3 * Copyright (c) 2000,2001 Fabrice Bellard
5 * This file is part of FFmpeg.
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.
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.
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
22 #include "libavutil/crc.h"
23 #include "libavutil/dict.h"
24 #include "libavutil/intreadwrite.h"
25 #include "libavutil/log.h"
26 #include "libavutil/opt.h"
27 #include "libavutil/avassert.h"
30 #include "avio_internal.h"
35 #define IO_BUFFER_SIZE 32768
38 * Do seeks within this distance ahead of the current buffer by skipping
39 * data instead of calling the protocol seek function, for seekable
42 #define SHORT_SEEK_THRESHOLD 4096
44 static void *ffio_url_child_next(void *obj, void *prev)
47 return prev ? NULL : s->opaque;
50 static const AVClass *ffio_url_child_class_next(const AVClass *prev)
52 return prev ? NULL : &ffurl_context_class;
55 static const AVOption ffio_url_options[] = {
59 const AVClass ffio_url_class = {
60 .class_name = "AVIOContext",
61 .item_name = av_default_item_name,
62 .version = LIBAVUTIL_VERSION_INT,
63 .option = ffio_url_options,
64 .child_next = ffio_url_child_next,
65 .child_class_next = ffio_url_child_class_next,
68 static void fill_buffer(AVIOContext *s);
69 static int url_resetbuf(AVIOContext *s, int flags);
71 int ffio_init_context(AVIOContext *s,
72 unsigned char *buffer,
76 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
77 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
78 int64_t (*seek)(void *opaque, int64_t offset, int whence))
82 s->buffer_size = buffer_size;
87 url_resetbuf(s, write_flag ? AVIO_FLAG_WRITE : AVIO_FLAG_READ);
89 s->write_packet = write_packet;
90 s->read_packet = read_packet;
96 s->seekable = seek ? AVIO_SEEKABLE_NORMAL : 0;
97 s->max_packet_size = 0;
98 s->update_checksum = NULL;
100 if (!read_packet && !write_flag) {
101 s->pos = buffer_size;
102 s->buf_end = s->buffer + buffer_size;
104 s->read_pause = NULL;
110 AVIOContext *avio_alloc_context(
111 unsigned char *buffer,
115 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
116 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
117 int64_t (*seek)(void *opaque, int64_t offset, int whence))
119 AVIOContext *s = av_mallocz(sizeof(AVIOContext));
122 ffio_init_context(s, buffer, buffer_size, write_flag, opaque,
123 read_packet, write_packet, seek);
127 static void writeout(AVIOContext *s, const uint8_t *data, int len)
129 if (s->write_packet && !s->error) {
130 int ret = s->write_packet(s->opaque, (uint8_t *)data, len);
135 s->writeout_count ++;
139 static void flush_buffer(AVIOContext *s)
141 if (s->buf_ptr > s->buffer) {
142 writeout(s, s->buffer, s->buf_ptr - s->buffer);
143 if (s->update_checksum) {
144 s->checksum = s->update_checksum(s->checksum, s->checksum_ptr,
145 s->buf_ptr - s->checksum_ptr);
146 s->checksum_ptr = s->buffer;
149 s->buf_ptr = s->buffer;
152 void avio_w8(AVIOContext *s, int b)
154 av_assert2(b>=-128 && b<=255);
156 if (s->buf_ptr >= s->buf_end)
160 void ffio_fill(AVIOContext *s, int b, int count)
163 int len = FFMIN(s->buf_end - s->buf_ptr, count);
164 memset(s->buf_ptr, b, len);
167 if (s->buf_ptr >= s->buf_end)
174 void avio_write(AVIOContext *s, const unsigned char *buf, int size)
176 if (s->direct && !s->update_checksum) {
178 writeout(s, buf, size);
182 int len = FFMIN(s->buf_end - s->buf_ptr, size);
183 memcpy(s->buf_ptr, buf, len);
186 if (s->buf_ptr >= s->buf_end)
194 void avio_flush(AVIOContext *s)
