ffmpeg/libavformat/avio.c

365 lines
9.4 KiB
C

/*
* Unbuffered io for ffmpeg system
* Copyright (c) 2001 Fabrice Bellard
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/* needed for usleep() */
#define _XOPEN_SOURCE 600
#include <unistd.h>
#include "libavutil/avstring.h"
#include "libavutil/opt.h"
#include "os_support.h"
#include "avformat.h"
#if CONFIG_NETWORK
#include "network.h"
#endif
#if FF_API_URL_CLASS
/** @name Logging context. */
/*@{*/
static const char *urlcontext_to_name(void *ptr)
{
URLContext *h = (URLContext *)ptr;
if(h->prot) return h->prot->name;
else return "NULL";
}
static const AVOption options[] = {{NULL}};
static const AVClass urlcontext_class =
{ "URLContext", urlcontext_to_name, options, LIBAVUTIL_VERSION_INT };
/*@}*/
#endif
static int default_interrupt_cb(void);
URLProtocol *first_protocol = NULL;
URLInterruptCB *url_interrupt_cb = default_interrupt_cb;
URLProtocol *av_protocol_next(URLProtocol *p)
{
if(p) return p->next;
else return first_protocol;
}
int av_register_protocol2(URLProtocol *protocol, int size)
{
URLProtocol **p;
if (size < sizeof(URLProtocol)) {
URLProtocol* temp = av_mallocz(sizeof(URLProtocol));
memcpy(temp, protocol, size);
protocol = temp;
}
p = &first_protocol;
while (*p != NULL) p = &(*p)->next;
*p = protocol;
protocol->next = NULL;
return 0;
}
#if FF_API_REGISTER_PROTOCOL
/* The layout of URLProtocol as of when major was bumped to 52 */
struct URLProtocol_compat {
const char *name;
int (*url_open)(URLContext *h, const char *filename, int flags);
int (*url_read)(URLContext *h, unsigned char *buf, int size);
int (*url_write)(URLContext *h, unsigned char *buf, int size);
int64_t (*url_seek)(URLContext *h, int64_t pos, int whence);
int (*url_close)(URLContext *h);
struct URLProtocol *next;
};
int av_register_protocol(URLProtocol *protocol)
{
return av_register_protocol2(protocol, sizeof(struct URLProtocol_compat));
}
int register_protocol(URLProtocol *protocol)
{
return av_register_protocol2(protocol, sizeof(struct URLProtocol_compat));
}
#endif
static int url_alloc_for_protocol (URLContext **puc, struct URLProtocol *up,
const char *filename, int flags)
{
URLContext *uc;
int err;
#if CONFIG_NETWORK
if (!ff_network_init())
return AVERROR(EIO);
#endif
uc = av_mallocz(sizeof(URLContext) + strlen(filename) + 1);
if (!uc) {
err = AVERROR(ENOMEM);
goto fail;
}
#if FF_API_URL_CLASS
uc->av_class = &urlcontext_class;
#endif
uc->filename = (char *) &uc[1];
strcpy(uc->filename, filename);
uc->prot = up;
uc->flags = flags;
uc->is_streamed = 0; /* default = not streamed */
uc->max_packet_size = 0; /* default: stream file */
if (up->priv_data_size) {
uc->priv_data = av_mallocz(up->priv_data_size);
if (up->priv_data_class) {
*(const AVClass**)uc->priv_data = up->priv_data_class;
av_opt_set_defaults(uc->priv_data);
}
}
*puc = uc;
return 0;
fail:
*puc = NULL;
#if CONFIG_NETWORK
ff_network_close();
#endif
return err;
}
int url_connect(URLContext* uc)
{
int err = uc->prot->url_open(uc, uc->filename, uc->flags);
if (err)
return err;
uc->is_connected = 1;
//We must be careful here as url_seek() could be slow, for example for http
if( (uc->flags & (URL_WRONLY | URL_RDWR))
|| !strcmp(uc->prot->name, "file"))
if(!uc->is_streamed && url_seek(uc, 0, SEEK_SET) < 0)
uc->is_streamed= 1;
return 0;
}
int url_open_protocol (URLContext **puc, struct URLProtocol *up,
const char *filename, int flags)
{
int ret;
ret = url_alloc_for_protocol(puc, up, filename, flags);
if (ret)
goto fail;
ret = url_connect(*puc);
if (!ret)
return 0;
fail:
url_close(*puc);
*puc = NULL;
return ret;
}
#define URL_SCHEME_CHARS \
"abcdefghijklmnopqrstuvwxyz" \
"ABCDEFGHIJKLMNOPQRSTUVWXYZ" \
"0123456789+-."
