diff options
Diffstat (limited to 'src/util.c')
| -rw-r--r-- | src/util.c | 79 |
1 files changed, 20 insertions, 59 deletions
diff --git a/src/util.c b/src/util.c index 03e911241..4a44f9988 100644 --- a/src/util.c +++ b/src/util.c @@ -331,66 +331,27 @@ uint32_t git__hash(const void *key, int len, uint32_t seed) } #endif -/* - * A merge sort implementation, simplified from the qsort implementation - * by Mike Haertel, which is a part of the GNU C Library. +/** + * A modified `bsearch` from the BSD glibc. + * + * Copyright (c) 1990 Regents of the University of California. + * All rights reserved. */ -static void msort_with_tmp(void *b, size_t n, size_t s, - int (*cmp)(const void *, const void *), - char *t) +void **git__bsearch(const void *key, void **base, size_t nmemb, int (*compar)(const void *, const void *)) { - 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); + int lim, cmp; + void **p; + + for (lim = nmemb; lim != 0; lim >>= 1) { + p = base + (lim >> 1); + cmp = (*compar)(key, *p); + if (cmp > 0) { /* key > p: move right */ + base = p + 1; + lim--; + } else if (cmp == 0) { + return (void **)p; + } /* else move left */ + } + return NULL; } -int git__msort(void *b, size_t n, size_t s, - int (*cmp)(const void *, const void *)) -{ - const size_t size = 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 = git__malloc(size); - if (tmp == NULL) - return GIT_ENOMEM; - msort_with_tmp(b, n, s, cmp, tmp); - free(tmp); - } - - return GIT_SUCCESS; -} |
