FreeBSD-5.3/sys/boot/ficl/dict.c
/*******************************************************************
** d i c t . c
** Forth Inspired Command Language - dictionary methods
** Author: John Sadler (john_sadler@alum.mit.edu)
** Created: 19 July 1997
** $Id: dict.c,v 1.14 2001/12/05 07:21:34 jsadler Exp $
*******************************************************************/
/*
** This file implements the dictionary -- FICL's model of
** memory management. All FICL words are stored in the
** dictionary. A word is a named chunk of data with its
** associated code. FICL treats all words the same, even
** precompiled ones, so your words become first-class
** extensions of the language. You can even define new
** control structures.
**
** 29 jun 1998 (sadler) added variable sized hash table support
*/
/*
** Copyright (c) 1997-2001 John Sadler (john_sadler@alum.mit.edu)
** All rights reserved.
**
** Get the latest Ficl release at http://ficl.sourceforge.net
**
** I am interested in hearing from anyone who uses ficl. If you have
** a problem, a success story, a defect, an enhancement request, or
** if you would like to contribute to the ficl release, please
** contact me by email at the address above.
**
** L I C E N S E and D I S C L A I M E R
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions
** are met:
** 1. Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** 2. Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in the
** documentation and/or other materials provided with the distribution.
**
** THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
** ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
** ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
** OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
** HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
** OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
** SUCH DAMAGE.
*/
/* $FreeBSD: src/sys/boot/ficl/dict.c,v 1.13 2002/04/09 17:45:11 dcs Exp $ */
#ifdef TESTMAIN
#include <stdio.h>
#include <ctype.h>
#else
#include <stand.h>
#endif
#include <string.h>
#include "ficl.h"
/* Dictionary on-demand resizing control variables */
CELL dictThreshold;
CELL dictIncrease;
static char *dictCopyName(FICL_DICT *pDict, STRINGINFO si);
/**************************************************************************
d i c t A b o r t D e f i n i t i o n
** Abort a definition in process: reclaim its memory and unlink it
** from the dictionary list. Assumes that there is a smudged
** definition in process...otherwise does nothing.
** NOTE: this function is not smart enough to unlink a word that
** has been successfully defined (ie linked into a hash). It
** only works for defs in process. If the def has been unsmudged,
** nothing happens.
**************************************************************************/
void dictAbortDefinition(FICL_DICT *pDict)
{
FICL_WORD *pFW;
ficlLockDictionary(TRUE);
pFW = pDict->smudge;
if (pFW->flags & FW_SMUDGE)
pDict->here = (CELL *)pFW->name;
ficlLockDictionary(FALSE);
return;
}
/**************************************************************************
a l i g n P t r
** Aligns the given pointer to FICL_ALIGN address units.
** Returns the aligned pointer value.
**************************************************************************/
void *alignPtr(void *ptr)
{
#if FICL_ALIGN > 0
char *cp;
CELL c;
cp = (char *)ptr + FICL_ALIGN_ADD;
c.p = (void *)cp;
c.u = c.u & (~FICL_ALIGN_ADD);
ptr = (CELL *)c.p;
#endif
return ptr;
}
/**************************************************************************
d i c t A l i g n
** Align the dictionary's free space pointer
**************************************************************************/
void dictAlign(FICL_DICT *pDict)
{
pDict->here = alignPtr(pDict->here);
}
/**************************************************************************
d i c t A l l o t
** Allocate or remove n chars of dictionary space, with
** checks for underrun and overrun
**************************************************************************/
int dictAllot(FICL_DICT *pDict, int n)
{
char *cp = (char *)pDict->here;
#if FICL_ROBUST
if (n > 0)
{
if ((unsigned)n <= dictCellsAvail(pDict) * sizeof (CELL))
cp += n;
else
return 1; /* dict is full */
}
else
{
n = -n;
if ((unsigned)n <= dictCellsUsed(pDict) * sizeof (CELL))
cp -= n;
else /* prevent underflow */
cp -= dictCellsUsed(pDict) * sizeof (CELL);
}
#else
cp += n;
#endif
pDict->here = PTRtoCELL cp;
return 0;
