Merge ../paraslash.fml/paraslash
[paraslash.git] / playlist_selector.c
1 /*
2 * Copyright (C) 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 playlist_selector.c The playlist audio file selector of paraslash */
20
21 #include "server.h"
22 #include "db.h"
23 #include "error.h"
24 #include "net.h"
25 #include "string.h"
26 #include "ipc.h"
27
28 /**
29 * structure used for transmission of the playlist
30 *
31 * There's one such struct which gets initialized during startup. It lives in
32 * shared memory and is used by com_lpl().
33 */
34 struct pls_client_data {
35 /** allocated and set by com_lpl() (child) */
36 int shm_id;
37 /** the size of the shared memory area identified by \a shm_id */
38 size_t size;
39 /** initially locked, gets unlocked by parent when it is done */
40 int mutex;
41 /** return value, set by parent */
42 int retval;
43 };
44
45 /** data specific to the playlist selector */
46 struct private_pls_data {
47 /** guards against concurrent client access */
48 int client_mutex;
49 /** guards against concurrent parent-child access */
50 int server_mutex;
51 /** pointer to the client data */
52 struct pls_client_data *client_data;
53 /** id of the shm corresponding to \a client_data */
54 int client_data_shm_id;
55 };
56
57 /** we refuse to load playlists bigger than that */
58 #define MAX_PLAYLIST_BYTES (1024 * 1024)
59
60 static unsigned playlist_len, playlist_size, current_playlist_entry;
61 static char **playlist;
62 static struct audio_file_selector *self;
63
64 static int com_ppl(int, int, char **);
65 static int com_lpl(int, int, char **);
66 extern struct misc_meta_data *mmd;
67
68 /* array of supported commands */
69 static struct server_command cmds[] = {
70 {
71 .name = "ppl",
72 .handler = com_ppl,
73 .perms = DB_READ,
74 .description = "print playlist",
75 .synopsis = "ppl",
76 .help =
77 "Print out the current playlist"
78 }, {
79 .name = "lpl",
80 .handler = com_lpl,
81 .perms = DB_WRITE,
82 .description = "load playlist",
83 .synopsis = "lpl",
84 .help =
85 "Read a new playlist from stdin. Example:\n"
86 "\tfind /audio -name '*.mp3' | para_client lpl"
87 }, {
88 .name = NULL,
89 }
90 };
91
92 static void playlist_add(char *path)
93 {
94 if (playlist_len >= playlist_size) {
95 playlist_size = 2 * playlist_size + 1;
96 playlist = para_realloc(playlist, playlist_size * sizeof(char *));
97 }
98 PARA_DEBUG_LOG("adding #%d/%d: %s\n", playlist_len, playlist_size, path);
99 playlist[playlist_len++] = para_strdup(path);
100 }
101
102 static int send_playlist_to_server(const char *buf, size_t size)
103 {
104 struct private_pls_data *ppd = self->private_data;
105 int ret, shm_mutex = -1, shm_id = -1;
106 void *shm = NULL;
107
108 PARA_DEBUG_LOG("new playlist (%zd bytes)\n", size);
109
110 ret = mutex_new();
111 if (ret < 0)
112 return ret;
113 shm_mutex = ret;
114
115 ret = shm_new(size);
116 if (ret < 0)
117 goto out;
118 shm_id = ret;
119
120 ret = shm_attach(shm_id, ATTACH_RW, &shm);
121 if (ret < 0)
122 goto out;
123 mutex_lock(shm_mutex);
124 memcpy(shm, buf, size);
125 mutex_lock(ppd->client_mutex);
126 mutex_lock(ppd->server_mutex);
127 ppd->client_data->size = size;
128 ppd->client_data->shm_id = shm_id;
