rockbox/apps/plugins/mpegplayer/disk_buf.c

908 lines
24 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* mpegplayer buffering routines
*
* Copyright (c) 2007 Michael Sevakis
*
* All files in this archive are subject to the GNU General Public License.
* See the file COPYING in the source tree root for full license agreement.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "plugin.h"
#include "mpegplayer.h"
static struct mutex disk_buf_mtx NOCACHEBSS_ATTR;
static struct event_queue disk_buf_queue NOCACHEBSS_ATTR;
static struct queue_sender_list disk_buf_queue_send NOCACHEBSS_ATTR;
static uint32_t disk_buf_stack[DEFAULT_STACK_SIZE*2/sizeof(uint32_t)];
struct disk_buf disk_buf NOCACHEBSS_ATTR;
static struct list_item nf_list;
static inline void disk_buf_lock(void)
{
rb->mutex_lock(&disk_buf_mtx);
}
static inline void disk_buf_unlock(void)
{
rb->mutex_unlock(&disk_buf_mtx);
}
static inline void disk_buf_on_clear_data_notify(struct stream_hdr *sh)
{
DEBUGF("DISK_BUF_CLEAR_DATA_NOTIFY: 0x%02X (cleared)\n",
STR_FROM_HEADER(sh)->id);
list_remove_item(&sh->nf);
}
static int disk_buf_on_data_notify(struct stream_hdr *sh)
{
DEBUGF("DISK_BUF_DATA_NOTIFY: 0x%02X ", STR_FROM_HEADER(sh)->id);
if (sh->win_left <= sh->win_right)
{
/* Check if the data is already ready already */
if (disk_buf_is_data_ready(sh, 0))
{
/* It was - don't register */
DEBUGF("(was ready)\n"
" swl:%lu swr:%lu\n"
" dwl:%lu dwr:%lu\n",
sh->win_left, sh->win_right,
disk_buf.win_left, disk_buf.win_right);
/* Be sure it's not listed though if multiple requests were made */
list_remove_item(&sh->nf);
return DISK_BUF_NOTIFY_OK;
}
switch (disk_buf.state)
{
case TSTATE_DATA:
case TSTATE_BUFFERING:
case TSTATE_INIT:
disk_buf.state = TSTATE_BUFFERING;
list_add_item(&nf_list, &sh->nf);
DEBUGF("(registered)\n"
" swl:%lu swr:%lu\n"
" dwl:%lu dwr:%lu\n",
sh->win_left, sh->win_right,
disk_buf.win_left, disk_buf.win_right);
return DISK_BUF_NOTIFY_REGISTERED;
}
}
DEBUGF("(error)\n");
return DISK_BUF_NOTIFY_ERROR;
}
static bool check_data_notifies_callback(struct list_item *item,
intptr_t data)
{
struct stream_hdr *sh = TYPE_FROM_MEMBER(struct stream_hdr, item, nf);
if (disk_buf_is_data_ready(sh, 0))
{
/* Remove from list then post notification - post because send
* could result in a wait for each thread to finish resulting
* in deadlock */
list_remove_item(item);
str_post_msg(STR_FROM_HEADER(sh), DISK_BUF_DATA_NOTIFY, 0);
DEBUGF("DISK_BUF_DATA_NOTIFY: 0x%02X (notified)\n",
STR_FROM_HEADER(sh)->id);
}
return true;
(void)data;
}
/* Check registered streams and notify them if their data is available */
static void check_data_notifies(void)
{
list_enum_items(&nf_list, check_data_notifies_callback, 0);
}
/* Clear all registered notifications - do not post them */
static inline void clear_data_notifies(void)
{
list_clear_all(&nf_list);
}
/* Background buffering when streaming */
static inline void disk_buf_buffer(void)
{
struct stream_window sw;
switch (disk_buf.state)
{
default:
{
size_t wm;
uint32_t time;
/* Get remaining minimum data based upon the stream closest to the
* right edge of the window */
if (!stream_get_window(&sw))
break;
time = stream_get_ticks(NULL);
wm = muldiv_uint32(5*CLOCK_RATE, sw.right - disk_buf.pos_last,
time - disk_buf.time_last);
wm = MIN(wm, (size_t)disk_buf.size);
wm = MAX(wm, DISK_BUF_LOW_WATERMARK);
disk_buf.time_last = time;
disk_buf.pos_last = sw.right;
/* Fast attack, slow decay */
disk_buf.low_wm = (wm > (size_t)disk_buf.low_wm) ?
