/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ /*- * Copyright (c) 1992, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* We need this because Solaris' version of qsort is broken and * causes array bounds reads. */ #include <stdlib.h> #include "nsAlgorithm.h" #include "nsQuickSort.h" extern "C" { #if !defined(DEBUG) && (defined(__cplusplus) || defined(__gcc)) # ifndef INLINE # define INLINE inline # endif #else # define INLINE #endif typedef int cmp_t(const void *, const void *, void *); static INLINE char *med3(char *, char *, char *, cmp_t *, void *); static INLINE void swapfunc(char *, char *, int, int); /* * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function". */ #define swapcode(TYPE, parmi, parmj, n) { \ long i = (n) / sizeof (TYPE); \ TYPE *pi = (TYPE *) (parmi); \ TYPE *pj = (TYPE *) (parmj); \ do { \ TYPE t = *pi; \ *pi++ = *pj; \ *pj++ = t; \ } while (--i > 0); \ } #define SWAPINIT(a, es) swaptype = ((char *)a - (char *)0) % sizeof(long) || \ es % sizeof(long) ? 2 : es == sizeof(long)? 0 : 1; static INLINE void swapfunc(char *a, char *b, int n, int swaptype) { if(swaptype <= 1) swapcode(long, a, b, n) else swapcode(char, a, b, n) } #define swap(a, b) \ if (swaptype == 0) { \ long t = *(long *)(a); \ *(long *)(a) = *(long *)(b); \ *(long *)(b) = t; \ } else \ swapfunc((char *)a, (char*)b, (int)es, swaptype) #define vecswap(a, b, n) if ((n) > 0) swapfunc((char *)a, (char *)b, (int)n, swaptype) static INLINE char * med3(char *a, char *b, char *c, cmp_t* cmp, void *data) { return cmp(a, b, data) < 0 ? (cmp(b, c, data) < 0 ? b : (cmp(a, c, data) < 0 ? c : a )) :(cmp(b, c, data) > 0 ? b : (cmp(a, c, data) < 0 ? a : c )); } void NS_QuickSort ( void *a, unsigned int n, unsigned int es, cmp_t *cmp, void *data ) { char *pa, *pb, *pc, *pd, *pl, *pm, *pn; int d, r, swaptype; loop: SWAPINIT(a, es); /* Use insertion sort when input is small */ if (n < 7) { for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es) for (pl = pm; pl > (char *)a && cmp(pl - es, pl, data) > 0; pl -= es) swap(pl, pl - es); return; } /* Choose pivot */ pm = (char *)a + (n / 2) * es; if (n > 7) { pl = (char *)a; pn = (char *)a + (n - 1) * es; if (n > 40) { d = (n / 8) * es; pl = med3(pl, pl + d, pl + 2 * d, cmp, data); pm = med3(pm - d, pm, pm + d, cmp, data); pn = med3(pn - 2 * d, pn - d, pn, cmp, data); } pm = med3(pl, pm, pn, cmp, data); } swap(a, pm); pa = pb = (char *)a + es; pc = pd = (char *)a + (n - 1) * es; /* loop invariants: * [a, pa) = pivot * [pa, pb) < pivot * [pb, pc + es) unprocessed * [pc + es, pd + es) > pivot * [pd + es, pn) = pivot */ for (;;) { while (pb <= pc && (r = cmp(pb, a, data)) <= 0) { if (r == 0) { swap(pa, pb); pa += es; } pb += es; } while (pb <= pc && (r = cmp(pc, a, data)) >= 0) { if (r == 0) { swap(pc, pd); pd -= es; } pc -= es; } if (pb > pc) break; swap(pb, pc); pb += es; pc -= es; } /* Move pivot values */ pn = (char *)a + n * es; r = XPCOM_MIN(pa - (char *)a, pb - pa); vecswap(a, pb - r, r); r = XPCOM_MIN<size_t>(pd - pc, pn - pd - es); vecswap(pb, pn - r, r); /* Recursively process partitioned items */ if ((r = pb - pa) > (int)es) NS_QuickSort(a, r / es, es, cmp, data); if ((r = pd - pc) > (int)es) { /* Iterate rather than recurse to save stack space */ a = pn - r; n = r / es; goto loop; } /* NS_QuickSort(pn - r, r / es, es, cmp, data);*/ } } #undef INLINE #undef swapcode #undef SWAPINIT #undef swap #undef vecswap