v4.0/src/INC/BUFFER.INC

   1 ;       SCCSID = @(#)buffer.asm 1.1 85/04/09
   2 BREAK <Disk I/O Buffer Header>
   3 ;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
   4 ;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
   5 ;                                                                          ;
   6
   7 ; Field definition for I/O buffer information
   8
   9 BUFFINFO        STRUC
  10 buf_next        DW      ?               ; Pointer to next buffer in list
  11 buf_prev        DW      ?               ; Pointer to prev buffer in list
  12 buf_ID          DB      ?               ; Drive of buffer (bit 7 = 0)
  13                                         ; SFT table index (bit 7 = 1)
  14                                         ; = FFH if buffer free
  15 buf_flags       DB      ?               ; Bit 7 = 1 if Remote file buffer
  16                                         ;       = 0 if Local device buffer
  17                                         ; Bit 6 = 1 if buffer dirty
  18                                         ; Bit 5 = Reserved
  19                                         ; Bit 4 = Search bit (bit 7 = 1)
  20                                         ; Bit 3 = 1 if buffer is DATA
  21                                         ; Bit 2 = 1 if buffer is DIR
  22                                         ; Bit 1 = 1 if buffer is FAT
  23                                         ; Bit 0 = Reserved
  24 buf_sector      DD      ?               ; Sector number of buffer (bit 7 = 0)
  25 ; The next two items are often refed as a word (bit 7 = 0)
  26 buf_wrtcnt      DB      ?               ; For FAT sectors, # times sector written out
  27 buf_wrtcntinc   DW      ?               ; "   "     "   , # sectors between each write
  28 buf_DPB         DD      ?               ; Pointer to drive parameters
  29 buf_fill        DW      ?               ; How full buffer is (bit 7 = 1)
  30 buf_reserved    DB      ?               ; make DWORD boundary for 386
  31 BUFFINFO        ENDS
  32
  33 buf_offset      EQU     DWORD PTR buf_sector
  34                                         ;For bit 7 = 1, this is the byte
  35                                         ;offset of the start of the buffer in
  36                                         ;the file pointed to by buf_ID.  Thus
  37                                         ;the buffer starts at location
  38                                         ;buf_offset in the file and contains
  39                                         ;buf_fill bytes.
  40
  41 BUFINSIZ        EQU     SIZE BUFFINFO
  42                                         ; Size of structure in bytes
  43
  44 buf_Free        EQU     0FFh            ; buf_id of free buffer
  45
  46 ;Flag byte masks
  47 buf_isnet       EQU     10000000B
  48 buf_dirty       EQU     01000000B
  49 ;***
  50 buf_visit       EQU     00100000B
  51 ;***
  52 buf_snbuf       EQU     00010000B
  53
  54 buf_isDATA      EQU     00001000B
  55 buf_isDIR       EQU     00000100B
  56 buf_isFAT       EQU     00000010B
  57 buf_type_0      EQU     11110001B       ; AND sets type to "none"
  58
  59 buf_NetID       EQU     BUFINSIZ
  60
  61 ;
  62 ; Buffer Hash Entry Structure
  63
  64 BUFFER_HASH_ENTRY       STRUC           ; DOS 4.00
  65 EMS_PAGE_NUM    DW      -1              ; logical page number for EMS handle
  66 BUFFER_BUCKET   DD       ?              ; pointer to buffers
  67 DIRTY_COUNT     DB       0              ; number of dirty buffers
  68 BUFFER_RESERVED DB       0              ; reserved
  69 BUFFER_HASH_ENTRY       ENDS
  70
  71 MaxBuffinBucket EQU     15              ; Max number of buffers per bucket
  72 MaxBucketinPage EQU      2              ; Max number of buckets per 16kb page
  73
  74
  75 ;                                                                          ;
  76 ;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
  77 ;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;