Diff for /gforth/blocks.fs between versions 1.2 and 1.18

version 1.2, 1994/08/31 19:42:43 version 1.18, 1998/04/12 21:49:12
Line 1 Line 1
 \ A simple immplementation of the blocks wordset.   \ A less simple implementation of the blocks wordset. 
   
 \ This implementation uses only a single buffer and will therefore be a  \ Copyright (C) 1995 Free Software Foundation, Inc.
 \ little slow. An efficient implementation would use mmap on OSs that  
   \ This file is part of Gforth.
   
   \ Gforth is free software; you can redistribute it and/or
   \ modify it under the terms of the GNU General Public License
   \ as published by the Free Software Foundation; either version 2
   \ of the License, or (at your option) any later version.
   
   \ This program is distributed in the hope that it will be useful,
   \ but WITHOUT ANY WARRANTY; without even the implied warranty of
   \ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   \ GNU General Public License for more details.
   
   \ You should have received a copy of the GNU General Public License
   \ along with this program; if not, write to the Free Software
   \ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   
   
   \ A more efficient implementation would use mmap on OSs that
 \ provide it and many buffers on OSs that do not provide mmap.  \ provide it and many buffers on OSs that do not provide mmap.
   
   \ Now, the replacement algorithm is "direct mapped"; change to LRU
   \ if too slow. Using more buffers helps, too.
   
 \ I think I avoid the assumption 1 char = 1 here, but I have not tested this  \ I think I avoid the assumption 1 char = 1 here, but I have not tested this
   
 \ 1024 constant chars/block \ mandated by the standard  \ 1024 constant chars/block \ mandated by the standard
   
 create block-buffer chars/block chars allot  require struct.fs
   
   struct
       cell%               field buffer-block   \ the block number
       cell%               field buffer-fid     \ the block's fid
       cell%               field buffer-dirty   \ the block dirty flag
       char% chars/block * field block-buffer   \ the data
       cell% 0 *           field next-buffer
   end-struct buffer-struct
   
   Variable block-buffers
   Variable last-block
   
   $20 Value buffers
   
   User block-fid
   
   : block-cold ( -- )
       block-fid off  last-block off
       buffer-struct buffers * %alloc dup block-buffers ! ( addr )
       buffer-struct %size buffers * erase ;
   
   ' block-cold INIT8 chained
   
 variable buffer-block 0 buffer-block ! \ the block currently in the buffer  block-cold
 variable block-fid 0 block-fid ! \ the file id of the current block file  
 variable buffer-dirty buffer-dirty off  
   
   Defer flush-blocks
   
   : open-blocks ( addr u -- ) \ gforth
       \g use the file, whose name is given by @var{addr u}, as blocks file 
       2dup open-fpath-file 0<>
       if
           r/w bin create-file throw
       else
           rot close-file throw  2dup file-status throw bin open-file throw
           >r 2drop r>
       then
       block-fid @ IF  flush-blocks block-fid @ close-file throw  THEN
       block-fid ! ;
   
   : use ( "file" -- ) \ gforth
       \g use @var{file} as blocks file
       name open-blocks ;
   
   \ the file is opened as binary file, since it either will contain text
   \ without newlines or binary data
 : get-block-fid ( -- fid )  : get-block-fid ( -- fid )
     block-fid @ 0=      block-fid @ 0=
     if      if
         s" blocks.fb" r/w open-file 0<>          s" blocks.fb" open-blocks
         if  
             s" blocks.fb" r/w create-file .s throw  
         then  
         block-fid !  
     then      then
     block-fid @ ;      block-fid @ ;
   
 : block-position ( u -- )  : block-position ( u -- )
     \ positions the block file to the start of block u      \ positions the block file to the start of block u
     1- chars/block chars um* get-block-fid reposition-file .s throw ;      1- chars/block chars um* get-block-fid reposition-file throw ;
   
 : update ( -- )  : update ( -- )
     buffer-dirty on ;      last-block @ ?dup IF  buffer-dirty on  THEN ;
   
 : save-buffers ( -- )  : save-buffer ( buffer -- ) >r
     buffer-dirty @      r@ buffer-dirty @ r@ buffer-block @ 0<> and
     if      if
         buffer-block @ block-position          r@ buffer-block @ block-position
         block-buffer chars/block get-block-fid write-file throw          r@ block-buffer chars/block  r@ buffer-fid @  write-file throw
         buffer-dirty off          r@ buffer-dirty off
     endif ;      endif
       rdrop ;
   
