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
23 #define IO_BUFFER_SIZE 32768
25 int init_put_byte(ByteIOContext *s,
26 unsigned char *buffer,
30 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
31 void (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
32 int (*seek)(void *opaque, offset_t offset, int whence))
35 s->buffer_size = buffer_size;
37 s->write_flag = write_flag;
41 s->buf_end = buffer + buffer_size;
43 s->write_packet = write_packet;
44 s->read_packet = read_packet;
50 s->max_packet_size = 0;
55 static void flush_buffer(ByteIOContext *s)
57 if (s->buf_ptr > s->buffer) {
59 s->write_packet(s->opaque, s->buffer, s->buf_ptr - s->buffer);
60 s->pos += s->buf_ptr - s->buffer;
62 s->buf_ptr = s->buffer;
65 void put_byte(ByteIOContext *s, int b)
68 if (s->buf_ptr >= s->buf_end)
72 void put_buffer(ByteIOContext *s, const unsigned char *buf, int size)
77 len = (s->buf_end - s->buf_ptr);
80 memcpy(s->buf_ptr, buf, len);
83 if (s->buf_ptr >= s->buf_end)
91 void put_flush_packet(ByteIOContext *s)
97 offset_t url_fseek(ByteIOContext *s, offset_t offset, int whence)
101 if (whence != SEEK_CUR && whence != SEEK_SET)
105 if (whence == SEEK_CUR) {
106 offset1 = s->pos + (s->buf_ptr - s->buffer);
111 offset1 = offset - s->pos;
112 if (!s->must_flush &&
113 offset1 >= 0 && offset1 < (s->buf_end - s->buffer)) {
114 /* can do the seek inside the buffer */
115 s->buf_ptr = s->buffer + offset1;
121 s->buf_ptr = s->buffer;
122 s->seek(s->opaque, offset, SEEK_SET);
126 if (whence == SEEK_CUR) {
127 offset1 = s->pos - (s->buf_end - s->buffer) + (s->buf_ptr - s->buffer);
132 offset1 = offset - (s->pos - (s->buf_end - s->buffer));
133 if (offset1 >= 0 && offset1 <= (s->buf_end - s->buffer)) {
134 /* can do the seek inside the buffer */
135 s->buf_ptr = s->buffer + offset1;
139 s->buf_ptr = s->buffer;
140 s->buf_end = s->buffer;
141 s->seek(s->opaque, offset, SEEK_SET);
149 void url_fskip(ByteIOContext *s, offset_t offset)
151 url_fseek(s, offset, SEEK_CUR);
154 offset_t url_ftell(ByteIOContext *s)
156 return url_fseek(s, 0, SEEK_CUR);
159 int url_feof(ByteIOContext *s)
161 return s->eof_reached;
164 void put_le32(ByteIOContext *s, unsigned int val)
167 put_byte(s, val >> 8);
168 put_byte(s, val >> 16);
169 put_byte(s, val >> 24);
172 void put_be32(ByteIOContext *s, unsigned int val)
174 put_byte(s, val >> 24);
175 put_byte(s, val >> 16);
176 put_byte(s, val >> 8);
180 /* IEEE format is assumed */
181 void put_be64_double(ByteIOContext *s, double val)
191 void put_strz(ByteIOContext *s, const char *str)
194 put_buffer(s, (const unsigned char *) str, strlen(str) + 1);
199 void put_le64(ByteIOContext *s, uint64_t val)
201 put_le32(s, (uint32_t)(val & 0xffffffff));
202 put_le32(s, (uint32_t)(val >> 32));
205 void put_be64(ByteIOContext *s, uint64_t val)
207 put_be32(s, (uint32_t)(val >> 32));
208 put_be32(s, (uint32_t)(val & 0xffffffff));
211 void put_le16(ByteIOContext *s, unsigned int val)
214 put_byte(s, val >> 8);
217 void put_be16(ByteIOContext *s, unsigned int val)
219 put_byte(s, val >> 8);
223 void put_tag(ByteIOContext *s, const char *tag)
232 static void fill_buffer(ByteIOContext *s)
236 /* no need to do anything if EOF already reached */
239 len = s->read_packet(s->opaque, s->buffer, s->buffer_size);
