Add proper const declaration to a cast, fixes a warning
[libav.git] / libavformat / avio.c
1 /*
2 * Unbuffered io for ffmpeg system
3 * Copyright (c) 2001 Fabrice Bellard
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 /* needed for usleep() */
23 #define _XOPEN_SOURCE 600
24 #include <unistd.h>
25 #include "libavutil/avstring.h"
26 #include "libavcodec/opt.h"
27 #include "os_support.h"
28 #include "avformat.h"
29 #if CONFIG_NETWORK
30 #include "network.h"
31 #endif
32
33 #if LIBAVFORMAT_VERSION_MAJOR >= 53
34 /** @name Logging context. */
35 /*@{*/
36 static const char *urlcontext_to_name(void *ptr)
37 {
38 URLContext *h = (URLContext *)ptr;
39 if(h->prot) return h->prot->name;
40 else return "NULL";
41 }
42 static const AVOption options[] = {{NULL}};
43 static const AVClass urlcontext_class =
44 { "URLContext", urlcontext_to_name, options, LIBAVUTIL_VERSION_INT };
45 /*@}*/
46 #endif
47
48 static int default_interrupt_cb(void);
49
50 URLProtocol *first_protocol = NULL;
51 URLInterruptCB *url_interrupt_cb = default_interrupt_cb;
52
53 URLProtocol *av_protocol_next(URLProtocol *p)
54 {
55 if(p) return p->next;
56 else return first_protocol;
57 }
58
59 int av_register_protocol2(URLProtocol *protocol, int size)
60 {
61 URLProtocol **p;
62 if (size < sizeof(URLProtocol)) {
63 URLProtocol* temp = av_mallocz(sizeof(URLProtocol));
64 memcpy(temp, protocol, size);
65 protocol = temp;
66 }
67 p = &first_protocol;
68 while (*p != NULL) p = &(*p)->next;
69 *p = protocol;
70 protocol->next = NULL;
71 return 0;
72 }
73
74 #if LIBAVFORMAT_VERSION_MAJOR < 53
75 /* The layout of URLProtocol as of when major was bumped to 52 */
76 struct URLProtocol_compat {
77 const char *name;
78 int (*url_open)(URLContext *h, const char *filename, int flags);
79 int (*url_read)(URLContext *h, unsigned char *buf, int size);
80 int (*url_write)(URLContext *h, unsigned char *buf, int size);
81 int64_t (*url_seek)(URLContext *h, int64_t pos, int whence);
82 int (*url_close)(URLContext *h);
83 struct URLProtocol *next;
84 };
85
86 int av_register_protocol(URLProtocol *protocol)
87 {
88 return av_register_protocol2(protocol, sizeof(struct URLProtocol_compat));
89 }
90
91 int register_protocol(URLProtocol *protocol)
92 {
93 return av_register_protocol(protocol);
94 }
95 #endif
96
97 static int url_alloc_for_protocol (URLContext **puc, struct URLProtocol *up,
98 const char *filename, int flags)
99 {
100 URLContext *uc;
101 int err;
102
103 #if CONFIG_NETWORK
104 if (!ff_network_init())
105 return AVERROR(EIO);
106 #endif
107 uc = av_mallocz(sizeof(URLContext) + strlen(filename) + 1);
108 if (!uc) {
109 err = AVERROR(ENOMEM);
110 goto fail;
111 }
112 #if LIBAVFORMAT_VERSION_MAJOR >= 53
113 uc->av_class = &urlcontext_class;
114 #endif
115 uc->filename = (char *) &uc[1];
116 strcpy(uc->filename, filename);
117 uc->prot = up;
118 uc->flags = flags;
119 uc->is_streamed = 0; /* default = not streamed */
120 uc->max_packet_size = 0; /* default: stream file */
121 if (up->priv_data_size) {
122 uc->priv_data = av_mallocz(up->priv_data_size);
123 if (up->priv_data_class) {
124 *(const AVClass**)uc->priv_data = up->priv_data_class;
125 av_opt_set_defaults(uc->priv_data);
126 }
127 }
128
129 *puc = uc;
130 return 0;
131 fail:
132 *puc = NULL;
133 #if CONFIG_NETWORK
134 ff_network_close();
135 #endif
136 return err;
137 }
138
139 int url_connect(URLContext* uc)
140 {
141 int err = uc->prot->url_open(uc, uc->filename, uc->flags);
142 if (err)
143 return err;
144 uc->is_connected = 1;
145 //We must be careful here as url_seek() could be slow, for example for http
146 if( (uc->flags & (URL_WRONLY | URL_RDWR))
147 || !strcmp(uc->prot->name, "file"))
148 if(!uc->is_streamed && url_seek(uc, 0, SEEK_SET) < 0)
149 uc->is_streamed= 1;
150 return 0;
151 }
152
153 int url_open_protocol (URLContext **puc, struct URLProtocol *up,
154 const char *filename, int flags)
155 {
156 int ret;
157
158 ret = url_alloc_for_protocol(puc, up, filename, flags);
159 if (ret)
160 goto fail;
161 ret = url_connect(*puc);
162 if (!ret)
163 return 0;
164 fail:
165 url_close(*puc);
166 *puc = NULL;
167 return ret;
168 }
169
170 int url_alloc(URLContext **puc, const char *filename, int flags)