wm : AVERAGE(disk_buf.low_wm, wm, 16);
#if 0
rb->splash(0, "*%10ld %10ld", disk_buf.low_wm,
disk_buf.win_right - sw.right);
#endif
if (disk_buf.win_right - sw.right > disk_buf.low_wm)
break;
disk_buf.state = TSTATE_BUFFERING;
} /* default: */
/* Fall-through */
case TSTATE_BUFFERING:
{
ssize_t len, n;
uint32_t tag, *tag_p;
/* Limit buffering up to the stream with the least progress */
if (!stream_get_window(&sw))
{
disk_buf.state = TSTATE_DATA;
break;
}
/* Wrap pointer */
if (disk_buf.tail >= disk_buf.end)
disk_buf.tail = disk_buf.start;
len = disk_buf.size - disk_buf.win_right + sw.left;
if (len < DISK_BUF_PAGE_SIZE)
{
/* Free space is less than one page */
disk_buf.state = TSTATE_DATA;
disk_buf.low_wm = DISK_BUF_LOW_WATERMARK;
break;
}
len = disk_buf.tail - disk_buf.start;
tag = MAP_OFFSET_TO_TAG(disk_buf.win_right);
tag_p = &disk_buf.cache[len >> DISK_BUF_PAGE_SHIFT];
if (*tag_p != tag)
{
if (disk_buf.need_seek)
{
rb->lseek(disk_buf.in_file, disk_buf.win_right, SEEK_SET);
disk_buf.need_seek = false;
}
n = rb->read(disk_buf.in_file, disk_buf.tail, DISK_BUF_PAGE_SIZE);
if (n <= 0)
{
/* Error or end of stream */
disk_buf.state = TSTATE_EOS;
break;
}
if (len < DISK_GUARDBUF_SIZE)
{
/* Autoguard guard-o-rama - maintain guardbuffer coherency */
rb->memcpy(disk_buf.end + len, disk_buf.tail,
MIN(DISK_GUARDBUF_SIZE - len, n));
}
/* Update the cache entry for this page */
*tag_p = tag;
}
else
{
/* Skipping a read */
n = MIN(DISK_BUF_PAGE_SIZE,
disk_buf.filesize - disk_buf.win_right);
disk_buf.need_seek = true;
}
disk_buf.tail += DISK_BUF_PAGE_SIZE;
/* Keep left edge moving forward */
/* Advance right edge in temp variable first, then move
* left edge if overflow would occur. This avoids a stream
* thinking its data might be available when it actually
* may not end up that way after a slide of the window. */
len = disk_buf.win_right + n;
if (len - disk_buf.win_left > disk_buf.size)
disk_buf.win_left += n;
disk_buf.win_right = len;
/* Continue buffering until filled or file end */
rb->yield();
} /* TSTATE_BUFFERING: */
case TSTATE_EOS:
break;
} /* end switch */
}
static void disk_buf_on_reset(ssize_t pos)
{
int page;
uint32_t tag;
off_t anchor;
disk_buf.state = TSTATE_INIT;
disk_buf.status = STREAM_STOPPED;
clear_data_notifies();
if (pos >= disk_buf.filesize)
{
/* Anchor on page immediately following the one containing final
* data */
anchor = disk_buf.file_pages * DISK_BUF_PAGE_SIZE;
disk_buf.win_left = disk_buf.filesize;
}
else
{
anchor = pos & ~DISK_BUF_PAGE_MASK;
disk_buf.win_left = anchor;
}
/* Collect all valid data already buffered that is contiguous with the
* current position - probe to left, then to right */
if (anchor > 0)
{
page = MAP_OFFSET_TO_PAGE(anchor);
tag = MAP_OFFSET_TO_TAG(anchor);
do
{
if (--tag, --page < 0)
page = disk_buf.pgcount - 1;
if (disk_buf.cache[page] != tag)
break;
disk_buf.win_left = tag << DISK_BUF_PAGE_SHIFT;
}
while (tag > 0);
