File:  [gforth] / gforth / blocks.fs
Revision 1.20: download - view: text, annotated - select for diffs
Sun Dec 13 23:29:58 1998 UTC (20 years, 7 months ago) by pazsan
Branches: MAIN
CVS tags: v0-4-0, HEAD
Added some documentation (files stup, blocks stub, Mini-OOF implementation)
Added Benchres for my machine
made DOS and Win32 compile and run
New gforthmi.bat script for DOS - needs a temporary file for the commands
instead of the -e option.
Added select.o again for DOS (DJGPP's select is broken wrt timing)
Improved select.c
Bug with DOS: engine-ditc doesn't compile with optimization on. Maybe I need
to get a new GCC version for DOS?

    1: \ A less simple implementation of the blocks wordset. 
    2: 
    3: \ Copyright (C) 1995,1996,1997,1998 Free Software Foundation, Inc.
    4: 
    5: \ This file is part of Gforth.
    6: 
    7: \ Gforth is free software; you can redistribute it and/or
    8: \ modify it under the terms of the GNU General Public License
    9: \ as published by the Free Software Foundation; either version 2
   10: \ of the License, or (at your option) any later version.
   11: 
   12: \ This program is distributed in the hope that it will be useful,
   13: \ but WITHOUT ANY WARRANTY; without even the implied warranty of
   14: \ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   15: \ GNU General Public License for more details.
   16: 
   17: \ You should have received a copy of the GNU General Public License
   18: \ along with this program; if not, write to the Free Software
   19: \ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   20: 
   21: 
   22: \ A more efficient implementation would use mmap on OSs that
   23: \ provide it and many buffers on OSs that do not provide mmap.
   24: 
   25: \ Now, the replacement algorithm is "direct mapped"; change to LRU
   26: \ if too slow. Using more buffers helps, too.
   27: 
   28: \ I think I avoid the assumption 1 char = 1 here, but I have not tested this
   29: 
   30: \ 1024 constant chars/block \ mandated by the standard
   31: 
   32: require struct.fs
   33: 
   34: struct
   35:     cell%		field buffer-block   \ the block number
   36:     cell%		field buffer-fid     \ the block's fid
   37:     cell%		field buffer-dirty   \ the block dirty flag
   38:     char% chars/block * field block-buffer   \ the data
   39:     cell% 0 *		field next-buffer
   40: end-struct buffer-struct
   41: 
   42: Variable block-buffers
   43: Variable last-block
   44: 
   45: $20 Value buffers
   46: 
   47: User block-fid
   48: 
   49: : block-cold ( -- )
   50:     block-fid off  last-block off
   51:     buffer-struct buffers * %alloc dup block-buffers ! ( addr )
   52:     buffer-struct %size buffers * erase ;
   53: 
   54: ' block-cold INIT8 chained
   55: 
   56: block-cold
   57: 
   58: Defer flush-blocks
   59: 
   60: : open-blocks ( addr u -- ) \ gforth
   61:     \g use the file, whose name is given by @var{addr u}, as blocks file 
   62:     2dup open-fpath-file 0<>
   63:     if
   64: 	r/w bin create-file throw
   65:     else
   66: 	rot close-file throw  2dup file-status throw bin open-file throw
   67: 	>r 2drop r>
   68:     then
   69:     block-fid @ IF  flush-blocks block-fid @ close-file throw  THEN
   70:     block-fid ! ;
   71: 
   72: : use ( "file" -- ) \ gforth
   73:     \g use @var{file} as blocks file
   74:     name open-blocks ;
   75: 
   76: \ the file is opened as binary file, since it either will contain text
   77: \ without newlines or binary data
   78: : get-block-fid ( -- fid ) \ gforth
   79:     block-fid @ 0=
   80:     if
   81: 	s" blocks.fb" open-blocks
   82:     then
   83:     block-fid @ ;
   84: 
   85: : block-position ( u -- ) \ block