200 int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
204 int force = whence & AVSEEK_FORCE;
206 whence &= ~AVSEEK_FORCE;
209 return AVERROR(EINVAL);
211 buffer_size = s->buf_end - s->buffer;
212 pos = s->pos - (s->write_flag ? 0 : buffer_size);
214 if (whence != SEEK_CUR && whence != SEEK_SET)
215 return AVERROR(EINVAL);
217 if (whence == SEEK_CUR) {
218 offset1 = pos + (s->buf_ptr - s->buffer);
223 offset1 = offset - pos;
224 if (!s->must_flush && (!s->direct || !s->seek) &&
225 offset1 >= 0 && offset1 <= buffer_size) {
226 /* can do the seek inside the buffer */
227 s->buf_ptr = s->buffer + offset1;
228 } else if ((!s->seekable ||
229 offset1 <= s->buf_end + SHORT_SEEK_THRESHOLD - s->buffer) &&
230 !s->write_flag && offset1 >= 0 &&
231 (!s->direct || !s->seek) &&
232 (whence != SEEK_END || force)) {
233 while(s->pos < offset && !s->eof_reached)
237 s->buf_ptr = s->buf_end + offset - s->pos;
238 } else if(!s->write_flag && offset1 < 0 && -offset1 < buffer_size>>1 && s->seek && offset > 0) {
241 pos -= FFMIN(buffer_size>>1, pos);
242 if ((res = s->seek(s->opaque, pos, SEEK_SET)) < 0)
245 s->buf_ptr = s->buffer;
249 return avio_seek(s, offset, SEEK_SET | force);
257 return AVERROR(EPIPE);
258 if ((res = s->seek(s->opaque, offset, SEEK_SET)) < 0)
262 s->buf_end = s->buffer;
263 s->buf_ptr = s->buffer;
270 int64_t avio_skip(AVIOContext *s, int64_t offset)
272 return avio_seek(s, offset, SEEK_CUR);
275 int64_t avio_size(AVIOContext *s)
280 return AVERROR(EINVAL);
283 return AVERROR(ENOSYS);
284 size = s->seek(s->opaque, 0, AVSEEK_SIZE);
286 if ((size = s->seek(s->opaque, -1, SEEK_END)) < 0)
289 s->seek(s->opaque, s->pos, SEEK_SET);
294 int url_feof(AVIOContext *s)
302 return s->eof_reached;
305 void avio_wl32(AVIOContext *s, unsigned int val)
307 avio_w8(s, (uint8_t) val );
308 avio_w8(s, (uint8_t)(val >> 8 ));
309 avio_w8(s, (uint8_t)(val >> 16));
310 avio_w8(s, val >> 24 );
313 void avio_wb32(AVIOContext *s, unsigned int val)
315 avio_w8(s, val >> 24 );
316 avio_w8(s, (uint8_t)(val >> 16));
317 avio_w8(s, (uint8_t)(val >> 8 ));
318 avio_w8(s, (uint8_t) val );
321 int avio_put_str(AVIOContext *s, const char *str)
326 avio_write(s, (const unsigned char *) str, len);
332 int avio_put_str16le(AVIOContext *s, const char *str)
334 const uint8_t *q = str;
342 GET_UTF8(ch, *q++, goto invalid;)
343 PUT_UTF16(ch, tmp, avio_wl16(s, tmp); ret += 2;)
346 av_log(s, AV_LOG_ERROR, "Invaid UTF8 sequence in avio_put_str16le\n");
347 err = AVERROR(EINVAL);
356 int ff_get_v_length(uint64_t val)
366 void ff_put_v(AVIOContext *bc, uint64_t val)
368 int i = ff_get_v_length(val);
371 avio_w8(bc, 128 | (uint8_t)(val >> (7*i)));
373 avio_w8(bc, val & 127);
376 void avio_wl64(AVIOContext *s, uint64_t val)
378 avio_wl32(s, (uint32_t)(val & 0xffffffff));
379 avio_wl32(s, (uint32_t)(val >> 32));
382 void avio_wb64(AVIOContext *s, uint64_t val)
384 avio_wb32(s, (uint32_t)(val >> 32));
385 avio_wb32(s, (uint32_t)(val & 0xffffffff));
388 void avio_wl16(AVIOContext *s, unsigned int val)
390 avio_w8(s, (uint8_t)val);
391 avio_w8(s, (int)val >> 8);
394 void avio_wb16(AVIOContext *s, unsigned int val)
396 avio_w8(s, (int)val >> 8);
397 avio_w8(s, (uint8_t)val);
400 void avio_wl24(AVIOContext *s, unsigned int val)
402 avio_wl16(s, val & 0xffff);
403 avio_w8(s, (int)val >> 16);
406 void avio_wb24(AVIOContext *s, unsigned int val)
408 avio_wb16(s, (int)val >> 8);
409 avio_w8(s, (uint8_t)val);
414 static void fill_buffer(AVIOContext *s)
416 int max_buffer_size = s->max_packet_size ?