241 /* do not modify buffer if EOF reached so that a seek back can
242 be done without rereading data */
246 s->buf_ptr = s->buffer;
247 s->buf_end = s->buffer + len;
251 /* NOTE: return 0 if EOF, so you cannot use it if EOF handling is
253 /* XXX: put an inline version */
254 int get_byte(ByteIOContext *s)
256 if (s->buf_ptr < s->buf_end) {
257 return *s->buf_ptr++;
260 if (s->buf_ptr < s->buf_end)
261 return *s->buf_ptr++;
267 /* NOTE: return URL_EOF (-1) if EOF */
268 int url_fgetc(ByteIOContext *s)
270 if (s->buf_ptr < s->buf_end) {
271 return *s->buf_ptr++;
274 if (s->buf_ptr < s->buf_end)
275 return *s->buf_ptr++;
281 int get_buffer(ByteIOContext *s, unsigned char *buf, int size)
287 len = s->buf_end - s->buf_ptr;
292 len = s->buf_end - s->buf_ptr;
296 memcpy(buf, s->buf_ptr, len);
305 unsigned int get_le16(ByteIOContext *s)
309 val |= get_byte(s) << 8;
313 unsigned int get_le32(ByteIOContext *s)
317 val |= get_byte(s) << 8;
318 val |= get_byte(s) << 16;
319 val |= get_byte(s) << 24;
323 uint64_t get_le64(ByteIOContext *s)
326 val = (uint64_t)get_le32(s);
327 val |= (uint64_t)get_le32(s) << 32;
331 unsigned int get_be16(ByteIOContext *s)
334 val = get_byte(s) << 8;
339 unsigned int get_be32(ByteIOContext *s)
342 val = get_byte(s) << 24;
343 val |= get_byte(s) << 16;
344 val |= get_byte(s) << 8;
349 double get_be64_double(ByteIOContext *s)
360 char *get_strz(ByteIOContext *s, char *buf, int maxlen)
365 while ((c = get_byte(s))) {
370 buf[i] = 0; /* Ensure null terminated, but may be truncated */
375 uint64_t get_be64(ByteIOContext *s)
378 val = (uint64_t)get_be32(s) << 32;
379 val |= (uint64_t)get_be32(s);
383 /* link with avio functions */
385 static void url_write_packet(void *opaque, uint8_t *buf, int buf_size)
387 URLContext *h = opaque;
388 url_write(h, buf, buf_size);
391 static int url_read_packet(void *opaque, uint8_t *buf, int buf_size)
393 URLContext *h = opaque;
394 return url_read(h, buf, buf_size);
397 static int url_seek_packet(void *opaque, int64_t offset, int whence)
399 URLContext *h = opaque;
400 url_seek(h, offset, whence);
404 int url_fdopen(ByteIOContext *s, URLContext *h)
407 int buffer_size, max_packet_size;
410 max_packet_size = url_get_max_packet_size(h);
411 if (max_packet_size) {
412 buffer_size = max_packet_size; /* no need to bufferize more than one packet */
414 buffer_size = IO_BUFFER_SIZE;
416 buffer = av_malloc(buffer_size);
420 if (init_put_byte(s, buffer, buffer_size,
421 (h->flags & URL_WRONLY) != 0, h,
422 url_read_packet, url_write_packet, url_seek_packet) < 0) {
426 s->is_streamed = h->is_streamed;
427 s->max_packet_size = max_packet_size;
431 /* XXX: must be called before any I/O */
432 int url_setbufsize(ByteIOContext *s, int buf_size)
435 buffer = av_malloc(buf_size);
441 s->buffer_size = buf_size;
446 s->buf_end = buffer + buf_size;
450 /* NOTE: when opened as read/write, the buffers are only used for
452 int url_fopen(ByteIOContext *s, const char *filename, int flags)
457 err = url_open(&h, filename, flags);
460 err = url_fdopen(s, h);
468 int url_fclose(ByteIOContext *s)
470 URLContext *h = s->opaque;
473 memset(s, 0, sizeof(ByteIOContext));
477 URLContext *url_fileno(ByteIOContext *s)
482 /* XXX: currently size is limited */
483 int url_fprintf(ByteIOContext *s, const char *fmt, ...)
