1 /***************************************************************************
3 * Open \______ \ ____ ____ | | _\_ |__ _______ ___
4 * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
5 * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
6 * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
10 * Copyright (C) 2007 Nicolas Pennequin
12 * All files in this archive are subject to the GNU General Public License.
13 * See the file COPYING in the source tree root for full license agreement.
15 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
16 * KIND, either express or implied.
18 ****************************************************************************/
25 #include "buffering.h"
44 #include "mp3_playback.h"
52 #include "ata_idle_notify.h"
55 #define ata_disk_is_active() 1
59 #define GUARD_BUFSIZE (32*1024)
61 #define GUARD_BUFSIZE (8*1024)
65 /* macros to enable logf for queues
66 logging on SYS_TIMEOUT can be disabled */
68 /* Define this for logf output of all queuing except SYS_TIMEOUT */
69 #define BUFFERING_LOGQUEUES
70 /* Define this to logf SYS_TIMEOUT messages */
71 /* #define BUFFERING_LOGQUEUES_SYS_TIMEOUT */
74 #ifdef BUFFERING_LOGQUEUES
75 #define LOGFQUEUE logf
77 #define LOGFQUEUE(...)
80 #ifdef BUFFERING_LOGQUEUES_SYS_TIMEOUT
81 #define LOGFQUEUE_SYS_TIMEOUT logf
83 #define LOGFQUEUE_SYS_TIMEOUT(...)
87 /* amount of data to read in one read() call */
88 #define AUDIO_DEFAULT_FILECHUNK (1024*32)
90 /* Ring buffer helper macros */
91 /* Buffer pointer (p) plus value (v), wrapped if necessary */
92 #define RINGBUF_ADD(p,v) ((p+v)<buffer_len ? p+v : p+v-buffer_len)
93 /* Buffer pointer (p) minus value (v), wrapped if necessary */
94 #define RINGBUF_SUB(p,v) ((p>=v) ? p-v : p+buffer_len-v)
95 /* How far value (v) plus buffer pointer (p1) will cross buffer pointer (p2) */
96 #define RINGBUF_ADD_CROSS(p1,v,p2) \
97 ((p1<p2) ? (int)(p1+v)-(int)p2 : (int)(p1+v-p2)-(int)buffer_len)
98 /* Bytes available in the buffer */
99 #define BUF_USED RINGBUF_SUB(buf_widx, buf_ridx)
101 struct memory_handle
{
102 int id
; /* A unique ID for the handle */
106 size_t data
; /* Start index of the handle's data buffer */
107 size_t ridx
; /* Current read pointer, relative to the main buffer */
108 size_t widx
; /* Current write pointer */
109 size_t filesize
; /* File total length */
110 size_t filerem
; /* Remaining bytes of file NOT in buffer */
111 size_t available
; /* Available bytes to read from buffer */
112 size_t offset
; /* Offset at which we started reading the file */
113 struct memory_handle
*next
;
115 /* at all times, we have: filesize == offset + available + filerem */
119 static char *guard_buffer
;
121 static size_t buffer_len
;
123 static size_t buf_widx
; /* current writing position */
124 static size_t buf_ridx
; /* current reading position */
125 /* buf_*idx are values relative to the buffer, not real pointers. */
127 static size_t conf_filechunk
= 0;
128 static size_t conf_watermark
= 0; /* Level to trigger filebuf fill */
130 static size_t high_watermark
= 0; /* High watermark for rebuffer */
134 /* current memory handle in the linked list. NULL when the list is empty. */
135 static struct memory_handle
*cur_handle
;
136 /* first memory handle in the linked list. NULL when the list is empty. */
137 static struct memory_handle
*first_handle
;
139 static int num_handles
; /* number of handles in the list */
141 static struct mutex llist_mutex
;
143 /* Handle cache (makes find_handle faster).
