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| #include "git-compat-util.h" | |
| /* | |
| * A merge sort implementation, simplified from the qsort implementation | |
| * by Mike Haertel, which is a part of the GNU C Library. | |
| */ | |
| static void msort_with_tmp(void *b, size_t n, size_t s, | |
| int (*cmp)(const void *, const void *), | |
| char *t) | |
| { | |
| char *tmp; | |
| char *b1, *b2; | |
| size_t n1, n2; | |
| if (n <= 1) | |
| return; | |
| n1 = n / 2; | |
| n2 = n - n1; | |
| b1 = b; | |
| b2 = (char *)b + (n1 * s); | |
| msort_with_tmp(b1, n1, s, cmp, t); | |
| msort_with_tmp(b2, n2, s, cmp, t); | |
| tmp = t; | |
| while (n1 > 0 && n2 > 0) { | |
| if (cmp(b1, b2) <= 0) { | |
| memcpy(tmp, b1, s); | |
| tmp += s; | |
| b1 += s; | |
| --n1; | |
| } else { | |
| memcpy(tmp, b2, s); | |
| tmp += s; | |
| b2 += s; | |
| --n2; | |
| } | |
| } | |
| if (n1 > 0) | |
| memcpy(tmp, b1, n1 * s); | |
| memcpy(b, t, (n - n2) * s); | |
| } | |
| void git_stable_qsort(void *b, size_t n, size_t s, | |
| int (*cmp)(const void *, const void *)) | |
| { | |
| const size_t size = st_mult(n, s); | |
| char buf[1024]; | |
| if (size < sizeof(buf)) { | |
| /* The temporary array fits on the small on-stack buffer. */ | |
| msort_with_tmp(b, n, s, cmp, buf); | |
| } else { | |
| /* It's somewhat large, so malloc it. */ | |
| char *tmp = xmalloc(size); | |
| msort_with_tmp(b, n, s, cmp, tmp); | |
| free(tmp); | |
| } | |
| } |