1 /*******************************************************************
3 ** Forth Inspired Command Language - dictionary methods
4 ** Author: John Sadler (john_sadler@alum.mit.edu)
5 ** Created: 19 July 1997
6 ** $Id: dict.c,v 1.14 2001/12/05 07:21:34 jsadler Exp $
7 *******************************************************************/
9 ** This file implements the dictionary -- FICL's model of
10 ** memory management. All FICL words are stored in the
11 ** dictionary. A word is a named chunk of data with its
12 ** associated code. FICL treats all words the same, even
13 ** precompiled ones, so your words become first-class
14 ** extensions of the language. You can even define new
15 ** control structures.
17 ** 29 jun 1998 (sadler) added variable sized hash table support
20 ** Copyright (c) 1997-2001 John Sadler (john_sadler@alum.mit.edu)
21 ** All rights reserved.
23 ** Get the latest Ficl release at http://ficl.sourceforge.net
25 ** I am interested in hearing from anyone who uses ficl. If you have
26 ** a problem, a success story, a defect, an enhancement request, or
27 ** if you would like to contribute to the ficl release, please
28 ** contact me by email at the address above.
30 ** L I C E N S E and D I S C L A I M E R
32 ** Redistribution and use in source and binary forms, with or without
33 ** modification, are permitted provided that the following conditions
35 ** 1. Redistributions of source code must retain the above copyright
36 ** notice, this list of conditions and the following disclaimer.
37 ** 2. Redistributions in binary form must reproduce the above copyright
38 ** notice, this list of conditions and the following disclaimer in the
39 ** documentation and/or other materials provided with the distribution.
41 ** THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
42 ** ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 ** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 ** ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 ** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 ** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 ** OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 ** HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 ** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 ** OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
65 /* Dictionary on-demand resizing control variables */
70 static char *dictCopyName(FICL_DICT *pDict, STRINGINFO si);
72 /**************************************************************************
73 d i c t A b o r t D e f i n i t i o n
74 ** Abort a definition in process: reclaim its memory and unlink it
75 ** from the dictionary list. Assumes that there is a smudged
76 ** definition in process...otherwise does nothing.
77 ** NOTE: this function is not smart enough to unlink a word that
78 ** has been successfully defined (ie linked into a hash). It
79 ** only works for defs in process. If the def has been unsmudged,
81 **************************************************************************/
82 void dictAbortDefinition(FICL_DICT *pDict)
85 ficlLockDictionary(TRUE);
88 if (pFW->flags & FW_SMUDGE)
89 pDict->here = (CELL *)pFW->name;
91 ficlLockDictionary(FALSE);
96 /**************************************************************************
98 ** Aligns the given pointer to FICL_ALIGN address units.
99 ** Returns the aligned pointer value.
100 **************************************************************************/
101 void *alignPtr(void *ptr)
106 cp = (char *)ptr + FICL_ALIGN_ADD;
108 c.u = c.u & (~FICL_ALIGN_ADD);
115 /**************************************************************************
117 ** Align the dictionary's free space pointer
118 **************************************************************************/
119 void dictAlign(FICL_DICT *pDict)
121 pDict->here = alignPtr(pDict->here);
125 /**************************************************************************
127 ** Allocate or remove n chars of dictionary space, with
128 ** checks for underrun and overrun
129 **************************************************************************/
130 int dictAllot(FICL_DICT *pDict, int n)
132 char *cp = (char *)pDict->here;
136 if ((unsigned)n <= dictCellsAvail(pDict) * sizeof (CELL))
139 return 1; /* dict is full */
144 if ((unsigned)n <= dictCellsUsed(pDict) * sizeof (CELL))
146 else /* prevent underflow */
147 cp -= dictCellsUsed(pDict) * sizeof (CELL);
152 pDict->here = PTRtoCELL cp;
157 /**************************************************************************
158 d i c t A l l o t C e l l s
159 ** Reserve space for the requested number of cells in the
160 ** dictionary. If nCells < 0 , removes space from the dictionary.
