fd: Improve error handling of write_nonblock().
[paraslash.git] / afh_common.c
1 /*
2 * Copyright (C) 1997-2012 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file afh_common.c Common audio format handler functions. */
8
9 #include <sys/mman.h> /* mmap */
10 #include <sys/time.h> /* gettimeofday */
11 #include <sys/types.h>
12 #include <regex.h>
13
14 #include "para.h"
15 #include "error.h"
16 #include "string.h"
17 #include "afh.h"
18
19 /* The mp3 audio format handler does not need any libs. */
20 void mp3_init(struct audio_format_handler *);
21
22 #ifdef HAVE_OGGVORBIS
23 void ogg_init(struct audio_format_handler *);
24 #endif
25 #ifdef HAVE_FAAD
26 void aac_afh_init(struct audio_format_handler *);
27 #endif
28 #ifdef HAVE_SPEEX
29 void spx_afh_init(struct audio_format_handler *);
30 #endif
31 #ifdef HAVE_FLAC
32 void flac_afh_init(struct audio_format_handler *);
33 #endif
34
35 void wma_afh_init(struct audio_format_handler *);
36 /**
37 * The list of supported audio formats.
38 *
39 * We always define the full array of audio formats even if some audio formats
40 * were not compiled in. This is because for each audio file the number of its
41 * audio format is stored in the database. We don't want that numbers to become
42 * stale just because the user installed a new version of paraslash that
43 * supports a different set of audio formats.
44 *
45 * It can still be easily detected whether an audio format is compiled in by
46 * checking if the init function pointer is not \p NULL.
47 */
48 static struct audio_format_handler afl[] = {
49 {
50 .name = "mp3",
51 .init = mp3_init,
52 },
53 {
54 .name = "ogg",
55 #ifdef HAVE_OGGVORBIS
56 .init = ogg_init,
57 #endif
58 },
59 {
60 .name = "aac",
61 #ifdef HAVE_FAAD
62 .init = aac_afh_init,
63 #endif
64 },
65 {
66 .name = "wma",
67 .init = wma_afh_init,
68 },
69 {
70 .name = "spx",
71 #ifdef HAVE_SPEEX
72 .init = spx_afh_init,
73 #endif
74 },
75 {
76 .name = "flac",
77 #ifdef HAVE_FLAC
78 .init = flac_afh_init,
79 #endif
80 },
81 {
82 .name = NULL,
83 }
84 };
85
86 static inline int next_audio_format(int format)
87 {
88 for (;;) {
89 if (!afl[format].name)
90 return format;
91 format++;
92 if (afl[format].init)
93 return format;
94 }
95
96 }
97
98 /** Iterate over each supported audio format. */
99 #define FOR_EACH_AUDIO_FORMAT(i) for (i = 0; afl[i].name; i = next_audio_format(i))
100
101 /**
102 * Call the init function of each supported audio format handler.
103 */
104 void afh_init(void)
105 {
106 int i;
107
108 PARA_INFO_LOG("supported audio formats: %s\n",
109 SERVER_AUDIO_FORMATS);
110 FOR_EACH_AUDIO_FORMAT(i) {
111 PARA_NOTICE_LOG("initializing %s handler\n",
112 audio_format_name(i));
113 afl[i].init(&afl[i]);
114 }
115 }
116
117 /**
118 * Guess the audio format judging from filename.
119 *
120 * \param name The filename.
121 *
122 * \return This function returns \p -E_AUDIO_FORMAT if it has no idea what kind
123 * of audio file this might be. Otherwise the (non-negative) number of the
124 * audio format is returned.
125 */
126 int guess_audio_format(const char *name)
127 {
128 int i,j, len = strlen(name);
129
130 FOR_EACH_AUDIO_FORMAT(i) {
131 for (j = 0; afl[i].suffixes[j]; j++) {
132 const char *p = afl[i].suffixes[j];
133 int plen = strlen(p);
134 if (len < plen + 1)
135 continue;
136 if (name[len - plen - 1] != '.')
137 continue;
138 if (strcasecmp(name + len - plen, p))
139 continue;
140 // PARA_DEBUG_LOG("might be %s\n", audio_format_name(i));
141 return i;
142 }
143 }
144 return -E_AUDIO_FORMAT;
145 }
146
147 /**
148 * Call get_file_info() to obtain an afhi structure.
149 *
150 * \param path The full path of the audio file.
151 * \param data Pointer to the contents of the (mapped) file.
152 * \param size The file size in bytes.
153 * \param fd The open file descriptor.
154 * \param afhi Result pointer.
155 *
156 * \return The number of the audio format on success, \p -E_AUDIO_FORMAT if no
157 * compiled in audio format handler is able to handler the file.
158 *
159 * This function tries to find an audio format handler that can interpret the
160 * file given by \a data and \a size.
161 *
162 * It first tries to determine the audio format from the filename given by \a
163 * path. If this doesn't work, all other audio format handlers are tried until
164 * one is found that can handle the file.