144 These need to be global so that move_handle can invalidate them. */
145 static int cached_handle_id
= -1;
146 static struct memory_handle
*cached_handle
= NULL
;
149 /* Messages available to communicate with the buffering thread */
151 Q_BUFFER_HANDLE
= 1, /* Request buffering of a handle */
152 Q_RESET_HANDLE
, /* (internal) Request resetting of a handle to its
153 offset (the offset has to be set beforehand) */
155 Q_BUFFERING_FILL_BUFFER_IF_ACTIVE_ATA
,
158 /* Buffering thread */
159 void buffering_thread(void);
160 static long buffering_stack
[(DEFAULT_STACK_SIZE
+ 0x2000)/sizeof(long)];
161 static const char buffering_thread_name
[] = "buffering";
162 struct thread_entry
*buffering_thread_p
;
163 struct event_queue buffering_queue
;
164 struct queue_sender_list buffering_queue_sender_list
;
168 LINKED LIST MANAGEMENT
169 ======================
171 add_handle : Add a handle to the list
172 rm_handle : Remove a handle from the list
173 find_handle : Get a handle pointer from an ID
174 move_handle : Move a handle in the buffer (with or without its data)
176 These functions only handle the linked list structure. They don't touch the
177 contents of the struct memory_handle headers. They also change the buf_*idx
178 pointers when necessary and manage the handle IDs.
180 The first and current (== last) handle are kept track of.
181 A new handle is added at buf_widx and becomes the current one.
182 buf_widx always points to the current writing position for the current handle
183 buf_ridx always points to the location of the first handle.
184 buf_ridx == buf_widx means the buffer is empty.
188 /* Add a new handle to the linked list and return it. It will have become the
189 new current handle. The handle will reserve "data_size" bytes or if that's
190 not possible, decrease "data_size" to allow adding the handle. */
191 static struct memory_handle
*add_handle(size_t *data_size
)
193 mutex_lock(&llist_mutex
);
195 /* this will give each handle a unique id */
196 static int cur_handle_id
= 1;
198 /* make sure buf_widx is 32-bit aligned so that the handle struct is,
199 but before that we check we can actually align. */
200 if (RINGBUF_ADD_CROSS(buf_widx
, 3, buf_ridx
) >= 0) {
201 mutex_unlock(&llist_mutex
);
204 buf_widx
= (RINGBUF_ADD(buf_widx
, 3)) & ~3;
206 size_t len
= (data_size
? *data_size
: 0)
207 + sizeof(struct memory_handle
);
209 /* check that we actually can add the handle and its data */
210 int overlap
= RINGBUF_ADD_CROSS(buf_widx
, len
, buf_ridx
);
212 *data_size
-= overlap
;
215 if (len
< sizeof(struct memory_handle
)) {
216 /* There isn't even enough space to write the struct */
217 mutex_unlock(&llist_mutex
);
221 struct memory_handle
*new_handle
=
222 (struct memory_handle
*)(&buffer
[buf_widx
]);
224 /* only advance the buffer write index of the size of the struct */
225 buf_widx
= RINGBUF_ADD(buf_widx
, sizeof(struct memory_handle
));
228 /* the new handle is the first one */
229 first_handle
= new_handle
;
233 cur_handle
->next
= new_handle
;
236 cur_handle
= new_handle
;
237 cur_handle
->id
= cur_handle_id
++;
238 cur_handle
->next
= NULL
;
241 mutex_unlock(&llist_mutex
);
245 /* Delete a given memory handle from the linked list
246 and return true for success. Nothing is actually erased from memory. */
247 static bool rm_handle(struct memory_handle
*h
)
249 mutex_lock(&llist_mutex
);
251 if (h
== first_handle
) {
252 first_handle
= h
->next
;
253 if (h
== cur_handle
) {
254 /* h was the first and last handle: the buffer is now empty */
258 /* update buf_ridx to point to the new first handle */
259 buf_ridx
= (void *)first_handle
- (void *)buffer
;
262 struct memory_handle
*m
= first_handle
;
263 while (m
&& m
->next
!= h
) {
266 if (h
&& m
&& m
->next
== h
) {
268 if (h
== cur_handle
) {
270 buf_widx
= cur_handle
->widx
;
273 mutex_unlock(&llist_mutex
);
278 /* Invalidate the cache to prevent it from keeping the old location of h */
279 if (h
== cached_handle
)
280 cached_handle
= NULL
;
284 mutex_unlock(&llist_mutex
);
288 /* Return a pointer to the memory handle of given ID.