161 **************************************************************************/
162 int dictAllotCells(FICL_DICT *pDict, int nCells)
167 if (nCells <= dictCellsAvail(pDict))
168 pDict->here += nCells;
170 return 1; /* dict is full */
175 if (nCells <= dictCellsUsed(pDict))
176 pDict->here -= nCells;
177 else /* prevent underflow */
178 pDict->here -= dictCellsUsed(pDict);
181 pDict->here += nCells;
187 /**************************************************************************
188 d i c t A p p e n d C e l l
189 ** Append the specified cell to the dictionary
190 **************************************************************************/
191 void dictAppendCell(FICL_DICT *pDict, CELL c)
198 /**************************************************************************
199 d i c t A p p e n d C h a r
200 ** Append the specified char to the dictionary
201 **************************************************************************/
202 void dictAppendChar(FICL_DICT *pDict, char c)
204 char *cp = (char *)pDict->here;
206 pDict->here = PTRtoCELL cp;
211 /**************************************************************************
212 d i c t A p p e n d W o r d
213 ** Create a new word in the dictionary with the specified
214 ** name, code, and flags. Name must be NULL-terminated.
215 **************************************************************************/
216 FICL_WORD *dictAppendWord(FICL_DICT *pDict,
222 SI_SETLEN(si, strlen(name));
224 return dictAppendWord2(pDict, si, pCode, flags);
228 /**************************************************************************
229 d i c t A p p e n d W o r d 2
230 ** Create a new word in the dictionary with the specified
231 ** STRINGINFO, code, and flags. Does not require a NULL-terminated
233 **************************************************************************/
234 FICL_WORD *dictAppendWord2(FICL_DICT *pDict,
239 FICL_COUNT len = (FICL_COUNT)SI_COUNT(si);
243 ficlLockDictionary(TRUE);
246 ** NOTE: dictCopyName advances "here" as a side-effect.
247 ** It must execute before pFW is initialized.
249 pName = dictCopyName(pDict, si);
250 pFW = (FICL_WORD *)pDict->here;
252 pFW->hash = hashHashCode(si);
254 pFW->flags = (UNS8)(flags | FW_SMUDGE);
255 pFW->nName = (char)len;
258 ** Point "here" to first cell of new word's param area...
260 pDict->here = pFW->param;
262 if (!(flags & FW_SMUDGE))
265 ficlLockDictionary(FALSE);
270 /**************************************************************************
271 d i c t A p p e n d U N S
272 ** Append the specified FICL_UNS to the dictionary
273 **************************************************************************/
274 void dictAppendUNS(FICL_DICT *pDict, FICL_UNS u)
276 *pDict->here++ = LVALUEtoCELL(u);
281 /**************************************************************************
282 d i c t C e l l s A v a i l
283 ** Returns the number of empty cells left in the dictionary
284 **************************************************************************/
285 int dictCellsAvail(FICL_DICT *pDict)
287 return pDict->size - dictCellsUsed(pDict);
291 /**************************************************************************
292 d i c t C e l l s U s e d
293 ** Returns the number of cells consumed in the dicionary
294 **************************************************************************/
295 int dictCellsUsed(FICL_DICT *pDict)
297 return pDict->here - pDict->dict;
301 /**************************************************************************
303 ** Checks the dictionary for corruption and throws appropriate
305 ** Input: +n number of ADDRESS UNITS (not Cells) proposed to allot
306 ** -n number of ADDRESS UNITS proposed to de-allot
307 ** 0 just do a consistency check
308 **************************************************************************/
309 void dictCheck(FICL_DICT *pDict, FICL_VM *pVM, int n)
311 if ((n >= 0) && (dictCellsAvail(pDict) * (int)sizeof(CELL) < n))
313 vmThrowErr(pVM, "Error: dictionary full");
316 if ((n <= 0) && (dictCellsUsed(pDict) * (int)sizeof(CELL) < -n))
318 vmThrowErr(pVM, "Error: dictionary underflow");
321 if (pDict->nLists > FICL_DEFAULT_VOCS)
323 dictResetSearchOrder(pDict);
324 vmThrowErr(pVM, "Error: search order overflow");
326 else if (pDict->nLists < 0)
328 dictResetSearchOrder(pDict);
329 vmThrowErr(pVM, "Error: search order underflow");
336 /**************************************************************************
337 d i c t C o p y N a m e
338 ** Copy up to nFICLNAME characters of the name specified by si into
339 ** the dictionary starting at "here", then NULL-terminate the name,
340 ** point "here" to the next available byte, and return the address of
341 ** the beginning of the name. Used by dictAppendWord.
