2 * Buffered I/O for ffmpeg system
3 * Copyright (c) 2000,2001 Fabrice Bellard
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 #define IO_BUFFER_SIZE 32768
24 int init_put_byte(ByteIOContext *s,
25 unsigned char *buffer,
29 int (*read_packet)(void *opaque, UINT8 *buf, int buf_size),
30 void (*write_packet)(void *opaque, UINT8 *buf, int buf_size),
31 int (*seek)(void *opaque, offset_t offset, int whence))
34 s->buffer_size = buffer_size;
36 s->write_flag = write_flag;
40 s->buf_end = buffer + buffer_size;
42 s->write_packet = write_packet;
43 s->read_packet = read_packet;
49 s->max_packet_size = 0;
54 static void flush_buffer(ByteIOContext *s)
56 if (s->buf_ptr > s->buffer) {
58 s->write_packet(s->opaque, s->buffer, s->buf_ptr - s->buffer);
59 s->pos += s->buf_ptr - s->buffer;
61 s->buf_ptr = s->buffer;
64 void put_byte(ByteIOContext *s, int b)
67 if (s->buf_ptr >= s->buf_end)
71 void put_buffer(ByteIOContext *s, unsigned char *buf, int size)
76 len = (s->buf_end - s->buf_ptr);
79 memcpy(s->buf_ptr, buf, len);
82 if (s->buf_ptr >= s->buf_end)
90 void put_flush_packet(ByteIOContext *s)
96 offset_t url_fseek(ByteIOContext *s, offset_t offset, int whence)
100 if (whence != SEEK_CUR && whence != SEEK_SET)
104 if (whence == SEEK_CUR) {
105 offset1 = s->pos + (s->buf_ptr - s->buffer);
110 offset1 = offset - s->pos;
111 if (!s->must_flush &&
112 offset1 >= 0 && offset1 < (s->buf_end - s->buffer)) {
113 /* can do the seek inside the buffer */
114 s->buf_ptr = s->buffer + offset1;
120 s->buf_ptr = s->buffer;
121 s->seek(s->opaque, offset, SEEK_SET);
125 if (whence == SEEK_CUR) {
126 offset1 = s->pos - (s->buf_end - s->buffer) + (s->buf_ptr - s->buffer);
131 offset1 = offset - (s->pos - (s->buf_end - s->buffer));
132 if (offset1 >= 0 && offset1 <= (s->buf_end - s->buffer)) {
133 /* can do the seek inside the buffer */
134 s->buf_ptr = s->buffer + offset1;
138 s->buf_ptr = s->buffer;
139 s->buf_end = s->buffer;
140 s->seek(s->opaque, offset, SEEK_SET);
148 void url_fskip(ByteIOContext *s, offset_t offset)
150 url_fseek(s, offset, SEEK_CUR);
153 offset_t url_ftell(ByteIOContext *s)
155 return url_fseek(s, 0, SEEK_CUR);
158 int url_feof(ByteIOContext *s)
160 return s->eof_reached;
163 void put_le32(ByteIOContext *s, unsigned int val)
166 put_byte(s, val >> 8);
167 put_byte(s, val >> 16);
168 put_byte(s, val >> 24);
171 void put_be32(ByteIOContext *s, unsigned int val)
173 put_byte(s, val >> 24);
174 put_byte(s, val >> 16);
175 put_byte(s, val >> 8);
179 void put_le64(ByteIOContext *s, UINT64 val)
181 put_le32(s, (UINT32)(val & 0xffffffff));
182 put_le32(s, (UINT32)(val >> 32));
185 void put_be64(ByteIOContext *s, UINT64 val)
187 put_be32(s, (UINT32)(val >> 32));
188 put_be32(s, (UINT32)(val & 0xffffffff));
191 void put_le16(ByteIOContext *s, unsigned int val)
194 put_byte(s, val >> 8);
197 void put_be16(ByteIOContext *s, unsigned int val)
199 put_byte(s, val >> 8);
203 void put_tag(ByteIOContext *s, char *tag)
212 static void fill_buffer(ByteIOContext *s)
216 /* no need to do anything if EOF already reached */
219 len = s->read_packet(s->opaque, s->buffer, s->buffer_size);
221 /* do not modify buffer if EOF reached so that a seek back can
222 be done without rereading data */
226 s->buf_ptr = s->buffer;
227 s->buf_end = s->buffer + len;
231 /* NOTE: return 0 if EOF, so you cannot use it if EOF handling is