129 ppd->client_data->mutex = shm_mutex;
130 kill(getppid(), SIGUSR1); /* wake up the server */
131 mutex_unlock(ppd->server_mutex);
132 mutex_lock(shm_mutex); /* wait until server is done */
133 mutex_unlock(shm_mutex);
134 ret = ppd->client_data->retval;
135 mutex_unlock(ppd->client_mutex);
136 shm_detach(shm);
137 out:
138 if (shm_id >= 0)
139 shm_destroy(shm_id);
140 mutex_destroy(shm_mutex);
141 PARA_DEBUG_LOG("returning %d\n", ret);
142 return ret;
143 }
144
145 static int com_lpl(int fd, __a_unused int argc, __a_unused char *argv[])
146 {
147 unsigned loaded = 0;
148 size_t bufsize = 4096; /* guess that's enough */
149 char *buf = para_malloc(bufsize);
150 ssize_t ret;
151 ret = send_buffer(fd, AWAITING_DATA_MSG);
152 if (ret < 0)
153 goto out;
154 again:
155 ret = recv_bin_buffer(fd, buf + loaded, bufsize - loaded);
156 if (ret < 0)
157 goto out;
158 if (!ret) {
159 ret = send_playlist_to_server(buf, loaded);
160 goto out;
161 }
162 loaded += ret;
163 ret = -E_LOAD_PLAYLIST;
164 if (loaded >= MAX_PLAYLIST_BYTES)
165 goto out;
166 if (loaded >= bufsize) {
167 bufsize *= 2;
168 buf = para_realloc(buf, bufsize);
169 }
170 goto again;
171 out:
172 free(buf);
173 return ret;
174 }
175
176 static int com_ppl(int fd, __a_unused int argc, __a_unused char *argv[])
177 {
178 unsigned i;
179
180 PARA_DEBUG_LOG("sending playlist to client (%d entries)\n", playlist_len);
181 for (i = 0; i < playlist_len; i++) {
182 int ret = send_va_buffer(fd, "%s\n", playlist[
183 (i + current_playlist_entry) % playlist_len]);
184 if (ret < 0)
185 return ret;
186 }
187 return 1;
188 }
189
190 static char **pls_get_audio_file_list(unsigned int num)
191 {
192 char **file_list;
193 unsigned i;
194
195 num = PARA_MIN(num, playlist_len);
196 if (!num)
197 return NULL;
198 file_list = para_malloc((num + 1) * sizeof(char *));
199 for (i = 0; i < num; i++) {
200 unsigned j = (current_playlist_entry + i + 1) % playlist_len;
201 file_list[i] = para_strdup(playlist[j]);
202 }
203 file_list[i] = NULL;
204 return file_list;
205 }
206
207 static void free_playlist_contents(void)
208 {
209 int i;
210
211 PARA_DEBUG_LOG("freeing playlist (%d entries)\n", playlist_len);
212 for (i = 0; i < playlist_len; i++)
213 free(playlist[i]);
214 current_playlist_entry = 0;
215 playlist_len = 0;
216 }
217
218 static void pls_shutdown(void)
219 {
220 struct private_pls_data *ppd = self->private_data;
221
222 shm_detach(ppd->client_data);
223 shm_destroy(ppd->client_data_shm_id);
224 mutex_destroy(ppd->server_mutex);
225 mutex_destroy(ppd->client_mutex);
226 free(ppd);
227 free_playlist_contents();
228 free(playlist);
229 playlist = NULL;
230 playlist_len = 0;
231 playlist_size = 0;
232 }
233
234 static void pls_post_select(__a_unused fd_set *rfds, __a_unused fd_set *wfds)
235 {
236 struct private_pls_data *ppd = self->private_data;
237 struct pls_client_data *pcd = ppd->client_data;
238 int ret;
239 void *shm;
240
241 mutex_lock(ppd->server_mutex);
242 if (!pcd->size)
243 goto out;
244 free_playlist_contents();
245 ret = shm_attach(pcd->shm_id, ATTACH_RW, &shm);
246 if (ret < 0) {
247 PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
248 goto out;
249 }