}
/**************************************************************************
d i c t A l l o t C e l l s
** Reserve space for the requested number of cells in the
** dictionary. If nCells < 0 , removes space from the dictionary.
**************************************************************************/
int dictAllotCells(FICL_DICT *pDict, int nCells)
{
#if FICL_ROBUST
if (nCells > 0)
{
if (nCells <= dictCellsAvail(pDict))
pDict->here += nCells;
else
return 1; /* dict is full */
}
else
{
nCells = -nCells;
if (nCells <= dictCellsUsed(pDict))
pDict->here -= nCells;
else /* prevent underflow */
pDict->here -= dictCellsUsed(pDict);
}
#else
pDict->here += nCells;
#endif
return 0;
}
/**************************************************************************
d i c t A p p e n d C e l l
** Append the specified cell to the dictionary
**************************************************************************/
void dictAppendCell(FICL_DICT *pDict, CELL c)
{
*pDict->here++ = c;
return;
}
/**************************************************************************
d i c t A p p e n d C h a r
** Append the specified char to the dictionary
**************************************************************************/
void dictAppendChar(FICL_DICT *pDict, char c)
{
char *cp = (char *)pDict->here;
*cp++ = c;
pDict->here = PTRtoCELL cp;
return;
}
/**************************************************************************
d i c t A p p e n d W o r d
** Create a new word in the dictionary with the specified
** name, code, and flags. Name must be NULL-terminated.
**************************************************************************/
FICL_WORD *dictAppendWord(FICL_DICT *pDict,
char *name,
FICL_CODE pCode,
UNS8 flags)
{
STRINGINFO si;
SI_SETLEN(si, strlen(name));
SI_SETPTR(si, name);
return dictAppendWord2(pDict, si, pCode, flags);
}
/**************************************************************************
d i c t A p p e n d W o r d 2
** Create a new word in the dictionary with the specified
** STRINGINFO, code, and flags. Does not require a NULL-terminated
** name.
**************************************************************************/
FICL_WORD *dictAppendWord2(FICL_DICT *pDict,
STRINGINFO si,
FICL_CODE pCode,
UNS8 flags)
{
FICL_COUNT len = (FICL_COUNT)SI_COUNT(si);
char *pName;
FICL_WORD *pFW;
ficlLockDictionary(TRUE);
/*
** NOTE: dictCopyName advances "here" as a side-effect.
** It must execute before pFW is initialized.
*/
pName = dictCopyName(pDict, si);
pFW = (FICL_WORD *)pDict->here;
pDict->smudge = pFW;
pFW->hash = hashHashCode(si);
pFW->code = pCode;
pFW->flags = (UNS8)(flags | FW_SMUDGE);
pFW->nName = (char)len;
pFW->name = pName;
/*
** Point "here" to first cell of new word's param area...
*/
pDict->here = pFW->param;
if (!(flags & FW_SMUDGE))
dictUnsmudge(pDict);
ficlLockDictionary(FALSE);
return pFW;
}
/**************************************************************************
d i c t A p p e n d U N S
** Append the specified FICL_UNS to the dictionary
**************************************************************************/
void dictAppendUNS(FICL_DICT *pDict, FICL_UNS u)
{
*pDict->here++ = LVALUEtoCELL(u);
return;
}
/**************************************************************************
d i c t C e l l s A v a i l
** Returns the number of empty cells left in the dictionary
**************************************************************************/
int dictCellsAvail(FICL_DICT *pDict)
{
return pDict->size - dictCellsUsed(pDict);
}
/**************************************************************************
d i c t C e l l s U s e d
** Returns the number of cells consumed in the dicionary
**************************************************************************/
int dictCellsUsed(FICL_DICT *pDict)
{
return pDict->here - pDict->dict;
}
/**************************************************************************
d i c t C h e c k
** Checks the dictionary for corruption and throws appropriate
** errors.
** Input: +n number of ADDRESS UNITS (not Cells) proposed to allot
** -n number of ADDRESS UNITS proposed to de-allot
** 0 just do a consistency check
**************************************************************************/
void dictCheck(FICL_DICT *pDict, FICL_VM *pVM, int n)
{
if ((n >= 0) && (dictCellsAvail(pDict) * (int)sizeof(CELL) < n))
{
vmThrowErr(pVM, "Error: dictionary full");
}
if ((n <= 0) && (dictCellsUsed(pDict) * (int)sizeof(CELL) < -n))
{
vmThrowErr(pVM, "Error: dictionary underflow");
}
if (pDict->nLists > FICL_DEFAULT_VOCS)
{
dictResetSearchOrder(pDict);
vmThrowErr(pVM, "Error: search order overflow");
}
else if (pDict->nLists < 0)
{
dictResetSearchOrder(pDict);
vmThrowErr(pVM, "Error: search order underflow");
}
return;