}
if (anchor < disk_buf.filesize)
{
page = MAP_OFFSET_TO_PAGE(anchor);
tag = MAP_OFFSET_TO_TAG(anchor);
do
{
if (disk_buf.cache[page] != tag)
break;
if (++tag, ++page >= disk_buf.pgcount)
page = 0;
anchor += DISK_BUF_PAGE_SIZE;
}
while (anchor < disk_buf.filesize);
}
if (anchor >= disk_buf.filesize)
{
disk_buf.win_right = disk_buf.filesize;
disk_buf.state = TSTATE_EOS;
}
else
{
disk_buf.win_right = anchor;
}
disk_buf.tail = disk_buf.start + MAP_OFFSET_TO_BUFFER(anchor);
DEBUGF("disk buf reset\n"
" dwl:%ld dwr:%ld\n",
disk_buf.win_left, disk_buf.win_right);
/* Next read position is at right edge */
rb->lseek(disk_buf.in_file, disk_buf.win_right, SEEK_SET);
disk_buf.need_seek = false;
disk_buf_reply_msg(disk_buf.win_right - disk_buf.win_left);
}
static void disk_buf_on_stop(void)
{
bool was_buffering = disk_buf.state == TSTATE_BUFFERING;
disk_buf.state = TSTATE_EOS;
disk_buf.status = STREAM_STOPPED;
clear_data_notifies();
disk_buf_reply_msg(was_buffering);
}
static void disk_buf_on_play_pause(bool play, bool forcefill)
{
struct stream_window sw;
if (disk_buf.state != TSTATE_EOS)
{
if (forcefill)
{
/* Force buffer filling to top */
disk_buf.state = TSTATE_BUFFERING;
}
else if (disk_buf.state != TSTATE_BUFFERING)
{
/* If not filling already, simply monitor */
disk_buf.state = TSTATE_DATA;
}
}
/* else end of stream - no buffering to do */
disk_buf.pos_last = stream_get_window(&sw) ? sw.right : 0;
disk_buf.time_last = stream_get_ticks(NULL);
disk_buf.status = play ? STREAM_PLAYING : STREAM_PAUSED;
}
static int disk_buf_on_load_range(struct dbuf_range *rng)
{
uint32_t tag = rng->tag_start;
uint32_t tag_end = rng->tag_end;
int page = rng->pg_start;
/* Check if a seek is required */
bool need_seek = rb->lseek(disk_buf.in_file, 0, SEEK_CUR)
!= (off_t)(tag << DISK_BUF_PAGE_SHIFT);
do
{
uint32_t *tag_p = &disk_buf.cache[page];
if (*tag_p != tag)
{
/* Page not cached - load it */
ssize_t o, n;
if (need_seek)
{
rb->lseek(disk_buf.in_file, tag << DISK_BUF_PAGE_SHIFT,
SEEK_SET);
need_seek = false;
}
o = page << DISK_BUF_PAGE_SHIFT;
n = rb->read(disk_buf.in_file, disk_buf.start + o,
DISK_BUF_PAGE_SIZE);
if (n < 0)
{
/* Read error */
return DISK_BUF_NOTIFY_ERROR;
}
if (n == 0)
{
/* End of file */
break;
}
if (o < DISK_GUARDBUF_SIZE)
{
/* Autoguard guard-o-rama - maintain guardbuffer coherency */
rb->memcpy(disk_buf.end + o, disk_buf.start + o,
MIN(DISK_GUARDBUF_SIZE - o, n));
}
/* Update the cache entry */
*tag_p = tag;
}
else
{
/* Skipping a disk read - must seek on next one */
need_seek = true;
}
if (++page >= disk_buf.pgcount)
page = 0;
}
while (++tag <= tag_end);
return DISK_BUF_NOTIFY_OK;
}
static void disk_buf_thread(void)
{
struct queue_event ev;
disk_buf.state = TSTATE_EOS;
disk_buf.status = STREAM_STOPPED;
while (1)
{
if (disk_buf.state != TSTATE_EOS)
{
/* Poll buffer status and messages */
rb->queue_wait_w_tmo(disk_buf.q, &ev,
disk_buf.state == TSTATE_BUFFERING ?
