[p5sagit/p5-mst-13.2.git] / hash.c

/* $Header: hash.c,v 3.0.1.6 90/10/15 17:32:52 lwall Locked $
 *
 *    Copyright (c) 1989, Larry Wall
 *
 *    You may distribute under the terms of the GNU General Public License
 *    as specified in the README file that comes with the perl 3.0 kit.
 *
 * $Log:	hash.c,v $
 * Revision 3.0.1.6  90/10/15  17:32:52  lwall
 * patch29: non-existent array values no longer cause core dumps
 * patch29: %foo = () will now clear dbm files
 * patch29: dbm files couldn't be opened read only
 * patch29: the cache array for dbm files wasn't correctly created on fetches
 * 
 * Revision 3.0.1.5  90/08/13  22:18:27  lwall
 * patch28: defined(@array) and defined(%array) didn't work right
 * 
 * Revision 3.0.1.4  90/08/09  03:50:22  lwall
 * patch19: dbmopen(name, 'filename', undef) now refrains from creating
 * 
 * Revision 3.0.1.3  90/03/27  15:59:09  lwall
 * patch16: @dbmvalues{'foo','bar'} could use the same cache entry for both values
 * 
 * Revision 3.0.1.2  89/12/21  20:03:39  lwall
 * patch7: errno may now be a macro with an lvalue
 * 
 * Revision 3.0.1.1  89/11/11  04:34:18  lwall
 * patch2: CX/UX needed to set the key each time in associative iterators
 * 
 * Revision 3.0  89/10/18  15:18:32  lwall
 * 3.0 baseline
 * 
 */

#include "EXTERN.h"
#include "perl.h"

static char coeff[] = {
		61,59,53,47,43,41,37,31,29,23,17,13,11,7,3,1,
		61,59,53,47,43,41,37,31,29,23,17,13,11,7,3,1,
		61,59,53,47,43,41,37,31,29,23,17,13,11,7,3,1,
		61,59,53,47,43,41,37,31,29,23,17,13,11,7,3,1,
		61,59,53,47,43,41,37,31,29,23,17,13,11,7,3,1,
		61,59,53,47,43,41,37,31,29,23,17,13,11,7,3,1,
		61,59,53,47,43,41,37,31,29,23,17,13,11,7,3,1,
		61,59,53,47,43,41,37,31,29,23,17,13,11,7,3,1};

static void hfreeentries();

STR *
hfetch(tb,key,klen,lval)
register HASH *tb;
char *key;
unsigned int klen;
int lval;
{
    register char *s;
    register int i;
    register int hash;
    register HENT *entry;
    register int maxi;
    STR *str;
#ifdef SOME_DBM
    datum dkey,dcontent;
#endif

    if (!tb)
	return &str_undef;
    if (!tb->tbl_array) {
	if (lval)
	    Newz(503,tb->tbl_array, tb->tbl_max + 1, HENT*);
	else
	    return &str_undef;
    }

    /* The hash function we use on symbols has to be equal to the first
     * character when taken modulo 128, so that str_reset() can be implemented
     * efficiently.  We throw in the second character and the last character
     * (times 128) so that long chains of identifiers starting with the
     * same letter don't have to be strEQ'ed within hfetch(), since it
     * compares hash values before trying strEQ().
     */
    if (!tb->tbl_coeffsize)
	hash = *key + 128 * key[1] + 128 * key[klen-1];	/* assuming klen > 0 */
    else {	/* use normal coefficients */
	if (klen < tb->tbl_coeffsize)
	    maxi = klen;
	else
	    maxi = tb->tbl_coeffsize;
	for (s=key,		i=0,	hash = 0;
			    i < maxi;
	     s++,		i++,	hash *= 5) {
	    hash += *s * coeff[i];
	}
    }

    entry = tb->tbl_array[hash & tb->tbl_max];
    for (; entry; entry = entry->hent_next) {
	if (entry->hent_hash != hash)		/* strings can't be equal */
	    continue;
	if (entry->hent_klen != klen)
	    continue;
	if (bcmp(entry->hent_key,key,klen))	/* is this it? */
	    continue;
	return entry->hent_val;
    }
#ifdef SOME_DBM
    if (tb->tbl_dbm) {
	dkey.dptr = key;
	dkey.dsize = klen;
	dcontent = dbm_fetch(tb->tbl_dbm,dkey);
	if (dcontent.dptr) {			/* found one */
	    str = Str_new(60,dcontent.dsize);
	    str_nset(str,dcontent.dptr,dcontent.dsize);
	    hstore(tb,key,klen,str,hash);		/* cache it */
	    return str;
	}
    }
#endif
    if (lval) {		/* gonna assign to this, so it better be there */
	str = Str_new(61,0);
	hstore(tb,key,klen,str,hash);
	return str;
    }
    return &str_undef;
}