}
/**************************************************************************
d i c t C o p y N a m e
** Copy up to nFICLNAME characters of the name specified by si into
** the dictionary starting at "here", then NULL-terminate the name,
** point "here" to the next available byte, and return the address of
** the beginning of the name. Used by dictAppendWord.
** N O T E S :
** 1. "here" is guaranteed to be aligned after this operation.
** 2. If the string has zero length, align and return "here"
**************************************************************************/
static char *dictCopyName(FICL_DICT *pDict, STRINGINFO si)
{
char *oldCP = (char *)pDict->here;
char *cp = oldCP;
char *name = SI_PTR(si);
int i = SI_COUNT(si);
if (i == 0)
{
dictAlign(pDict);
return (char *)pDict->here;
}
if (i > nFICLNAME)
i = nFICLNAME;
for (; i > 0; --i)
{
*cp++ = *name++;
}
*cp++ = '\0';
pDict->here = PTRtoCELL cp;
dictAlign(pDict);
return oldCP;
}
/**************************************************************************
d i c t C r e a t e
** Create and initialize a dictionary with the specified number
** of cells capacity, and no hashing (hash size == 1).
**************************************************************************/
FICL_DICT *dictCreate(unsigned nCells)
{
return dictCreateHashed(nCells, 1);
}
FICL_DICT *dictCreateHashed(unsigned nCells, unsigned nHash)
{
FICL_DICT *pDict;
size_t nAlloc;
nAlloc = sizeof (FICL_HASH) + nCells * sizeof (CELL)
+ (nHash - 1) * sizeof (FICL_WORD *);
pDict = ficlMalloc(sizeof (FICL_DICT));
assert(pDict);
memset(pDict, 0, sizeof (FICL_DICT));
pDict->dict = ficlMalloc(nAlloc);
assert(pDict->dict);
pDict->size = nCells;
dictEmpty(pDict, nHash);
return pDict;
}
/**************************************************************************
d i c t C r e a t e W o r d l i s t
** Create and initialize an anonymous wordlist
**************************************************************************/
FICL_HASH *dictCreateWordlist(FICL_DICT *dp, int nBuckets)
{
FICL_HASH *pHash;
dictAlign(dp);
pHash = (FICL_HASH *)dp->here;
dictAllot(dp, sizeof (FICL_HASH)
+ (nBuckets-1) * sizeof (FICL_WORD *));
pHash->size = nBuckets;
hashReset(pHash);
return pHash;
}
/**************************************************************************
d i c t D e l e t e
** Free all memory allocated for the given dictionary
**************************************************************************/
void dictDelete(FICL_DICT *pDict)
{
assert(pDict);
ficlFree(pDict);
return;
}
/**************************************************************************
d i c t E m p t y
** Empty the dictionary, reset its hash table, and reset its search order.
** Clears and (re-)creates the hash table with the size specified by nHash.
**************************************************************************/
void dictEmpty(FICL_DICT *pDict, unsigned nHash)
{
FICL_HASH *pHash;
pDict->here = pDict->dict;
dictAlign(pDict);
pHash = (FICL_HASH *)pDict->here;
dictAllot(pDict,
sizeof (FICL_HASH) + (nHash - 1) * sizeof (FICL_WORD *));
pHash->size = nHash;
hashReset(pHash);
pDict->pForthWords = pHash;
pDict->smudge = NULL;
dictResetSearchOrder(pDict);
return;