0 : HZ/5);
}
else
{
/* Sit idle and wait for commands */
rb->queue_wait(disk_buf.q, &ev);
}
switch (ev.id)
{
case SYS_TIMEOUT:
if (disk_buf.state == TSTATE_EOS)
break;
disk_buf_buffer();
/* Check for any due notifications if any are pending */
if (nf_list.next != NULL)
check_data_notifies();
/* Still more data left? */
if (disk_buf.state != TSTATE_EOS)
continue;
/* Nope - end of stream */
break;
case DISK_BUF_CACHE_RANGE:
disk_buf_reply_msg(disk_buf_on_load_range(
(struct dbuf_range *)ev.data));
break;
case STREAM_RESET:
disk_buf_on_reset(ev.data);
break;
case STREAM_STOP:
disk_buf_on_stop();
break;
case STREAM_PAUSE:
case STREAM_PLAY:
disk_buf_on_play_pause(ev.id == STREAM_PLAY, ev.data != 0);
disk_buf_reply_msg(1);
break;
case STREAM_QUIT:
disk_buf.state = TSTATE_EOS;
return;
case DISK_BUF_DATA_NOTIFY:
disk_buf_reply_msg(disk_buf_on_data_notify(
(struct stream_hdr *)ev.data));
break;
case DISK_BUF_CLEAR_DATA_NOTIFY:
disk_buf_on_clear_data_notify((struct stream_hdr *)ev.data);
disk_buf_reply_msg(1);
break;
}
}
}
/* Caches some data from the current file */
static int disk_buf_probe(off_t start, size_t length,
void **p, size_t *outlen)
{
off_t end;
uint32_t tag, tag_end;
int page;
/* Can't read past end of file */
if (length > (size_t)(disk_buf.filesize - disk_buf.offset))
{
length = disk_buf.filesize - disk_buf.offset;
}
/* Can't cache more than the whole buffer size */
if (length > (size_t)disk_buf.size)
{
length = disk_buf.size;
}
/* Zero-length probes permitted */
end = start + length;
/* Prepare the range probe */
tag = MAP_OFFSET_TO_TAG(start);
tag_end = MAP_OFFSET_TO_TAG(end);
page = MAP_OFFSET_TO_PAGE(start);
/* If the end is on a page boundary, check one less or an extra
* one will be probed */
if (tag_end > tag && (end & DISK_BUF_PAGE_MASK) == 0)
{
tag_end--;
}
if (p != NULL)
{
*p = disk_buf.start + (page << DISK_BUF_PAGE_SHIFT)
+ (start & DISK_BUF_PAGE_MASK);
}
if (outlen != NULL)
{
*outlen = length;
}
/* Obtain initial load point. If all data was cached, no message is sent
* otherwise begin on the first page that is not cached. Since we have to
* send the message anyway, the buffering thread will determine what else
* requires loading on its end in order to cache the specified range. */
do
{
if (disk_buf.cache[page] != tag)
{
static struct dbuf_range rng NOCACHEBSS_ATTR;
DEBUGF("disk_buf: cache miss\n");
rng.tag_start = tag;
rng.tag_end = tag_end;
rng.pg_start = page;
return rb->queue_send(disk_buf.q, DISK_BUF_CACHE_RANGE,
(intptr_t)&rng);
}
if (++page >= disk_buf.pgcount)
page = 0;
}
while (++tag <= tag_end);
return DISK_BUF_NOTIFY_OK;
}
/* Attempt to get a pointer to size bytes on the buffer. Returns real amount of
* data available as well as the size of non-wrapped data after *p. */
ssize_t _disk_buf_getbuffer(size_t size, void **pp, void **pwrap, size_t *sizewrap)
{
disk_buf_lock();
if (disk_buf_probe(disk_buf.offset, size, pp, &size) == DISK_BUF_NOTIFY_OK)
{
if (pwrap && sizewrap)
{
uint8_t *p = (uint8_t *)*pp;
