1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
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;
}
}
|
