| | 1 | /* The following is the NetBSD libc qsort implementation modified in order to |
| | 2 | * support partial sorting of ranges for Redis. |
| | 3 | * |
| | 4 | * Copyright(C) 2009 Salvatore Sanfilippo. All rights reserved. |
| | 5 | * |
| | 6 | * The original copyright notice follows. */ |
| | 7 | |
| | 8 | |
| | 9 | /* $NetBSD: qsort.c,v 1.19 2009/01/30 23:38:44 lukem Exp $ */ |
| | 10 | |
| | 11 | /*- |
| | 12 | * Copyright (c) 1992, 1993 |
| | 13 | * The Regents of the University of California. All rights reserved. |
| | 14 | * |
| | 15 | * Redistribution and use in source and binary forms, with or without |
| | 16 | * modification, are permitted provided that the following conditions |
| | 17 | * are met: |
| | 18 | * 1. Redistributions of source code must retain the above copyright |
| | 19 | * notice, this list of conditions and the following disclaimer. |
| | 20 | * 2. Redistributions in binary form must reproduce the above copyright |
| | 21 | * notice, this list of conditions and the following disclaimer in the |
| | 22 | * documentation and/or other materials provided with the distribution. |
| | 23 | * 3. Neither the name of the University nor the names of its contributors |
| | 24 | * may be used to endorse or promote products derived from this software |
| | 25 | * without specific prior written permission. |
| | 26 | * |
| | 27 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| | 28 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| | 29 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| | 30 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| | 31 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| | 32 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| | 33 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| | 34 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| | 35 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| | 36 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| | 37 | * SUCH DAMAGE. |
| | 38 | */ |
| | 39 | |
| | 40 | #include <sys/cdefs.h> |
| | 41 | #if defined(LIBC_SCCS) && !defined(lint) |
| | 42 | #if 0 |
| | 43 | static char sccsid[] = "@(#)qsort.c 8.1 (Berkeley) 6/4/93"; |
| | 44 | #else |
| | 45 | __RCSID("$NetBSD: qsort.c,v 1.19 2009/01/30 23:38:44 lukem Exp $"); |
| | 46 | #endif |
| | 47 | #endif /* LIBC_SCCS and not lint */ |
| | 48 | |
| | 49 | #include <sys/types.h> |
| | 50 | |
| | 51 | #include <assert.h> |
| | 52 | #include <errno.h> |
| | 53 | #include <stdlib.h> |
| | 54 | |
| | 55 | static inline char *med3 __P((char *, char *, char *, |
| | 56 | int (*)(const void *, const void *))); |
| | 57 | static inline void swapfunc __P((char *, char *, size_t, int)); |
| | 58 | |
| | 59 | #define min(a, b) (a) < (b) ? a : b |
| | 60 | |
| | 61 | /* |
| | 62 | * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function". |
| | 63 | */ |
| | 64 | #define swapcode(TYPE, parmi, parmj, n) { \ |
| | 65 | size_t i = (n) / sizeof (TYPE); \ |
| | 66 | TYPE *pi = (TYPE *)(void *)(parmi); \ |
| | 67 | TYPE *pj = (TYPE *)(void *)(parmj); \ |
| | 68 | do { \ |
| | 69 | TYPE t = *pi; \ |
| | 70 | *pi++ = *pj; \ |
| | 71 | *pj++ = t; \ |
| | 72 | } while (--i > 0); \ |
| | 73 | } |
| | 74 | |
| | 75 | #define SWAPINIT(a, es) swaptype = ((char *)a - (char *)0) % sizeof(long) || \ |
| | 76 | es % sizeof(long) ? 2 : es == sizeof(long)? 0 : 1; |
| | 77 | |
| | 78 | static inline void |
| | 79 | swapfunc(char *a, char *b, size_t n, int swaptype) |
| | 80 | { |
| | 81 | |
| | 82 | if (swaptype <= 1) |
| | 83 | swapcode(long, a, b, n) |
| | 84 | else |
| | 85 | swapcode(char, a, b, n) |
| | 86 | } |
| | 87 | |
| | 88 | #define swap(a, b) \ |
| | 89 | if (swaptype == 0) { \ |
| | 90 | long t = *(long *)(void *)(a); \ |
| | 91 | *(long *)(void *)(a) = *(long *)(void *)(b); \ |
| | 92 | *(long *)(void *)(b) = t; \ |
| | 93 | } else \ |