if (p + size > disk_buf.end + DISK_GUARDBUF_SIZE)
{
/* Return pointer to wraparound and the size of same */
size_t nowrap = (disk_buf.end + DISK_GUARDBUF_SIZE) - p;
*pwrap = disk_buf.start + DISK_GUARDBUF_SIZE;
*sizewrap = size - nowrap;
}
else
{
*pwrap = NULL;
*sizewrap = 0;
}
}
}
else
{
size = -1;
}
disk_buf_unlock();
return size;
}
/* Read size bytes of data into a buffer - advances the buffer pointer
* and returns the real size read. */
ssize_t disk_buf_read(void *buffer, size_t size)
{
uint8_t *p;
disk_buf_lock();
if (disk_buf_probe(disk_buf.offset, size, PUN_PTR(void **, &p),
&size) == DISK_BUF_NOTIFY_OK)
{
if (p + size > disk_buf.end + DISK_GUARDBUF_SIZE)
{
/* Read wraps */
size_t nowrap = (disk_buf.end + DISK_GUARDBUF_SIZE) - p;
rb->memcpy(buffer, p, nowrap);
rb->memcpy(buffer + nowrap, disk_buf.start + DISK_GUARDBUF_SIZE,
size - nowrap);
}
else
{
/* Read wasn't wrapped or guardbuffer holds it */
rb->memcpy(buffer, p, size);
}
disk_buf.offset += size;
}
else
{
size = -1;
}
disk_buf_unlock();
return size;
}
off_t disk_buf_lseek(off_t offset, int whence)
{
disk_buf_lock();
/* The offset returned is the result of the current thread's action and
* may be invalidated so a local result is returned and not the value
* of disk_buf.offset directly */
switch (whence)
{
case SEEK_SET:
/* offset is just the offset */
break;
case SEEK_CUR:
offset += disk_buf.offset;
break;
case SEEK_END:
offset = disk_buf.filesize + offset;
break;
default:
disk_buf_unlock();
return -2; /* Invalid request */
}
if (offset < 0 || offset > disk_buf.filesize)
{
offset = -3;
}
else
{
disk_buf.offset = offset;
}
disk_buf_unlock();
return offset;
}
/* Prepare the buffer to enter the streaming state. Evaluates the available
* streaming window. */
ssize_t disk_buf_prepare_streaming(off_t pos, size_t len)
{
disk_buf_lock();
if (pos < 0)
pos = 0;
else if (pos > disk_buf.filesize)
pos = disk_buf.filesize;
DEBUGF("prepare streaming:\n pos:%ld len:%lu\n", pos, len);
pos = disk_buf_lseek(pos, SEEK_SET);
disk_buf_probe(pos, len, NULL, &len);
DEBUGF(" probe done: pos:%ld len:%lu\n", pos, len);
len = disk_buf_send_msg(STREAM_RESET, pos);
disk_buf_unlock();
return len;
}
/* Set the streaming window to an arbitrary position within the file. Makes no
* probes to validate data. Use after calling another function to cause data
* to be cached and correct values are known. */
ssize_t disk_buf_set_streaming_window(off_t left, off_t right)
{
ssize_t len;
disk_buf_lock();
if (left < 0)
left = 0;
else if (left > disk_buf.filesize)
left = disk_buf.filesize;
if (left > right)
right = left;
if (right > disk_buf.filesize)
right = disk_buf.filesize;
disk_buf.win_left = left;
disk_buf.win_right = right;
disk_buf.tail = disk_buf.start + ((right + DISK_BUF_PAGE_SIZE-1) &
~DISK_BUF_PAGE_MASK) % disk_buf.size;
len = disk_buf.win_right - disk_buf.win_left;
disk_buf_unlock();
return len;
}
void * disk_buf_offset2ptr(off_t offset)
{
if (offset < 0)
offset = 0;
else if (offset > disk_buf.filesize)
offset = disk_buf.filesize;