343 ** 1. "here" is guaranteed to be aligned after this operation.
344 ** 2. If the string has zero length, align and return "here"
345 **************************************************************************/
346 static char *dictCopyName(FICL_DICT *pDict, STRINGINFO si)
348 char *oldCP = (char *)pDict->here;
350 char *name = SI_PTR(si);
351 int i = SI_COUNT(si);
356 return (char *)pDict->here;
369 pDict->here = PTRtoCELL cp;
375 /**************************************************************************
377 ** Create and initialize a dictionary with the specified number
378 ** of cells capacity, and no hashing (hash size == 1).
379 **************************************************************************/
380 FICL_DICT *dictCreate(unsigned nCells)
382 return dictCreateHashed(nCells, 1);
386 FICL_DICT *dictCreateHashed(unsigned nCells, unsigned nHash)
391 nAlloc = sizeof (FICL_HASH) + nCells * sizeof (CELL)
392 + (nHash - 1) * sizeof (FICL_WORD *);
394 pDict = ficlMalloc(sizeof (FICL_DICT));
396 memset(pDict, 0, sizeof (FICL_DICT));
397 pDict->dict = ficlMalloc(nAlloc);
400 pDict->size = nCells;
401 dictEmpty(pDict, nHash);
406 /**************************************************************************
407 d i c t C r e a t e W o r d l i s t
408 ** Create and initialize an anonymous wordlist
409 **************************************************************************/
410 FICL_HASH *dictCreateWordlist(FICL_DICT *dp, int nBuckets)
415 pHash = (FICL_HASH *)dp->here;
416 dictAllot(dp, sizeof (FICL_HASH)
417 + (nBuckets-1) * sizeof (FICL_WORD *));
419 pHash->size = nBuckets;
425 /**************************************************************************
427 ** Free all memory allocated for the given dictionary
428 **************************************************************************/
429 void dictDelete(FICL_DICT *pDict)
437 /**************************************************************************
439 ** Empty the dictionary, reset its hash table, and reset its search order.
440 ** Clears and (re-)creates the hash table with the size specified by nHash.
441 **************************************************************************/
442 void dictEmpty(FICL_DICT *pDict, unsigned nHash)
446 pDict->here = pDict->dict;
449 pHash = (FICL_HASH *)pDict->here;
451 sizeof (FICL_HASH) + (nHash - 1) * sizeof (FICL_WORD *));
456 pDict->pForthWords = pHash;
457 pDict->smudge = NULL;
458 dictResetSearchOrder(pDict);
463 /**************************************************************************
464 d i c t H a s h S u m m a r y
465 ** Calculate a figure of merit for the dictionary hash table based
466 ** on the average search depth for all the words in the dictionary,
467 ** assuming uniform distribution of target keys. The figure of merit
468 ** is the ratio of the total search depth for all keys in the table
469 ** versus a theoretical optimum that would be achieved if the keys
470 ** were distributed into the table as evenly as possible.
471 ** The figure would be worse if the hash table used an open
472 ** addressing scheme (i.e. collisions resolved by searching the
473 ** table for an empty slot) for a given size table.
