1 /* ncmpc
2 * Copyright (C) 2008 Max Kellermann <max@duempel.org>
3 * This project's homepage is: http://www.musicpd.org
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
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 02111-1307 USA
17 */
19 #include "lyrics.h"
20 #include "gcc.h"
21 #include "../config.h"
23 #include <assert.h>
24 #include <stdlib.h>
25 #include <unistd.h>
26 #include <string.h>
27 #include <sys/stat.h>
28 #include <sys/signal.h>
29 #include <sys/wait.h>
31 static GPtrArray *plugins;
33 struct lyrics_loader {
34 char *artist, *title;
36 lyrics_callback_t callback;
37 void *callback_data;
39 guint next_plugin;
41 pid_t pid;
42 int fd;
43 GIOChannel *channel;
44 guint event_id;
46 GString *data;
47 };
49 static int lyrics_register_plugin(const char *path0)
50 {
51 int ret;
52 struct stat st;
53 char *path;
55 ret = stat(path0, &st);
56 if (ret < 0)
57 return -1;
59 path = g_strdup(path0);
60 g_ptr_array_add(plugins, path);
61 return 0;
62 }
64 void lyrics_init(void)
65 {
66 GDir *dir;
68 plugins = g_ptr_array_new();
70 dir = g_dir_open(LYRICS_PLUGIN_DIR, 0, NULL);
71 if (dir != NULL) {
72 const char *name;
73 char path[sizeof(LYRICS_PLUGIN_DIR) + 128];
75 memcpy(path, LYRICS_PLUGIN_DIR, sizeof(LYRICS_PLUGIN_DIR) - 1);
76 path[sizeof(LYRICS_PLUGIN_DIR) - 1] = G_DIR_SEPARATOR;
78 while ((name = g_dir_read_name(dir)) != NULL) {
79 g_strlcpy(path + sizeof(LYRICS_PLUGIN_DIR), name,
80 sizeof(path) - sizeof(LYRICS_PLUGIN_DIR));
81 lyrics_register_plugin(path);
82 }
84 g_dir_close(dir);
85 }
86 }
88 void lyrics_deinit(void)
89 {
90 guint i;
92 for (i = 0; i < plugins->len; ++i)
93 free(g_ptr_array_index(plugins, i));
94 g_ptr_array_free(plugins, TRUE);
95 }
97 static void
98 lyrics_next_plugin(struct lyrics_loader *loader);
100 static void
101 lyrics_eof(struct lyrics_loader *loader)
102 {
103 int ret, status;
105 g_io_channel_unref(loader->channel);
106 close(loader->fd);
107 loader->fd = -1;
109 ret = waitpid(loader->pid, &status, 0);
110 loader->pid = -1;
112 if (ret < 0 || !WIFEXITED(status) || WEXITSTATUS(status) != 0) {
113 g_string_free(loader->data, TRUE);
114 loader->data = NULL;
116 lyrics_next_plugin(loader);
117 } else {
118 loader->callback(loader->data, loader->callback_data);
119 }
120 }
122 static gboolean
123 lyrics_data(mpd_unused GIOChannel *source,
124 mpd_unused GIOCondition condition, gpointer data)
125 {
126 struct lyrics_loader *loader = data;
127 char buffer[256];
128 ssize_t nbytes;
130 assert(loader != NULL);
131 assert(loader->fd >= 0);
132 assert(loader->pid > 0);
133 assert(source == loader->channel);
135 if ((condition & G_IO_IN) == 0) {
136 lyrics_eof(loader);
137 return FALSE;
138 }
140 nbytes = condition & G_IO_IN
141 ? read(loader->fd, buffer, sizeof(buffer))
142 : 0;
143 if (nbytes <= 0) {
144 lyrics_eof(loader);
145 return FALSE;
146 }
148 g_string_append_len(loader->data, buffer, nbytes);
149 return TRUE;
150 }
152 /**
153 * This is a timer callback which calls the lyrics callback "some
154 * timer later". This solves the problem that lyrics_load() may fail
155 * immediately, leaving its return value in an undefined state.
156 * Instead, install a timer which calls the lyrics callback in the
157 * moment after.
158 */
159 static gboolean
160 lyrics_delayed_fail(gpointer data)
161 {
162 struct lyrics_loader *loader = data;
164 assert(loader != NULL);
165 assert(loader->fd < 0);
166 assert(loader->pid < 0);
167 assert(loader->data == NULL);
169 loader->callback(NULL, loader->callback_data);
171 return FALSE;
172 }
174 static int
175 lyrics_start_plugin(struct lyrics_loader *loader, const char *plugin_path)
176 {
177 int ret, fds[2];
178 pid_t pid;
180 assert(loader != NULL);
181 assert(loader->pid < 0);
182 assert(loader->fd < 0);
183 assert(loader->data == NULL);
185 ret = pipe(fds);
186 if (ret < 0)
187 return -1;
189 pid = fork();
191 if (pid < 0) {
192 close(fds[0]);
193 close(fds[1]);
194 return -1;
195 }
197 if (pid == 0) {
198 dup2(fds[1], 1);
199 dup2(fds[1], 1);
200 close(fds[0]);
201 close(fds[1]);
202 close(0);
203 /* XXX close other fds? */
205 execl(plugin_path, plugin_path,
206 loader->artist, loader->title, NULL);
207 _exit(1);
208 }
210 close(fds[1]);
212 loader->pid = pid;
213 loader->fd = fds[0];
214 loader->data = g_string_new(NULL);
216 /* XXX CLOEXEC? */
218 loader->channel = g_io_channel_unix_new(loader->fd);
219 loader->event_id = g_io_add_watch(loader->channel, G_IO_IN|G_IO_HUP,
220 lyrics_data, loader);
222 return 0;
223 }
225 static void
226 lyrics_next_plugin(struct lyrics_loader *loader)
227 {
228 const char *plugin_path;
229 int ret = -1;
231 assert(loader->pid < 0);
232 assert(loader->fd < 0);
233 assert(loader->data == NULL);
235 if (loader->next_plugin >= plugins->len) {
236 /* no plugins left */
237 g_timeout_add(0, lyrics_delayed_fail, loader);
238 return;
239 }
241 plugin_path = g_ptr_array_index(plugins, loader->next_plugin++);
242 ret = lyrics_start_plugin(loader, plugin_path);
243 if (ret < 0) {
244 /* system error */
245 g_timeout_add(0, lyrics_delayed_fail, loader);
246 return;
247 }
248 }
250 struct lyrics_loader *
251 lyrics_load(const char *artist, const char *title,
252 lyrics_callback_t callback, void *data)
253 {
254 struct lyrics_loader *loader = g_new(struct lyrics_loader, 1);
256 assert(artist != NULL);
257 assert(title != NULL);
259 if (loader == NULL)
260 return NULL;
262 loader->artist = g_strdup(artist);
263 loader->title = g_strdup(title);
264 loader->callback = callback;
265 loader->data = data;
266 loader->next_plugin = 0;
267 loader->pid = -1;
268 loader->fd = -1;
269 loader->data = NULL;
271 lyrics_next_plugin(loader);
273 return loader;
274 }
276 void
277 lyrics_free(struct lyrics_loader *loader)
278 {
279 if (loader->fd >= 0) {
280 g_source_remove(loader->event_id);
281 g_io_channel_unref(loader->channel);
282 close(loader->fd);
283 }
285 if (loader->pid > 0) {
286 int status;
288 kill(loader->pid, SIGTERM);
289 waitpid(loader->pid, &status, 0);
290 }
292 if (loader->data != NULL)
293 g_string_free(loader->data, TRUE);
294 }