return disk_buf.start + (offset % disk_buf.size);
}
void disk_buf_close(void)
{
disk_buf_lock();
if (disk_buf.in_file >= 0)
{
rb->close(disk_buf.in_file);
disk_buf.in_file = -1;
/* Invalidate entire cache */
rb->memset(disk_buf.cache, 0xff,
disk_buf.pgcount*sizeof (*disk_buf.cache));
disk_buf.file_pages = 0;
disk_buf.filesize = 0;
disk_buf.offset = 0;
}
disk_buf_unlock();
}
int disk_buf_open(const char *filename)
{
int fd;
disk_buf_lock();
disk_buf_close();
fd = rb->open(filename, O_RDONLY);
if (fd >= 0)
{
ssize_t filesize = rb->filesize(fd);
if (filesize <= 0)
{
rb->close(disk_buf.in_file);
}
else
{
disk_buf.filesize = filesize;
/* Number of file pages rounded up toward +inf */
disk_buf.file_pages = ((size_t)filesize + DISK_BUF_PAGE_SIZE-1)
/ DISK_BUF_PAGE_SIZE;
disk_buf.in_file = fd;
}
}
disk_buf_unlock();
return fd;
}
intptr_t disk_buf_send_msg(long id, intptr_t data)
{
return rb->queue_send(disk_buf.q, id, data);
}
void disk_buf_post_msg(long id, intptr_t data)
{
rb->queue_post(disk_buf.q, id, data);
}
void disk_buf_reply_msg(intptr_t retval)
{
rb->queue_reply(disk_buf.q, retval);
}
bool disk_buf_init(void)
{
disk_buf.thread = NULL;
list_initialize(&nf_list);
rb->mutex_init(&disk_buf_mtx);
disk_buf.q = &disk_buf_queue;
rb->queue_init(disk_buf.q, false);
disk_buf.state = TSTATE_EOS;
disk_buf.status = STREAM_STOPPED;
disk_buf.in_file = -1;
disk_buf.filesize = 0;
disk_buf.win_left = 0;
disk_buf.win_right = 0;
disk_buf.time_last = 0;
disk_buf.pos_last = 0;
disk_buf.low_wm = DISK_BUF_LOW_WATERMARK;
disk_buf.start = mpeg_malloc_all(&disk_buf.size, MPEG_ALLOC_DISKBUF);
if (disk_buf.start == NULL)
return false;
#ifdef PROC_NEEDS_CACHEALIGN
disk_buf.size = CACHEALIGN_BUFFER(&disk_buf.start, disk_buf.size);
disk_buf.start = UNCACHED_ADDR(disk_buf.start);
#endif
disk_buf.size -= DISK_GUARDBUF_SIZE;
disk_buf.pgcount = disk_buf.size / DISK_BUF_PAGE_SIZE;
/* Fit it as tightly as possible */
while (disk_buf.pgcount*(sizeof (*disk_buf.cache) + DISK_BUF_PAGE_SIZE)
> (size_t)disk_buf.size)
{
disk_buf.pgcount--;
}
disk_buf.cache = (typeof (disk_buf.cache))disk_buf.start;
disk_buf.start += sizeof (*disk_buf.cache)*disk_buf.pgcount;
disk_buf.size = disk_buf.pgcount*DISK_BUF_PAGE_SIZE;
disk_buf.end = disk_buf.start + disk_buf.size;
disk_buf.tail = disk_buf.start;
DEBUGF("disk_buf info:\n"
" page count: %d\n"
" size: %ld\n",
disk_buf.pgcount, disk_buf.size);
rb->memset(disk_buf.cache, 0xff,
disk_buf.pgcount*sizeof (*disk_buf.cache));
disk_buf.thread = rb->create_thread(
disk_buf_thread, disk_buf_stack, sizeof(disk_buf_stack), 0,
"mpgbuffer" IF_PRIO(, PRIORITY_BUFFERING) IF_COP(, CPU));
rb->queue_enable_queue_send(disk_buf.q, &disk_buf_queue_send,
disk_buf.thread);
if (disk_buf.thread == NULL)
return false;
/* Wait for thread to initialize */
disk_buf_send_msg(STREAM_NULL, 0);
return true;
}
void disk_buf_exit(void)
{
if (disk_buf.thread != NULL)
{
rb->queue_post(disk_buf.q, STREAM_QUIT, 0);
rb->thread_wait(disk_buf.thread);
disk_buf.thread = NULL;
}
}