File:  [gforth] / gforth / hash.fs
Revision 1.25: download - view: text, annotated - select for diffs
Sat Sep 23 15:06:00 2000 UTC (21 years, 1 month ago) by anton
Branches: MAIN
CVS tags: HEAD
updated copyright dates in many files (not in ec-related files)

    1: \ Hashed dictionaries                                  15jul94py
    2: 
    3: \ Copyright (C) 1995,1998,2000 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: [IFUNDEF] allocate
   22: : reserve-mem here swap allot ;
   23: \ move to a kernel/memory.fs
   24: [ELSE]
   25: : reserve-mem allocate throw ;
   26: [THEN]
   27: 
   28: [IFUNDEF] hashbits
   29: 11 Value hashbits
   30: [THEN]
   31: 1 hashbits lshift Value Hashlen
   32: 
   33: \ compute hash key                                     15jul94py
   34: 
   35: [IFUNDEF] hash
   36: : hash ( addr len -- key )
   37:     hashbits (hashkey1) ;
   38: [THEN]
   39: 
   40: Variable insRule        insRule on
   41: Variable revealed
   42: 
   43: \ Memory handling                                      10oct94py
   44: 
   45: Variable HashPointer
   46: Variable HashIndex
   47: 0 Value HashTable
   48: 
   49: \ forward declarations
   50: 0 Value hashsearch-map
   51: Defer hash-alloc ( addr -- addr )
   52: 
   53: \ DelFix and NewFix are from bigFORTH                  15jul94py
   54: 
   55: : DelFix ( addr root -- ) dup @ 2 pick ! ! ;
   56: : NewFix  ( root len # -- addr )
   57:   BEGIN  2 pick @ ?dup  0= WHILE  2dup * reserve-mem
   58:          over 0 ?DO  dup 4 pick DelFix 2 pick +  LOOP  drop
   59:   REPEAT  >r drop r@ @ rot ! r@ swap erase r> ;
   60: 
   61: : bucket ( addr len wordlist -- bucket-addr )
   62:     \ @var{bucket-addr} is the address of a cell that points to the first
   63:     \ element in the list of the bucket for the string @var{addr len}
   64:     wordlist-extend @ -rot hash xor ( bucket# )
   65:     cells HashTable + ;
   66: 
   67: : hash-find ( addr len wordlist -- nfa / false )
   68:     >r 2dup r> bucket @ (hashfind) ;
   69: 
   70: \ hash vocabularies                                    16jul94py
   71: 
   72: : lastlink! ( addr link -- )
   73:   BEGIN  dup @ dup  WHILE  nip  REPEAT  drop ! ;
   74: 
   75: : (reveal ( nfa wid -- )
   76:     over name>string rot bucket >r
   77:     HashPointer 2 Cells $400 NewFix
   78:     tuck cell+ ! r> insRule @
   79:     IF
   80: 	dup @ 2 pick ! !
   81:     ELSE
   82: 	lastlink!
   83:     THEN
   84:     revealed on ;
   85: 
   86: : hash-reveal ( nfa wid -- )
   87:     2dup (reveal) (reveal ;
   88: 
   89: : inithash ( wid -- )
   90:     wordlist-extend
   91:     insRule @ >r  insRule off  hash-alloc 3 cells -
   92:     dup wordlist-id
   93:     BEGIN  @ dup  WHILE  2dup swap (reveal  REPEAT
   94:     2drop  r> insRule ! ;
   95: 
   96: : addall  ( -- )
   97:     voclink
   98:     BEGIN  @ dup WHILE
   99: 	   dup 0 wordlist-link -
  100: 	   dup wordlist-map @ reveal-method @ ['] hash-reveal = 
  101: 	   IF  inithash ELSE drop THEN
  102:     REPEAT  drop ;
  103: 
  104: : clearhash  ( -- )
  105:     HashTable Hashlen cells bounds
  106:     DO  I @
  107: 	BEGIN  dup  WHILE
  108: 	    dup @ swap HashPointer DelFix
  109: 	REPEAT
  110: 	I !