   86:     \G positions the block file to the start of block u
   87:     1- chars/block chars um* get-block-fid reposition-file throw ;
   88: 
   89: : update ( -- ) \ block
   90:     last-block @ ?dup IF  buffer-dirty on  THEN ;
   91: 
   92: : save-buffer ( buffer -- ) \ gforth
   93:     >r
   94:     r@ buffer-dirty @ r@ buffer-block @ 0<> and
   95:     if
   96: 	r@ buffer-block @ block-position
   97: 	r@ block-buffer chars/block  r@ buffer-fid @  write-file throw
   98: 	r@ buffer-dirty off
   99:     endif
  100:     rdrop ;
  101: 
  102: : empty-buffer ( buffer -- ) \ gforth
  103:     buffer-block off ;
  104: 
  105: : save-buffers  ( -- ) \ block
  106:     block-buffers @
  107:     buffers 0 ?DO  dup save-buffer  next-buffer  LOOP  drop ;
  108: 
  109: : empty-buffers ( -- ) \ block
  110:     block-buffers @
  111:     buffers 0 ?DO  dup empty-buffer  next-buffer  LOOP  drop ;
  112: 
  113: : flush ( -- ) \ block
  114:     save-buffers
  115:     empty-buffers ;
  116: 
  117: ' flush IS flush-blocks
  118: 
  119: : get-buffer ( n -- a-addr ) \ gforth
  120:     buffers mod buffer-struct %size * block-buffers @ + ;
  121: 
  122: : block ( u -- a-addr ) \ block
  123:     dup 0= -35 and throw
  124:     dup get-buffer >r
  125:     dup r@ buffer-block @ <>
  126:     r@ buffer-fid @ block-fid @ <> or
  127:     if
  128: 	r@ save-buffer
  129: 	dup block-position
  130: 	r@ block-buffer chars/block get-block-fid read-file throw
  131: 	\ clear the rest of the buffer if the file is too short
  132: 	r@ block-buffer over chars + chars/block rot chars - blank
  133: 	r@ buffer-block !
  134: 	get-block-fid r@ buffer-fid !
  135:     else
  136: 	drop
  137:     then
  138:     r> dup last-block ! block-buffer ;
  139: 
  140: : buffer ( u -- a-addr ) \ block
  141:     \ reading in the block is unnecessary, but simpler
  142:     block ;
  143: 
  144: User scr 0 scr !
  145: 
  146: : updated?  ( n -- f ) \ gforth
  147:     scr @ buffer
  148:     [ 0 buffer-dirty 0 block-buffer - ] Literal + @ ;
  149: 
  150: : list ( u -- ) \ block
  151:     \ calling block again and again looks inefficient but is necessary
  152:     \ in a multitasking environment
  153:     dup scr !
  154:     ." Screen " u.
  155:     updated?  0= IF ." not "  THEN  ." modified     " cr
  156:     16 0
  157:     ?do
  158: 	i 2 .r space scr @ block i 64 * chars + 64 type cr
  159:     loop ;
  160: 
  161: : (source)  ( -- addr len )
  162:   blk @ ?dup
  163:   IF    block chars/block
  164:   ELSE  tib #tib @
  165:   THEN ;
  166: 
  167: ' (source) IS source
  168: 
  169: : load ( i*x n -- j*x ) \ block
  170:   push-file
  171:   dup loadline ! blk ! >in off ['] interpret catch
  172:   pop-file throw ;
  173: 
  174: : thru ( i*x n1 n2 -- j*x ) \ block
  175:   1+ swap ?DO  I load  LOOP ;
  176: 
  177: : +load ( i*x n -- j*x ) \ block
  178:     blk @ + load ;
  179: 
  180: : +thru ( i*x n1 n2 -- j*x ) \ block
  181:   1+ swap ?DO  I +load  LOOP ;
  182: 
  183: : --> ( -- ) \ block- block
  184:     refill drop ; immediate
  185: 
  186: : block-included ( addr u -- ) \ gforth
  187:     block-fid @ >r block-fid off open-blocks
  188:     1 load block-fid @ close-file throw flush
  189:     r> block-fid ! ;
  190: 
  191: \ thrown out because it may provide unpleasant surprises - anton
  192: \ : include ( "name" -- )
  193: \     name 2dup dup 3 - /string s" .fb" compare
  194: \     0= IF  block-included  ELSE  included  THEN ;
  195: 
  196: get-current environment-wordlist set-current
  197: true constant block
  198: true constant block-ext
  199: set-current
  200: 
  201: : bye  ['] flush catch drop bye ;

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