aboutsummaryrefslogtreecommitdiffstats
path: root/libavformat/avio.c
blob: 3cd9e4d991599d5a1a9921db91aec281dc226bbf (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
/*
 * Unbuffered io for ffmpeg system
 * Copyright (c) 2001 Fabrice Bellard
 *
 * This library 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 of the License, or (at your option) any later version.
 *
 * This library 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 this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
#include "avformat.h"
#include <ctype.h>

URLProtocol *first_protocol = NULL;

int register_protocol(URLProtocol *protocol)
{
    URLProtocol **p;
    p = &first_protocol;
    while (*p != NULL) p = &(*p)->next;
    *p = protocol;
    protocol->next = NULL;
    return 0;
}

int url_open(URLContext **puc, const char *filename, int flags)
{
    URLContext *uc;
    URLProtocol *up;
    const char *p;
    char proto_str[128], *q;
    int err;

    p = filename;
    q = proto_str;
    while (*p != '\0' && *p != ':') {
        /* protocols can only contain alphabetic chars */
        if (!isalpha(*p))
            goto file_proto;
        if ((q - proto_str) < sizeof(proto_str) - 1)
            *q++ = *p;
        p++;
    }
    /* if the protocol has length 1, we consider it is a dos drive */
    if (*p == '\0' || (q - proto_str) <= 1) {
    file_proto:
        strcpy(proto_str, "file");
    } else {
        *q = '\0';
    }
    
    up = first_protocol;
    while (up != NULL) {
        if (!strcmp(proto_str, up->name))
            goto found;
        up = up->next;
    }
    err = -ENOENT;
    goto fail;
 found:
    uc = av_malloc(sizeof(URLContext) + strlen(filename));
    if (!uc) {
        err = -ENOMEM;
        goto fail;
    }
    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 */
    err = up->url_open(uc, filename, flags);
    if (err < 0) {
        av_free(uc);
        *puc = NULL;
        return err;
    }
    *puc = uc;
    return 0;
 fail:
    *puc = NULL;
    return err;
}

int url_read(URLContext *h, unsigned char *buf, int size)
{
    int ret;
    if (h->flags & URL_WRONLY)
        return -EIO;
    ret = h->prot->url_read(h, buf, size);
    return ret;
}

int url_write(URLContext *h, unsigned char *buf, int size)
{
    int ret;
    if (!(h->flags & (URL_WRONLY | URL_RDWR)))
        return -EIO;
    /* avoid sending too big packets */
    if (h->max_packet_size && size > h->max_packet_size)
        return -EIO; 
    ret = h->prot->url_write(h, buf, size);
    return ret;
}

offset_t url_seek(URLContext *h, offset_t pos, int whence)
{
    offset_t ret;

    if (!h->prot->url_seek)
        return -EPIPE;
    ret = h->prot->url_seek(h, pos, whence);
    return ret;
}

int url_close(URLContext *h)
{
    int ret;

    ret = h->prot->url_close(h);
    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;
}

offset_t url_filesize(URLContext *h)
{
    offset_t pos, size;
    
    pos = url_seek(h, 0, SEEK_CUR);
    size = url_seek(h, 0, SEEK_END);
    url_seek(h, pos, SEEK_SET);
    return size;
}

/* 
 * Return the maximum packet size associated to packetized file
 * handle. If the file is not packetized (stream like http or file on
 * disk), then 0 is returned.
 * 
 * @param h file handle
 * @return maximum packet size in bytes
 */
int url_get_max_packet_size(URLContext *h)
{
    return h->max_packet_size;
}

void url_get_filename(URLContext *h, char *buf, int buf_size)
{
    pstrcpy(buf, buf_size, h->filename);
}