417 s->max_packet_size : IO_BUFFER_SIZE;
418 uint8_t *dst = s->buf_end - s->buffer + max_buffer_size < s->buffer_size ?
419 s->buf_end : s->buffer;
420 int len = s->buffer_size - (dst - s->buffer);
422 /* can't fill the buffer without read_packet, just set EOF if appropriate */
423 if (!s->read_packet && s->buf_ptr >= s->buf_end)
426 /* no need to do anything if EOF already reached */
430 if (s->update_checksum && dst == s->buffer) {
431 if (s->buf_end > s->checksum_ptr)
432 s->checksum = s->update_checksum(s->checksum, s->checksum_ptr,
433 s->buf_end - s->checksum_ptr);
434 s->checksum_ptr = s->buffer;
437 /* make buffer smaller in case it ended up large after probing */
438 if (s->read_packet && s->orig_buffer_size && s->buffer_size > s->orig_buffer_size) {
439 if (dst == s->buffer) {
440 ffio_set_buf_size(s, s->orig_buffer_size);
442 s->checksum_ptr = dst = s->buffer;
444 av_assert0(len >= s->orig_buffer_size);
445 len = s->orig_buffer_size;
449 len = s->read_packet(s->opaque, dst, len);
453 /* do not modify buffer if EOF reached so that a seek back can
454 be done without rereading data */
461 s->buf_end = dst + len;
462 s->bytes_read += len;
466 unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,
469 return av_crc(av_crc_get_table(AV_CRC_32_IEEE), checksum, buf, len);
472 unsigned long ffio_get_checksum(AVIOContext *s)
474 s->checksum = s->update_checksum(s->checksum, s->checksum_ptr,
475 s->buf_ptr - s->checksum_ptr);
476 s->update_checksum = NULL;
480 void ffio_init_checksum(AVIOContext *s,
481 unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
482 unsigned long checksum)
484 s->update_checksum = update_checksum;
485 if (s->update_checksum) {
486 s->checksum = checksum;
487 s->checksum_ptr = s->buf_ptr;
491 /* XXX: put an inline version */
492 int avio_r8(AVIOContext *s)
494 if (s->buf_ptr >= s->buf_end)
496 if (s->buf_ptr < s->buf_end)
497 return *s->buf_ptr++;
501 int avio_read(AVIOContext *s, unsigned char *buf, int size)
507 len = s->buf_end - s->buf_ptr;
510 if (len == 0 || s->write_flag) {
511 if((s->direct || size > s->buffer_size) && !s->update_checksum){
513 len = s->read_packet(s->opaque, buf, size);
515 /* do not modify buffer if EOF reached so that a seek back can
516 be done without rereading data */
523 s->bytes_read += len;
526 s->buf_ptr = s->buffer;
527 s->buf_end = s->buffer/* + len*/;
531 len = s->buf_end - s->buf_ptr;
536 memcpy(buf, s->buf_ptr, len);
543 if (s->error) return s->error;
544 if (url_feof(s)) return AVERROR_EOF;
549 int ffio_read_indirect(AVIOContext *s, unsigned char *buf, int size, const unsigned char **data)
551 if (s->buf_end - s->buf_ptr >= size && !s->write_flag) {
557 return avio_read(s, buf, size);
561 int ffio_read_partial(AVIOContext *s, unsigned char *buf, int size)
568 if (s->read_packet && s->write_flag) {
569 len = s->read_packet(s->opaque, buf, size);
575 len = s->buf_end - s->buf_ptr;
577 /* Reset the buf_end pointer to the start of the buffer, to make sure
578 * the fill_buffer call tries to read as much data as fits into the
579 * full buffer, instead of just what space is left after buf_end.
