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 }