289 NULL if the handle wasn't found */
290 static struct memory_handle
*find_handle(int handle_id
)
292 mutex_lock(&llist_mutex
);
294 /* simple caching because most of the time the requested handle
295 will either be the same as the last, or the one after the last */
298 if (cached_handle_id
== handle_id
&&
299 cached_handle_id
== cached_handle
->id
) {
300 mutex_unlock(&llist_mutex
);
301 return cached_handle
;
302 } else if (cached_handle
->next
&&
303 (cached_handle
->next
->id
== handle_id
)) {
304 cached_handle
= cached_handle
->next
;
305 cached_handle_id
= handle_id
;
306 mutex_unlock(&llist_mutex
);
307 return cached_handle
;
311 struct memory_handle
*m
= first_handle
;
312 while (m
&& m
->id
!= handle_id
) {
315 cached_handle_id
= handle_id
;
317 struct memory_handle
*ret
= (m
&& m
->id
== handle_id
) ? m
: NULL
;
319 mutex_unlock(&llist_mutex
);
323 /* Move a memory handle and data_size of its data of delta.
324 Return a pointer to the new location of the handle.
325 delta is the value of which to move the struct data.
326 data_size is the amount of data to move along with the struct. */
327 static struct memory_handle
*move_handle(struct memory_handle
*h
,
328 size_t *delta
, size_t data_size
)
330 mutex_lock(&llist_mutex
);
333 /* aligning backwards would yield a negative result,
334 and moving the handle of such a small amount is a waste
336 mutex_unlock(&llist_mutex
);
339 /* make sure delta is 32-bit aligned so that the handle struct is. */
340 *delta
= (*delta
- 3) & ~3;
342 size_t newpos
= RINGBUF_ADD((void *)h
- (void *)buffer
, *delta
);
344 struct memory_handle
*dest
= (struct memory_handle
*)(&buffer
[newpos
]);
346 /* Invalidate the cache to prevent it from keeping the old location of h */
347 if (h
== cached_handle
)
348 cached_handle
= NULL
;
350 /* the cur_handle pointer might need updating */
351 if (h
== cur_handle
) {
355 if (h
== first_handle
) {
359 struct memory_handle
*m
= first_handle
;
360 while (m
&& m
->next
!= h
) {
363 if (h
&& m
&& m
->next
== h
) {
366 mutex_unlock(&llist_mutex
);
371 memmove(dest
, h
, sizeof(struct memory_handle
) + data_size
);
373 mutex_unlock(&llist_mutex
);
379 BUFFER SPACE MANAGEMENT
380 =======================
382 yield_codec : Used by buffer_handle to know if it should interrupt buffering
383 buffer_handle : Buffer data for a handle
384 reset_handle : Reset writing position and data buffer of a handle to its
386 rebuffer_handle : Seek to a nonbuffered part of a handle by rebuffering the data
387 shrink_handle : Free buffer space by moving a handle
388 fill_buffer : Call buffer_handle for all handles that have data to buffer
389 can_add_handle : Indicate whether it's safe to add a handle
390 data_rem : Total amount of data needing to be buffered
391 wasted_space : Total amount of space available for freeing
392 buffered_data : Total amount of data currently in the buffer
394 These functions are used by the buffering thread to manage buffer space.
397 static bool filebuf_is_lowdata(void)
399 return BUF_USED
< AUDIO_FILEBUF_CRITICAL
;
402 /* Yield to the codec thread for as long as possible if it is in need of data.
