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 #define DISK_BUF_PAGE_SHIFT 15  /* 32KB cache lines */
  31 #define DISK_BUF_PAGE_SIZE (1 << DISK_BUF_PAGE_SHIFT)
  32 #define DISK_BUF_PAGE_MASK (DISK_BUF_PAGE_SIZE-1)
  33
  34 enum
  35 {
  36     DISK_BUF_NOTIFY_ERROR = -1,
  37     DISK_BUF_NOTIFY_NULL  =  0,
  38     DISK_BUF_NOTIFY_OK,
  39     DISK_BUF_NOTIFY_TIMEDOUT,
  40     DISK_BUF_NOTIFY_PROCESS_EVENT,
  41     DISK_BUF_NOTIFY_REGISTERED,
  42 };
  43
  44 /** Macros to map file offsets to cached data **/
  45
  46 /* Returns a cache tag given a file offset */
  47 #define MAP_OFFSET_TO_TAG(o) \
  48     ((o) >> DISK_BUF_PAGE_SHIFT)
  49
  50 /* Returns the cache page number given a file offset */
  51 #define MAP_OFFSET_TO_PAGE(o) \
  52     (MAP_OFFSET_TO_TAG(o) % disk_buf.pgcount)
  53
  54 /* Returns the buffer offset given a file offset */
  55 #define MAP_OFFSET_TO_BUFFER(o) \
  56     (MAP_OFFSET_TO_PAGE(o) * DISK_BUF_PAGE_SIZE)
  57
  58 struct dbuf_range
  59 {
  60     uint32_t tag_start;
  61     uint32_t tag_end;
  62     int pg_start;
  63 };
  64
  65 #define DISK_BUF_L2_CACHE_SHIFT 6
  66 #define DISK_BUF_L2_CACHE_SIZE (1 << DISK_BUF_L2_CACHE_SHIFT)
  67 #define DISK_BUF_L2_CACHE_MASK (DISK_BUF_L2_CACHE_SIZE-1)
  68
  69 struct dbuf_l2_cache
  70 {
  71     off_t addr;                              /* L2 file offset */
  72     size_t size;                             /* Real size */
  73     uint8_t data[DISK_BUF_L2_CACHE_SIZE*2];  /* Local data and guard */
  74 };
  75
  76 void dbuf_l2_init(struct dbuf_l2_cache *l2_p);
  77
  78 /* This object is an extension of the stream manager and handles some
  79  * playback events as well as buffering */
  80 struct disk_buf
  81 {
  82     unsigned int thread;
  83     struct event_queue *q;
  84     uint8_t *start;   /* Start pointer */
  85     uint8_t *end;     /* End of buffer pointer less MPEG_GUARDBUF_SIZE. The
  86                          guard space is used to wrap data at the buffer start to
  87                          pass continuous data packets */
  88     uint8_t *tail;    /* Location of last data + 1 filled into the buffer */
  89     ssize_t size;     /* The buffer length _not_ including the guard space (end-start) */
  90     int    pgcount;   /* Total number of available cached pages */
  91     uint32_t *cache;  /* Pointer to cache structure - allocated on buffer */
  92     int    in_file;   /* File being read */
  93     ssize_t filesize; /* Size of file in_file in bytes */
  94     int file_pages;   /* Number of pages in file (rounded up) */
  95     off_t offset;     /* Current position (random access) */
  96     off_t win_left;   /* Left edge of buffer window (streaming) */
  97     off_t win_right;  /* Right edge of buffer window (streaming) */
  98     uint32_t time_last; /* Last time watermark was checked */
  99     off_t pos_last;   /* Last position at watermark check time */
 100     ssize_t low_wm;   /* The low watermark for automatic rebuffering */
 101     int status;       /* Status as stream */
 102     int state;        /* Current thread state */
 103     bool need_seek;   /* Need to seek because a read was not contiguous */
 104 };
 105
 106 extern struct disk_buf disk_buf SHAREDBSS_ATTR;
 107
 108 struct stream_hdr;
 109 bool disk_buf_is_data_ready(struct stream_hdr *sh, ssize_t margin);
 110
 111 bool disk_buf_init(void);
 112 void disk_buf_exit(void);
 113
 114 static inline int disk_buf_status(void)
 115     { return disk_buf.status; }
 116
 117 int disk_buf_open(const char *filename);
 118 void disk_buf_close(void);
 119 ssize_t disk_buf_getbuffer(size_t size, void **pp, void **pwrap,
 120                            size_t *sizewrap);
 121 ssize_t disk_buf_getbuffer_l2(struct dbuf_l2_cache *l2,
 122                               size_t size, void **pp);
 123 ssize_t disk_buf_read(void *buffer, size_t size);
 124 ssize_t disk_buf_lseek(off_t offset, int whence);
 125
 126 static inline off_t disk_buf_ftell(void)
 127     { return disk_buf.offset; }
 128
 129 static inline ssize_t disk_buf_filesize(void)
 130     { return disk_buf.filesize; }
 131
 132 ssize_t disk_buf_prepare_streaming(off_t pos, size_t len);
 133 ssize_t disk_buf_set_streaming_window(off_t left, off_t right);
 134 void * disk_buf_offset2ptr(off_t offset);
 135 int disk_buf_check_streaming_window(off_t left, off_t right);
 136
 137 intptr_t disk_buf_send_msg(long id, intptr_t data);
 138 void disk_buf_post_msg(long id, intptr_t data);
 139 void disk_buf_reply_msg(intptr_t retval);
 140
 141 #endif /* DISK_BUF_H */