2 * ustream - library for stream buffer management
4 * Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
6 * Permission to use, copy, modify, and/or distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
27 static void ustream_init_buf(struct ustream_buf
*buf
, int len
)
32 memset(buf
, 0, sizeof(*buf
));
33 buf
->data
= buf
->tail
= buf
->head
;
34 buf
->end
= buf
->head
+ len
;
38 static void ustream_add_buf(struct ustream_buf_list
*l
, struct ustream_buf
*buf
)
48 l
->data_tail
= l
->head
;
51 static bool ustream_can_alloc(struct ustream_buf_list
*l
)
53 if (l
->max_buffers
<= 0)
56 return (l
->buffers
< l
->max_buffers
);
59 static int ustream_alloc_default(struct ustream
*s
, struct ustream_buf_list
*l
)
61 struct ustream_buf
*buf
;
63 if (!ustream_can_alloc(l
))
66 buf
= malloc(sizeof(*buf
) + l
->buffer_len
+ s
->string_data
);
67 ustream_init_buf(buf
, l
->buffer_len
);
68 ustream_add_buf(l
, buf
);
73 static void ustream_free_buffers(struct ustream_buf_list
*l
)
75 struct ustream_buf
*buf
= l
->head
;
78 struct ustream_buf
*next
= buf
->next
;
88 void ustream_free(struct ustream
*s
)
93 uloop_timeout_cancel(&s
->state_change
);
94 ustream_free_buffers(&s
->r
);
95 ustream_free_buffers(&s
->w
);
96 s
->write_error
= false;
101 static void ustream_state_change_cb(struct uloop_timeout
*t
)
103 struct ustream
*s
= container_of(t
, struct ustream
, state_change
);
106 ustream_free_buffers(&s
->w
);
110 void ustream_init_defaults(struct ustream
*s
)
112 #define DEFAULT_SET(_f, _default) \
118 DEFAULT_SET(s
->r
.alloc
, ustream_alloc_default
);
119 DEFAULT_SET(s
->w
.alloc
, ustream_alloc_default
);
121 DEFAULT_SET(s
->r
.min_buffers
, 1);
122 DEFAULT_SET(s
->r
.max_buffers
, 1);
123 DEFAULT_SET(s
->r
.buffer_len
, 4096);
125 DEFAULT_SET(s
->w
.min_buffers
, 2);
126 DEFAULT_SET(s
->w
.max_buffers
, -1);
127 DEFAULT_SET(s
->w
.buffer_len
, 256);
131 s
->state_change
.cb
= ustream_state_change_cb
;
134 static bool ustream_should_move(struct ustream_buf_list
*l
, struct ustream_buf
*buf
, int len
)
139 if (buf
->data
== buf
->head
)
142 maxlen
= buf
->end
- buf
->head
;
143 offset
= buf
->data
- buf
->head
;
145 if (offset
> maxlen
/ 2)
148 if (buf
->tail
- buf
->data
< 32 && offset
> maxlen
/ 4)
151 if (buf
!= l
->tail
|| ustream_can_alloc(l
))
154 return (buf
->end
- buf
->tail
< len
);
157 static void ustream_free_buf(struct ustream_buf_list
*l
, struct ustream_buf
*buf
)
162 if (buf
== l
->data_tail
)
163 l
->data_tail
= buf
->next
;
168 if (--l
->buffers
>= l
->min_buffers
) {
174 ustream_init_buf(buf
, buf
->end
- buf
->head
);
175 ustream_add_buf(l
, buf
);
178 static void __ustream_set_read_blocked(struct ustream
*s
, unsigned char val
)
180 bool changed
= !!s
->read_blocked
!= !!val
;
182 s
->read_blocked
= val
;
184 s
->set_read_blocked(s
);
187 void ustream_set_read_blocked(struct ustream
*s
, bool set
)
189 unsigned char val
= s
->read_blocked
& ~READ_BLOCKED_USER
;
192 val
|= READ_BLOCKED_USER
;
194 __ustream_set_read_blocked(s
, val
);
197 void ustream_consume(struct ustream
*s
, int len
)
199 struct ustream_buf
*buf
= s
->r
.head
;
204 s
->r
.data_bytes
-= len
;
205 if (s
->r
.data_bytes
< 0)
209 struct ustream_buf
*next
= buf
->next
;
210 int buf_len
= buf
->tail
- buf
->data
;
218 ustream_free_buf(&s
->r
, buf
);
222 __ustream_set_read_blocked(s
, s
->read_blocked
& ~READ_BLOCKED_FULL
);
225 static void ustream_fixup_string(struct ustream
*s
, struct ustream_buf
*buf
)
233 static bool ustream_prepare_buf(struct ustream
*s
, struct ustream_buf_list