403 Return true if the caller should break to let the buffering thread process
405 static bool yield_codec(void)
409 if (!queue_empty(&buffering_queue
))
412 while (pcmbuf_is_lowdata() && !filebuf_is_lowdata())
416 if (!queue_empty(&buffering_queue
))
423 /* Buffer data for the given handle. Return the amount of data buffered
424 or -1 if the handle wasn't found */
425 static ssize_t
buffer_handle(int handle_id
)
427 DEBUGF("buffer_handle(%d)\n", handle_id
);
428 struct memory_handle
*h
= find_handle(handle_id
);
432 if (h
->filerem
== 0) {
433 /* nothing left to buffer */
437 if (h
->fd
< 0) /* file closed, reopen */
440 h
->fd
= open(h
->path
, O_RDONLY
);
448 lseek(h
->fd
, h
->offset
, SEEK_SET
);
454 while (h
->filerem
> 0)
456 /* max amount to copy */
457 size_t copy_n
= MIN( MIN(h
->filerem
, conf_filechunk
),
458 buffer_len
- h
->widx
);
460 /* stop copying if it would overwrite the reading position
461 or the next handle */
462 if (RINGBUF_ADD_CROSS(h
->widx
, copy_n
, buf_ridx
) >= 0 || (h
->next
&&
463 RINGBUF_ADD_CROSS(h
->widx
, copy_n
, (unsigned)
464 ((void *)h
->next
- (void *)buffer
)) > 0))
467 /* rc is the actual amount read */
468 int rc
= read(h
->fd
, &buffer
[h
->widx
], copy_n
);
472 if (h
->type
== TYPE_CODEC
) {
473 DEBUGF("Partial codec\n");
477 DEBUGF("File ended %ld bytes early\n", (long)h
->filerem
);
478 h
->filesize
-= h
->filerem
;
484 h
->widx
= RINGBUF_ADD(h
->widx
, rc
);
491 /* DEBUGF("buffer_handle(%d): buffered %ld bytes. done: %ld. remaining: %ld.\n",
492 h->id, rc, h->available, h->filerem); */
494 /* Stop buffering if new queue events have arrived */
499 if (h
->filerem
== 0) {
500 /* finished buffering the file */
505 DEBUGF("buffer_handle(%d): buffered %ld bytes (%ld of %ld available, "
506 "rem: %ld, off: %ld)\n",
507 handle_id
, (long)ret
, (long)h
->available
, (long)h
->filesize
,
508 (long)h
->filerem
, (long)h
->offset
);
513 void request_buffer_handle(int handle_id
)
515 LOGFQUEUE("buffering >| buffering Q_BUFFER_HANDLE");
516 queue_send(&buffering_queue
, Q_BUFFER_HANDLE
, handle_id
);
519 /* Reset writing position and data buffer of a handle to its current offset.
520 Use this after having set the new offset to use.
521 Returns 0 for success or -1 if the handle wasn't found. */
522 static void reset_handle(int handle_id
)
524 DEBUGF("reset_handle(%d)\n", handle_id
);
526 struct memory_handle
*h
= find_handle(handle_id
);
534 h
->filerem
= h
->filesize
- h
->offset
;
537 lseek(h
->fd
, h
->offset
, SEEK_SET
);
541 /* Seek to a nonbuffered part of a handle by rebuffering the data. */
542 static void rebuffer_handle(int handle_id
, size_t newpos
)
544 struct memory_handle
*h
= find_handle(handle_id
);
548 DEBUGF("rebuffer_handle: resetting the handle to offset %ld\n", (long)newpos
);
551 LOGFQUEUE("? >| buffering Q_RESET_HANDLE");
552 queue_send(&buffering_queue
, Q_RESET_HANDLE
, handle_id
);
554 LOGFQUEUE("? >| buffering Q_BUFFER_HANDLE");
555 queue_send(&buffering_queue
, Q_BUFFER_HANDLE
, handle_id
);
560 static int close_handle(int handle_id
)
562 struct memory_handle
*h
= find_handle(handle_id
);
575 /* Free buffer space by moving the handle struct right before the useful
576 part of its data buffer or by moving all the data. */
577 static void shrink_handle(int handle_id
)
579 struct memory_handle
*h
= find_handle(handle_id
);
584 /* The value of delta might change for alignment reasons */
586 if (h
->next
&& (h
->type
== TYPE_ID3
|| h
->type
== TYPE_CUESHEET
||
587 h
->type
== TYPE_IMAGE
) && h
->filerem
== 0 )
589 /* metadata handle: we can move all of it */
590 delta
= RINGBUF_SUB( (unsigned)((void *)h
->next
- (void *)buffer
),
591 h
->data
) - h
->available
;
