gui: fix default stat command
[paraslash.git] / random_selector.c
1 /*
2 * Copyright (C) 2004-2006 Andre Noll <maan@systemlinux.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
17 */
18
19 /** \file random_selector.c An audio file selector which chooses files by random */
20
21 #include <sys/time.h> /* gettimeofday */
22 #include "server.cmdline.h"
23 #include "server.h"
24 #include "db.h"
25 #include "error.h"
26 #include "net.h"
27 #include "string.h"
28
29 static int com_random_info(int, int, char **);
30 extern struct misc_meta_data *mmd;
31
32 static unsigned int num_audio_files, audio_file_count;
33 static char **audio_file_list;
34
35 static int count_audio_files(__a_unused const char *dir, __a_unused const char *name)
36 {
37 num_audio_files++;
38 return 1;
39 }
40
41 static int remember_file(const char *dir, const char *name)
42 {
43 if (audio_file_count >= num_audio_files)
44 return -E_FILE_COUNT;
45 audio_file_list[audio_file_count] = make_message("%s/%s", dir, name);
46 audio_file_count++;
47 return 1;
48 }
49
50 /* array of commands that are supported by this selector */
51 static struct server_command cmds[] = {
52 {
53 .name = "random_info",
54 .handler = com_random_info,
55 .perms = 0,
56 .description = "about the random audio file selector",
57 .synopsis = "random_info",
58 .help =
59
60 "Select a random file under the given directory"
61 }, {
62 .name = NULL,
63 }
64 };
65
66 static int com_random_info(int fd, __a_unused int argc, __a_unused char *argv[])
67 {
68 return send_buffer(fd, "Don't use for huge directories as it is "
69 "very inefficient in this case.\n");
70 }
71
72 /*
73 * Load a list of all audio files into memory and chose num of them randomly.
74 * Called by server to determine next audio file to be streamed.
75 */
76 static char **random_get_audio_file_list(unsigned int num)
77 {
78 int i, ret;
79 unsigned int len;
80 char **ret_list = NULL; /* what we are going to return */
81
82 audio_file_list = NULL;
83 num_audio_files = 0;
84 /* first run, just count all audio files. dopey */
85 ret = find_audio_files(conf.random_dir_arg, count_audio_files);
86 if (ret < 0)
87 goto out;
88 ret = -E_NOTHING_FOUND;
89 if (!num_audio_files)
90 goto out;
91 /* yeah, that doesn't scale, also dopey */
92 audio_file_list = para_malloc(num_audio_files * sizeof(char *));
93 audio_file_count = 0;
94 /* second run (hot dentry cache, hopefully), fill audio_file_list */
95 ret = find_audio_files(conf.random_dir_arg, remember_file);
96 if (ret < 0)
97 goto out;
98 /* careful, files might got deleted underneath */
99 num_audio_files = audio_file_count; /* can only decrease */
100 len = PARA_MIN(num, num_audio_files);
101 ret = -E_NOTHING_FOUND;
102 if (!len) /* nothing found, return NULL */
103 goto out;
104 /* success, return NULL-terminated list */
105 ret_list = para_calloc((len + 1) * sizeof(char *));
106 for (i = 0; i < len; i++) { /* choose randomly */
107 int r = (int) ((num_audio_files + 0.0) * (rand()
108 / (RAND_MAX + 1.0)));
109 ret_list[i] = para_strdup(audio_file_list[r]);
110 }
111 ret = 1;
112 out:
113 if (audio_file_list) {
114 for (i = 0; i < num_audio_files; i++)
115 free(audio_file_list[i]);
116 free(audio_file_list);
117 }
118 if (ret > 0) {
119 } else
120 sprintf(mmd->selector_info, "dbinfo1:%s\n", PARA_STRERROR(-ret));
121 return ret_list;
122 }
123
124 void random_update_audio_file(char *audio_file)
125 {
126 char *dn = para_dirname(audio_file);
127 snprintf(mmd->selector_info, MMD_INFO_SIZE - 1,
128 "dbinfo1:current dir: %s\n"
129 "dbinfo2:random_dir: %s\n"
130 "dbinfo3:%d files available\n",
131 dn, conf.random_dir_arg, num_audio_files);
132 free(dn);
133 mmd->selector_info[MMD_INFO_SIZE - 1] = '\0';
134 }
135 static void random_shutdown(void)
136 {
137 }
138
139 /**
140 * the init function for the random audio file selector
141 *
142 * Init all function pointers of \a s, init the info text and seed the
143 * PRNG.
144 *
145 * \sa struct audio_file_selector, misc_meta_data::selector_info, mysql.c
146 */
147 int random_selector_init(struct audio_file_selector *s)
148 {
149 struct timeval now;
150
151 PARA_INFO_LOG("%s", "registering random handlers ;)\n");
152 gettimeofday(&now, NULL);
153 srand(now.tv_usec);
154 s->cmd_list = cmds;
155 s->get_audio_file_list = random_get_audio_file_list;
156 s->shutdown = random_shutdown;
157 s->update_audio_file = random_update_audio_file;
158 snprintf(mmd->selector_info, MMD_INFO_SIZE - 1,
159 "dbinfo1: Welcome to the random selector\n"
160 "dbinfo2: random_dir: %s\n", conf.random_dir_arg);
161 mmd->selector_info[MMD_INFO_SIZE - 1] = '\0';
162 return 1;
163 }