c18eecbe5c
The speed of the merged_iter_pqueue_add() can be improved by using a pointer to the pq_entry struct, which is 96 bytes. Since the pq_entry param is worked directly on the stack and does not currently have a pointer to it, the merged_iter_pqueue_add() function is slightly slower. References to pq_entry in reftable have typically included pointers, such as both of the params for pq_less(). Since we are working with pointers in the pq_entry param, as keenly pointed out, the pq_entry param has also been made into a const since the contents of the pq_entry param are copied and not manipulated. Signed-off-by: Elijah Conners <business@elijahpepe.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
107 lines
1.9 KiB
C
107 lines
1.9 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)
|
|
{
|
|
struct strbuf ak = STRBUF_INIT;
|
|
struct strbuf bk = STRBUF_INIT;
|
|
int cmp = 0;
|
|
reftable_record_key(&a->rec, &ak);
|
|
reftable_record_key(&b->rec, &bk);
|
|
|
|
cmp = strbuf_cmp(&ak, &bk);
|
|
|
|
strbuf_release(&ak);
|
|
strbuf_release(&bk);
|
|
|
|
if (cmp == 0)
|
|
return a->index > b->index;
|
|
|
|
return cmp < 0;
|
|
}
|
|
|
|
struct pq_entry merged_iter_pqueue_top(struct merged_iter_pqueue pq)
|
|
{
|
|
return pq.heap[0];
|
|
}
|
|
|
|
int merged_iter_pqueue_is_empty(struct merged_iter_pqueue pq)
|
|
{
|
|
return pq.len == 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;
|
|
|
|
if (pq->len == pq->cap) {
|
|
pq->cap = 2 * pq->cap + 1;
|
|
pq->heap = reftable_realloc(pq->heap,
|
|
pq->cap * sizeof(struct pq_entry));
|
|
}
|
|
|
|
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)
|
|
{
|
|
int i = 0;
|
|
for (i = 0; i < pq->len; i++) {
|
|
reftable_record_release(&pq->heap[i].rec);
|
|
}
|
|
FREE_AND_NULL(pq->heap);
|
|
pq->len = pq->cap = 0;
|
|
}
|