ffmpeg/libavformat/avio.c

388 lines
11 KiB
C

/*
* unbuffered I/O
* 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
*/
#include "libavutil/avstring.h"
#include "libavutil/dict.h"
#include "libavutil/opt.h"
#include "libavutil/time.h"
#include "os_support.h"
#include "avformat.h"
#if CONFIG_NETWORK
#include "network.h"
#endif
#include "url.h"
static URLProtocol *first_protocol = NULL;
URLProtocol *ffurl_protocol_next(const URLProtocol *prev)
{
return prev ? prev->next : first_protocol;
}
/** @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 void *urlcontext_child_next(void *obj, void *prev)
{
URLContext *h = obj;
if (!prev && h->priv_data && h->prot->priv_data_class)
return h->priv_data;
return NULL;
}
static const AVClass *urlcontext_child_class_next(const AVClass *prev)
{
URLProtocol *p = NULL;
/* find the protocol that corresponds to prev */
while (prev && (p = ffurl_protocol_next(p)))
if (p->priv_data_class == prev)
break;
/* find next protocol with priv options */
while (p = ffurl_protocol_next(p))
if (p->priv_data_class)
return p->priv_data_class;
return NULL;
}
static const AVOption options[] = { { NULL } };
const AVClass ffurl_context_class = {
.class_name = "URLContext",
.item_name = urlcontext_to_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
.child_next = urlcontext_child_next,
.child_class_next = urlcontext_child_class_next,
};
/*@}*/
const char *avio_enum_protocols(void **opaque, int output)
{
URLProtocol *p;
*opaque = ffurl_protocol_next(*opaque);
if (!(p = *opaque))
return NULL;
if ((output && p->url_write) || (!output && p->url_read))
return p->name;
return avio_enum_protocols(opaque, output);
}
int ffurl_register_protocol(URLProtocol *protocol)
{
URLProtocol **p;
p = &first_protocol;
while (*p)
p = &(*p)->next;
*p = protocol;
protocol->next = NULL;
return 0;
}
static int url_alloc_for_protocol(URLContext **puc, struct URLProtocol *up,
const char *filename, int flags,
const AVIOInterruptCB *int_cb)
{
URLContext *uc;
int err;
#if CONFIG_NETWORK
if (up->flags & URL_PROTOCOL_FLAG_NETWORK && !ff_network_init())
return AVERROR(EIO);
#endif
uc = av_mallocz(sizeof(URLContext) + strlen(filename) + 1);
if (!uc) {
err = AVERROR(ENOMEM);
goto fail;
}
uc->av_class = &ffurl_context_class;
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 (!uc->priv_data) {
err = AVERROR(ENOMEM);
goto fail;
}
if (up->priv_data_class) {
*(const AVClass **)uc->priv_data = up->priv_data_class;
av_opt_set_defaults(uc->priv_data);
}
}
if (int_cb)
uc->interrupt_callback = *int_cb;
*puc = uc;
return 0;
fail:
*puc = NULL;
if (uc)
av_freep(&uc->priv_data);
av_freep(&uc);
#if CONFIG_NETWORK
if (up->flags & URL_PROTOCOL_FLAG_NETWORK)
ff_network_close();
#endif
return err;
}
int ffurl_connect(URLContext *uc, AVDictionary **options)
{
int err =
uc->prot->url_open2 ? uc->prot->url_open2(uc,
uc->filename,
uc->flags,
options) :
uc->prot->url_open(uc, uc->filename, uc->flags);
if (err)
return err;
uc->is_connected = 1;
/* We must be careful here as ffurl_seek() could be slow,
* for example for http */
if ((uc->flags & AVIO_FLAG_WRITE) || !strcmp(uc->prot->name, "file"))
if (!uc->is_streamed && ffurl_seek(uc, 0, SEEK_SET) < 0)
uc->is_streamed = 1;
return 0;
}
#define URL_SCHEME_CHARS \
"abcdefghijklmnopqrstuvwxyz" \
"ABCDEFGHIJKLMNOPQRSTUVWXYZ" \
"0123456789+-."