592 h
= move_handle(h
, &delta
, h
->available
);
594 h
->data
= RINGBUF_ADD(h
->data
, delta
);
595 h
->ridx
= RINGBUF_ADD(h
->ridx
, delta
);
596 h
->widx
= RINGBUF_ADD(h
->widx
, delta
);
598 /* when moving a struct mp3entry we need to readjust its pointers. */
599 if (h
->type
== TYPE_ID3
&& h
->filesize
== sizeof(struct mp3entry
)) {
600 adjust_mp3entry((struct mp3entry
*)&buffer
[h
->data
],
601 (void *)&buffer
[h
->data
],
602 (void *)&buffer
[RINGBUF_SUB(h
->data
, delta
)]);
605 DEBUGF("shrink_handle(%d): metadata, moved by %ld bytes\n",
606 handle_id
, (long)delta
);
610 /* only move the handle struct */
611 delta
= RINGBUF_SUB(h
->ridx
, h
->data
);
612 h
= move_handle(h
, &delta
, 0);
614 h
->data
= RINGBUF_ADD(h
->data
, delta
);
615 h
->available
-= delta
;
617 DEBUGF("shrink_handle(%d): audio, %ld bytes freed\n",
618 handle_id
, (long)delta
);
622 /* Fill the buffer by buffering as much data as possible for handles that still
623 have data left to buffer */
624 static void fill_buffer(void)
626 DEBUGF("fill_buffer()\n");
627 struct memory_handle
*m
= first_handle
;
628 while (queue_empty(&buffering_queue
) && m
) {
629 if (m
->filerem
> 0) {
630 buffer_handle(m
->id
);
636 if (queue_empty(&buffering_queue
)) {
637 /* only spin the disk down if the filling wasn't interrupted by an
638 event arriving in the queue. */
644 /* Check whether it's safe to add a new handle and reserve space to let the
645 current one finish buffering its data. Used by bufopen and bufalloc as
646 a preliminary check before even trying to physically add the handle.
647 Returns true if it's ok to add a new handle, false if not.
649 static bool can_add_handle(void)
651 if (cur_handle
&& cur_handle
->filerem
> 0) {
652 /* the current handle hasn't finished buffering. We can only add
653 a new one if there is already enough free space to finish
655 if (cur_handle
->filerem
< (buffer_len
- BUF_USED
)) {
656 /* Before adding the new handle we reserve some space for the
657 current one to finish buffering its data. */
658 buf_widx
= RINGBUF_ADD(buf_widx
, cur_handle
->filerem
);
667 /* Return the total amount of data left to be buffered for all the handles */
668 static size_t data_rem(void)
672 struct memory_handle
*m
= first_handle
;
681 /* Return the amount of data we have but don't need anymore. This data can be
682 safely erased to reclaim buffer space. */
683 static size_t wasted_space(void)
687 struct memory_handle
*m
= first_handle
;
689 ret
+= RINGBUF_SUB(m
->ridx
, m
->data
);
696 static size_t buffered_data(void)
699 struct memory_handle
*m
= first_handle
;
707 size_t useful_data(int start_handle_id
)
709 /* use a static var to remember which handle to start with when the caller
710 doesn't have access to the playback data. */
711 static int start_id
= 0;
712 if (start_handle_id
> 0)
713 start_id
= start_handle_id
;
716 struct memory_handle
*m
= first_handle
;
718 if (m
->id
>= start_id
)
719 ret
+= m
->available
- RINGBUF_SUB(m
->ridx
, m
->data
);
727 BUFFERING API FUNCTIONS
728 =======================
730 bufopen : Request the opening of a new handle for a file
731 bufalloc : Open a new handle for data other than a file.
732 bufclose : Close an open handle
733 bufseek : Set the read pointer in a handle
734 bufadvance : Move the read pointer in a handle
735 bufread : Copy data from a handle into a given buffer
736 bufgetdata : Give a pointer to the handle's data
737 bufused : Return the amount of buffer space used
739 These functions are exported, to allow interaction with the buffer.
740 They take care of the content of the structs, and rely on the linked list
741 management functions for all the actual handle management work.