}
/**************************************************************************
d i c t H a s h S u m m a r y
** Calculate a figure of merit for the dictionary hash table based
** on the average search depth for all the words in the dictionary,
** assuming uniform distribution of target keys. The figure of merit
** is the ratio of the total search depth for all keys in the table
** versus a theoretical optimum that would be achieved if the keys
** were distributed into the table as evenly as possible.
** The figure would be worse if the hash table used an open
** addressing scheme (i.e. collisions resolved by searching the
** table for an empty slot) for a given size table.
**************************************************************************/
#if FICL_WANT_FLOAT
void dictHashSummary(FICL_VM *pVM)
{
FICL_DICT *dp = vmGetDict(pVM);
FICL_HASH *pFHash;
FICL_WORD **pHash;
unsigned size;
FICL_WORD *pFW;
unsigned i;
int nMax = 0;
int nWords = 0;
int nFilled;
double avg = 0.0;
double best;
int nAvg, nRem, nDepth;
dictCheck(dp, pVM, 0);
pFHash = dp->pSearch[dp->nLists - 1];
pHash = pFHash->table;
size = pFHash->size;
nFilled = size;
for (i = 0; i < size; i++)
{
int n = 0;
pFW = pHash[i];
while (pFW)
{
++n;
++nWords;
pFW = pFW->link;
}
avg += (double)(n * (n+1)) / 2.0;
if (n > nMax)
nMax = n;
if (n == 0)
--nFilled;
}
/* Calc actual avg search depth for this hash */
avg = avg / nWords;
/* Calc best possible performance with this size hash */
nAvg = nWords / size;
nRem = nWords % size;
nDepth = size * (nAvg * (nAvg+1))/2 + (nAvg+1)*nRem;
best = (double)nDepth/nWords;
sprintf(pVM->pad,
"%d bins, %2.0f%% filled, Depth: Max=%d, Avg=%2.1f, Best=%2.1f, Score: %2.0f%%",
size,
(double)nFilled * 100.0 / size, nMax,
avg,
best,
100.0 * best / avg);
ficlTextOut(pVM, pVM->pad, 1);
return;
}
#endif
/**************************************************************************
d i c t I n c l u d e s
** Returns TRUE iff the given pointer is within the address range of
** the dictionary.
**************************************************************************/
int dictIncludes(FICL_DICT *pDict, void *p)
{
return ((p >= (void *) &pDict->dict)
&& (p < (void *)(&pDict->dict + pDict->size))
);
}
/**************************************************************************
d i c t L o o k u p
** Find the FICL_WORD that matches the given name and length.
** If found, returns the word's address. Otherwise returns NULL.
** Uses the search order list to search multiple wordlists.
**************************************************************************/
FICL_WORD *dictLookup(FICL_DICT *pDict, STRINGINFO si)
{
FICL_WORD *pFW = NULL;
FICL_HASH *pHash;
int i;
UNS16 hashCode = hashHashCode(si);
assert(pDict);
ficlLockDictionary(1);
for (i = (int)pDict->nLists - 1; (i >= 0) && (!pFW); --i)
{
pHash = pDict->pSearch[i];
pFW = hashLookup(pHash, si, hashCode);
}
ficlLockDictionary(0);
return pFW;
}
/**************************************************************************
f i c l L o o k u p L o c
** Same as dictLookup, but looks in system locals dictionary first...
** Assumes locals dictionary has only one wordlist...
**************************************************************************/
#if FICL_WANT_LOCALS
FICL_WORD *ficlLookupLoc(FICL_SYSTEM *pSys, STRINGINFO si)
{
FICL_WORD *pFW = NULL;
FICL_DICT *pDict = pSys->dp;
FICL_HASH *pHash = ficlGetLoc(pSys)->pForthWords;
int i;
UNS16 hashCode = hashHashCode(si);
assert(pHash);
assert(pDict);
ficlLockDictionary(1);
/*
** check the locals dict first...
*/
pFW = hashLookup(pHash, si, hashCode);
/*
** If no joy, (!pFW) --------------------------v
** iterate over the search list in the main dict
*/
for (i = (int)pDict->nLists - 1; (i >= 0) && (!pFW); --i)
{
pHash = pDict->pSearch[i];
pFW = hashLookup(pHash, si, hashCode);
}
ficlLockDictionary(0);
return pFW;
}
#endif
/**************************************************************************
d i c t R e s e t S e a r c h O r d e r
** Initialize the dictionary search order list to sane state
**************************************************************************/
void dictResetSearchOrder(FICL_DICT *pDict)
{
assert(pDict);
pDict->pCompile = pDict->pForthWords;
pDict->nLists = 1;
pDict->pSearch[0] = pDict->pForthWords;
return;
}
/**************************************************************************
d i c t S e t F l a g s
** Changes the flags field of the most recently defined word:
** Set all bits that are ones in the set parameter, clear all bits
** that are ones in the clr parameter. Clear wins in case the same bit
** is set in both parameters.
**************************************************************************/
void dictSetFlags(FICL_DICT *pDict, UNS8 set, UNS8 clr)
{
assert(pDict->smudge);
pDict->smudge->flags |= set;
pDict->smudge->flags &= ~clr;
return;
}
/**************************************************************************
d i c t S e t I m m e d i a t e
** Set the most recently defined word as IMMEDIATE
**************************************************************************/
void dictSetImmediate(FICL_DICT *pDict)
{
assert(pDict->smudge);
pDict->smudge->flags |= FW_IMMEDIATE;
return;
}
/**************************************************************************
d i c t U n s m u d g e
** Completes the definition of a word by linking it
** into the main list
**************************************************************************/
void dictUnsmudge(FICL_DICT *pDict)
{
FICL_WORD *pFW = pDict->smudge;
FICL_HASH *pHash = pDict->pCompile;
assert(pHash);
assert(pFW);
