libavformat/avio.c

   1 /*
   2  * unbuffered I/O
   3  * Copyright (c) 2001 Fabrice Bellard
   4  *
   5  * This file is part of Libav.
   6  *
   7  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include <unistd.h>
  23
  24 #include "libavutil/avstring.h"
  25 #include "libavutil/opt.h"
  26 #include "os_support.h"
  27 #include "avformat.h"
  28 #if CONFIG_NETWORK
  29 #include "network.h"
  30 #endif
  31 #include "url.h"
  32
  33 /** @name Logging context. */
  34 /*@{*/
  35 static const char *urlcontext_to_name(void *ptr)
  36 {
  37     URLContext *h = (URLContext *)ptr;
  38     if(h->prot) return h->prot->name;
  39     else        return "NULL";
  40 }
  41 static const AVOption options[] = {{NULL}};
  42 static const AVClass urlcontext_class = {
  43     .class_name     = "URLContext",
  44     .item_name      = urlcontext_to_name,
  45     .option         = options,
  46     .version        = LIBAVUTIL_VERSION_INT,
  47 };
  48 /*@}*/
  49
  50 static int default_interrupt_cb(void);
  51
  52 URLProtocol *first_protocol = NULL;
  53 int (*url_interrupt_cb)(void) = default_interrupt_cb;
  54
  55 #if FF_API_OLD_AVIO
  56 URLProtocol *av_protocol_next(URLProtocol *p)
  57 {
  58     if(p) return p->next;
  59     else  return first_protocol;
  60 }
  61 #endif
  62
  63 const char *avio_enum_protocols(void **opaque, int output)
  64 {
  65     URLProtocol **p = opaque;
  66     *p = *p ? (*p)->next : first_protocol;
  67     if (!*p) return NULL;
  68     if ((output && (*p)->url_write) || (!output && (*p)->url_read))
  69         return (*p)->name;
  70     return avio_enum_protocols(opaque, output);
  71 }
  72
  73 int ffurl_register_protocol(URLProtocol *protocol, int size)
  74 {
  75     URLProtocol **p;
  76     if (size < sizeof(URLProtocol)) {
  77         URLProtocol* temp = av_mallocz(sizeof(URLProtocol));
  78         memcpy(temp, protocol, size);
  79         protocol = temp;
  80     }
  81     p = &first_protocol;
  82     while (*p != NULL) p = &(*p)->next;
  83     *p = protocol;
  84     protocol->next = NULL;
  85     return 0;
  86 }
  87
  88 static int url_alloc_for_protocol (URLContext **puc, struct URLProtocol *up,
  89                                    const char *filename, int flags)
  90 {
  91     URLContext *uc;
  92     int err;
  93
  94 #if CONFIG_NETWORK
  95     if (!ff_network_init())
  96         return AVERROR(EIO);
  97 #endif
  98     uc = av_mallocz(sizeof(URLContext) + strlen(filename) + 1);
  99     if (!uc) {
 100         err = AVERROR(ENOMEM);
 101         goto fail;
 102     }
 103     uc->av_class = &urlcontext_class;
 104     uc->filename = (char *) &uc[1];
 105     strcpy(uc->filename, filename);
 106     uc->prot = up;
 107     uc->flags = flags;
 108     uc->is_streamed = 0; /* default = not streamed */
 109     uc->max_packet_size = 0; /* default: stream file */
 110     if (up->priv_data_size) {
 111         uc->priv_data = av_mallocz(up->priv_data_size);
 112         if (up->priv_data_class) {
 113             *(const AVClass**)uc->priv_data = up->priv_data_class;
 114             av_opt_set_defaults(uc->priv_data);
 115         }
 116     }
 117
 118     *puc = uc;
 119     return 0;
 120  fail:
 121     *puc = NULL;
 122 #if CONFIG_NETWORK
 123     ff_network_close();
 124 #endif
 125     return err;
 126 }
 127
 128 int ffurl_connect(URLContext* uc)
 129 {
 130     int err = uc->prot->url_open(uc, uc->filename, uc->flags);
 131     if (err)
 132         return err;
 133     uc->is_connected = 1;
 134     //We must be careful here as ffurl_seek() could be slow, for example for http
 135     if(   (uc->flags & AVIO_FLAG_WRITE)
 136        || !strcmp(uc->prot->name, "file"))
 137         if(!uc->is_streamed && ffurl_seek(uc, 0, SEEK_SET) < 0)
 138             uc->is_streamed= 1;
 139     return 0;
 140 }
 141
 142 #if FF_API_OLD_AVIO
 143 int url_open_protocol (URLContext **puc, struct URLProtocol *up,
 144                        const char *filename, int flags)
 145 {
 146     int ret;
 147
 148     ret = url_alloc_for_protocol(puc, up, filename, flags);
 149     if (ret)
 150         goto fail;
 151     ret = ffurl_connect(*puc);