bool
hstore(tb,key,klen,val,hash)
register HASH *tb;
char *key;
unsigned int klen;
STR *val;
register int hash;
{
    register char *s;
    register int i;
    register HENT *entry;
    register HENT **oentry;
    register int maxi;

    if (!tb)
	return FALSE;

    if (hash)
	;
    else if (!tb->tbl_coeffsize)
	hash = *key + 128 * key[1] + 128 * key[klen-1];
    else {	/* use normal coefficients */
	if (klen < tb->tbl_coeffsize)
	    maxi = klen;
	else
	    maxi = tb->tbl_coeffsize;
	for (s=key,		i=0,	hash = 0;
			    i < maxi;
	     s++,		i++,	hash *= 5) {
	    hash += *s * coeff[i];
	}
    }

    if (!tb->tbl_array)
	Newz(505,tb->tbl_array, tb->tbl_max + 1, HENT*);

    oentry = &(tb->tbl_array[hash & tb->tbl_max]);
    i = 1;

    for (entry = *oentry; entry; i=0, entry = entry->hent_next) {
	if (entry->hent_hash != hash)		/* strings can't be equal */
	    continue;
	if (entry->hent_klen != klen)
	    continue;
	if (bcmp(entry->hent_key,key,klen))	/* is this it? */
	    continue;
	Safefree(entry->hent_val);
	entry->hent_val = val;
	return TRUE;
    }
    New(501,entry, 1, HENT);

    entry->hent_klen = klen;
    entry->hent_key = nsavestr(key,klen);
    entry->hent_val = val;
    entry->hent_hash = hash;
    entry->hent_next = *oentry;
    *oentry = entry;

    /* hdbmstore not necessary here because it's called from stabset() */

    if (i) {				/* initial entry? */
	tb->tbl_fill++;
#ifdef SOME_DBM
	if (tb->tbl_dbm && tb->tbl_max >= DBM_CACHE_MAX)
	    return FALSE;
#endif
	if (tb->tbl_fill > tb->tbl_dosplit)
	    hsplit(tb);
    }
#ifdef SOME_DBM
    else if (tb->tbl_dbm) {		/* is this just a cache for dbm file? */
	void hentdelayfree();

	entry = tb->tbl_array[hash & tb->tbl_max];
	oentry = &entry->hent_next;
	entry = *oentry;
	while (entry) {	/* trim chain down to 1 entry */
	    *oentry = entry->hent_next;
	    hentdelayfree(entry);	/* no doubt they'll want this next. */
	    entry = *oentry;
	}
    }
#endif

    return FALSE;
}

STR *
hdelete(tb,key,klen)
register HASH *tb;
char *key;
unsigned int klen;
{
    register char *s;
    register int i;
    register int hash;
    register HENT *entry;
    register HENT **oentry;
    STR *str;
    int maxi;
#ifdef SOME_DBM
    datum dkey;
#endif

    if (!tb || !tb->tbl_array)
	return Nullstr;
    if (!tb->tbl_coeffsize)
	hash = *key + 128 * key[1] + 128 * key[klen-1];
    else {	/* use normal coefficients */
	if (klen < tb->tbl_coeffsize)
	    maxi = klen;
	else
	    maxi = tb->tbl_coeffsize;
	for (s=key,		i=0,	hash = 0;
			    i < maxi;
	     s++,		i++,	hash *= 5) {
	    hash += *s * coeff[i];
	}
    }

    oentry = &(tb->tbl_array[hash & tb->tbl_max]);
    entry = *oentry;
    i = 1;
    for (; entry; i=0, oentry = &entry->hent_next, entry = *oentry) {
	if (entry->hent_hash != hash)		/* strings can't be equal */
	    continue;
	if (entry->hent_klen != klen)
	    continue;
	if (bcmp(entry->hent_key,key,klen))	/* is this it? */
	    continue;
	*oentry = entry->hent_next;
	str = str_static(entry->hent_val);
	hentfree(entry);
	if (i)
	    tb->tbl_fill--;
#ifdef SOME_DBM
      do_dbm_delete:
	if (tb->tbl_dbm) {
	    dkey.dptr = key;
	    dkey.dsize = klen;
	    dbm_delete(tb->tbl_dbm,dkey);
	}
#endif
	return str;
    }
#ifdef SOME_DBM
    str = Nullstr;
    goto do_dbm_delete;
#else
    return Nullstr;
#endif
}