745 /* Reserve space in the buffer for a file.
746 filename: name of the file to open
747 offset: offset at which to start buffering the file, useful when the first
748 (offset-1) bytes of the file aren't needed.
749 return value: <0 if the file cannot be opened, or one file already
750 queued to be opened, otherwise the handle for the file in the buffer
752 int bufopen(char *file
, size_t offset
, enum data_type type
)
754 if (!can_add_handle())
757 int fd
= open(file
, O_RDONLY
);
761 size_t size
= filesize(fd
) - offset
;
763 if (type
!= TYPE_AUDIO
&&
764 size
+ sizeof(struct memory_handle
) > buffer_len
- buf_widx
)
766 /* for types other than audio, the data can't wrap, so we force it */
770 DEBUGF("bufopen: %s (offset: %ld) (%ld bytes needed)...\n",
771 file
, (long)offset
, (long)size
);
773 struct memory_handle
*h
= add_handle(&size
);
776 DEBUGF("bufopen: failed to add handle\n");
781 strncpy(h
->path
, file
, MAX_PATH
);
783 h
->filesize
= filesize(fd
);
784 h
->filerem
= h
->filesize
- offset
;
794 DEBUGF("bufopen: allocated %ld bytes. ID: %d\n", (long)size
, h
->id
);
796 if (type
== TYPE_CODEC
|| type
== TYPE_CUESHEET
|| type
== TYPE_IMAGE
) {
797 /* Immediately buffer those */
798 LOGFQUEUE("? >| buffering Q_BUFFER_HANDLE");
799 queue_send(&buffering_queue
, Q_BUFFER_HANDLE
, h
->id
);
802 DEBUGF("bufopen: opened handle %d\n", h
->id
);
806 /* Open a new handle from data that needs to be copied from memory.
807 src is the source buffer from which to copy data. It can be NULL to simply
808 reserve buffer space.
809 size is the requested size. The call will only be successful if the
810 requested amount of data can entirely fit in the buffer without wrapping.
811 Return value is the handle id for success or <0 for failure.
813 int bufalloc(void *src
, size_t size
, enum data_type type
)
815 if (!can_add_handle())
818 if (size
+ sizeof(struct memory_handle
) > buffer_len
- buf_widx
) {
819 /* The data would need to wrap. */
820 DEBUGF("bufalloc: data wrap\n");
824 size_t allocsize
= size
;
825 struct memory_handle
*h
= add_handle(&allocsize
);
827 if (!h
|| allocsize
!= size
)
831 if (type
== TYPE_ID3
&& size
== sizeof(struct mp3entry
)) {
832 DEBUGF("bufalloc: allocating metadata\n");
833 /* specially take care of struct mp3entry */
834 copy_mp3entry((struct mp3entry
*)&buffer
[buf_widx
],
835 (struct mp3entry
*)src
);
837 memcpy(&buffer
[buf_widx
], src
, size
);
852 buf_widx
= RINGBUF_ADD(buf_widx
, size
);
854 DEBUGF("bufalloc: opened handle %d\n", h
->id
);
858 /* Close the handle. Return 0 for success and < 0 for failure */
859 int bufclose(int handle_id
)
861 DEBUGF("bufclose(%d)\n", handle_id
);
863 LOGFQUEUE("buffering >| Q_CLOSE_HANDLE");
864 return queue_send(&buffering_queue
, Q_CLOSE_HANDLE
, handle_id
);
867 /* Set reading index in handle (relatively to the start of the file).
868 Access before the available data will trigger a rebuffer.
869 Return 0 for success and < 0 for failure:
870 -1 if the handle wasn't found
871 -2 if the new requested position was beyond the end of the file
873 int bufseek(int handle_id
, size_t newpos
)
875 struct memory_handle
*h
= find_handle(handle_id
);
879 if (newpos
> h
->filesize
) {
880 /* access beyond the end of the file */
883 else if (newpos
< h
->offset
|| h
->offset
+ h
->available
< newpos
) {
884 /* access before or after buffered data. A rebuffer is needed. */
885 rebuffer_handle(handle_id
, newpos
);
888 h
->ridx
= RINGBUF_ADD(h
->data
, newpos
- h
->offset
);
893 /* Advance the reading index in a handle (relatively to its current position).