   : empty-buffer ( buffer -- )
       buffer-block off ;
   
   : save-buffers  ( -- )    block-buffers @
       buffers 0 ?DO  dup save-buffer  next-buffer  LOOP  drop ;
   
 : empty-buffers ( -- )  : empty-buffers ( -- )    block-buffers @
     0 buffer-block ! ;      buffers 0 ?DO  dup empty-buffer  next-buffer  LOOP  drop ;
   
 : flush ( -- )  : flush ( -- )
     save-buffers      save-buffers
     empty-buffers ;      empty-buffers ;
   
   ' flush IS flush-blocks
   
   : get-buffer ( n -- a-addr )
       buffers mod buffer-struct %size * block-buffers @ + ;
   
 : block ( u -- a-addr )  : block ( u -- a-addr )
     dup 0= -35 and throw      dup 0= -35 and throw
     dup buffer-block @ <>      dup get-buffer >r
       dup r@ buffer-block @ <>
       r@ buffer-fid @ block-fid @ <> or
     if      if
         save-buffers          r@ save-buffer
         dup block-position          dup block-position
         block-buffer chars/block get-block-fid read-file .s throw          r@ block-buffer chars/block get-block-fid read-file throw
         \ clear the rest of the buffer if the file is too short          \ clear the rest of the buffer if the file is too short
         block-buffer over chars + chars/block rot - blank          r@ block-buffer over chars + chars/block rot chars - blank
         buffer-block !              r@ buffer-block !
           get-block-fid r@ buffer-fid !
     else      else
         drop          drop
     then      then
     block-buffer ;      r> dup last-block ! block-buffer ;
   
 : buffer ( u -- a-addr )  : buffer ( u -- a-addr )
     \ reading in the block is unnecessary, but simpler      \ reading in the block is unnecessary, but simpler
Line 69  variable buffer-dirty buffer-dirty off Line 140  variable buffer-dirty buffer-dirty off
   
 User scr 0 scr !  User scr 0 scr !
   
   : updated?  ( n -- f )   scr @ buffer
       [ 0 buffer-dirty 0 block-buffer - ] Literal + @ ;
   
 : list ( u -- )  : list ( u -- )
     \ calling block again and again looks inefficient but is necessary      \ calling block again and again looks inefficient but is necessary
     \ in a multitasking environment      \ in a multitasking environment
     dup scr !      dup scr !
     ." Screen " u. cr      ." Screen " u.
       updated?  0= IF ." not "  THEN  ." modified     " cr
     16 0      16 0
     ?do      ?do
         scr @ block i 64 * chars + 64 type cr          i 2 .r space scr @ block i 64 * chars + 64 type cr
     loop ;      loop ;
   
 : (source)  ( -- addr len )  : (source)  ( -- addr len )
Line 89  User scr 0 scr ! Line 164  User scr 0 scr !
   
 : load ( i*x n -- j*x )  : load ( i*x n -- j*x )
   push-file    push-file
   dup loadline ! blk ! >in off ( ['] ) interpret ( catch )    dup loadline ! blk ! >in off ['] interpret catch
   pop-file ( throw ) ;    pop-file throw ;
   
 : thru ( i*x n1 n2 -- j*x )  : thru ( i*x n1 n2 -- j*x )
   1+ swap 0 ?DO  I load  LOOP ;    1+ swap ?DO  I load  LOOP ;
   
 : +load ( i*x n -- j*x )  blk @ + load ;  : +load ( i*x n -- j*x )  blk @ + load ;
   
 : +thru ( i*x n1 n2 -- j*x )  : +thru ( i*x n1 n2 -- j*x )
   1+ swap 0 ?DO  I +load  LOOP ;    1+ swap ?DO  I +load  LOOP ;
   
   : --> ( -- )  refill drop ; immediate
   
   : block-included ( addr u -- )
       block-fid @ >r block-fid off open-blocks
       1 load block-fid @ close-file throw flush
       r> block-fid ! ;
   
   \ thrown out because it may provide unpleasant surprises - anton
   \ : include ( "name" -- )
   \     name 2dup dup 3 - /string s" .fb" compare
   \     0= IF  block-included  ELSE  included  THEN ;
   
   get-current environment-wordlist set-current
   true constant block
   true constant block-ext
   set-current
   
   : bye  ['] flush catch drop bye ;

Removed from v.1.2  
changed lines
  Added in v.1.18


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