hsplit(tb)
HASH *tb;
{
    int oldsize = tb->tbl_max + 1;
    register int newsize = oldsize * 2;
    register int i;
    register HENT **a;
    register HENT **b;
    register HENT *entry;
    register HENT **oentry;

    a = tb->tbl_array;
    Renew(a, newsize, HENT*);
    Zero(&a[oldsize], oldsize, HENT*);		/* zero 2nd half*/
    tb->tbl_max = --newsize;
    tb->tbl_dosplit = tb->tbl_max * FILLPCT / 100;
    tb->tbl_array = a;

    for (i=0; i<oldsize; i++,a++) {
	if (!*a)				/* non-existent */
	    continue;
	b = a+oldsize;
	for (oentry = a, entry = *a; entry; entry = *oentry) {
	    if ((entry->hent_hash & newsize) != i) {
		*oentry = entry->hent_next;
		entry->hent_next = *b;
		if (!*b)
		    tb->tbl_fill++;
		*b = entry;
		continue;
	    }
	    else
		oentry = &entry->hent_next;
	}
	if (!*a)				/* everything moved */
	    tb->tbl_fill--;
    }
}

HASH *
hnew(lookat)
unsigned int lookat;
{
    register HASH *tb;

    Newz(502,tb, 1, HASH);
    if (lookat) {
	tb->tbl_coeffsize = lookat;
	tb->tbl_max = 7;		/* it's a normal associative array */
	tb->tbl_dosplit = tb->tbl_max * FILLPCT / 100;
    }
    else {
	tb->tbl_max = 127;		/* it's a symbol table */
	tb->tbl_dosplit = 128;		/* so never split */
    }
    tb->tbl_fill = 0;
#ifdef SOME_DBM
    tb->tbl_dbm = 0;
#endif
    (void)hiterinit(tb);	/* so each() will start off right */
    return tb;
}

void
hentfree(hent)
register HENT *hent;
{
    if (!hent)
	return;
    str_free(hent->hent_val);
    Safefree(hent->hent_key);
    Safefree(hent);
}

void
hentdelayfree(hent)
register HENT *hent;
{
    if (!hent)
	return;
    str_2static(hent->hent_val);	/* free between statements */
    Safefree(hent->hent_key);
    Safefree(hent);
}

void
hclear(tb,dodbm)
register HASH *tb;
int dodbm;
{
    if (!tb)
	return;
    hfreeentries(tb,dodbm);
    tb->tbl_fill = 0;
#ifndef lint
    if (tb->tbl_array)
	(void)bzero((char*)tb->tbl_array, (tb->tbl_max + 1) * sizeof(HENT*));
#endif
}

static void
hfreeentries(tb,dodbm)
register HASH *tb;
int dodbm;
{
    register HENT *hent;
    register HENT *ohent = Null(HENT*);
#ifdef SOME_DBM
    datum dkey;
    datum nextdkey;
#ifdef NDBM
    DBM *old_dbm;
#else
    int old_dbm;
#endif
#endif

    if (!tb || !tb->tbl_array)
	return;
#ifdef SOME_DBM
    if ((old_dbm = tb->tbl_dbm) && dodbm) {
	while (dkey = dbm_firstkey(tb->tbl_dbm), dkey.dptr) {
	    do {
		nextdkey = dbm_nextkey(tb->tbl_dbm, dkey);
		dbm_delete(tb->tbl_dbm,dkey);
		dkey = nextdkey;
	    } while (dkey.dptr);	/* one way or another, this works */
	}
    }
    tb->tbl_dbm = 0;			/* now clear just cache */
#endif
    (void)hiterinit(tb);
    while (hent = hiternext(tb)) {	/* concise but not very efficient */
	hentfree(ohent);
	ohent = hent;
    }
    hentfree(ohent);
#ifdef SOME_DBM
    tb->tbl_dbm = old_dbm;
#endif
}

void
hfree(tb,dodbm)
register HASH *tb;
int dodbm;
{
    if (!tb)
	return;
    hfreeentries(tb,dodbm);
    Safefree(tb->tbl_array);
    Safefree(tb);
}

int
hiterinit(tb)
register HASH *tb;
{
    tb->tbl_riter = -1;
    tb->tbl_eiter = Null(HENT*);
    return tb->tbl_fill;
}