 152     if (!ret)
 153         return 0;
 154  fail:
 155     ffurl_close(*puc);
 156     *puc = NULL;
 157     return ret;
 158 }
 159 int url_alloc(URLContext **puc, const char *filename, int flags)
 160 {
 161     return ffurl_alloc(puc, filename, flags);
 162 }
 163 int url_connect(URLContext* uc)
 164 {
 165     return ffurl_connect(uc);
 166 }
 167 int url_open(URLContext **puc, const char *filename, int flags)
 168 {
 169     return ffurl_open(puc, filename, flags);
 170 }
 171 int url_read(URLContext *h, unsigned char *buf, int size)
 172 {
 173     return ffurl_read(h, buf, size);
 174 }
 175 int url_read_complete(URLContext *h, unsigned char *buf, int size)
 176 {
 177     return ffurl_read_complete(h, buf, size);
 178 }
 179 int url_write(URLContext *h, const unsigned char *buf, int size)
 180 {
 181     return ffurl_write(h, buf, size);
 182 }
 183 int64_t url_seek(URLContext *h, int64_t pos, int whence)
 184 {
 185     return ffurl_seek(h, pos, whence);
 186 }
 187 int url_close(URLContext *h)
 188 {
 189     return ffurl_close(h);
 190 }
 191 int64_t url_filesize(URLContext *h)
 192 {
 193     return ffurl_size(h);
 194 }
 195 int url_get_file_handle(URLContext *h)
 196 {
 197     return ffurl_get_file_handle(h);
 198 }
 199 int url_get_max_packet_size(URLContext *h)
 200 {
 201     return h->max_packet_size;
 202 }
 203 void url_get_filename(URLContext *h, char *buf, int buf_size)
 204 {
 205     av_strlcpy(buf, h->filename, buf_size);
 206 }
 207 void url_set_interrupt_cb(URLInterruptCB *interrupt_cb)
 208 {
 209     avio_set_interrupt_cb(interrupt_cb);
 210 }
 211 int av_register_protocol2(URLProtocol *protocol, int size)
 212 {
 213     return ffurl_register_protocol(protocol, size);
 214 }
 215 #endif
 216
 217 #define URL_SCHEME_CHARS                        \
 218     "abcdefghijklmnopqrstuvwxyz"                \
 219     "ABCDEFGHIJKLMNOPQRSTUVWXYZ"                \
 220     "0123456789+-."
 221
 222 int ffurl_alloc(URLContext **puc, const char *filename, int flags)
 223 {
 224     URLProtocol *up;
 225     char proto_str[128], proto_nested[128], *ptr;
 226     size_t proto_len = strspn(filename, URL_SCHEME_CHARS);
 227
 228     if (filename[proto_len] != ':' || is_dos_path(filename))
 229         strcpy(proto_str, "file");
 230     else
 231         av_strlcpy(proto_str, filename, FFMIN(proto_len+1, sizeof(proto_str)));
 232
 233     av_strlcpy(proto_nested, proto_str, sizeof(proto_nested));
 234     if ((ptr = strchr(proto_nested, '+')))
 235         *ptr = '\0';
 236
 237     up = first_protocol;
 238     while (up != NULL) {
 239         if (!strcmp(proto_str, up->name))
 240             return url_alloc_for_protocol (puc, up, filename, flags);
 241         if (up->flags & URL_PROTOCOL_FLAG_NESTED_SCHEME &&
 242             !strcmp(proto_nested, up->name))
 243             return url_alloc_for_protocol (puc, up, filename, flags);
 244         up = up->next;
 245     }
 246     *puc = NULL;
 247     return AVERROR(ENOENT);
 248 }
 249
 250 int ffurl_open(URLContext **puc, const char *filename, int flags)
 251 {
 252     int ret = ffurl_alloc(puc, filename, flags);
 253     if (ret)
 254         return ret;
 255     ret = ffurl_connect(*puc);
 256     if (!ret)
 257         return 0;
 258     ffurl_close(*puc);
 259     *puc = NULL;
 260     return ret;
 261 }
 262
 263 static inline int retry_transfer_wrapper(URLContext *h, unsigned char *buf, int size, int size_min,
 264                                          int (*transfer_func)(URLContext *h, unsigned char *buf, int size))
 265 {
 266     int ret, len;
 267     int fast_retries = 5;
 268
 269     len = 0;
 270     while (len < size_min) {
 271         ret = transfer_func(h, buf+len, size-len);
 272         if (ret == AVERROR(EINTR))
 273             continue;
 274         if (h->flags & AVIO_FLAG_NONBLOCK)
 275             return ret;
 276         if (ret == AVERROR(EAGAIN)) {
 277             ret = 0;
 278             if (fast_retries)
 279                 fast_retries--;
 280             else
 281                 usleep(1000);
 282         } else if (ret < 1)
 283             return ret < 0 ? ret : len;