int ffurl_alloc(URLContext **puc, const char *filename, int flags,
const AVIOInterruptCB *int_cb)
{
URLProtocol *up = NULL;
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';
while (up = ffurl_protocol_next(up)) {
if (!strcmp(proto_str, up->name))
return url_alloc_for_protocol(puc, up, filename, flags, int_cb);
if (up->flags & URL_PROTOCOL_FLAG_NESTED_SCHEME &&
!strcmp(proto_nested, up->name))
return url_alloc_for_protocol(puc, up, filename, flags, int_cb);
}
*puc = NULL;
return AVERROR_PROTOCOL_NOT_FOUND;
}
int ffurl_open(URLContext **puc, const char *filename, int flags,
const AVIOInterruptCB *int_cb, AVDictionary **options)
{
int ret = ffurl_alloc(puc, filename, flags, int_cb);
if (ret)
return ret;
if (options && (*puc)->prot->priv_data_class &&
(ret = av_opt_set_dict((*puc)->priv_data, options)) < 0)
goto fail;
ret = ffurl_connect(*puc, options);
if (!ret)
return 0;
fail:
ffurl_close(*puc);
*puc = NULL;
return ret;
}
static inline int retry_transfer_wrapper(URLContext *h, uint8_t *buf,
int size, int size_min,
int (*transfer_func)(URLContext *h,
uint8_t *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 & AVIO_FLAG_NONBLOCK)
return ret;
if (ret == AVERROR(EAGAIN)) {
ret = 0;
if (fast_retries)
fast_retries--;
else
av_usleep(1000);
} else if (ret < 1)
return (ret < 0 && ret != AVERROR_EOF) ? ret : len;
if (ret)
fast_retries = FFMAX(fast_retries, 2);
len += ret;
if (ff_check_interrupt(&h->interrupt_callback))
return AVERROR_EXIT;
}
return len;
}
int ffurl_read(URLContext *h, unsigned char *buf, int size)
{
if (!(h->flags & AVIO_FLAG_READ))
return AVERROR(EIO);
return retry_transfer_wrapper(h, buf, size, 1, h->prot->url_read);
}
int ffurl_read_complete(URLContext *h, unsigned char *buf, int size)
{
if (!(h->flags & AVIO_FLAG_READ))
return AVERROR(EIO);
return retry_transfer_wrapper(h, buf, size, size, h->prot->url_read);
}
int ffurl_write(URLContext *h, const unsigned char *buf, int size)
{
if (!(h->flags & AVIO_FLAG_WRITE))
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 ffurl_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 ffurl_close(URLContext *h)
{
int ret = 0;
if (!h)
return 0; /* can happen when ffurl_open fails */
if (h->is_connected && h->prot->url_close)
ret = h->prot->url_close(h);
#if CONFIG_NETWORK
if (h->prot->flags & URL_PROTOCOL_FLAG_NETWORK)
ff_network_close();
#endif
if (h->prot->priv_data_size) {
if (h->prot->priv_data_class)
av_opt_free(h->priv_data);
av_free(h->priv_data);
}
av_free(h);
return ret;
}
int avio_check(const char *url, int flags)
{
URLContext *h;
int ret = ffurl_alloc(&h, url, flags, NULL);
if (ret)
return ret;
if (h->prot->url_check) {
ret = h->prot->url_check(h, flags);
} else {
ret = ffurl_connect(h, NULL);
if (ret >= 0)
ret = flags;
}
ffurl_close(h);
return ret;
}
int64_t ffurl_size(URLContext *h)
{
int64_t pos, size;
size = ffurl_seek(h, 0, AVSEEK_SIZE);
if (size < 0) {
pos = ffurl_seek(h, 0, SEEK_CUR);
if ((size = ffurl_seek(h, -1, SEEK_END)) < 0)
return size;
size++;
ffurl_seek(h, pos, SEEK_SET);
}
return size;
}
int ffurl_get_file_handle(URLContext *h)
{
if (!h->prot->url_get_file_handle)
return -1;
return h->prot->url_get_file_handle(h);
}
int ffurl_get_multi_file_handle(URLContext *h, int **handles, int *numhandles)
{
if (!h->prot->url_get_multi_file_handle) {
if (!h->prot->url_get_file_handle)
return AVERROR(ENOSYS);
*handles = av_malloc(sizeof(**handles));
if (!*handles)
return AVERROR(ENOMEM);
*numhandles = 1;
*handles[0] = h->prot->url_get_file_handle(h);
return 0;
}
return h->prot->url_get_multi_file_handle(h, handles, numhandles);
}
int ffurl_shutdown(URLContext *h, int flags)
{
if (!h->prot->url_shutdown)
return AVERROR(EINVAL);
return h->prot->url_shutdown(h, flags);
}
int ff_check_interrupt(AVIOInterruptCB *cb)
{
int ret;
if (cb && cb->callback && (ret = cb->callback(cb->opaque)))
return ret;
return 0;
}