894 Return 0 for success and < 0 for failure */
895 int bufadvance(int handle_id
, off_t offset
)
897 struct memory_handle
*h
= find_handle(handle_id
);
901 size_t newpos
= h
->offset
+ RINGBUF_SUB(h
->ridx
, h
->data
) + offset
;
903 return bufseek(handle_id
, newpos
);
906 /* Copy data from the given handle to the dest buffer.
907 Return the number of bytes copied or < 0 for failure. */
908 ssize_t
bufread(int handle_id
, size_t size
, void *dest
)
910 struct memory_handle
*h
= find_handle(handle_id
);
911 size_t buffered_data
;
915 if (size
== 0 && h
->filerem
> 0 &&
916 h
->available
- RINGBUF_SUB(h
->ridx
, h
->data
) == 0)
917 /* Data isn't ready */
920 if (h
->available
- RINGBUF_SUB(h
->ridx
, h
->data
) < size
&& h
->filerem
> 0)
921 /* Data isn't ready */
924 if (h
->available
- RINGBUF_SUB(h
->ridx
, h
->data
) == 0 && h
->filerem
== 0)
925 /* File is finished reading */
928 buffered_data
= MIN(size
, h
->available
- RINGBUF_SUB(h
->ridx
, h
->data
));
930 if (h
->ridx
+ buffered_data
> buffer_len
)
932 /* the data wraps around the end of the buffer */
933 size_t read
= buffer_len
- h
->ridx
;
934 memcpy(dest
, &buffer
[h
->ridx
], read
);
935 memcpy(dest
+read
, buffer
, buffered_data
- read
);
937 else memcpy(dest
, &buffer
[h
->ridx
], buffered_data
);
939 return buffered_data
;
942 /* Update the "data" pointer to make the handle's data available to the caller.
943 Return the length of the available linear data or < 0 for failure.
944 size is the amount of linear data requested. it can be 0 to get as
946 The guard buffer may be used to provide the requested size */
947 ssize_t
bufgetdata(int handle_id
, size_t size
, void **data
)
949 struct memory_handle
*h
= find_handle(handle_id
);
953 if (size
== 0 && h
->filerem
> 0 &&
954 h
->available
- RINGBUF_SUB(h
->ridx
, h
->data
) == 0)
955 /* Data isn't ready */
958 if (h
->available
- RINGBUF_SUB(h
->ridx
, h
->data
) < size
&& h
->filerem
> 0)
959 /* Data isn't ready */
962 if (h
->available
- RINGBUF_SUB(h
->ridx
, h
->data
) == 0 && h
->filerem
== 0)
963 /* File is finished reading */
968 if (h
->ridx
+ size
> buffer_len
&&
969 h
->available
- RINGBUF_SUB(h
->ridx
, h
->data
) >= size
)
971 /* the data wraps around the end of the buffer :
972 use the guard buffer to provide the requested amount of data. */
973 size_t copy_n
= MIN(h
->ridx
+ size
- buffer_len
, GUARD_BUFSIZE
);
974 memcpy(guard_buffer
, (unsigned char *)buffer
, copy_n
);
975 ret
= buffer_len
- h
->ridx
+ copy_n
;
976 DEBUGF("used the guard buffer to complete\n");
980 ret
= MIN(h
->available
- RINGBUF_SUB(h
->ridx
, h
->data
),
981 buffer_len
- h
->ridx
);
984 *data
= &buffer
[h
->ridx
];
986 /* DEBUGF("bufgetdata(%d): h->ridx=%ld, ret=%ld\n", handle_id,
987 (long)h->ridx, ret); */
991 /* Return the amount of buffer space used */
997 /* Initialise the buffering subsystem */
998 bool buffering_init(char *filebuf
, size_t filebuflen
)
1000 if (!filebuf
|| !filebuflen
)
1004 buffer_len
= filebuflen
;
1005 guard_buffer
= buffer