/*
** :noname words never get linked into the list...
*/
if (pFW->nName > 0)
hashInsertWord(pHash, pFW);
pFW->flags &= ~(FW_SMUDGE);
return;
}
/**************************************************************************
d i c t W h e r e
** Returns the value of the HERE pointer -- the address
** of the next free cell in the dictionary
**************************************************************************/
CELL *dictWhere(FICL_DICT *pDict)
{
return pDict->here;
}
/**************************************************************************
h a s h F o r g e t
** Unlink all words in the hash that have addresses greater than or
** equal to the address supplied. Implementation factor for FORGET
** and MARKER.
**************************************************************************/
void hashForget(FICL_HASH *pHash, void *where)
{
FICL_WORD *pWord;
unsigned i;
assert(pHash);
assert(where);
for (i = 0; i < pHash->size; i++)
{
pWord = pHash->table[i];
while ((void *)pWord >= where)
{
pWord = pWord->link;
}
pHash->table[i] = pWord;
}
return;
}
/**************************************************************************
h a s h H a s h C o d e
**
** Generate a 16 bit hashcode from a character string using a rolling
** shift and add stolen from PJ Weinberger of Bell Labs fame. Case folds
** the name before hashing it...
** N O T E : If string has zero length, returns zero.
**************************************************************************/
UNS16 hashHashCode(STRINGINFO si)
{
/* hashPJW */
UNS8 *cp;
UNS16 code = (UNS16)si.count;
UNS16 shift = 0;
if (si.count == 0)
return 0;
/* changed to run without errors under Purify -- lch */
for (cp = (UNS8 *)si.cp; si.count && *cp; cp++, si.count--)
{
code = (UNS16)((code << 4) + tolower(*cp));
shift = (UNS16)(code & 0xf000);
if (shift)
{
code ^= (UNS16)(shift >> 8);
code ^= (UNS16)shift;
}
}
return (UNS16)code;
}
/**************************************************************************
h a s h I n s e r t W o r d
** Put a word into the hash table using the word's hashcode as
** an index (modulo the table size).
**************************************************************************/
void hashInsertWord(FICL_HASH *pHash, FICL_WORD *pFW)
{
FICL_WORD **pList;
assert(pHash);
assert(pFW);
if (pHash->size == 1)
{
pList = pHash->table;
}
else
{
pList = pHash->table + (pFW->hash % pHash->size);
}
pFW->link = *pList;
*pList = pFW;
return;
}
/**************************************************************************
h a s h L o o k u p
** Find a name in the hash table given the hashcode and text of the name.
** Returns the address of the corresponding FICL_WORD if found,
** otherwise NULL.
** Note: outer loop on link field supports inheritance in wordlists.
** It's not part of ANS Forth - ficl only. hashReset creates wordlists
** with NULL link fields.
**************************************************************************/
FICL_WORD *hashLookup(FICL_HASH *pHash, STRINGINFO si, UNS16 hashCode)
{
FICL_UNS nCmp = si.count;
FICL_WORD *pFW;
UNS16 hashIdx;
if (nCmp > nFICLNAME)
nCmp = nFICLNAME;
for (; pHash != NULL; pHash = pHash->link)
{
if (pHash->size > 1)
hashIdx = (UNS16)(hashCode % pHash->size);
else /* avoid the modulo op for single threaded lists */
hashIdx = 0;
for (pFW = pHash->table[hashIdx]; pFW; pFW = pFW->link)
{
if ( (pFW->nName == si.count)
&& (!strincmp(si.cp, pFW->name, nCmp)) )
return pFW;
#if FICL_ROBUST
assert(pFW != pFW->link);
#endif
}
}
return NULL;
}
/**************************************************************************
h a s h R e s e t
** Initialize a FICL_HASH to empty state.
**************************************************************************/
void hashReset(FICL_HASH *pHash)
{
unsigned i;
assert(pHash);
for (i = 0; i < pHash->size; i++)
{
pHash->table[i] = NULL;
}
pHash->link = NULL;
pHash->name = NULL;
return;
}
/**************************************************************************
d i c t C h e c k T h r e s h o l d
** Verify if an increase in the dictionary size is warranted, and do it if
** so.
**************************************************************************/
void dictCheckThreshold(FICL_DICT* dp)
{
if( dictCellsAvail(dp) < dictThreshold.u ) {
dp->dict = ficlMalloc( dictIncrease.u * sizeof (CELL) );
assert(dp->dict);
dp->here = dp->dict;
dp->size = dictIncrease.u;
dictAlign(dp);
}
}