474 **************************************************************************/
476 void dictHashSummary(FICL_VM *pVM)
478 FICL_DICT *dp = vmGetDict(pVM);
489 int nAvg, nRem, nDepth;
491 dictCheck(dp, pVM, 0);
493 pFHash = dp->pSearch[dp->nLists - 1];
494 pHash = pFHash->table;
498 for (i = 0; i < size; i++)
510 avg += (double)(n * (n+1)) / 2.0;
518 /* Calc actual avg search depth for this hash */
521 /* Calc best possible performance with this size hash */
522 nAvg = nWords / size;
523 nRem = nWords % size;
524 nDepth = size * (nAvg * (nAvg+1))/2 + (nAvg+1)*nRem;
525 best = (double)nDepth/nWords;
528 "%d bins, %2.0f%% filled, Depth: Max=%d, Avg=%2.1f, Best=%2.1f, Score: %2.0f%%",
530 (double)nFilled * 100.0 / size, nMax,
535 ficlTextOut(pVM, pVM->pad, 1);
541 /**************************************************************************
542 d i c t I n c l u d e s
543 ** Returns TRUE iff the given pointer is within the address range of
545 **************************************************************************/
546 int dictIncludes(FICL_DICT *pDict, void *p)
548 return ((p >= (void *) &pDict->dict)
549 && (p < (void *)(&pDict->dict + pDict->size))
553 /**************************************************************************
555 ** Find the FICL_WORD that matches the given name and length.
556 ** If found, returns the word's address. Otherwise returns NULL.
557 ** Uses the search order list to search multiple wordlists.
558 **************************************************************************/
559 FICL_WORD *dictLookup(FICL_DICT *pDict, STRINGINFO si)
561 FICL_WORD *pFW = NULL;
564 UNS16 hashCode = hashHashCode(si);
568 ficlLockDictionary(1);
570 for (i = (int)pDict->nLists - 1; (i >= 0) && (!pFW); --i)
572 pHash = pDict->pSearch[i];
573 pFW = hashLookup(pHash, si, hashCode);
576 ficlLockDictionary(0);
581 /**************************************************************************
582 f i c l L o o k u p L o c
583 ** Same as dictLookup, but looks in system locals dictionary first...
584 ** Assumes locals dictionary has only one wordlist...
585 **************************************************************************/
587 FICL_WORD *ficlLookupLoc(FICL_SYSTEM *pSys, STRINGINFO si)
589 FICL_WORD *pFW = NULL;
590 FICL_DICT *pDict = pSys->dp;
591 FICL_HASH *pHash = ficlGetLoc(pSys)->pForthWords;
593 UNS16 hashCode = hashHashCode(si);
598 ficlLockDictionary(1);
600 ** check the locals dict first...
602 pFW = hashLookup(pHash, si, hashCode);
605 ** If no joy, (!pFW) --------------------------v
606 ** iterate over the search list in the main dict
608 for (i = (int)pDict->nLists - 1; (i >= 0) && (!pFW); --i)
610 pHash = pDict->pSearch[i];
611 pFW = hashLookup(pHash, si, hashCode);
614 ficlLockDictionary(0);
620 /**************************************************************************
621 d i c t R e s e t S e a r c h O r d e r
622 ** Initialize the dictionary search order list to sane state
623 **************************************************************************/
624 void dictResetSearchOrder(FICL_DICT *pDict)
627 pDict->pCompile = pDict->pForthWords;
629 pDict->pSearch[0] = pDict->pForthWords;
634 /**************************************************************************
635 d i c t S e t F l a g s
636 ** Changes the flags field of the most recently defined word:
637 ** Set all bits that are ones in the set parameter, clear all bits
638 ** that are ones in the clr parameter. Clear wins in case the same bit
639 ** is set in both parameters.
640 **************************************************************************/
641 void dictSetFlags(FICL_DICT *pDict, UNS8 set, UNS8 clr)
643 assert(pDict->smudge);
644 pDict->smudge->flags |= set;
645 pDict->smudge->flags &= ~clr;
650 /**************************************************************************
651 d i c t S e t I m m e d i a t e
652 ** Set the most recently defined word as IMMEDIATE
653 **************************************************************************/
654 void dictSetImmediate(FICL_DICT *pDict)
656 assert(pDict->smudge);
657 pDict->smudge->flags |= FW_IMMEDIATE;
662 /**************************************************************************
663 d i c t U n s m u d g e
664 ** Completes the definition of a word by linking it
665 ** into the main list
666 **************************************************************************/
667 void dictUnsmudge(FICL_DICT *pDict)
669 FICL_WORD *pFW = pDict->smudge;
670 FICL_HASH *pHash = pDict->pCompile;
675 ** :noname words never get linked into the list...