171 {
172 URLProtocol *up;
173 const char *p;
174 char proto_str[128], *q;
175
176 p = filename;
177 q = proto_str;
178 while (*p != '\0' && *p != ':') {
179 /* protocols can only contain alphabetic chars */
180 if (!isalpha(*p))
181 goto file_proto;
182 if ((q - proto_str) < sizeof(proto_str) - 1)
183 *q++ = *p;
184 p++;
185 }
186 /* if the protocol has length 1, we consider it is a dos drive */
187 if (*p == '\0' || is_dos_path(filename)) {
188 file_proto:
189 strcpy(proto_str, "file");
190 } else {
191 *q = '\0';
192 }
193
194 up = first_protocol;
195 while (up != NULL) {
196 if (!strcmp(proto_str, up->name))
197 return url_alloc_for_protocol (puc, up, filename, flags);
198 up = up->next;
199 }
200 *puc = NULL;
201 return AVERROR(ENOENT);
202 }
203
204 int url_open(URLContext **puc, const char *filename, int flags)
205 {
206 int ret = url_alloc(puc, filename, flags);
207 if (ret)
208 return ret;
209 ret = url_connect(*puc);
210 if (!ret)
211 return 0;
212 fail:
213 url_close(*puc);
214 *puc = NULL;
215 return ret;
216 }
217
218 int url_read(URLContext *h, unsigned char *buf, int size)
219 {
220 int ret;
221 if (h->flags & URL_WRONLY)
222 return AVERROR(EIO);
223 ret = h->prot->url_read(h, buf, size);
224 return ret;
225 }
226
227 int url_read_complete(URLContext *h, unsigned char *buf, int size)
228 {
229 int ret, len;
230 int fast_retries = 5;
231
232 len = 0;
233 while (len < size) {
234 ret = url_read(h, buf+len, size-len);
235 if (ret == AVERROR(EAGAIN)) {
236 ret = 0;
237 if (fast_retries)
238 fast_retries--;
239 else
240 usleep(1000);
241 } else if (ret < 1)
242 return ret < 0 ? ret : len;
243 if (ret)
244 fast_retries = FFMAX(fast_retries, 2);
245 len += ret;
246 }
247 return len;
248 }
249
250 int url_write(URLContext *h, const unsigned char *buf, int size)
251 {
252 int ret;
253 if (!(h->flags & (URL_WRONLY | URL_RDWR)))
254 return AVERROR(EIO);
255 /* avoid sending too big packets */
256 if (h->max_packet_size && size > h->max_packet_size)
257 return AVERROR(EIO);
258 ret = h->prot->url_write(h, buf, size);
259 return ret;
260 }
261
262 int64_t url_seek(URLContext *h, int64_t pos, int whence)
263 {
264 int64_t ret;
265
266 if (!h->prot->url_seek)
267 return AVERROR(ENOSYS);
268 ret = h->prot->url_seek(h, pos, whence & ~AVSEEK_FORCE);
269 return ret;
270 }
271
272 int url_close(URLContext *h)
273 {
274 int ret = 0;
275 if (!h) return 0; /* can happen when url_open fails */
276
277 if (h->is_connected && h->prot->url_close)
278 ret = h->prot->url_close(h);
279 #if CONFIG_NETWORK
280 ff_network_close();
281 #endif
282 if (h->prot->priv_data_size)
283 av_free(h->priv_data);
284 av_free(h);
285 return ret;
286 }
287
288 int url_exist(const char *filename)
289 {
290 URLContext *h;
291 if (url_open(&h, filename, URL_RDONLY) < 0)
292 return 0;
293 url_close(h);
294 return 1;
295 }
296
297 int64_t url_filesize(URLContext *h)
298 {
299 int64_t pos, size;
300
301 size= url_seek(h, 0, AVSEEK_SIZE);
302 if(size<0){
303 pos = url_seek(h, 0, SEEK_CUR);
304 if ((size = url_seek(h, -1, SEEK_END)) < 0)
305 return size;
306 size++;
307 url_seek(h, pos, SEEK_SET);
308 }
309 return size;
310 }
311
312 int url_get_file_handle(URLContext *h)
313 {
314 if (!h->prot->url_get_file_handle)
315 return -1;
316 return h->prot->url_get_file_handle(h);
317 }
318
319 int url_get_max_packet_size(URLContext *h)
320 {
321 return h->max_packet_size;
322 }
323
324 void url_get_filename(URLContext *h, char *buf, int buf_size)
325 {
326 av_strlcpy(buf, h->filename, buf_size);
327 }
328
329
330 static int default_interrupt_cb(void)
331 {
332 return 0;
333 }
334
335 void url_set_interrupt_cb(URLInterruptCB *interrupt_cb)
336 {
337 if (!interrupt_cb)
338 interrupt_cb = default_interrupt_cb;
339 url_interrupt_cb = interrupt_cb;
340 }
341
342 int av_url_read_pause(URLContext *h, int pause)
343 {
344 if (!h->prot->url_read_pause)
345 return AVERROR(ENOSYS);
346 return h->prot->url_read_pause(h, pause);
347 }
348
349 int64_t av_url_read_seek(URLContext *h,
350 int stream_index, int64_t timestamp, int flags)
351 {
352 if (!h->prot->url_read_seek)
353 return AVERROR(ENOSYS);
354 return h->prot->url_read_seek(h, stream_index, timestamp, flags);
355 }