1 /***************************************************************************
3 * Open \______ \ ____ ____ | | _\_ |__ _______ ___
4 * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
5 * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
6 * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
10 * AV disk buffer declarations
12 * Copyright (c) 2007 Michael Sevakis
14 * This program is free software; you can redistribute it and/or
15 * modify it under the terms of the GNU General Public License
16 * as published by the Free Software Foundation; either version 2
17 * of the License, or (at your option) any later version.
19 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
20 * KIND, either express or implied.
22 ****************************************************************************/
26 #define DISK_BUF_PAGE_SHIFT 15 /* 32KB cache lines */
27 #define DISK_BUF_PAGE_SIZE (1 << DISK_BUF_PAGE_SHIFT)
28 #define DISK_BUF_PAGE_MASK (DISK_BUF_PAGE_SIZE-1)
32 DISK_BUF_NOTIFY_ERROR
= -1,
33 DISK_BUF_NOTIFY_NULL
= 0,
35 DISK_BUF_NOTIFY_TIMEDOUT
,
36 DISK_BUF_NOTIFY_PROCESS_EVENT
,
37 DISK_BUF_NOTIFY_REGISTERED
,
40 /** Macros to map file offsets to cached data **/
42 /* Returns a cache tag given a file offset */
43 #define MAP_OFFSET_TO_TAG(o) \
44 ((o) >> DISK_BUF_PAGE_SHIFT)
46 /* Returns the cache page number given a file offset */
47 #define MAP_OFFSET_TO_PAGE(o) \
48 (MAP_OFFSET_TO_TAG(o) % disk_buf.pgcount)
50 /* Returns the buffer offset given a file offset */
51 #define MAP_OFFSET_TO_BUFFER(o) \
52 (MAP_OFFSET_TO_PAGE(o) * DISK_BUF_PAGE_SIZE)
61 /* This object is an extension of the stream manager and handles some
62 * playback events as well as buffering */
65 struct thread_entry
*thread
;
66 struct event_queue
*q
;
67 uint8_t *start
; /* Start pointer */
68 uint8_t *end
; /* End of buffer pointer less MPEG_GUARDBUF_SIZE. The
69 guard space is used to wrap data at the buffer start to
70 pass continuous data packets */
71 uint8_t *tail
; /* Location of last data + 1 filled into the buffer */
72 ssize_t size
; /* The buffer length _not_ including the guard space (end-start) */
73 int pgcount
; /* Total number of available cached pages */
74 uint32_t *cache
; /* Pointer to cache structure - allocated on buffer */
75 int in_file
; /* File being read */
76 ssize_t filesize
; /* Size of file in_file in bytes */
77 int file_pages
; /* Number of pages in file (rounded up) */
78 off_t offset
; /* Current position (random access) */
79 off_t win_left
; /* Left edge of buffer window (streaming) */
80 off_t win_right
; /* Right edge of buffer window (streaming) */
81 uint32_t time_last
; /* Last time watermark was checked */
82 off_t pos_last
; /* Last position at watermark check time */
83 ssize_t low_wm
; /* The low watermark for automatic rebuffering */
84 int status
; /* Status as stream */
85 int state
; /* Current thread state */
86 bool need_seek
; /* Need to seek because a read was not contiguous */
89 extern struct disk_buf disk_buf SHAREDBSS_ATTR
;
91 static inline bool disk_buf_is_data_ready(struct stream_hdr
*sh
,
94 /* Data window available? */
95 off_t right
= sh
->win_right
;
97 /* Margins past end-of-file can still return true */
98 if (right
> disk_buf
.filesize
- margin
)
99 right
= disk_buf
.filesize
- margin
;
101 return sh
->win_left
>= disk_buf
.win_left
&&
102 right
+ margin
<= disk_buf
.win_right
;
106 bool disk_buf_init(void);
107 void disk_buf_exit(void);
109 static inline int disk_buf_status(void)
110 { return disk_buf
.status
; }
112 int disk_buf_open(const char *filename
);
113 void disk_buf_close(void);
114 ssize_t
_disk_buf_getbuffer(size_t size
, void **pp
, void **pwrap
,
116 #define disk_buf_getbuffer(size, pp, pwrap, sizewrap) \
117 _disk_buf_getbuffer((size), PUN_PTR(void **, (pp)), \
118 PUN_PTR(void **, (pwrap)), (sizewrap))
119 ssize_t
disk_buf_read(void *buffer
, size_t size
);
120 ssize_t
disk_buf_lseek(off_t offset
, int whence
);
122 static inline off_t
disk_buf_ftell(void)
123 { return disk_buf
.offset
; }
125 static inline ssize_t
disk_buf_filesize(void)
126 { return disk_buf
.filesize
; }
128 ssize_t
disk_buf_prepare_streaming(off_t pos
, size_t len
);
129 ssize_t
disk_buf_set_streaming_window(off_t left
, off_t right
);
130 void * disk_buf_offset2ptr(off_t offset
);
131 int disk_buf_check_streaming_window(off_t left
, off_t right
);
133 intptr_t disk_buf_send_msg(long id
, intptr_t data
);
134 void disk_buf_post_msg(long id
, intptr_t data
);
135 void disk_buf_reply_msg(intptr_t retval
);
137 #endif /* DISK_BUF_H */