165 */
166 int compute_afhi(const char *path, char *data, size_t size, int fd,
167 struct afh_info *afhi)
168 {
169 int ret, i, format;
170
171 afhi->header_len = 0;
172 afhi->techinfo = NULL;
173 afhi->tags.artist = NULL;
174 afhi->tags.title = NULL;
175 afhi->tags.year = NULL;
176 afhi->tags.album = NULL;
177 afhi->tags.comment = NULL;
178 format = guess_audio_format(path);
179
180 if (format >= 0) {
181 ret = afl[format].get_file_info(data, size, fd, afhi);
182 if (ret >= 0) {
183 ret = format;
184 goto success;
185 }
186 }
187 FOR_EACH_AUDIO_FORMAT(i) {
188 if (i == format) /* we already tried this one to no avail */
189 continue;
190 ret = afl[i].get_file_info(data, size, fd, afhi);
191 if (ret >= 0) {
192 ret = i;
193 goto success;
194 }
195 PARA_WARNING_LOG("%s\n", para_strerror(-ret));
196 }
197 return -E_AUDIO_FORMAT;
198 success:
199 if (!afhi->techinfo)
200 afhi->techinfo = para_strdup(NULL);
201 if (!afhi->tags.artist)
202 afhi->tags.artist = para_strdup(NULL);
203 if (!afhi->tags.title)
204 afhi->tags.title = para_strdup(NULL);
205 if (!afhi->tags.year)
206 afhi->tags.year = para_strdup(NULL);
207 if (!afhi->tags.album)
208 afhi->tags.album = para_strdup(NULL);
209 if (!afhi->tags.comment)
210 afhi->tags.comment = para_strdup(NULL);
211 PARA_DEBUG_LOG("techinfo: %s\n", afhi->techinfo);
212 PARA_DEBUG_LOG("artist: %s\n", afhi->tags.artist);
213 PARA_DEBUG_LOG("title: %s\n", afhi->tags.title);
214 PARA_DEBUG_LOG("year: %s\n", afhi->tags.year);
215 PARA_DEBUG_LOG("album: %s\n", afhi->tags.album);
216 PARA_DEBUG_LOG("comment: %s\n", afhi->tags.comment);
217 return ret;
218 }
219
220 /**
221 * Get the name of the given audio format.
222 *
223 * \param i The audio format number.
224 *
225 * \return This returns a pointer to statically allocated memory so it
226 * must not be freed by the caller.
227 */
228 const char *audio_format_name(int i)
229 {
230 if (i < 0 || i >= ARRAY_SIZE(afl) - 1)
231 return "???";
232 return afl[i].name;
233 }
234
235 /**
236 * Get one chunk of audio data.
237 *
238 * \param chunk_num The number of the chunk to get.
239 * \param afhi Describes the audio file.
240 * \param map The memory mapped audio file.
241 * \param buf Result pointer.
242 * \param len The length of the chunk in bytes.
243 *
244 * Upon return, \a buf will point so memory inside \a map. The returned buffer
245 * must therefore not be freed by the caller.
246 */
247 void afh_get_chunk(long unsigned chunk_num, struct afh_info *afhi,
248 void *map, const char **buf, size_t *len)
249 {
250 size_t pos = afhi->chunk_table[chunk_num];
251 *buf = map + pos;
252 *len = afhi->chunk_table[chunk_num + 1] - pos;
253 }
254
255 /**
256 * Get the header of an audio file.
257 *
258 * \param afhi The audio file handler data describing the file.
259 * \param audio_format_id Determines the audio format handler.
260 * \param map The data of the audio file.
261 * \param mapsize The amount of bytes of the mmapped audio file.
262 * \param buf The length of the header is stored here.
263 * \param len Points to a buffer containing the header on return.
264 *
265 * This function sets \a buf to \p NULL and \a len to zero if \a map or \a
266 * afhi is \p NULL, or if the current audio format does not need special
267 * header treatment.
268 *
269 * Otherwise, it is checked whether the audio format handler given by
270 * \a audio_format_id defines a ->get_header() method. If it does, this
271 * method is called to obtain the header. If ->get_header() is \p NULL,
272 * a reference to the first chunk of the audio file is returned.
273 *
274 * Once the header is no longer needed, the caller must call \ref
275 * afh_free_header() to free the resources allocated by this function.
276 */
277 void afh_get_header(struct afh_info *afhi, uint8_t audio_format_id,
278 void *map, size_t mapsize, char **buf, size_t *len)
279 {
280 struct audio_format_handler *afh = afl + audio_format_id;
281
282 if (!map || !afhi || !afhi->header_len) {
283 *buf = NULL;
284 *len = 0;
285 return;
286 }
287 if (!afh->get_header) {
288 *len = afhi->header_len;
289 *buf = map;
290 return;
291 }
292 afh->get_header(map, mapsize, buf, len);
293 }
294
295 /**
296 * Deallocate any resources obtained from afh_get_header().
297 *
298 * \param header_buf Pointer obtained via afh_get_header().
299 * \param audio_format_id Determines the audio format handler.
300 */
301 void afh_free_header(char *header_buf, uint8_t audio_format_id)
302 {
303 struct audio_format_handler *afh = afl + audio_format_id;
304
305 if (afh->get_header)
306 free(header_buf);
307 }