580 * This avoids returning partial packets at the end of the buffer,
581 * for packet based inputs.
583 s->buf_end = s->buf_ptr = s->buffer;
585 len = s->buf_end - s->buf_ptr;
589 memcpy(buf, s->buf_ptr, len);
592 if (s->error) return s->error;
593 if (url_feof(s)) return AVERROR_EOF;
598 unsigned int avio_rl16(AVIOContext *s)
602 val |= avio_r8(s) << 8;
606 unsigned int avio_rl24(AVIOContext *s)
610 val |= avio_r8(s) << 16;
614 unsigned int avio_rl32(AVIOContext *s)
618 val |= avio_rl16(s) << 16;
622 uint64_t avio_rl64(AVIOContext *s)
625 val = (uint64_t)avio_rl32(s);
626 val |= (uint64_t)avio_rl32(s) << 32;
630 unsigned int avio_rb16(AVIOContext *s)
633 val = avio_r8(s) << 8;
638 unsigned int avio_rb24(AVIOContext *s)
641 val = avio_rb16(s) << 8;
645 unsigned int avio_rb32(AVIOContext *s)
648 val = avio_rb16(s) << 16;
653 int ff_get_line(AVIOContext *s, char *buf, int maxlen)
660 if (c && i < maxlen-1)
662 } while (c != '\n' && c);
668 int avio_get_str(AVIOContext *s, int maxlen, char *buf, int buflen)
673 return AVERROR(EINVAL);
674 // reserve 1 byte for terminating 0
675 buflen = FFMIN(buflen - 1, maxlen);
676 for (i = 0; i < buflen; i++)
677 if (!(buf[i] = avio_r8(s)))
680 for (; i < maxlen; i++)
686 #define GET_STR16(type, read) \
687 int avio_get_str16 ##type(AVIOContext *pb, int maxlen, char *buf, int buflen)\
692 return AVERROR(EINVAL); \
693 while (ret + 1 < maxlen) {\
696 GET_UTF16(ch, (ret += 2) <= maxlen ? read(pb) : 0, break;)\
699 PUT_UTF8(ch, tmp, if (q - buf < buflen - 1) *q++ = tmp;)\
705 GET_STR16(le, avio_rl16)
706 GET_STR16(be, avio_rb16)
710 uint64_t avio_rb64(AVIOContext *s)
713 val = (uint64_t)avio_rb32(s) << 32;
714 val |= (uint64_t)avio_rb32(s);
718 uint64_t ffio_read_varlen(AVIOContext *bc){
724 val= (val<<7) + (tmp&127);
729 int ffio_fdopen(AVIOContext **s, URLContext *h)
732 int buffer_size, max_packet_size;
734 max_packet_size = h->max_packet_size;
735 if (max_packet_size) {
736 buffer_size = max_packet_size; /* no need to bufferize more than one packet */
738 buffer_size = IO_BUFFER_SIZE;
740 buffer = av_malloc(buffer_size);
742 return AVERROR(ENOMEM);
744 *s = avio_alloc_context(buffer, buffer_size, h->flags & AVIO_FLAG_WRITE, h,
745 (void*)ffurl_read, (void*)ffurl_write, (void*)ffurl_seek);
748 return AVERROR(ENOMEM);
750 (*s)->direct = h->flags & AVIO_FLAG_DIRECT;
751 (*s)->seekable = h->is_streamed ? 0 : AVIO_SEEKABLE_NORMAL;
752 (*s)->max_packet_size = max_packet_size;
754 (*s)->read_pause = (int (*)(void *, int))h->prot->url_read_pause;
755 (*s)->read_seek = (int64_t (*)(void *, int, int64_t, int))h->prot->url_read_seek;
757 (*s)->av_class = &ffio_url_class;
761 int ffio_ensure_seekback(AVIOContext *s, int buf_size)
764 int max_buffer_size = s->max_packet_size ?