490 ret = vsnprintf(buf, sizeof(buf), fmt, ap);
492 put_buffer(s, buf, strlen(buf));
496 /* note: unlike fgets, the EOL character is not returned and a whole
497 line is parsed. return NULL if first char read was EOF */
498 char *url_fgets(ByteIOContext *s, char *buf, int buf_size)
508 if (c == EOF || c == '\n')
510 if ((q - buf) < buf_size - 1)
520 * Return the maximum packet size associated to packetized buffered file
521 * handle. If the file is not packetized (stream like http or file on
522 * disk), then 0 is returned.
524 * @param h buffered file handle
525 * @return maximum packet size in bytes
527 int url_fget_max_packet_size(ByteIOContext *s)
529 return s->max_packet_size;
532 /* buffer handling */
533 int url_open_buf(ByteIOContext *s, uint8_t *buf, int buf_size, int flags)
535 return init_put_byte(s, buf, buf_size,
536 (flags & URL_WRONLY) != 0, NULL, NULL, NULL, NULL);
539 /* return the written or read size */
540 int url_close_buf(ByteIOContext *s)
543 return s->buf_ptr - s->buffer;
546 /* output in a dynamic buffer */
548 typedef struct DynBuffer {
549 int pos, size, allocated_size;
552 uint8_t io_buffer[1];
555 static void dyn_buf_write(void *opaque, uint8_t *buf, int buf_size)
557 DynBuffer *d = opaque;
558 int new_size, new_allocated_size;
560 /* reallocate buffer if needed */
561 new_size = d->pos + buf_size;
562 new_allocated_size = d->allocated_size;
563 while (new_size > new_allocated_size) {
564 if (!new_allocated_size)
565 new_allocated_size = new_size;
567 new_allocated_size = (new_allocated_size * 3) / 2 + 1;
570 if (new_allocated_size > d->allocated_size) {
571 d->buffer = av_realloc(d->buffer, new_allocated_size);
572 if(d->buffer == NULL)
574 d->allocated_size = new_allocated_size;
576 memcpy(d->buffer + d->pos, buf, buf_size);
578 if (d->pos > d->size)
582 static void dyn_packet_buf_write(void *opaque, uint8_t *buf, int buf_size)
584 unsigned char buf1[4];
586 /* packetized write: output the header */
587 buf1[0] = (buf_size >> 24);
588 buf1[1] = (buf_size >> 16);
589 buf1[2] = (buf_size >> 8);
590 buf1[3] = (buf_size);
591 dyn_buf_write(opaque, buf1, 4);
594 dyn_buf_write(opaque, buf, buf_size);
597 static int dyn_buf_seek(void *opaque, offset_t offset, int whence)
599 DynBuffer *d = opaque;
601 if (whence == SEEK_CUR)
603 else if (whence == SEEK_END)
605 if (offset < 0 || offset > 0x7fffffffLL)
611 static int url_open_dyn_buf_internal(ByteIOContext *s, int max_packet_size)
614 int io_buffer_size, ret;
617 io_buffer_size = max_packet_size;
619 io_buffer_size = 1024;
621 d = av_malloc(sizeof(DynBuffer) + io_buffer_size);
624 d->io_buffer_size = io_buffer_size;
628 d->allocated_size = 0;
629 ret = init_put_byte(s, d->io_buffer, io_buffer_size,
631 max_packet_size ? dyn_packet_buf_write : dyn_buf_write,
632 max_packet_size ? NULL : dyn_buf_seek);
634 s->max_packet_size = max_packet_size;
640 * Open a write only memory stream.
642 * @param s new IO context
643 * @return zero if no error.
645 int url_open_dyn_buf(ByteIOContext *s)
647 return url_open_dyn_buf_internal(s, 0);
651 * Open a write only packetized memory stream with a maximum packet
652 * size of 'max_packet_size'. The stream is stored in a memory buffer
653 * with a big endian 4 byte header giving the packet size in bytes.
655 * @param s new IO context
656 * @param max_packet_size maximum packet size (must be > 0)
657 * @return zero if no error.
659 int url_open_dyn_packet_buf(ByteIOContext *s, int max_packet_size)
661 if (max_packet_size <= 0)
663 return url_open_dyn_buf_internal(s, max_packet_size);
667 * Return the written size and a pointer to the buffer. The buffer
668 * must be freed with av_free().
669 * @param s IO context
670 * @param pointer to a byte buffer
671 * @return the length of the byte buffer
673 int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer)
675 DynBuffer *d = s->opaque;
680 *pbuffer = d->buffer;