Only special-case absolute DOS paths on systems that support them.
[libav.git] / 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 #include "libavutil/avstring.h"
23 #include "libavcodec/opt.h"
24 #include "os_support.h"
25 #include "avformat.h"
26
27 #if LIBAVFORMAT_VERSION_MAJOR >= 53
28 /** @name Logging context. */
29 /*@{*/
30 static const char *urlcontext_to_name(void *ptr)
31 {
32 URLContext *h = (URLContext *)ptr;
33 if(h->prot) return h->prot->name;
34 else return "NULL";
35 }
36 static const AVOption options[] = {{NULL}};
37 static const AVClass urlcontext_class =
38 { "URLContext", urlcontext_to_name, options };
39 /*@}*/
40 #endif
41
42 static int default_interrupt_cb(void);
43
44 URLProtocol *first_protocol = NULL;
45 URLInterruptCB *url_interrupt_cb = default_interrupt_cb;
46
47 URLProtocol *av_protocol_next(URLProtocol *p)
48 {
49 if(p) return p->next;
50 else return first_protocol;
51 }
52
53 int register_protocol(URLProtocol *protocol)
54 {
55 URLProtocol **p;
56 p = &first_protocol;
57 while (*p != NULL) p = &(*p)->next;
58 *p = protocol;
59 protocol->next = NULL;
60 return 0;
61 }
62
63 int url_open_protocol (URLContext **puc, struct URLProtocol *up,
64 const char *filename, int flags)
65 {
66 URLContext *uc;
67 int err;
68
69 uc = av_malloc(sizeof(URLContext) + strlen(filename) + 1);
70 if (!uc) {
71 err = AVERROR(ENOMEM);
72 goto fail;
73 }
74 #if LIBAVFORMAT_VERSION_MAJOR >= 53
75 uc->av_class = &urlcontext_class;
76 #endif
77 uc->filename = (char *) &uc[1];
78 strcpy(uc->filename, filename);
79 uc->prot = up;
80 uc->flags = flags;
81 uc->is_streamed = 0; /* default = not streamed */
82 uc->max_packet_size = 0; /* default: stream file */
83 err = up->url_open(uc, filename, flags);
84 if (err < 0) {
85 av_free(uc);
86 *puc = NULL;
87 return err;
88 }
89
90 //We must be carefull here as url_seek() could be slow, for example for http
91 if( (flags & (URL_WRONLY | URL_RDWR))
92 || !strcmp(up->name, "file"))
93 if(!uc->is_streamed && url_seek(uc, 0, SEEK_SET) < 0)
94 uc->is_streamed= 1;
95 *puc = uc;
96 return 0;
97 fail:
98 *puc = NULL;
99 return err;
100 }
101
102 int url_open(URLContext **puc, const char *filename, int flags)
103 {
104 URLProtocol *up;
105 const char *p;
106 char proto_str[128], *q;
107
108 p = filename;
109 q = proto_str;
110 while (*p != '\0' && *p != ':') {
111 /* protocols can only contain alphabetic chars */
112 if (!isalpha(*p))
113 goto file_proto;
114 if ((q - proto_str) < sizeof(proto_str) - 1)
115 *q++ = *p;
116 p++;
117 }
118 /* if the protocol has length 1, we consider it is a dos drive */
119 if (*p == '\0' || is_dos_path(filename)) {
120 file_proto:
121 strcpy(proto_str, "file");
122 } else {
123 *q = '\0';
124 }
125
126 up = first_protocol;
127 while (up != NULL) {
128 if (!strcmp(proto_str, up->name))
129 return url_open_protocol (puc, up, filename, flags);
130 up = up->next;
131 }
132 *puc = NULL;
133 return AVERROR(ENOENT);
134 }
135
136 int url_read(URLContext *h, unsigned char *buf, int size)
137 {
138 int ret;
139 if (h->flags & URL_WRONLY)
140 return AVERROR(EIO);
141 ret = h->prot->url_read(h, buf, size);
142 return ret;
143 }
144
145 int url_write(URLContext *h, unsigned char *buf, int size)
146 {
147 int ret;
148 if (!(h->flags & (URL_WRONLY | URL_RDWR)))
149 return AVERROR(EIO);
150 /* avoid sending too big packets */
151 if (h->max_packet_size && size > h->max_packet_size)
152 return AVERROR(EIO);
153 ret = h->prot->url_write(h, buf, size);
154 return ret;
155 }
156
157 int64_t url_seek(URLContext *h, int64_t pos, int whence)
158 {
159 int64_t ret;
160
161 if (!h->prot->url_seek)
162 return AVERROR(EPIPE);
163 ret = h->prot->url_seek(h, pos, whence);
164 return ret;
165 }
166
167 int url_close(URLContext *h)
168 {
169 int ret = 0;
170 if (!h) return 0; /* can happen when url_open fails */
171
172 if (h->prot->url_close)
173 ret = h->prot->url_close(h);
174 av_free(h);
175 return ret;
176 }
177
178 int url_exist(const char *filename)
179 {
180 URLContext *h;
181 if (url_open(&h, filename, URL_RDONLY) < 0)
182 return 0;
183 url_close(h);
184 return 1;
185 }
186
187 int64_t url_filesize(URLContext *h)
188 {
189 int64_t pos, size;
190
191 size= url_seek(h, 0, AVSEEK_SIZE);
192 if(size<0){
193 pos = url_seek(h, 0, SEEK_CUR);
194 if ((size = url_seek(h, -1, SEEK_END)) < 0)
195 return size;
196 size++;
197 url_seek(h, pos, SEEK_SET);
198 }
199 return size;
200 }
201
202 int url_get_max_packet_size(URLContext *h)
203 {
204 return h->max_packet_size;
205 }
206
207 void url_get_filename(URLContext *h, char *buf, int buf_size)
208 {
209 av_strlcpy(buf, h->filename, buf_size);
210 }
211
212
213 static int default_interrupt_cb(void)
214 {
215 return 0;
216 }
217
218 void url_set_interrupt_cb(URLInterruptCB *interrupt_cb)
219 {
220 if (!interrupt_cb)
221 interrupt_cb = default_interrupt_cb;
222 url_interrupt_cb = interrupt_cb;
223 }
224
225 int av_url_read_pause(URLContext *h, int pause)
226 {
227 if (!h->prot->url_read_pause)
228 return AVERROR(ENOSYS);
229 return h->prot->url_read_pause(h, pause);
230 }
231
232 int64_t av_url_read_seek(URLContext *h,
233 int stream_index, int64_t timestamp, int flags)
234 {
235 if (!h->prot->url_read_seek)
236 return AVERROR(ENOSYS);
237 return h->prot->url_read_seek(h, stream_index, timestamp, flags);
238 }