HENT *
hiternext(tb)
register HASH *tb;
{
    register HENT *entry;
#ifdef SOME_DBM
    datum key;
#endif

    entry = tb->tbl_eiter;
#ifdef SOME_DBM
    if (tb->tbl_dbm) {
	if (entry) {
#ifdef NDBM
#ifdef _CX_UX
	    key.dptr = entry->hent_key;
	    key.dsize = entry->hent_klen;
	    key = dbm_nextkey(tb->tbl_dbm, key);
#else
	    key = dbm_nextkey(tb->tbl_dbm);
#endif /* _CX_UX */
#else
	    key.dptr = entry->hent_key;
	    key.dsize = entry->hent_klen;
	    key = nextkey(key);
#endif
	}
	else {
	    Newz(504,entry, 1, HENT);
	    tb->tbl_eiter = entry;
	    key = dbm_firstkey(tb->tbl_dbm);
	}
	entry->hent_key = key.dptr;
	entry->hent_klen = key.dsize;
	if (!key.dptr) {
	    if (entry->hent_val)
		str_free(entry->hent_val);
	    Safefree(entry);
	    tb->tbl_eiter = Null(HENT*);
	    return Null(HENT*);
	}
	return entry;
    }
#endif
    if (!tb->tbl_array)
	Newz(506,tb->tbl_array, tb->tbl_max + 1, HENT*);
    do {
	if (entry)
	    entry = entry->hent_next;
	if (!entry) {
	    tb->tbl_riter++;
	    if (tb->tbl_riter > tb->tbl_max) {
		tb->tbl_riter = -1;
		break;
	    }
	    entry = tb->tbl_array[tb->tbl_riter];
	}
    } while (!entry);

    tb->tbl_eiter = entry;
    return entry;
}

char *
hiterkey(entry,retlen)
register HENT *entry;
int *retlen;
{
    *retlen = entry->hent_klen;
    return entry->hent_key;
}

STR *
hiterval(tb,entry)
register HASH *tb;
register HENT *entry;
{
#ifdef SOME_DBM
    datum key, content;

    if (tb->tbl_dbm) {
	key.dptr = entry->hent_key;
	key.dsize = entry->hent_klen;
	content = dbm_fetch(tb->tbl_dbm,key);
	if (!entry->hent_val)
	    entry->hent_val = Str_new(62,0);
	str_nset(entry->hent_val,content.dptr,content.dsize);
    }
#endif
    return entry->hent_val;
}

#ifdef SOME_DBM
#if	defined(FCNTL) && ! defined(O_CREAT)
#include <fcntl.h>
#endif

#ifndef O_RDONLY
#define O_RDONLY 0
#endif
#ifndef O_RDWR
#define O_RDWR 2
#endif
#ifndef O_CREAT
#define O_CREAT 01000
#endif

#ifndef NDBM
static int dbmrefcnt = 0;
#endif

bool
hdbmopen(tb,fname,mode)
register HASH *tb;
char *fname;
int mode;
{
    if (!tb)
	return FALSE;
#ifndef NDBM
    if (tb->tbl_dbm)	/* never really closed it */
	return TRUE;
#endif
    if (tb->tbl_dbm) {
	hdbmclose(tb);
	tb->tbl_dbm = 0;
    }
    hclear(tb, FALSE);	/* clear cache */
#ifdef NDBM
    if (mode >= 0)
	tb->tbl_dbm = dbm_open(fname, O_RDWR|O_CREAT, mode);
    if (!tb->tbl_dbm)
	tb->tbl_dbm = dbm_open(fname, O_RDWR, mode);
    if (!tb->tbl_dbm)
	tb->tbl_dbm = dbm_open(fname, O_RDONLY, mode);
#else
    if (dbmrefcnt++)
	fatal("Old dbm can only open one database");
    sprintf(buf,"%s.dir",fname);
    if (stat(buf, &statbuf) < 0) {
	if (mode < 0 || close(creat(buf,mode)) < 0)
	    return FALSE;
	sprintf(buf,"%s.pag",fname);
	if (close(creat(buf,mode)) < 0)
	    return FALSE;
    }
    tb->tbl_dbm = dbminit(fname) >= 0;
#endif
    if (!tb->tbl_array && tb->tbl_dbm != 0)
	Newz(507,tb->tbl_array, tb->tbl_max + 1, HENT*);
    return tb->tbl_dbm != 0;
}