| | 94 | swapfunc(a, b, es, swaptype) |
| | 95 | |
| | 96 | #define vecswap(a, b, n) if ((n) > 0) swapfunc((a), (b), (size_t)(n), swaptype) |
| | 97 | |
| | 98 | static inline char * |
| | 99 | med3(char *a, char *b, char *c, |
| | 100 | int (*cmp) __P((const void *, const void *))) |
| | 101 | { |
| | 102 | |
| | 103 | return cmp(a, b) < 0 ? |
| | 104 | (cmp(b, c) < 0 ? b : (cmp(a, c) < 0 ? c : a )) |
| | 105 | :(cmp(b, c) > 0 ? b : (cmp(a, c) < 0 ? a : c )); |
| | 106 | } |
| | 107 | |
| | 108 | static void |
| | 109 | _pqsort(void *a, size_t n, size_t es, |
| | 110 | int (*cmp) __P((const void *, const void *)), void *lrange, void *rrange) |
| | 111 | { |
| | 112 | char *pa, *pb, *pc, *pd, *pl, *pm, *pn; |
| | 113 | size_t d, r; |
| | 114 | int swaptype, swap_cnt, cmp_result; |
| | 115 | |
| | 116 | loop: SWAPINIT(a, es); |
| | 117 | swap_cnt = 0; |
| | 118 | if (n < 7) { |
| | 119 | for (pm = (char *) a + es; pm < (char *) a + n * es; pm += es) |
| | 120 | for (pl = pm; pl > (char *) a && cmp(pl - es, pl) > 0; |
| | 121 | pl -= es) |
| | 122 | swap(pl, pl - es); |
| | 123 | return; |
| | 124 | } |
| | 125 | pm = (char *) a + (n / 2) * es; |
| | 126 | if (n > 7) { |
| | 127 | pl = (char *) a; |
| | 128 | pn = (char *) a + (n - 1) * es; |
| | 129 | if (n > 40) { |
| | 130 | d = (n / 8) * es; |
| | 131 | pl = med3(pl, pl + d, pl + 2 * d, cmp); |
| | 132 | pm = med3(pm - d, pm, pm + d, cmp); |
| | 133 | pn = med3(pn - 2 * d, pn - d, pn, cmp); |
| | 134 | } |
| | 135 | pm = med3(pl, pm, pn, cmp); |
| | 136 | } |
| | 137 | swap(a, pm); |
| | 138 | pa = pb = (char *) a + es; |
| | 139 | |
| | 140 | pc = pd = (char *) a + (n - 1) * es; |
| | 141 | for (;;) { |
| | 142 | while (pb <= pc && (cmp_result = cmp(pb, a)) <= 0) { |
| | 143 | if (cmp_result == 0) { |
| | 144 | swap_cnt = 1; |
| | 145 | swap(pa, pb); |
| | 146 | pa += es; |
| | 147 | } |
| | 148 | pb += es; |
| | 149 | } |
| | 150 | while (pb <= pc && (cmp_result = cmp(pc, a)) >= 0) { |
| | 151 | if (cmp_result == 0) { |
| | 152 | swap_cnt = 1; |
| | 153 | swap(pc, pd); |
| | 154 | pd -= es; |
| | 155 | } |
| | 156 | pc -= es; |
| | 157 | } |
| | 158 | if (pb > pc) |
| | 159 | break; |
| | 160 | swap(pb, pc); |
| | 161 | swap_cnt = 1; |
| | 162 | pb += es; |
| | 163 | pc -= es; |
| | 164 | } |
| | 165 | if (swap_cnt == 0) { /* Switch to insertion sort */ |
| | 166 | for (pm = (char *) a + es; pm < (char *) a + n * es; pm += es) |
| | 167 | for (pl = pm; pl > (char *) a && cmp(pl - es, pl) > 0; |
| | 168 | pl -= es) |
| | 169 | swap(pl, pl - es); |
| | 170 | return; |
| | 171 | } |
| | 172 | |
| | 173 | pn = (char *) a + n * es; |
| | 174 | r = min(pa - (char *) a, pb - pa); |
| | 175 | vecswap(a, pb - r, r); |
| | 176 | r = min((size_t)(pd - pc), pn - pd - es); |
| | 177 | vecswap(pb, pn - r, r); |
| | 178 | if ((r = pb - pa) > es) { |
| | 179 | void *_l = a, *_r = ((unsigned char*)a)+r-1; |
| | 180 | if (!((lrange < _l && rrange < _l) || |
| | 181 | (lrange > _r && rrange > _r))) |
| | 182 | _pqsort(a, r / es, es, cmp, lrange, rrange); |
| | 183 | } |
| | 184 | if ((r = pd - pc) > es) { |
| | 185 | void *_l, *_r; |
| | 186 | |
| | 187 | /* Iterate rather than recurse to save stack space */ |
| | 188 | a = pn - r; |
| | 189 | n = r / es; |
| | 190 | |
| | 191 | _l = a; |
| | 192 | _r = ((unsigned char*)a)+r-1; |
| | 193 | if (!((lrange < _l && rrange < _l) || |
| | 194 | (lrange > _r && rrange > _r))) |
| | 195 | goto loop; |
| | 196 | } |
| | 197 | /* qsort(pn - r, r / es, es, cmp);*/ |
| | 198 | } |
| | 199 | |
| | 200 | void |
| | 201 | pqsort(void *a, size_t n, size_t es, |
| | 202 | int (*cmp) __P((const void *, const void *)), size_t lrange, size_t rrange) |
| | 203 | { |
| | 204 | _pqsort(a,n,es,cmp,((unsigned char*)a)+(lrange*es), |
| | 205 | ((unsigned char*)a)+((rrange+1)*es)-1); |
| | 206 | } |
projects / redis.git / blame_incremental