Makefile.in: kill sample_conf variable
[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 gengetopt_args_info conf;
31 extern struct misc_meta_data *mmd;
32
33 static unsigned int num_audio_files, audio_file_count;
34 static char **audio_file_list;
35
36 static int count_audio_files(__a_unused const char *dir, __a_unused const char *name)
37 {
38 num_audio_files++;
39 return 1;
40 }
41
42 static int remember_file(const char *dir, const char *name)
43 {
44 if (audio_file_count >= num_audio_files)
45 return -E_FILE_COUNT;
46 audio_file_list[audio_file_count] = make_message("%s/%s", dir, name);
47 audio_file_count++;
48 return 1;
49 }
50
51 /* array of commands that are supported by this selector */
52 static struct server_command cmds[] = {
53 {
54 .name = "random_info",
55 .handler = com_random_info,
56 .perms = 0,
57 .description = "about the random audio file selector",
58 .synopsis = "random_info",
59 .help =
60
61 "Select a random file under the given directory"
62 }, {
63 .name = NULL,
64 }
65 };
66
67 static int com_random_info(int fd, __a_unused int argc, __a_unused char *argv[])
68 {
69 return send_buffer(fd, "Don't use for huge directories as it is "
70 "very inefficient in this case.\n");
71 }
72
73 /*
74 * Load a list of all audio files into memory and chose num of them randomly.
75 * Called by server to determine next audio file to be streamed.
76 */
77 static char **random_get_audio_file_list(unsigned int num)
78 {
79 int i, ret;
80 unsigned int len;
81 char **ret_list = NULL; /* what we are going to return */
82
83 audio_file_list = NULL;
84 num_audio_files = 0;
85 /* first run, just count all audio files. dopey */
86 ret = find_audio_files(conf.random_dir_arg, count_audio_files);
87 if (ret < 0)
88 goto out;
89 ret = -E_NOTHING_FOUND;
90 if (!num_audio_files)
91 goto out;
92 /* yeah, that doesn't scale, also dopey */
93 audio_file_list = para_malloc(num_audio_files * sizeof(char *));
94 audio_file_count = 0;
95 /* second run (hot dentry cache, hopefully), fill audio_file_list */
96 ret = find_audio_files(conf.random_dir_arg, remember_file);
97 if (ret < 0)
98 goto out;
99 /* careful, files might got deleted underneath */
100 num_audio_files = audio_file_count; /* can only decrease */
101 len = PARA_MIN(num, num_audio_files);
102 ret = -E_NOTHING_FOUND;
103 if (!len) /* nothing found, return NULL */
104 goto out;
105 /* success, return NULL-terminated list */
106 ret_list = para_calloc((len + 1) * sizeof(char *));
107 for (i = 0; i < len; i++) { /* choose randomly */
108 int r = (int) ((num_audio_files + 0.0) * (rand()
109 / (RAND_MAX + 1.0)));
110 ret_list[i] = para_strdup(audio_file_list[r]);
111 }
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 // PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
120 return ret_list;
121 }
122
123 static void random_shutdown(void)
124 {
125 }
126
127 /**
128 * the init function for the random audio file selector
129 *
130 * Init all function pointers of \a db, init the info text and seed the
131 * PRNG.
132 *
133 * \sa struct audio_file_selector, misc_meta_data::selector_info, mysql.c
134 */
135 int random_selector_init(struct audio_file_selector *db)
136 {
137 struct timeval now;
138
139 PARA_INFO_LOG("%s", "registering random handlers ;)\n");
140 sprintf(mmd->selector_info, "dbinfo1:database info? You're kidding. "
141 "I'm still dopey!\ndbinfo2:\ndbinfo3:\n");
142 gettimeofday(&now, NULL);
143 srand(now.tv_usec);
144 db->cmd_list = cmds;
145 db->get_audio_file_list = random_get_audio_file_list;
146 db->shutdown = random_shutdown;
147 return 1;
148 }