250 PARA_DEBUG_LOG("loading new playlist (%zd bytes)\n", pcd->size);
251 ret = for_each_line((char *)shm, pcd->size, &playlist_add);
252 shm_detach(shm);
253 PARA_NOTICE_LOG("new playlist (%d entries)\n", playlist_len);
254 sprintf(mmd->selector_info, "dbinfo1:new playlist: %d files\n"
255 "dbinfo2:\ndbinfo3:\n", playlist_len);
256 pcd->retval = 1;
257 pcd->size = 0;
258 mutex_unlock(pcd->mutex);
259 out:
260 mutex_unlock(ppd->server_mutex);
261 }
262
263 static size_t string_offset(const char *str, size_t max)
264 {
265 size_t l = strlen(str);
266
267 if (l <= max)
268 return 0;
269 return l - max;
270 }
271
272 void pls_update_audio_file(char *audio_file)
273 {
274 unsigned i;
275 char *dir = para_dirname(audio_file),
276 *prev = playlist[current_playlist_entry % playlist_len];
277 size_t dir_off = string_offset(dir, 50),
278 prev_off = string_offset(prev, 70);
279
280 for (i = 1; i <= playlist_len; i++) {
281 char *next;
282 size_t next_off;
283 unsigned j = (current_playlist_entry + i) % playlist_len;
284 if (strcmp(playlist[j], audio_file))
285 continue;
286 current_playlist_entry = j;
287 next = playlist[(j + 1) %playlist_len];
288 next_off = string_offset(next, 70);
289 snprintf(mmd->selector_info, MMD_INFO_SIZE,
290 "dbinfo1: %d files, current dir: %s%s\n"
291 "dbinfo2: prev: %s%s\n"
292 "dbinfo3: next: %s%s\n",
293 playlist_len,
294 dir_off? "... " : "", dir + dir_off,
295 prev_off? "... " : "", prev + prev_off,
296 next_off? "... " : "", next + next_off
297 );
298 break;
299 }
300 free(dir);
301 }
302
303 /**
304 * the init function for the playlist selector
305 *
306 * Init all function pointers of \a db
307 *
308 * \sa struct audio_file_selector, misc_meta_data::selector_info, mysql.c
309 * random_selector.c.
310 */
311 int playlist_selector_init(struct audio_file_selector *db)
312 {
313 int ret;
314 struct private_pls_data *ppd = NULL;
315 void *shm = NULL;
316
317 self = db;
318 db->cmd_list = cmds;
319 db->get_audio_file_list = pls_get_audio_file_list;
320 db->shutdown = pls_shutdown;
321 db->post_select = pls_post_select;
322 db->update_audio_file = pls_update_audio_file;
323 ppd = para_calloc(sizeof(struct private_pls_data));
324 db->private_data = ppd;
325
326 ppd->client_mutex = -1;
327 ppd->server_mutex = -1;
328 ppd->client_data_shm_id = -1;
329 ppd->client_data = NULL;
330
331 ret = mutex_new();
332 if (ret < 0)
333 goto err_out;
334 ppd->client_mutex = ret;
335
336 ret = mutex_new();
337 if (ret < 0)
338 goto err_out;
339 ppd->server_mutex = ret;
340
341 ret = shm_new(sizeof(struct pls_client_data));
342 if (ret < 0)
343 goto err_out;
344 ppd->client_data_shm_id = ret;
345
346 ret = shm_attach(ppd->client_data_shm_id, ATTACH_RW, &shm);
347 if (ret < 0)
348 goto err_out;
349 ppd->client_data = shm;
350 ppd->client_data->size = 0;
351 sprintf(mmd->selector_info, "dbinfo1: Welcome to the playlist "
352 "selector\ndbinfo2: no playlist loaded\ndbinfo3:\n");
353 return 1;
354 err_out:
355 if (ppd->client_data_shm_id >= 0)
356 shm_destroy(ppd->client_data_shm_id);
357 if (ppd->client_mutex >= 0)
358 mutex_destroy(ppd->client_mutex);
359 if (ppd->server_mutex >= 0)
360 mutex_destroy(ppd->server_mutex);
361 free(ppd);
362 return ret;
363 }