+ buffer_len
;
1010 first_handle
= NULL
;
1013 mutex_init(&llist_mutex
);
1015 conf_filechunk
= AUDIO_DEFAULT_FILECHUNK
;
1016 conf_watermark
= AUDIO_DEFAULT_WATERMARK
;
1018 /* Set the high watermark as 75% full...or 25% empty :) */
1020 high_watermark
= 3*filebuflen
/ 4;
1023 buffering_thread_p
= create_thread( buffering_thread
, buffering_stack
,
1024 sizeof(buffering_stack
), 0,
1025 buffering_thread_name
IF_PRIO(, PRIORITY_BUFFERING
)
1028 queue_init(&buffering_queue
, true);
1029 queue_enable_queue_send(&buffering_queue
, &buffering_queue_sender_list
);
1035 /* we dont want this rebuffering on targets with little ram
1036 because the disk may never spin down */
1037 static bool ata_fillbuffer_callback(void)
1039 queue_post(&buffering_queue
, Q_BUFFERING_FILL_BUFFER_IF_ACTIVE_ATA
, 0);
1044 void buffering_thread(void)
1046 struct queue_event ev
;
1050 queue_wait_w_tmo(&buffering_queue
, &ev
, HZ
/2);
1053 if ((ev
.id
== SYS_TIMEOUT
) && (buffered_data() < high_watermark
))
1054 register_ata_idle_func(ata_fillbuffer_callback
);
1059 case Q_BUFFER_HANDLE
:
1060 LOGFQUEUE("buffering < Q_BUFFER_HANDLE");
1061 queue_reply(&buffering_queue
, 1);
1062 buffer_handle((int)ev
.data
);
1065 case Q_RESET_HANDLE
:
1066 LOGFQUEUE("buffering < Q_RESET_HANDLE");
1067 queue_reply(&buffering_queue
, 1);
1068 reset_handle((int)ev
.data
);
1071 case Q_CLOSE_HANDLE
:
1072 LOGFQUEUE("buffering < Q_CLOSE_HANDLE");
1073 queue_reply(&buffering_queue
, close_handle((int)ev
.data
));
1077 case Q_BUFFERING_FILL_BUFFER_IF_ACTIVE_ATA
:
1078 /* only fill if the disk is still spining */
1080 if (!ata_disk_is_active())
1083 if (num_handles
> 0 && data_rem() > 0)
1086 #endif /* MEM > 8 */
1089 case SYS_USB_CONNECTED
:
1090 LOGFQUEUE("buffering < SYS_USB_CONNECTED");
1091 usb_acknowledge(SYS_USB_CONNECTED_ACK
);
1092 usb_wait_for_disconnect(&buffering_queue
);
1097 LOGFQUEUE_SYS_TIMEOUT("buffering < SYS_TIMEOUT");
1101 if (ev
.id
== SYS_TIMEOUT
&& queue_empty(&buffering_queue
))
1103 if (data_rem() > 0 && wasted_space() > buffered_data()/2)
1105 DEBUGF("there is %ld bytes of wasted space\n",
1106 (long)wasted_space());
1108 /* free buffer from outdated audio data */
1109 struct memory_handle
*m
= first_handle
;
1111 if (m
->type
== TYPE_AUDIO
)
1112 shrink_handle(m
->id
);
1116 /* free buffer by moving metadata */
1119 if (m
->type
!= TYPE_AUDIO
)
1120 shrink_handle(m
->id
);
1126 if (data_rem() > 0 && buffered_data() < conf_watermark
)
1128 DEBUGF("%ld bytes left to buffer and the buffer is low\n",
1137 /* Get a buffer offset from a pointer */
1138 ssize_t
get_offset(int handle_id
, void *ptr
)
1140 struct memory_handle
*h
= find_handle(handle_id
);
1144 return (size_t)ptr
- (size_t)&buffer
[h
->ridx
];
1147 void buffering_get_debugdata(struct buffering_debug
*dbgdata
)
1149 dbgdata
->num_handles
= num_handles
;
1150 dbgdata
->data_rem
= data_rem();
1151 dbgdata
->wasted_space
= wasted_space();
1152 dbgdata
->buffered_data
= buffered_data();
1153 dbgdata
->useful_data
= useful_data(0);