yading@11: /*
yading@11:  * Concat URL protocol
yading@11:  * Copyright (c) 2006 Steve Lhomme
yading@11:  * Copyright (c) 2007 Wolfram Gloger
yading@11:  * Copyright (c) 2010 Michele Orrù
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: #include "avformat.h"
yading@11: #include "libavutil/avstring.h"
yading@11: #include "libavutil/mem.h"
yading@11: #include "url.h"
yading@11: 
yading@11: #define AV_CAT_SEPARATOR "|"
yading@11: 
yading@11: struct concat_nodes {
yading@11:     URLContext *uc;                ///< node's URLContext
yading@11:     int64_t     size;              ///< url filesize
yading@11: };
yading@11: 
yading@11: struct concat_data {
yading@11:     struct concat_nodes *nodes;    ///< list of nodes to concat
yading@11:     size_t               length;   ///< number of cat'ed nodes
yading@11:     size_t               current;  ///< index of currently read node
yading@11: };
yading@11: 
yading@11: static av_cold int concat_close(URLContext *h)
yading@11: {
yading@11:     int err = 0;
yading@11:     size_t i;
yading@11:     struct concat_data  *data  = h->priv_data;
yading@11:     struct concat_nodes *nodes = data->nodes;
yading@11: 
yading@11:     for (i = 0; i != data->length; i++)
yading@11:         err |= ffurl_close(nodes[i].uc);
yading@11: 
yading@11:     av_freep(&data->nodes);
yading@11: 
yading@11:     return err < 0 ? -1 : 0;
yading@11: }
yading@11: 
yading@11: static av_cold int concat_open(URLContext *h, const char *uri, int flags)
yading@11: {
yading@11:     char *node_uri = NULL, *tmp_uri;
yading@11:     int err = 0;
yading@11:     int64_t size;
yading@11:     size_t  len, i;
yading@11:     URLContext *uc;
yading@11:     struct concat_data  *data = h->priv_data;
yading@11:     struct concat_nodes *nodes;
yading@11: 
yading@11:     av_strstart(uri, "concat:", &uri);
yading@11: 
yading@11:     for (i = 0, len = 1; uri[i]; i++)
yading@11:         if (uri[i] == *AV_CAT_SEPARATOR)
yading@11:             /* integer overflow */
yading@11:             if (++len == UINT_MAX / sizeof(*nodes)) {
yading@11:                 av_freep(&h->priv_data);
yading@11:                 return AVERROR(ENAMETOOLONG);
yading@11:             }
yading@11: 
yading@11:     if (!(nodes = av_malloc(sizeof(*nodes) * len))) {
yading@11:         return AVERROR(ENOMEM);
yading@11:     } else
yading@11:         data->nodes = nodes;
yading@11: 
yading@11:     /* handle input */
yading@11:     if (!*uri)
yading@11:         err = AVERROR(ENOENT);
yading@11:     for (i = 0; *uri; i++) {
yading@11:         /* parsing uri */
yading@11:         len = strcspn(uri, AV_CAT_SEPARATOR);
yading@11:         if (!(tmp_uri = av_realloc(node_uri, len+1))) {
yading@11:             err = AVERROR(ENOMEM);
yading@11:             break;
yading@11:         } else
yading@11:             node_uri = tmp_uri;
yading@11:         av_strlcpy(node_uri, uri, len+1);
yading@11:         uri += len + strspn(uri+len, AV_CAT_SEPARATOR);
yading@11: 
yading@11:         /* creating URLContext */
yading@11:         if ((err = ffurl_open(&uc, node_uri, flags,
yading@11:                               &h->interrupt_callback, NULL)) < 0)
yading@11:             break;
yading@11: 
yading@11:         /* creating size */
yading@11:         if ((size = ffurl_size(uc)) < 0) {
yading@11:             ffurl_close(uc);
yading@11:             err = AVERROR(ENOSYS);
yading@11:             break;
yading@11:         }
yading@11: 
yading@11:         /* assembling */
yading@11:         nodes[i].uc   = uc;
yading@11:         nodes[i].size = size;
yading@11:     }
yading@11:     av_free(node_uri);
yading@11:     data->length = i;
yading@11: 
yading@11:     if (err < 0)
yading@11:         concat_close(h);
yading@11:     else if (!(nodes = av_realloc(nodes, data->length * sizeof(*nodes)))) {
yading@11:         concat_close(h);
yading@11:         err = AVERROR(ENOMEM);
yading@11:     } else
yading@11:         data->nodes = nodes;
yading@11:     return err;
yading@11: }
yading@11: 
yading@11: static int concat_read(URLContext *h, unsigned char *buf, int size)
yading@11: {
yading@11:     int result, total = 0;
yading@11:     struct concat_data  *data  = h->priv_data;
yading@11:     struct concat_nodes *nodes = data->nodes;
yading@11:     size_t i = data->current;
yading@11: 
yading@11:     while (size > 0) {
yading@11:         result = ffurl_read(nodes[i].uc, buf, size);
yading@11:         if (result < 0)
yading@11:             return total ? total : result;
yading@11:         if (!result)
yading@11:             if (i + 1 == data->length ||
yading@11:                 ffurl_seek(nodes[++i].uc, 0, SEEK_SET) < 0)
yading@11:                 break;
yading@11:         total += result;
yading@11:         buf   += result;
yading@11:         size  -= result;
yading@11:     }
yading@11:     data->current = i;
yading@11:     return total;
yading@11: }
yading@11: 
yading@11: static int64_t concat_seek(URLContext *h, int64_t pos, int whence)
yading@11: {
yading@11:     int64_t result;
yading@11:     struct concat_data  *data  = h->priv_data;
yading@11:     struct concat_nodes *nodes = data->nodes;
yading@11:     size_t i;
yading@11: 
yading@11:     switch (whence) {
yading@11:     case SEEK_END:
yading@11:         for (i = data->length - 1;
yading@11:              i && pos < -nodes[i].size;
yading@11:              i--)
yading@11:             pos += nodes[i].size;
yading@11:         break;
yading@11:     case SEEK_CUR:
yading@11:         /* get the absolute position */
yading@11:         for (i = 0; i != data->current; i++)
yading@11:             pos += nodes[i].size;
yading@11:         pos += ffurl_seek(nodes[i].uc, 0, SEEK_CUR);
yading@11:         whence = SEEK_SET;
yading@11:         /* fall through with the absolute position */
yading@11:     case SEEK_SET:
yading@11:         for (i = 0; i != data->length - 1 && pos >= nodes[i].size; i++)
yading@11:             pos -= nodes[i].size;
yading@11:         break;
yading@11:     default:
yading@11:         return AVERROR(EINVAL);
yading@11:     }
yading@11: 
yading@11:     result = ffurl_seek(nodes[i].uc, pos, whence);
yading@11:     if (result >= 0) {
yading@11:         data->current = i;
yading@11:         while (i)
yading@11:             result += nodes[--i].size;
yading@11:     }
yading@11:     return result;
yading@11: }
yading@11: 
yading@11: URLProtocol ff_concat_protocol = {
yading@11:     .name           = "concat",
yading@11:     .url_open       = concat_open,
yading@11:     .url_read       = concat_read,
yading@11:     .url_seek       = concat_seek,
yading@11:     .url_close      = concat_close,
yading@11:     .priv_data_size = sizeof(struct concat_data),
yading@11: };