git/reftable/pq.c
Patrick Steinhardt f1bf54aee3 reftable: allow inlining of a few functions
We have a few functions which are basically just accessors to
structures. As those functions are executed inside the hot loop when
iterating through many refs, the fact that they cannot be inlined is
costing us some performance.

Move the function definitions into their respective headers so that they
can be inlined. This results in a performance improvement when iterating
over 1 million refs:

    Benchmark 1: show-ref: single matching ref (revision = HEAD~)
      Time (mean ± σ):     105.9 ms ±   3.6 ms    [User: 103.0 ms, System: 2.8 ms]
      Range (min … max):   103.1 ms … 133.4 ms    1000 runs

    Benchmark 2: show-ref: single matching ref (revision = HEAD)
      Time (mean ± σ):     100.7 ms ±   3.4 ms    [User: 97.8 ms, System: 2.8 ms]
      Range (min … max):    97.8 ms … 124.0 ms    1000 runs

    Summary
      show-ref: single matching ref (revision = HEAD) ran
        1.05 ± 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>
2024-03-04 10:19:49 -08:00

78 lines
1.4 KiB
C

/*
Copyright 2020 Google LLC
Use of this source code is governed by a BSD-style
license that can be found in the LICENSE file or at
https://developers.google.com/open-source/licenses/bsd
*/
#include "pq.h"
#include "reftable-record.h"
#include "system.h"
#include "basics.h"
int pq_less(struct pq_entry *a, struct pq_entry *b)
{
int cmp = reftable_record_cmp(a->rec, b->rec);
if (cmp == 0)
return a->index > b->index;
return cmp < 0;
}
struct pq_entry merged_iter_pqueue_remove(struct merged_iter_pqueue *pq)
{
int i = 0;
struct pq_entry e = pq->heap[0];
pq->heap[0] = pq->heap[pq->len - 1];
pq->len--;
i = 0;
while (i < pq->len) {
int min = i;
int j = 2 * i + 1;
int k = 2 * i + 2;
if (j < pq->len && pq_less(&pq->heap[j], &pq->heap[i])) {
min = j;
}
if (k < pq->len && pq_less(&pq->heap[k], &pq->heap[min])) {
min = k;
}
if (min == i) {
break;
}
SWAP(pq->heap[i], pq->heap[min]);
i = min;
}
return e;
}
void merged_iter_pqueue_add(struct merged_iter_pqueue *pq, const struct pq_entry *e)
{
int i = 0;
REFTABLE_ALLOC_GROW(pq->heap, pq->len + 1, pq->cap);
pq->heap[pq->len++] = *e;
i = pq->len - 1;
while (i > 0) {
int j = (i - 1) / 2;
if (pq_less(&pq->heap[j], &pq->heap[i])) {
break;
}
SWAP(pq->heap[j], pq->heap[i]);
i = j;
}
}
void merged_iter_pqueue_release(struct merged_iter_pqueue *pq)
{
FREE_AND_NULL(pq->heap);
memset(pq, 0, sizeof(*pq));
}