  111: 	cell +LOOP
  112:     HashIndex off 
  113:     voclink
  114:     BEGIN ( wordlist-link-addr )
  115: 	@ dup
  116:     WHILE ( wordlist-link )
  117: 	dup 0 wordlist-link - ( wordlist-link wid ) 
  118: 	dup wordlist-map @ hashsearch-map = 
  119: 	IF ( wordlist-link wid )
  120: 	    0 swap wordlist-extend !
  121: 	ELSE
  122: 	    drop
  123: 	THEN
  124:     REPEAT
  125:     drop ;
  126: 
  127: : rehashall  ( wid -- ) 
  128:   drop revealed @ 
  129:   IF 	clearhash addall revealed off 
  130:   THEN ;
  131: 
  132: : (rehash)   ( wid -- )
  133:   dup wordlist-extend @ 0=
  134:   IF   inithash
  135:   ELSE rehashall THEN ;
  136: 
  137: \ >rom ?!
  138: align here    ' hash-find A, ' hash-reveal A, ' (rehash) A, ' (rehash) A,
  139: to hashsearch-map
  140: 
  141: \ hash allocate and vocabulary initialization          10oct94py
  142: 
  143: :noname ( addr -- addr )
  144:   HashTable 0= 
  145:   IF  Hashlen cells reserve-mem TO HashTable
  146:       HashTable Hashlen cells erase THEN
  147:   HashIndex @ over !  1 HashIndex +!
  148:   HashIndex @ Hashlen >=
  149:   [ [IFUNDEF] allocate ]
  150:   ABORT" no more space in hashtable"
  151:   [ [ELSE] ]
  152:   IF  HashTable >r clearhash
  153:       1 hashbits 1+ dup  to hashbits  lshift  to hashlen
  154:       r> free >r  0 to HashTable
  155:       addall r> throw
  156:   THEN 
  157:   [ [THEN] ] ; is hash-alloc
  158: 
  159: \ Hash-Find                                            01jan93py
  160: has? cross 0= 
  161: [IF]
  162: : make-hash
  163:   hashsearch-map forth-wordlist wordlist-map !
  164:   addall ;
  165:   make-hash \ Baumsuche ist installiert.
  166: [ELSE]
  167:   hashsearch-map forth-wordlist wordlist-map !
  168: [THEN]
  169: 
  170: \ for ec version display that vocabulary goes hashed
  171: 
  172: : hash-cold  ( -- )
  173: [ has? ec [IF] ] ." Hashing..." [ [THEN] ]
  174:   HashPointer off  0 TO HashTable  HashIndex off
  175:   addall
  176: \  voclink
  177: \  BEGIN  @ dup WHILE
  178: \         dup 0 wordlist-link - initvoc
  179: \  REPEAT  drop 
  180: [ has? ec [IF] ] ." Done" cr [ [THEN] ] ;
  181: 
  182: ' hash-cold INIT8 chained
  183: 
  184: : .words  ( -- )
  185:   base @ >r hex HashTable  Hashlen 0
  186:   DO  cr  i 2 .r ." : " dup i cells +
  187:       BEGIN  @ dup  WHILE
  188:              dup cell+ @ name>string type space  REPEAT  drop
  189:   LOOP  drop r> base ! ;
  190: 
  191: \ \ this stuff is for evaluating the hash function
  192: \ : square dup * ;
  193: 
  194: \ : countwl  ( -- sum sumsq )
  195: \     \ gives the number of words in the current wordlist
  196: \     \ and the sum of squares for the sublist lengths
  197: \     0 0
  198: \     hashtable Hashlen cells bounds DO
  199: \        0 i BEGIN
  200: \            @ dup WHILE
  201: \            swap 1+ swap
  202: \        REPEAT
  203: \        drop
  204: \        swap over square +
  205: \        >r + r>
  206: \        1 cells
  207: \    +LOOP ;
  208: 
  209: \ : chisq ( -- n )
  210: \     \ n should have about the same size as Hashlen
  211: \     countwl Hashlen 2 pick */ swap - ;

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