678 hashInsertWord(pHash, pFW);
679 pFW->flags &= ~(FW_SMUDGE);
684 /**************************************************************************
686 ** Returns the value of the HERE pointer -- the address
687 ** of the next free cell in the dictionary
688 **************************************************************************/
689 CELL *dictWhere(FICL_DICT *pDict)
695 /**************************************************************************
697 ** Unlink all words in the hash that have addresses greater than or
698 ** equal to the address supplied. Implementation factor for FORGET
700 **************************************************************************/
701 void hashForget(FICL_HASH *pHash, void *where)
709 for (i = 0; i < pHash->size; i++)
711 pWord = pHash->table[i];
713 while ((void *)pWord >= where)
718 pHash->table[i] = pWord;
725 /**************************************************************************
726 h a s h H a s h C o d e
728 ** Generate a 16 bit hashcode from a character string using a rolling
729 ** shift and add stolen from PJ Weinberger of Bell Labs fame. Case folds
730 ** the name before hashing it...
731 ** N O T E : If string has zero length, returns zero.
732 **************************************************************************/
733 UNS16 hashHashCode(STRINGINFO si)
737 UNS16 code = (UNS16)si.count;
743 /* changed to run without errors under Purify -- lch */
744 for (cp = (UNS8 *)si.cp; si.count && *cp; cp++, si.count--)
746 code = (UNS16)((code << 4) + tolower(*cp));
747 shift = (UNS16)(code & 0xf000);
750 code ^= (UNS16)(shift >> 8);
751 code ^= (UNS16)shift;
761 /**************************************************************************
762 h a s h I n s e r t W o r d
763 ** Put a word into the hash table using the word's hashcode as
764 ** an index (modulo the table size).
765 **************************************************************************/
766 void hashInsertWord(FICL_HASH *pHash, FICL_WORD *pFW)
773 if (pHash->size == 1)
775 pList = pHash->table;
779 pList = pHash->table + (pFW->hash % pHash->size);
788 /**************************************************************************
790 ** Find a name in the hash table given the hashcode and text of the name.
791 ** Returns the address of the corresponding FICL_WORD if found,
793 ** Note: outer loop on link field supports inheritance in wordlists.
794 ** It's not part of ANS Forth - ficl only. hashReset creates wordlists
795 ** with NULL link fields.
796 **************************************************************************/
797 FICL_WORD *hashLookup(FICL_HASH *pHash, STRINGINFO si, UNS16 hashCode)
799 FICL_UNS nCmp = si.count;
803 if (nCmp > nFICLNAME)
806 for (; pHash != NULL; pHash = pHash->link)
809 hashIdx = (UNS16)(hashCode % pHash->size);
810 else /* avoid the modulo op for single threaded lists */
813 for (pFW = pHash->table[hashIdx]; pFW; pFW = pFW->link)
815 if ( (pFW->nName == si.count)
816 && (!strincmp(si.cp, pFW->name, nCmp)) )
819 assert(pFW != pFW->link);
828 /**************************************************************************
830 ** Initialize a FICL_HASH to empty state.
831 **************************************************************************/
832 void hashReset(FICL_HASH *pHash)
838 for (i = 0; i < pHash->size; i++)
840 pHash->table[i] = NULL;
848 /**************************************************************************
849 d i c t C h e c k T h r e s h o l d
850 ** Verify if an increase in the dictionary size is warranted, and do it if
852 **************************************************************************/
854 void dictCheckThreshold(FICL_DICT* dp)
856 if( dictCellsAvail(dp) < dictThreshold.u ) {
857 dp->dict = ficlMalloc( dictIncrease.u * sizeof (CELL) );
860 dp->size = dictIncrease.u;