765 s->max_packet_size : IO_BUFFER_SIZE;
766 int filled = s->buf_end - s->buffer;
768 buf_size += s->buf_ptr - s->buffer + max_buffer_size;
770 if (buf_size < filled || s->seekable)
772 av_assert0(!s->write_flag);
774 buffer = av_malloc(buf_size);
776 return AVERROR(ENOMEM);
778 memcpy(buffer, s->buffer, filled);
780 s->buf_ptr = buffer + (s->buf_ptr - s->buffer);
781 s->buf_end = buffer + (s->buf_end - s->buffer);
783 s->buffer_size = buf_size;
787 int ffio_set_buf_size(AVIOContext *s, int buf_size)
790 buffer = av_malloc(buf_size);
792 return AVERROR(ENOMEM);
796 s->orig_buffer_size =
797 s->buffer_size = buf_size;
799 url_resetbuf(s, s->write_flag ? AVIO_FLAG_WRITE : AVIO_FLAG_READ);
803 static int url_resetbuf(AVIOContext *s, int flags)
805 av_assert1(flags == AVIO_FLAG_WRITE || flags == AVIO_FLAG_READ);
807 if (flags & AVIO_FLAG_WRITE) {
808 s->buf_end = s->buffer + s->buffer_size;
811 s->buf_end = s->buffer;
817 int ffio_rewind_with_probe_data(AVIOContext *s, unsigned char **bufp, int buf_size)
819 int64_t buffer_start;
821 int overlap, new_size, alloc_size;
822 uint8_t *buf = *bufp;
826 return AVERROR(EINVAL);
829 buffer_size = s->buf_end - s->buffer;
831 /* the buffers must touch or overlap */
832 if ((buffer_start = s->pos - buffer_size) > buf_size) {
834 return AVERROR(EINVAL);
837 overlap = buf_size - buffer_start;
838 new_size = buf_size + buffer_size - overlap;
840 alloc_size = FFMAX(s->buffer_size, new_size);
841 if (alloc_size > buf_size)
842 if (!(buf = (*bufp) = av_realloc_f(buf, 1, alloc_size)))
843 return AVERROR(ENOMEM);
845 if (new_size > buf_size) {
846 memcpy(buf + buf_size, s->buffer + overlap, buffer_size - overlap);
851 s->buf_ptr = s->buffer = buf;
852 s->buffer_size = alloc_size;
854 s->buf_end = s->buf_ptr + buf_size;
861 int avio_open(AVIOContext **s, const char *filename, int flags)
863 return avio_open2(s, filename, flags, NULL, NULL);
866 int avio_open2(AVIOContext **s, const char *filename, int flags,
867 const AVIOInterruptCB *int_cb, AVDictionary **options)
872 err = ffurl_open(&h, filename, flags, int_cb, options);
875 err = ffio_fdopen(s, h);
883 int avio_close(AVIOContext *s)
892 av_freep(&s->buffer);
894 av_log(s, AV_LOG_DEBUG, "Statistics: %d seeks, %d writeouts\n", s->seek_count, s->writeout_count);
896 av_log(s, AV_LOG_DEBUG, "Statistics: %"PRId64" bytes read, %d seeks\n", s->bytes_read, s->seek_count);
898 return ffurl_close(h);
901 int avio_closep(AVIOContext **s)
903 int ret = avio_close(*s);
908 int avio_printf(AVIOContext *s, const char *fmt, ...)