233 /* XXX: put an inline version */
234 int get_byte(ByteIOContext *s)
236 if (s->buf_ptr < s->buf_end) {
237 return *s->buf_ptr++;
240 if (s->buf_ptr < s->buf_end)
241 return *s->buf_ptr++;
247 /* NOTE: return URL_EOF (-1) if EOF */
248 int url_fgetc(ByteIOContext *s)
250 if (s->buf_ptr < s->buf_end) {
251 return *s->buf_ptr++;
254 if (s->buf_ptr < s->buf_end)
255 return *s->buf_ptr++;
261 int get_buffer(ByteIOContext *s, unsigned char *buf, int size)
267 len = s->buf_end - s->buf_ptr;
272 len = s->buf_end - s->buf_ptr;
276 memcpy(buf, s->buf_ptr, len);
285 unsigned int get_le16(ByteIOContext *s)
289 val |= get_byte(s) << 8;
293 unsigned int get_le32(ByteIOContext *s)
297 val |= get_byte(s) << 8;
298 val |= get_byte(s) << 16;
299 val |= get_byte(s) << 24;
303 UINT64 get_le64(ByteIOContext *s)
306 val = (UINT64)get_le32(s);
307 val |= (UINT64)get_le32(s) << 32;
311 unsigned int get_be16(ByteIOContext *s)
314 val = get_byte(s) << 8;
319 unsigned int get_be32(ByteIOContext *s)
322 val = get_byte(s) << 24;
323 val |= get_byte(s) << 16;
324 val |= get_byte(s) << 8;
329 UINT64 get_be64(ByteIOContext *s)
332 val = (UINT64)get_be32(s) << 32;
333 val |= (UINT64)get_be32(s);
337 /* link with avio functions */
339 void url_write_packet(void *opaque, UINT8 *buf, int buf_size)
341 URLContext *h = opaque;
342 url_write(h, buf, buf_size);
345 int url_read_packet(void *opaque, UINT8 *buf, int buf_size)
347 URLContext *h = opaque;
348 return url_read(h, buf, buf_size);
351 int url_seek_packet(void *opaque, INT64 offset, int whence)
353 URLContext *h = opaque;
354 url_seek(h, offset, whence);
358 int url_fdopen(ByteIOContext *s, URLContext *h)
361 int buffer_size, max_packet_size;
364 max_packet_size = url_get_max_packet_size(h);
365 if (max_packet_size) {
366 buffer_size = max_packet_size; /* no need to bufferize more than one packet */
368 buffer_size = IO_BUFFER_SIZE;
370 buffer = av_malloc(buffer_size);
374 if (init_put_byte(s, buffer, buffer_size,
375 (h->flags & URL_WRONLY) != 0, h,
376 url_read_packet, url_write_packet, url_seek_packet) < 0) {
380 s->is_streamed = h->is_streamed;
381 s->max_packet_size = max_packet_size;
385 /* XXX: must be called before any I/O */
386 int url_setbufsize(ByteIOContext *s, int buf_size)
389 buffer = av_malloc(buf_size);
395 s->buffer_size = buf_size;
400 s->buf_end = buffer + buf_size;
404 /* NOTE: when opened as read/write, the buffers are only used for
406 int url_fopen(ByteIOContext *s, const char *filename, int flags)
411 err = url_open(&h, filename, flags);
414 err = url_fdopen(s, h);
422 int url_fclose(ByteIOContext *s)
424 URLContext *h = s->opaque;
427 memset(s, 0, sizeof(ByteIOContext));
431 URLContext *url_fileno(ByteIOContext *s)
436 /* XXX: currently size is limited */
437 int url_fprintf(ByteIOContext *s, const char *fmt, ...)
444 ret = vsnprintf(buf, sizeof(buf), fmt, ap);
446 put_buffer(s, buf, strlen(buf));
450 /* note: unlike fgets, the EOL character is not returned and a whole
451 line is parsed. return NULL if first char read was EOF */
452 char *url_fgets(ByteIOContext *s, char *buf, int buf_size)
462 if (c == EOF || c == '\n')
464 if ((q - buf) < buf_size - 1)
474 * Return the maximum packet size associated to packetized buffered file
475 * handle. If the file is not packetized (stream like http or file on
476 * disk), then 0 is returned.
