, System: 2.8 ms] Range (min … max): 109.2 ms … 140.7 ms 1000 runs Summary show-ref: single matching ref (revision = HEAD) ran 1.01 ± 0.05 times faster than show-ref: single matching ref (revision = HEAD~) Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Patrick Steinhardt committed Mar 4, 2024 at 11:49 UTC 6620f9134cc36189eecd88375a226a7bd7836a8a
1 file changed +15 -3
reftable/record.c
+15 -3
index 2b52e47c30..12a44f70e5 100644 --- a/reftable/record.c +++ b/reftable/record.c @@ -205,14 +205,26 @@ static void reftable_ref_record_copy_from(void *rec, const void *src_rec, { struct reftable_ref_record *ref = rec; const struct reftable_ref_record *src = src_rec; + char *refname = NULL; + size_t refname_cap = 0; + assert(hash_size > 0); - /* This is simple and correct, but we could probably reuse the hash - * fields. */ + SWAP(refname, ref->refname); + SWAP(refname_cap, ref->refname_cap); reftable_ref_record_release(ref); + SWAP(ref->refname, refname); + SWAP(ref->refname_cap, refname_cap); + if (src->refname) { - ref->refname = xstrdup(src->refname); + size_t refname_len = strlen(src->refname); + + REFTABLE_ALLOC_GROW(ref->refname, refname_len + 1, + ref->refname_cap); + memcpy(ref->refname, src->refname, refname_len); + ref->refname[refname_len] = 0; } + ref->update_index = src->update_index; ref->value_type = src->value_type; switch (src->value_type) {