initial population

1 files changed, 217 insertions, 0 deletions

diff --git a/usr.bin/sort/radix_sort.c b/usr.bin/sort/radix_sort.c
new file mode 100644
index 0000000..4ec5ff8
--- /dev/null
+++ b/usr.bin/sort/radix_sort.c
@@ -0,0 +1,217 @@
+/*	$NetBSD: radix_sort.c,v 1.4 2009/09/19 16:18:00 dsl Exp $	*/
+
+/*-
+ * Copyright (c) 1990, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Peter McIlroy and by Dan Bernstein at New York University, 
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+#if defined(LIBC_SCCS) && !defined(lint)
+#if 0
+static char sccsid[] = "@(#)radixsort.c	8.2 (Berkeley) 4/28/95";
+#else
+__RCSID("$NetBSD: radix_sort.c,v 1.4 2009/09/19 16:18:00 dsl Exp $");
+#endif
+#endif /* LIBC_SCCS and not lint */
+
+/*
+ * 'stable' radix sort initially from libc/stdlib/radixsort.c
+ */
+
+#include <sys/types.h>
+
+#include <assert.h>
+#include <errno.h>
+#include <util.h>
+#include "sort.h"
+
+typedef struct {
+	RECHEADER **sa;		/* Base of saved area */
+	int sn;			/* Number of entries */
+	int si;			/* index into data for compare */
+} stack;
+
+static void simplesort(RECHEADER **, int, int);
+
+#define	THRESHOLD	20		/* Divert to simplesort(). */
+
+#define empty(s)	(s >= sp)
+#define pop(a, n, i)	a = (--sp)->sa, n = sp->sn, i = sp->si
+#define push(a, n, i)	sp->sa = a, sp->sn = n, (sp++)->si = i
+#define swap(a, b, t)	t = a, a = b, b = t
+
+void
+radix_sort(RECHEADER **a, RECHEADER **ta, int n)
+{
+	u_int count[256], nc, bmin;
+	u_int c;
+	RECHEADER **ak, **tai, **lim;
+	RECHEADER *hdr;
+	int stack_size = 512;
+	stack *s, *sp, *sp0, *sp1, temp;
+	RECHEADER **top[256];
+	u_int *cp, bigc;
+	int data_index = 0;
+
+	if (n < THRESHOLD && !DEBUG('r')) {
+		simplesort(a, n, 0);
+		return;
+	}
+
+	s = emalloc(stack_size * sizeof *s);
+	memset(&count, 0, sizeof count);
+	/* Technically 'top' doesn't need zeroing */
+	memset(&top, 0, sizeof top);
+
+	sp = s;
+	push(a, n, data_index);
+	while (!empty(s)) {
+		pop(a, n, data_index);
+		if (n < THRESHOLD && !DEBUG('r')) {
+			simplesort(a, n, data_index);
+			continue;
+		}
+
+		/* Count number of times each 'next byte' occurs */
+		nc = 0;
+		bmin = 255;
+		lim = a + n;
+		for (ak = a, tai = ta; ak < lim; ak++) {
+			hdr = *ak;
+			if (data_index >= hdr->keylen) {
+				/* Short key, copy to start of output */
+				if (UNIQUE && a != sp->sa)
+					/* Stop duplicate being written out */
+					hdr->keylen = -1;
+				*a++ = hdr;
+				n--;
+				continue;
+			}
+			/* Save in temp buffer for distribute */
+			*tai++ = hdr;
+			c = hdr->data[data_index];
+			if (++count[c] == 1) {
+				if (c < bmin)
+					bmin = c;
+				nc++;
+			}
+		}
+		/*
+		 * We need save the bounds for each 'next byte' that
+		 * occurs more so we can sort each block.
+		 */
+		if (sp + nc > s + stack_size) {
+			stack_size *= 2;
+			sp1 = erealloc(s, stack_size * sizeof *s);
+			sp = sp1 + (sp - s);
+			s = sp1;
+		}
+
+		/* Minor optimisation to do the largest set last */
+		sp0 = sp1 = sp;
+		bigc = 2;
+		/* Convert 'counts' positions, saving bounds for later sorts */
+		ak = a;
+		for (cp = count + bmin; nc > 0; cp++) {
+			while (*cp == 0)
+				cp++;
+			if ((c = *cp) > 1) {
+				if (c > bigc) {
+					bigc = c;
+					sp1 = sp;
+				}
+				push(ak, c, data_index+1);
+			}
+			ak += c;
+			top[cp-count] = ak;
+			*cp = 0;			/* Reset count[]. */
+			nc--;
+		}
+		swap(*sp0, *sp1, temp);
+
+		for (ak = ta+n; --ak >= ta;)		/* Deal to piles. */
+			*--top[(*ak)->data[data_index]] = *ak;
+	}
+
+	free(s);
+}
+
+/* insertion sort, short records are sorted before long ones */
+static void
+simplesort(RECHEADER **a, int n, int data_index)
+{
+	RECHEADER **ak, **ai;
+	RECHEADER *akh;
+	RECHEADER **lim = a + n;
+	const u_char *s, *t;
+	int s_len, t_len;
+	int i;
+	int r;
+
+	if (n <= 1)
+		return;
+
+	for (ak = a+1; ak < lim; ak++) {
+		akh = *ak;
+		s = akh->data;
+		s_len = akh->keylen;
+		for (ai = ak; ;) {
+			ai--;
+			t_len = (*ai)->keylen;
+			if (t_len != -1) {
+				t = (*ai)->data;
+				for (i = data_index; ; i++) {
+					if (i >= s_len || i >= t_len) {
+						r = s_len - t_len;
+						break;
+					}
+					r =  s[i]  - t[i];
+					if (r != 0)
+						break;
+				}
+				if (r >= 0) {
+					if (r == 0 && UNIQUE) {
+						/* Put record below existing */
+						ai[1] = ai[0];
+						/* Mark as duplicate - ignore */
+						akh->keylen = -1;
+					} else {
+						ai++;
+					}
+					break;
+				}
+			}
+			ai[1] = ai[0];
+			if (ai == a)
+				break;
+		}
+		ai[0] = akh;
+	}
+}