478 * @param h buffered file handle
479 * @return maximum packet size in bytes
481 int url_fget_max_packet_size(ByteIOContext *s)
483 return s->max_packet_size;
486 /* buffer handling */
487 int url_open_buf(ByteIOContext *s, UINT8 *buf, int buf_size, int flags)
489 return init_put_byte(s, buf, buf_size,
490 (flags & URL_WRONLY) != 0, NULL, NULL, NULL, NULL);
493 /* return the written or read size */
494 int url_close_buf(ByteIOContext *s)
497 return s->buf_ptr - s->buffer;
500 /* output in a dynamic buffer */
502 typedef struct DynBuffer {
503 int pos, size, allocated_size;
509 static void dyn_buf_write(void *opaque, UINT8 *buf, int buf_size)
511 DynBuffer *d = opaque;
512 int new_size, new_allocated_size;
515 /* reallocate buffer if needed */
516 new_size = d->pos + buf_size;
517 new_allocated_size = d->allocated_size;
518 while (new_size > new_allocated_size) {
519 if (!new_allocated_size)
520 new_allocated_size = new_size;
522 new_allocated_size = (new_allocated_size * 3) / 2 + 1;
525 if (new_allocated_size > d->allocated_size) {
526 new_buffer = av_malloc(new_allocated_size);
529 memcpy(new_buffer, d->buffer, d->size);
531 d->buffer = new_buffer;
532 d->allocated_size = new_allocated_size;
534 memcpy(d->buffer + d->pos, buf, buf_size);
536 if (d->pos > d->size)
540 static void dyn_packet_buf_write(void *opaque, UINT8 *buf, int buf_size)
542 unsigned char buf1[4];
544 /* packetized write: output the header */
545 buf1[0] = (buf_size >> 24);
546 buf1[1] = (buf_size >> 16);
547 buf1[2] = (buf_size >> 8);
548 buf1[3] = (buf_size);
549 dyn_buf_write(opaque, buf1, 4);
552 dyn_buf_write(opaque, buf, buf_size);
555 static int dyn_buf_seek(void *opaque, offset_t offset, int whence)
557 DynBuffer *d = opaque;
559 if (whence == SEEK_CUR)
561 else if (whence == SEEK_END)
563 if (offset < 0 || offset > 0x7fffffffLL)
569 static int url_open_dyn_buf_internal(ByteIOContext *s, int max_packet_size)
572 int io_buffer_size, ret;
575 io_buffer_size = max_packet_size;
577 io_buffer_size = 1024;
579 d = av_malloc(sizeof(DynBuffer) + io_buffer_size);
582 d->io_buffer_size = io_buffer_size;
586 d->allocated_size = 0;
587 ret = init_put_byte(s, d->io_buffer, io_buffer_size,
589 max_packet_size ? dyn_packet_buf_write : dyn_buf_write,
590 max_packet_size ? NULL : dyn_buf_seek);
592 s->max_packet_size = max_packet_size;
598 * Open a write only memory stream.
600 * @param s new IO context
601 * @return zero if no error.
603 int url_open_dyn_buf(ByteIOContext *s)
605 return url_open_dyn_buf_internal(s, 0);
609 * Open a write only packetized memory stream with a maximum packet
610 * size of 'max_packet_size'. The stream is stored in a memory buffer
611 * with a big endian 4 byte header giving the packet size in bytes.
613 * @param s new IO context
614 * @param max_packet_size maximum packet size (must be > 0)
615 * @return zero if no error.
617 int url_open_dyn_packet_buf(ByteIOContext *s, int max_packet_size)
619 if (max_packet_size <= 0)
621 return url_open_dyn_buf_internal(s, max_packet_size);
625 * Return the written size and a pointer to the buffer. The buffer
626 * must be freed with av_free().
627 * @param s IO context
628 * @param pointer to a byte buffer
629 * @return the length of the byte buffer
631 int url_close_dyn_buf(ByteIOContext *s, UINT8 **pbuffer)
633 DynBuffer *d = s->opaque;
638 *pbuffer = d->buffer;