int url_alloc(URLContext **puc, const char *filename, int flags)
{
URLProtocol *up;
char proto_str[128], proto_nested[128], *ptr;
size_t proto_len = strspn(filename, URL_SCHEME_CHARS);
if (filename[proto_len] != ':' || is_dos_path(filename))
strcpy(proto_str, "file");
else
av_strlcpy(proto_str, filename, FFMIN(proto_len+1, sizeof(proto_str)));
av_strlcpy(proto_nested, proto_str, sizeof(proto_nested));
if ((ptr = strchr(proto_nested, '+')))
*ptr = '\0';
up = first_protocol;
while (up != NULL) {
if (!strcmp(proto_str, up->name))
return url_alloc_for_protocol (puc, up, filename, flags);
if (up->flags & URL_PROTOCOL_FLAG_NESTED_SCHEME &&
!strcmp(proto_nested, up->name))
return url_alloc_for_protocol (puc, up, filename, flags);
up = up->next;
}
*puc = NULL;
return AVERROR(ENOENT);
}
int url_open(URLContext **puc, const char *filename, int flags)
{
int ret = url_alloc(puc, filename, flags);
if (ret)
return ret;
ret = url_connect(*puc);
if (!ret)
return 0;
url_close(*puc);
*puc = NULL;
return ret;
}
static inline int retry_transfer_wrapper(URLContext *h, unsigned char *buf, int size, int size_min,
int (*transfer_func)(URLContext *h, unsigned char *buf, int size))
{
int ret, len;
int fast_retries = 5;
len = 0;
while (len < size_min) {
ret = transfer_func(h, buf+len, size-len);
if (ret == AVERROR(EINTR))
continue;
if (h->flags & URL_FLAG_NONBLOCK)
return ret;
if (ret == AVERROR(EAGAIN)) {
ret = 0;
if (fast_retries)
fast_retries--;
else
usleep(1000);
} else if (ret < 1)
return ret < 0 ? ret : len;
if (ret)
fast_retries = FFMAX(fast_retries, 2);
len += ret;
if (url_interrupt_cb())
return AVERROR_EXIT;
}
return len;
}
int url_read(URLContext *h, unsigned char *buf, int size)
{
if (h->flags & URL_WRONLY)
return AVERROR(EIO);
return retry_transfer_wrapper(h, buf, size, 1, h->prot->url_read);
}
int url_read_complete(URLContext *h, unsigned char *buf, int size)
{
if (h->flags & URL_WRONLY)
return AVERROR(EIO);
return retry_transfer_wrapper(h, buf, size, size, h->prot->url_read);
}
int url_write(URLContext *h, const unsigned char *buf, int size)
{
if (!(h->flags & (URL_WRONLY | URL_RDWR)))
return AVERROR(EIO);
/* avoid sending too big packets */
if (h->max_packet_size && size > h->max_packet_size)
return AVERROR(EIO);
return retry_transfer_wrapper(h, buf, size, size, h->prot->url_write);
}
int64_t url_seek(URLContext *h, int64_t pos, int whence)
{
int64_t ret;
if (!h->prot->url_seek)
return AVERROR(ENOSYS);
ret = h->prot->url_seek(h, pos, whence & ~AVSEEK_FORCE);
return ret;
}
int url_close(URLContext *h)
{
int ret = 0;
if (!h) return 0; /* can happen when url_open fails */
if (h->is_connected && h->prot->url_close)
ret = h->prot->url_close(h);
#if CONFIG_NETWORK
ff_network_close();
#endif
if (h->prot->priv_data_size)
av_free(h->priv_data);
av_free(h);
return ret;
}
int url_exist(const char *filename)
{
URLContext *h;
if (url_open(&h, filename, URL_RDONLY) < 0)
return 0;
url_close(h);
return 1;
}
int64_t url_filesize(URLContext *h)
{
int64_t pos, size;
size= url_seek(h, 0, AVSEEK_SIZE);
if(size<0){
pos = url_seek(h, 0, SEEK_CUR);
if ((size = url_seek(h, -1, SEEK_END)) < 0)
return size;
size++;
url_seek(h, pos, SEEK_SET);
}
return size;
}
int url_get_file_handle(URLContext *h)
{
if (!h->prot->url_get_file_handle)
return -1;
return h->prot->url_get_file_handle(h);
}
int url_get_max_packet_size(URLContext *h)
{
return h->max_packet_size;
}
void url_get_filename(URLContext *h, char *buf, int buf_size)
{
av_strlcpy(buf, h->filename, buf_size);
}
static int default_interrupt_cb(void)
{
return 0;
}
void url_set_interrupt_cb(URLInterruptCB *interrupt_cb)
{
if (!interrupt_cb)
interrupt_cb = default_interrupt_cb;
url_interrupt_cb = interrupt_cb;
}
int av_url_read_pause(URLContext *h, int pause)
{
if (!h->prot->url_read_pause)
return AVERROR(ENOSYS);
return h->prot->url_read_pause(h, pause);
}
int64_t av_url_read_seek(URLContext *h,
int stream_index, int64_t timestamp, int flags)
{
if (!h->prot->url_read_seek)
return AVERROR(ENOSYS);
return h->prot->url_read_seek(h, stream_index, timestamp, flags);
}