1 /*-
2 * Copyright (C) 2003 Sean Chittenden <seanc@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: src/games/random/randomize_fd.c,v 1.2.2.1 2003/02/15 10:34:35 seanc Exp $
27 */
28
29 #include <sys/types.h>
30 #include <sys/param.h>
31
32 #include <ctype.h>
33 #include <err.h>
34 #include <stdlib.h>
35 #include <stdio.h>
36 #include <string.h>
37 #include <unistd.h>
38
39 #include "randomize_fd.h"
40
41 static struct rand_node *rand_root;
42 static struct rand_node *rand_tail;
43
44 static struct rand_node *
rand_node_allocate(void)45 rand_node_allocate(void)
46 {
47 struct rand_node *n;
48
49 n = (struct rand_node *)malloc(sizeof(struct rand_node));
50 if (n == NULL)
51 err(1, "malloc");
52
53 n->len = 0;
54 n->cp = NULL;
55 n->next = NULL;
56 return(n);
57 }
58
59 static void
rand_node_free(struct rand_node * n)60 rand_node_free(struct rand_node *n)
61 {
62 if (n != NULL) {
63 if (n->cp != NULL)
64 free(n->cp);
65
66 free(n);
67 }
68 }
69
70 static void
rand_node_free_rec(struct rand_node * n)71 rand_node_free_rec(struct rand_node *n)
72 {
73 if (n != NULL) {
74 if (n->next != NULL)
75 rand_node_free_rec(n->next);
76
77 rand_node_free(n);
78 }
79 }
80
81 static void
rand_node_append(struct rand_node * n)82 rand_node_append(struct rand_node *n)
83 {
84 if (rand_root == NULL)
85 rand_root = rand_tail = n;
86 else {
87 rand_tail->next = n;
88 rand_tail = n;
89 }
90 }
91
92 int
randomize_fd(int fd,int type,int unique,double denom)93 randomize_fd(int fd, int type, int unique, double denom)
94 {
95 u_char *buf, *p;
96 u_int numnode, j, selected, slen;
97 struct rand_node *n, *prev;
98 int bufleft, eof, fndstr, ret;
99 size_t bufc, buflen, i;
100 ssize_t len;
101
102 rand_root = rand_tail = NULL;
103 bufc = i = 0;
104 bufleft = eof = fndstr = numnode = ret = 0;
105
106 if (type == RANDOM_TYPE_UNSET)
107 type = RANDOM_TYPE_LINES;
108
109 buflen = sizeof(u_char) * MAXBSIZE;
110 buf = (u_char *)malloc(buflen);
111 if (buf == NULL)
112 err(1, "malloc");
113
114 while (!eof) {
115 /* Check to see if we have bits in the buffer */
116 if (bufleft == 0) {
117 len = read(fd, buf, buflen);
118 if (len == -1)
119 err(1, "read");
120 else if (len == 0) {
121 eof++;
122 break;
123 } else if ((size_t)len < buflen)
124 buflen = (size_t)len;
125
126 bufleft = (int)len;
127 }
128
129 /* Look for a newline */
130 for (i = bufc; i <= buflen && bufleft >= 0; i++, bufleft--) {
131 if (i == buflen) {
132 if (fndstr) {
133 if (!eof) {
134 memmove(buf, &buf[bufc], i - bufc);
135 i -= bufc;
136 bufc = 0;
137 len = read(fd, &buf[i], buflen - i);
138 if (len == -1)
139 err(1, "read");
140 else if (len == 0) {
141 eof++;
142 break;
143 } else if (len < (ssize_t)(buflen - i))
144 buflen = i + (size_t)len;
145
146 bufleft = (int)len;
147 fndstr = 0;
148 }
149 } else {
150 p = (u_char *)realloc(buf, buflen * 2);
151 if (p == NULL)
152 err(1, "realloc");
153
154 buf = p;
155 if (!eof) {
156 len = read(fd, &buf[i], buflen);
157 if (len == -1)
158 err(1, "read");
159 else if (len == 0) {
160 eof++;
161 break;
162 } else if (len < (ssize_t)(buflen - i))
163 buflen = (size_t)len;
164
165 bufleft = (int)len;
166 }
167
168 buflen *= 2;
169 }
170 }
171
172 if ((type == RANDOM_TYPE_LINES && buf[i] == '\n') ||
173 (type == RANDOM_TYPE_WORDS && isspace((int)buf[i])) ||
174 (eof && i == buflen - 1)) {
175 make_token:
176 n = rand_node_allocate();
177 if (-1 != (int)i) {
178 slen = i - (u_long)bufc;
179 n->len = slen + 2;
180 n->cp = (u_char *)malloc(slen + 2);
181 if (n->cp == NULL)
182 err(1, "malloc");
183
184 memmove(n->cp, &buf[bufc], slen);
185 n->cp[slen] = buf[i];
186 n->cp[slen + 1] = '\0';
187 bufc = i + 1;
188 }
189 rand_node_append(n);
190 fndstr = 1;
191 numnode++;
192 }
193 }
194 }
195
196 close(fd);
197
198 /* Necessary evil to compensate for files that don't end with a newline */
199 if (bufc != i) {
200 i--;
201 goto make_token;
202 }
203
204 for (i = numnode; i > 0; i--) {
205 selected = ((int)denom * random())/(((double)RAND_MAX + 1) / numnode);
206
207 for (j = 0, prev = n = rand_root; n != NULL; j++, prev = n, n = n->next) {
208 if (j == selected) {
209 if (n->cp == NULL)
210 break;
211
212 ret = printf("%.*s", (int)n->len - 1, n->cp);
213 if (ret < 0)
214 err(1, "printf");
215 if (unique) {
216 if (n == rand_root)
217 rand_root = n->next;
218 if (n == rand_tail)
219 rand_tail = prev;
220
221 prev->next = n->next;
222 rand_node_free(n);
223 numnode--;
224 break;
225 }
226 }
227 }
228 }
229
230 fflush(stdout);
231
232 if (!unique)
233 rand_node_free_rec(rand_root);
234
235 return(0);
236 }
237