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_protocol(URLProtocol *protocol)
  60 {
  61     URLProtocol **p;
  62     p = &first_protocol;
  63     while (*p != NULL) p = &(*p)->next;
  64     *p = protocol;
  65     protocol->next = NULL;
  66     return 0;
  67 }
  68
  69 #if LIBAVFORMAT_VERSION_MAJOR < 53
  70 int register_protocol(URLProtocol *protocol)
  71 {
  72     return av_register_protocol(protocol);
  73 }
  74 #endif
  75
  76 int url_open_protocol (URLContext **puc, struct URLProtocol *up,
  77                        const char *filename, int flags)
  78 {
  79     URLContext *uc;
  80     int err;
  81
  82 #if CONFIG_NETWORK
  83     if (!ff_network_init())
  84         return AVERROR(EIO);
  85 #endif
  86     uc = av_mallocz(sizeof(URLContext) + strlen(filename) + 1);
  87     if (!uc) {
  88         err = AVERROR(ENOMEM);
  89         goto fail;
  90     }
  91 #if LIBAVFORMAT_VERSION_MAJOR >= 53
  92     uc->av_class = &urlcontext_class;
  93 #endif
  94     uc->filename = (char *) &uc[1];
  95     strcpy(uc->filename, filename);
  96     uc->prot = up;
  97     uc->flags = flags;
  98     uc->is_streamed = 0; /* default = not streamed */
  99     uc->max_packet_size = 0; /* default: stream file */
 100     err = up->url_open(uc, filename, flags);
 101     if (err < 0) {
 102         av_free(uc);
 103         goto fail;
 104     }
 105
 106     //We must be careful here as url_seek() could be slow, for example for http
 107     if(   (flags & (URL_WRONLY | URL_RDWR))
 108        || !strcmp(up->name, "file"))
 109         if(!uc->is_streamed && url_seek(uc, 0, SEEK_SET) < 0)
 110             uc->is_streamed= 1;
 111     *puc = uc;
 112     return 0;
 113  fail:
 114     *puc = NULL;
 115 #if CONFIG_NETWORK
 116     ff_network_close();
 117 #endif
 118     return err;
 119 }
 120
 121 int url_open(URLContext **puc, const char *filename, int flags)
 122 {
 123     URLProtocol *up;
 124     const char *p;
 125     char proto_str[128], *q;
 126
 127     p = filename;
 128     q = proto_str;
 129     while (*p != '\0' && *p != ':') {
 130         /* protocols can only contain alphabetic chars */
 131         if (!isalpha(*p))
 132             goto file_proto;
 133         if ((q - proto_str) < sizeof(proto_str) - 1)
 134             *q++ = *p;
 135         p++;
 136     }
 137     /* if the protocol has length 1, we consider it is a dos drive */
 138     if (*p == '\0' || is_dos_path(filename)) {
 139     file_proto:
 140         strcpy(proto_str, "file");
 141     } else {
 142         *q = '\0';
 143     }
 144
 145     up = first_protocol;
 146     while (up != NULL) {
 147         if (!strcmp(proto_str, up->name))
 148             return url_open_protocol (puc, up, filename, flags);
 149         up = up->next;
 150     }
 151     *puc = NULL;
 152     return AVERROR(ENOENT);
 153 }
 154
 155 int url_read(URLContext *h, unsigned char *buf, int size)
 156 {
 157     int ret;
 158     if (h->flags & URL_WRONLY)
 159         return AVERROR(EIO);
 160     ret = h->prot->url_read(h, buf, size);
 161     return ret;
 162 }
 163
 164 int url_read_complete(URLContext *h, unsigned char *buf, int size)
 165 {
 166     int ret, len;
 167     int fast_retries = 5;
 168
 169     len = 0;
 170     while (len < size) {
 171         ret = url_read(h, buf+len, size-len);
 172         if (ret == AVERROR(EAGAIN)) {
 173             ret = 0;
 174             if (fast_retries)
 175                 fast_retries--;
 176             else
 177                 usleep(1000);
 178         } else if (ret < 1)
 179             return ret < 0 ? ret : len;
 180         if (ret)
 181            fast_retries = FFMAX(fast_retries, 2);
 182         len += ret;
 183     }
 184     return len;
 185 }
 186
 187 int url_write(URLContext *h, unsigned char *buf, int size)
 188 {
 189     int ret;
 190     if (!(h->flags & (URL_WRONLY | URL_RDWR)))
 191         return AVERROR(EIO);
 192     /* avoid sending too big packets */
 193     if (h->max_packet_size && size > h->max_packet_size)
 194         return AVERROR(EIO);
 195     ret = h->prot->url_write(h, buf, size);
 196     return ret;
 197 }
 198
 199 int64_t url_seek(URLContext *h, int64_t pos, int whence)
 200 {
 201     int64_t ret;
 202
 203     if (!h->prot->url_seek)
 204         return AVERROR(ENOSYS);
 205     ret = h->prot->url_seek(h, pos, whence & ~AVSEEK_FORCE);
 206     return ret;
 207 }
 208
 209 int url_close(URLContext *h)
 210 {
 211     int ret = 0;
 212     if (!h) return 0; /* can happen when url_open fails */
 213
 214     if (h->prot->url_close)
 215         ret = h->prot->url_close(h);
 216 #if CONFIG_NETWORK
 217     ff_network_close();
 218 #endif
 219     av_free(h);
 220     return ret;
 221 }
 222
 223 int url_exist(const char *filename)
 224 {
 225     URLContext *h;
 226     if (url_open(&h, filename, URL_RDONLY) < 0)
 227         return 0;
 228     url_close(h);
 229     return 1;
 230 }
 231
 232 int64_t url_filesize(URLContext *h)
 233 {
 234     int64_t pos, size;
 235
 236     size= url_seek(h, 0, AVSEEK_SIZE);
 237     if(size<0){
 238         pos = url_seek(h, 0, SEEK_CUR);
 239         if ((size = url_seek(h, -1, SEEK_END)) < 0)
 240             return size;
 241         size++;
 242         url_seek(h, pos, SEEK_SET);
 243     }
 244     return size;
 245 }
 246
 247 int url_get_file_handle(URLContext *h)
 248 {
 249     if (!h->prot->url_get_file_handle)
 250         return -1;
 251     return h->prot->url_get_file_handle(h);
 252 }
 253
 254 int url_get_max_packet_size(URLContext *h)
 255 {
 256     return h->max_packet_size;
 257 }
 258
 259 void url_get_filename(URLContext *h, char *buf, int buf_size)
 260 {
 261     av_strlcpy(buf, h->filename, buf_size);
 262 }
 263
 264
 265 static int default_interrupt_cb(void)
 266 {
 267     return 0;
 268 }
 269
 270 void url_set_interrupt_cb(URLInterruptCB *interrupt_cb)
 271 {
 272     if (!interrupt_cb)
 273         interrupt_cb = default_interrupt_cb;
 274     url_interrupt_cb = interrupt_cb;
 275 }
 276
 277 int av_url_read_pause(URLContext *h, int pause)
 278 {
 279     if (!h->prot->url_read_pause)
 280         return AVERROR(ENOSYS);
 281     return h->prot->url_read_pause(h, pause);
 282 }
 283
 284 int64_t av_url_read_seek(URLContext *h,
 285         int stream_index, int64_t timestamp, int flags)
 286 {
 287     if (!h->prot->url_read_seek)
 288         return AVERROR(ENOSYS);
 289     return h->prot->url_read_seek(h, stream_index, timestamp, flags);
 290 }