 284         if (ret)
 285            fast_retries = FFMAX(fast_retries, 2);
 286         len += ret;
 287         if (url_interrupt_cb())
 288             return AVERROR_EXIT;
 289     }
 290     return len;
 291 }
 292
 293 int ffurl_read(URLContext *h, unsigned char *buf, int size)
 294 {
 295     if (!(h->flags & AVIO_FLAG_READ))
 296         return AVERROR(EIO);
 297     return retry_transfer_wrapper(h, buf, size, 1, h->prot->url_read);
 298 }
 299
 300 int ffurl_read_complete(URLContext *h, unsigned char *buf, int size)
 301 {
 302     if (!(h->flags & AVIO_FLAG_READ))
 303         return AVERROR(EIO);
 304     return retry_transfer_wrapper(h, buf, size, size, h->prot->url_read);
 305 }
 306
 307 int ffurl_write(URLContext *h, const unsigned char *buf, int size)
 308 {
 309     if (!(h->flags & AVIO_FLAG_WRITE))
 310         return AVERROR(EIO);
 311     /* avoid sending too big packets */
 312     if (h->max_packet_size && size > h->max_packet_size)
 313         return AVERROR(EIO);
 314
 315     return retry_transfer_wrapper(h, buf, size, size, h->prot->url_write);
 316 }
 317
 318 int64_t ffurl_seek(URLContext *h, int64_t pos, int whence)
 319 {
 320     int64_t ret;
 321
 322     if (!h->prot->url_seek)
 323         return AVERROR(ENOSYS);
 324     ret = h->prot->url_seek(h, pos, whence & ~AVSEEK_FORCE);
 325     return ret;
 326 }
 327
 328 int ffurl_close(URLContext *h)
 329 {
 330     int ret = 0;
 331     if (!h) return 0; /* can happen when ffurl_open fails */
 332
 333     if (h->is_connected && h->prot->url_close)
 334         ret = h->prot->url_close(h);
 335 #if CONFIG_NETWORK
 336     ff_network_close();
 337 #endif
 338     if (h->prot->priv_data_size) {
 339         if (h->prot->priv_data_class)
 340             av_opt_free(h->priv_data);
 341         av_free(h->priv_data);
 342     }
 343     av_free(h);
 344     return ret;
 345 }
 346
 347 #if FF_API_OLD_AVIO
 348 int url_exist(const char *filename)
 349 {
 350     URLContext *h;
 351     if (ffurl_open(&h, filename, AVIO_FLAG_READ) < 0)
 352         return 0;
 353     ffurl_close(h);
 354     return 1;
 355 }
 356 #endif
 357
 358 int avio_check(const char *url, int flags)
 359 {
 360     URLContext *h;
 361     int ret = ffurl_alloc(&h, url, flags);
 362     if (ret)
 363         return ret;
 364
 365     if (h->prot->url_check) {
 366         ret = h->prot->url_check(h, flags);
 367     } else {
 368         ret = ffurl_connect(h);
 369         if (ret >= 0)
 370             ret = flags;
 371     }
 372
 373     ffurl_close(h);
 374     return ret;
 375 }
 376
 377 int64_t ffurl_size(URLContext *h)
 378 {
 379     int64_t pos, size;
 380
 381     size= ffurl_seek(h, 0, AVSEEK_SIZE);
 382     if(size<0){
 383         pos = ffurl_seek(h, 0, SEEK_CUR);
 384         if ((size = ffurl_seek(h, -1, SEEK_END)) < 0)
 385             return size;
 386         size++;
 387         ffurl_seek(h, pos, SEEK_SET);
 388     }
 389     return size;
 390 }
 391
 392 int ffurl_get_file_handle(URLContext *h)
 393 {
 394     if (!h->prot->url_get_file_handle)
 395         return -1;
 396     return h->prot->url_get_file_handle(h);
 397 }
 398
 399 static int default_interrupt_cb(void)
 400 {
 401     return 0;
 402 }
 403
 404 void avio_set_interrupt_cb(int (*interrupt_cb)(void))
 405 {
 406     if (!interrupt_cb)
 407         interrupt_cb = default_interrupt_cb;
 408     url_interrupt_cb = interrupt_cb;
 409 }
 410
 411 int ff_check_interrupt(AVIOInterruptCB *cb)
 412 {
 413     int ret;
 414     if (cb && cb->callback && (ret = cb->callback(cb->opaque)))
 415         return ret;
 416     return url_interrupt_cb();
 417 }
 418
 419 #if FF_API_OLD_AVIO
 420 int av_url_read_pause(URLContext *h, int pause)
 421 {
 422     if (!h->prot->url_read_pause)
 423         return AVERROR(ENOSYS);
 424     return h->prot->url_read_pause(h, pause);
 425 }
 426
 427 int64_t av_url_read_seek(URLContext *h,
 428         int stream_index, int64_t timestamp, int flags)
 429 {
 430     if (!h->prot->url_read_seek)
 431         return AVERROR(ENOSYS);
 432     return h->prot->url_read_seek(h, stream_index, timestamp, flags);
 433 }
 434 #endif