*l
, int len
)
235 struct ustream_buf
*buf
;
239 if (ustream_should_move(l
, buf
, len
)) {
240 int len
= buf
->tail
- buf
->data
;
242 memmove(buf
->head
, buf
->data
, len
);
243 buf
->data
= buf
->head
;
244 buf
->tail
= buf
->data
+ len
;
247 ustream_fixup_string(s
, buf
);
249 if (buf
->tail
!= buf
->end
)
253 if (buf
&& buf
->next
) {
254 l
->data_tail
= buf
->next
;
258 if (!ustream_can_alloc(l
))
261 if (l
->alloc(s
, l
) < 0)
264 l
->data_tail
= l
->tail
;
268 char *ustream_reserve(struct ustream
*s
, int len
, int *maxlen
)
270 struct ustream_buf
*buf
= s
->r
.head
;
272 if (!ustream_prepare_buf(s
, &s
->r
, len
)) {
273 __ustream_set_read_blocked(s
, s
->read_blocked
| READ_BLOCKED_FULL
);
278 buf
= s
->r
.data_tail
;
279 *maxlen
= buf
->end
- buf
->tail
;
283 void ustream_fill_read(struct ustream
*s
, int len
)
285 struct ustream_buf
*buf
= s
->r
.data_tail
;
289 s
->r
.data_bytes
+= len
;
294 maxlen
= buf
->end
- buf
->tail
;
300 ustream_fixup_string(s
, buf
);
302 s
->r
.data_tail
= buf
;
307 s
->notify_read(s
, n
);
310 char *ustream_get_read_buf(struct ustream
*s
, int *buflen
)
316 len
= s
->r
.head
->tail
- s
->r
.head
->data
;
317 data
= s
->r
.head
->data
;
329 static void ustream_write_error(struct ustream
*s
)
331 s
->write_error
= true;
332 ustream_state_change(s
);
335 bool ustream_write_pending(struct ustream
*s
)
337 struct ustream_buf
*buf
= s
->w
.head
;
344 struct ustream_buf
*next
= buf
->next
;
345 int maxlen
= buf
->tail
- buf
->data
;
347 len
= s
->write(s
, buf
->data
, maxlen
, !!buf
->next
);
349 ustream_write_error(s
);
357 s
->w
.data_bytes
-= len
;
363 ustream_free_buf(&s
->w
, buf
);
368 s
->notify_write(s
, wr
);
370 if (s
->eof
&& wr
&& !s
->w
.data_bytes
)
371 ustream_state_change(s
);
373 return !s
->w
.data_bytes
;
376 static int ustream_write_buffered(struct ustream
*s
, const char *data
, int len
, int wr
)
378 struct ustream_buf_list
*l
= &s
->w
;
379 struct ustream_buf
*buf
;
383 if (!ustream_prepare_buf(s
, &s
->w
, len
))
388 maxlen
= buf
->end
- buf
->tail
;
392 memcpy(buf
->tail
, data
, maxlen
);
397 l
->data_bytes
+= maxlen
;
403 int ustream_write(struct ustream
*s
, const char *data
, int len
, bool more
)
405 struct ustream_buf_list
*l
= &s
->w
;
411 if (!l
->data_bytes
) {
412 wr
= s
->write(s
, data
, len
, more
);
417 ustream_write_error(s
);
425 return ustream_write_buffered(s
, data
, len
, wr
);
428 #define MAX_STACK_BUFLEN 256
430 int ustream_vprintf(struct ustream
*s
, const char *format
, va_list arg
)
432 struct ustream_buf_list
*l
= &s
->w
;
435 int wr
, maxlen
, buflen
;
437 if (!l
->data_bytes
) {
438 buf
= alloca(MAX_STACK_BUFLEN
);
440 maxlen
= vsnprintf(buf
, MAX_STACK_BUFLEN
, format
, arg2
);
442 if (maxlen
< MAX_STACK_BUFLEN
) {
443 wr
= s
->write(s
, buf
, maxlen
, false);
445 ustream_write_error(s
);
453 return ustream_write_buffered(s
, buf
, maxlen
, wr
);
455 buf
= malloc(maxlen
+ 1);
456 wr
= vsnprintf(buf
, maxlen
+ 1, format
, arg
);
457 wr
= ustream_write(s
, buf
, wr
, false);
463 if (!ustream_prepare_buf(s
, l
, 1))
466 buf
= l
->data_tail
->tail
;
467 buflen
= l
->data_tail
->end
- buf
;
470 maxlen
= vsnprintf(buf
, buflen
, format
, arg2
);
477 l
->data_tail
->tail
+= wr
;
482 buf
= malloc(maxlen
+ 1);
483 maxlen
= vsnprintf(buf
, maxlen
+ 1, format
, arg
);
484 wr
= ustream_write_buffered(s
, buf
+ wr
, maxlen
- wr
, wr
);
490 int ustream_printf(struct ustream
*s
, const char *format
, ...)
495 va_start(arg
, format
);
496 ret
= ustream_vprintf(s
, format
, arg
);