915 ret = vsnprintf(buf, sizeof(buf), fmt, ap);
917 avio_write(s, buf, strlen(buf));
921 int avio_pause(AVIOContext *s, int pause)
924 return AVERROR(ENOSYS);
925 return s->read_pause(s->opaque, pause);
928 int64_t avio_seek_time(AVIOContext *s, int stream_index,
929 int64_t timestamp, int flags)
931 URLContext *h = s->opaque;
934 return AVERROR(ENOSYS);
935 ret = s->read_seek(h, stream_index, timestamp, flags);
938 s->buf_ptr = s->buf_end; // Flush buffer
939 pos = s->seek(h, 0, SEEK_CUR);
942 else if (pos != AVERROR(ENOSYS))
948 /* output in a dynamic buffer */
950 typedef struct DynBuffer {
951 int pos, size, allocated_size;
954 uint8_t io_buffer[1];
957 static int dyn_buf_write(void *opaque, uint8_t *buf, int buf_size)
959 DynBuffer *d = opaque;
960 unsigned new_size, new_allocated_size;
962 /* reallocate buffer if needed */
963 new_size = d->pos + buf_size;
964 new_allocated_size = d->allocated_size;
965 if (new_size < d->pos || new_size > INT_MAX/2)
967 while (new_size > new_allocated_size) {
968 if (!new_allocated_size)
969 new_allocated_size = new_size;
971 new_allocated_size += new_allocated_size / 2 + 1;
974 if (new_allocated_size > d->allocated_size) {
976 if ((err = av_reallocp(&d->buffer, new_allocated_size)) < 0) {
977 d->allocated_size = 0;
981 d->allocated_size = new_allocated_size;
983 memcpy(d->buffer + d->pos, buf, buf_size);
985 if (d->pos > d->size)
990 static int dyn_packet_buf_write(void *opaque, uint8_t *buf, int buf_size)
992 unsigned char buf1[4];
995 /* packetized write: output the header */
996 AV_WB32(buf1, buf_size);
997 ret = dyn_buf_write(opaque, buf1, 4);
1002 return dyn_buf_write(opaque, buf, buf_size);
1005 static int64_t dyn_buf_seek(void *opaque, int64_t offset, int whence)
1007 DynBuffer *d = opaque;
1009 if (whence == SEEK_CUR)
1011 else if (whence == SEEK_END)
1013 if (offset < 0 || offset > 0x7fffffffLL)
1019 static int url_open_dyn_buf_internal(AVIOContext **s, int max_packet_size)
1022 unsigned io_buffer_size = max_packet_size ? max_packet_size : 1024;
1024 if (sizeof(DynBuffer) + io_buffer_size < io_buffer_size)
1026 d = av_mallocz(sizeof(DynBuffer) + io_buffer_size);
1028 return AVERROR(ENOMEM);
1029 d->io_buffer_size = io_buffer_size;
1030 *s = avio_alloc_context(d->io_buffer, d->io_buffer_size, 1, d, NULL,
1031 max_packet_size ? dyn_packet_buf_write : dyn_buf_write,
1032 max_packet_size ? NULL : dyn_buf_seek);
1035 return AVERROR(ENOMEM);
1037 (*s)->max_packet_size = max_packet_size;
1041 int avio_open_dyn_buf(AVIOContext **s)
1043 return url_open_dyn_buf_internal(s, 0);
1046 int ffio_open_dyn_packet_buf(AVIOContext **s, int max_packet_size)
1048 if (max_packet_size <= 0)
1050 return url_open_dyn_buf_internal(s, max_packet_size);
1053 int avio_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer)
1057 static const char padbuf[FF_INPUT_BUFFER_PADDING_SIZE] = {0};
1066 /* don't attempt to pad fixed-size packet buffers */
1067 if (!s->max_packet_size) {
1068 avio_write(s, padbuf, sizeof(padbuf));
1069 padding = FF_INPUT_BUFFER_PADDING_SIZE;
1074 *pbuffer = d->buffer;
1078 return size - padding;
1081 static int null_buf_write(void *opaque, uint8_t *buf, int buf_size)
1083 DynBuffer *d = opaque;
1086 if (d->pos > d->size)
1091 int ffio_open_null_buf(AVIOContext **s)
1093 int ret = url_open_dyn_buf_internal(s, 0);
1095 AVIOContext *pb = *s;
1096 pb->write_packet = null_buf_write;
1101 int ffio_close_null_buf(AVIOContext *s)
1103 DynBuffer *d = s->opaque;