@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
@@ -205,14 +205,26 @@ static void reftable_ref_record_copy_from(void *rec, const void *src_rec,
205 {
206 struct reftable_ref_record *ref = rec;
207 const struct reftable_ref_record *src = src_rec;
208 + char *refname = NULL;
209 + size_t refname_cap = 0;
210 +
211 assert(hash_size > 0);
212
210 - /* This is simple and correct, but we could probably reuse the hash
211 - * fields. */
213 + SWAP(refname, ref->refname);
214 + SWAP(refname_cap, ref->refname_cap);
215 reftable_ref_record_release(ref);
216 + SWAP(ref->refname, refname);
217 + SWAP(ref->refname_cap, refname_cap);
218 +
219 if (src->refname) {
214 - ref->refname = xstrdup(src->refname);
220 + size_t refname_len = strlen(src->refname);
221 +
222 + REFTABLE_ALLOC_GROW(ref->refname, refname_len + 1,
223 + ref->refname_cap);
224 + memcpy(ref->refname, src->refname, refname_len);
225 + ref->refname[refname_len] = 0;
226 }
227 +
228 ref->update_index = src->update_index;
229 ref->value_type = src->value_type;
230 switch (src->value_type) {