games/random/randomize_fd.c

   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  * $DragonFly: src/games/random/randomize_fd.c,v 1.2 2003/06/17 04:25:24 dillon Exp $
  28  */
  29
  30 #include <sys/types.h>
  31 #include <sys/param.h>
  32
  33 #include <ctype.h>
  34 #include <err.h>
  35 #include <stdlib.h>
  36 #include <stdio.h>
  37 #include <string.h>
  38 #include <unistd.h>
  39
  40 #include "randomize_fd.h"
  41
  42 static struct rand_node *rand_root;
  43 static struct rand_node *rand_tail;
  44
  45 static struct rand_node *
  46 rand_node_allocate(void)
  47 {
  48         struct rand_node *n;
  49
  50         n = (struct rand_node *)malloc(sizeof(struct rand_node));
  51         if (n == NULL)
  52                 err(1, "malloc");
  53
  54         n->len = 0;
  55         n->cp = NULL;
  56         n->next = NULL;
  57         return(n);
  58 }
  59
  60 static void
  61 rand_node_free(struct rand_node *n)
  62 {
  63         if (n != NULL) {
  64                 if (n->cp != NULL)
  65                         free(n->cp);
  66
  67                 free(n);
  68         }
  69 }
  70
  71 static void
  72 rand_node_free_rec(struct rand_node *n)
  73 {
  74         if (n != NULL) {
  75                 if (n->next != NULL)
  76                         rand_node_free_rec(n->next);
  77
  78                 rand_node_free(n);
  79         }
  80 }
  81
  82 static void
  83 rand_node_append(struct rand_node *n)
  84 {
  85         if (rand_root == NULL)
  86                 rand_root = rand_tail = n;
  87         else {
  88                 rand_tail->next = n;
  89                 rand_tail = n;
  90         }
  91 }
  92
  93 int
  94 randomize_fd(int fd, int type, int unique, double denom)
  95 {
  96         u_char *buf, *p;
  97         u_int numnode, j, selected, slen;
  98         struct rand_node *n, *prev;
  99         int bufleft, eof, fndstr, ret;
 100         size_t bufc, buflen, i;
 101         ssize_t len;
 102
 103         rand_root = rand_tail = NULL;
 104         bufc = i = 0;
 105         bufleft = eof = fndstr = numnode = ret = 0;
 106
 107         if (type == RANDOM_TYPE_UNSET)
 108                 type = RANDOM_TYPE_LINES;
 109
 110         buflen = sizeof(u_char) * MAXBSIZE;
 111         buf = (u_char *)malloc(buflen);
 112         if (buf == NULL)
 113                 err(1, "malloc");
 114
 115         while (!eof) {
 116                 /* Check to see if we have bits in the buffer */
 117                 if (bufleft == 0) {
 118                         len = read(fd, buf, buflen);
 119                         if (len == -1)
 120                                 err(1, "read");
 121                         else if (len == 0) {
 122                                 eof++;
 123                                 break;
 124                         } else if ((size_t)len < buflen)
 125                                 buflen = (size_t)len;
 126
 127                         bufleft = (int)len;
 128                 }
 129
 130                 /* Look for a newline */
 131                 for (i = bufc; i <= buflen && bufleft >= 0; i++, bufleft--) {
 132                         if (i == buflen) {
 133                                 if (fndstr) {
 134                                         if (!eof) {
 135                                                 memmove(buf, &buf[bufc], i - bufc);
 136                                                 i -= bufc;
 137                                                 bufc = 0;
 138                                                 len = read(fd, &buf[i], buflen - i);
 139                                                 if (len == -1)
 140                                                         err(1, "read");
 141                                                 else if (len == 0) {
 142                                                         eof++;
 143                                                         break;
 144                                                 } else if (len < (ssize_t)(buflen - i))
 145                                                         buflen = i + (size_t)len;
 146
 147                                                 bufleft = (int)len;
 148                                                 fndstr = 0;
 149                                         }
 150                                 } else {
 151                                         p = (u_char *)realloc(buf, buflen * 2);
 152                                         if (p == NULL)
 153                                                 err(1, "realloc");
 154
 155                                         buf = p;
 156                                         if (!eof) {
 157                                                 len = read(fd, &buf[i], buflen);
 158                                                 if (len == -1)
 159                                                         err(1, "read");
 160                                                 else if (len == 0) {
 161                                                         eof++;
 162                                                         break;
 163                                                 } else if (len < (ssize_t)(buflen - i))
 164                                                         buflen = (size_t)len;
 165
 166                                                 bufleft = (int)len;
 167                                         }
 168
 169                                         buflen *= 2;
 170                                 }
 171                         }
 172
 173                         if ((type == RANDOM_TYPE_LINES && buf[i] == '\n') ||
 174                             (type == RANDOM_TYPE_WORDS && isspace((int)buf[i])) ||
 175                             (eof && i == buflen - 1)) {
 176                         make_token:
 177                                 n = rand_node_allocate();
 178                                 if (-1 != (int)i) {
 179                                         slen = i - (u_long)bufc;
 180                                         n->len = slen + 2;
 181                                         n->cp = (u_char *)malloc(slen + 2);
 182                                         if (n->cp == NULL)
 183                                                 err(1, "malloc");
 184
 185                                         memmove(n->cp, &buf[bufc], slen);
 186                                         n->cp[slen] = buf[i];
 187                                         n->cp[slen + 1] = '\0';
 188                                         bufc = i + 1;
 189                                 }
 190                                 rand_node_append(n);
 191                                 fndstr = 1;
 192                                 numnode++;
 193                         }
 194                 }
 195         }
 196
 197         (void)close(fd);
 198
 199         /* Necessary evil to compensate for files that don't end with a newline */
 200         if (bufc != i) {
 201                 i--;
 202                 goto make_token;
 203         }
 204
 205         for (i = numnode; i > 0; i--) {
 206                 selected = ((int)denom * random())/(((double)RAND_MAX + 1) / numnode);
 207
 208                 for (j = 0, prev = n = rand_root; n != NULL; j++, prev = n, n = n->next) {
 209                         if (j == selected) {
 210                                 if (n->cp == NULL)
 211                                         break;
 212
 213                                 ret = printf("%.*s", (int)n->len - 1, n->cp);
 214                                 if (ret < 0)
 215                                         err(1, "printf");
 216                                 if (unique) {
 217                                         if (n == rand_root)
 218                                                 rand_root = n->next;
 219                                         if (n == rand_tail)
 220                                                 rand_tail = prev;
 221
 222                                         prev->next = n->next;
 223                                         rand_node_free(n);
 224                                         numnode--;
 225                                         break;
 226                                 }
 227                         }
 228                 }
 229         }
 230
 231         fflush(stdout);
 232
 233         if (!unique)
 234                 rand_node_free_rec(rand_root);
 235
 236         return(0);
 237 }