apps/plugins/mpegplayer/disk_buf.h

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * AV disk buffer declarations
  11  *
  12  * Copyright (c) 2007 Michael Sevakis
  13  *
  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.
  18  *
  19  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  20  * KIND, either express or implied.
  21  *
  22  ****************************************************************************/
  23 #ifndef DISK_BUF_H
  24 #define DISK_BUF_H
  25
  26 #ifndef OFF_T_MAX
  27 #define OFF_T_MAX (~((off_t)1 << (sizeof (off_t)*8 - 1)))
  28 #endif
  29
  30 #ifndef OFF_T_MIN
  31 #define OFF_T_MIN ((off_t)1 << (sizeof (off_t)*8 - 1))
  32 #endif
  33
  34 #define DISK_BUF_PAGE_SHIFT 15  /* 32KB cache lines */
  35 #define DISK_BUF_PAGE_SIZE (1 << DISK_BUF_PAGE_SHIFT)
  36 #define DISK_BUF_PAGE_MASK (DISK_BUF_PAGE_SIZE-1)
  37
  38 enum
  39 {
  40     DISK_BUF_NOTIFY_ERROR = -1,
  41     DISK_BUF_NOTIFY_NULL  =  0,
  42     DISK_BUF_NOTIFY_OK,
  43     DISK_BUF_NOTIFY_TIMEDOUT,
  44     DISK_BUF_NOTIFY_PROCESS_EVENT,
  45     DISK_BUF_NOTIFY_REGISTERED,
  46 };
  47
  48 /** Macros to map file offsets to cached data **/
  49
  50 /* Returns a cache tag given a file offset */
  51 #define MAP_OFFSET_TO_TAG(o) \
  52     ((o) >> DISK_BUF_PAGE_SHIFT)
  53
  54 /* Returns the cache page number given a file offset */
  55 #define MAP_OFFSET_TO_PAGE(o) \
  56     (MAP_OFFSET_TO_TAG(o) % disk_buf.pgcount)
  57
  58 /* Returns the buffer offset given a file offset */
  59 #define MAP_OFFSET_TO_BUFFER(o) \
  60     (MAP_OFFSET_TO_PAGE(o) * DISK_BUF_PAGE_SIZE)
  61
  62 struct dbuf_range
  63 {
  64     uint32_t tag_start;
  65     uint32_t tag_end;
  66     int pg_start;
  67 };
  68
  69 #define DISK_BUF_L2_CACHE_SHIFT 6
  70 #define DISK_BUF_L2_CACHE_SIZE (1 << DISK_BUF_L2_CACHE_SHIFT)
  71 #define DISK_BUF_L2_CACHE_MASK (DISK_BUF_L2_CACHE_SIZE-1)
  72
  73 struct dbuf_l2_cache
  74 {
  75     off_t addr;                              /* L2 file offset */
  76     size_t size;                             /* Real size */
  77     uint8_t data[DISK_BUF_L2_CACHE_SIZE*2];  /* Local data and guard */
  78 };
  79
  80 void dbuf_l2_init(struct dbuf_l2_cache *l2_p);
  81
  82 /* This object is an extension of the stream manager and handles some
  83  * playback events as well as buffering */
  84 struct disk_buf
  85 {
  86     unsigned int thread;
  87     struct event_queue *q;
  88     uint8_t *start;   /* Start pointer */
  89     uint8_t *end;     /* End of buffer pointer less MPEG_GUARDBUF_SIZE. The
  90                          guard space is used to wrap data at the buffer start to
  91                          pass continuous data packets */
  92     uint8_t *tail;    /* Location of last data + 1 filled into the buffer */
  93     ssize_t size;     /* The buffer length _not_ including the guard space (end-start) */
  94     int    pgcount;   /* Total number of available cached pages */
  95     uint32_t *cache;  /* Pointer to cache structure - allocated on buffer */
  96     int    in_file;   /* File being read */
  97     ssize_t filesize; /* Size of file in_file in bytes */
  98     int file_pages;   /* Number of pages in file (rounded up) */
  99     off_t offset;     /* Current position (random access) */
 100     off_t win_left;   /* Left edge of buffer window (streaming) */
 101     off_t win_right;  /* Right edge of buffer window (streaming) */
 102     uint32_t time_last; /* Last time watermark was checked */
 103     off_t pos_last;   /* Last position at watermark check time */
 104     ssize_t low_wm;   /* The low watermark for automatic rebuffering */
 105     int status;       /* Status as stream */
 106     int state;        /* Current thread state */
 107     bool need_seek;   /* Need to seek because a read was not contiguous */
 108 };
 109
 110 extern struct disk_buf disk_buf SHAREDBSS_ATTR;
 111
 112 struct stream_hdr;
 113 bool disk_buf_is_data_ready(struct stream_hdr *sh, ssize_t margin);
 114
 115 bool disk_buf_init(void);
 116 void disk_buf_exit(void);
 117
 118 static inline int disk_buf_status(void)
 119     { return disk_buf.status; }
 120
 121 int disk_buf_open(const char *filename);
 122 void disk_buf_close(void);
 123 ssize_t _disk_buf_getbuffer(size_t size, void **pp, void **pwrap,
 124                             size_t *sizewrap);
 125 #define disk_buf_getbuffer(size, pp, pwrap, sizewrap) \
 126         _disk_buf_getbuffer((size), PUN_PTR(void **, (pp)), \
 127                             PUN_PTR(void **, (pwrap)), (sizewrap))
 128
 129 ssize_t _disk_buf_getbuffer_l2(struct dbuf_l2_cache *l2,
 130                                size_t size, void **pp);
 131 #define disk_buf_getbuffer_l2(l2, size, pp) \
 132         _disk_buf_getbuffer_l2((l2), (size), PUN_PTR(void **, (pp)))
 133
 134 ssize_t disk_buf_read(void *buffer, size_t size);
 135 ssize_t disk_buf_lseek(off_t offset, int whence);
 136
 137 static inline off_t disk_buf_ftell(void)
 138     { return disk_buf.offset; }
 139
 140 static inline ssize_t disk_buf_filesize(void)
 141     { return disk_buf.filesize; }
 142
 143 ssize_t disk_buf_prepare_streaming(off_t pos, size_t len);
 144 ssize_t disk_buf_set_streaming_window(off_t left, off_t right);
 145 void * disk_buf_offset2ptr(off_t offset);
 146 int disk_buf_check_streaming_window(off_t left, off_t right);
 147
 148 intptr_t disk_buf_send_msg(long id, intptr_t data);
 149 void disk_buf_post_msg(long id, intptr_t data);
 150 void disk_buf_reply_msg(intptr_t retval);
 151
 152 #endif /* DISK_BUF_H */