void
hdbmclose(tb)
register HASH *tb;
{
    if (tb && tb->tbl_dbm) {
#ifdef NDBM
	dbm_close(tb->tbl_dbm);
	tb->tbl_dbm = 0;
#else
	/* dbmrefcnt--;  */	/* doesn't work, rats */
#endif
    }
    else if (dowarn)
	warn("Close on unopened dbm file");
}

bool
hdbmstore(tb,key,klen,str)
register HASH *tb;
char *key;
unsigned int klen;
register STR *str;
{
    datum dkey, dcontent;
    int error;

    if (!tb || !tb->tbl_dbm)
	return FALSE;
    dkey.dptr = key;
    dkey.dsize = klen;
    dcontent.dptr = str_get(str);
    dcontent.dsize = str->str_cur;
    error = dbm_store(tb->tbl_dbm, dkey, dcontent, DBM_REPLACE);
    if (error) {
	if (errno == EPERM)
	    fatal("No write permission to dbm file");
	warn("dbm store returned %d, errno %d, key \"%s\"",error,errno,key);
#ifdef NDBM
        dbm_clearerr(tb->tbl_dbm);
#endif
    }
    return !error;
}
#endif /* SOME_DBM */
Commit	Line	Data
d9d8d8de	1	/* $Header: hash.c,v 3.0.1.6 90/10/15 17:32:52 lwall Locked $
a687059c	2	*
	3	* Copyright (c) 1989, Larry Wall
	4	*
	5	* You may distribute under the terms of the GNU General Public License
	6	* as specified in the README file that comes with the perl 3.0 kit.
8d063cd8	7	*
8d063cd8	8	* $Log: hash.c,v $
d9d8d8de	9	* Revision 3.0.1.6 90/10/15 17:32:52 lwall
	10	* patch29: non-existent array values no longer cause core dumps
	11	* patch29: %foo = () will now clear dbm files
	12	* patch29: dbm files couldn't be opened read only
	13	* patch29: the cache array for dbm files wasn't correctly created on fetches
	14	*
6eb13c3b	15	* Revision 3.0.1.5 90/08/13 22:18:27 lwall
	16	* patch28: defined(@array) and defined(%array) didn't work right
	17	*
154e51a4	18	* Revision 3.0.1.4 90/08/09 03:50:22 lwall
	19	* patch19: dbmopen(name, 'filename', undef) now refrains from creating
	20	*
b1248f16	21	* Revision 3.0.1.3 90/03/27 15:59:09 lwall
	22	* patch16: @dbmvalues{'foo','bar'} could use the same cache entry for both values
	23	*
663a0e37	24	* Revision 3.0.1.2 89/12/21 20:03:39 lwall
	25	* patch7: errno may now be a macro with an lvalue
	26	*
bf38876a	27	* Revision 3.0.1.1 89/11/11 04:34:18 lwall
	28	* patch2: CX/UX needed to set the key each time in associative iterators
	29	*
a687059c	30	* Revision 3.0 89/10/18 15:18:32 lwall
a687059c	31	* 3.0 baseline
8d063cd8	32	*
	33	*/
	34
8d063cd8	35	#include "EXTERN.h"
8d063cd8	36	#include "perl.h"
8d063cd8	37
154e51a4	38	static char coeff[] = {
	39	61,59,53,47,43,41,37,31,29,23,17,13,11,7,3,1,
	40	61,59,53,47,43,41,37,31,29,23,17,13,11,7,3,1,
	41	61,59,53,47,43,41,37,31,29,23,17,13,11,7,3,1,
	42	61,59,53,47,43,41,37,31,29,23,17,13,11,7,3,1,
	43	61,59,53,47,43,41,37,31,29,23,17,13,11,7,3,1,
	44	61,59,53,47,43,41,37,31,29,23,17,13,11,7,3,1,
	45	61,59,53,47,43,41,37,31,29,23,17,13,11,7,3,1,
	46	61,59,53,47,43,41,37,31,29,23,17,13,11,7,3,1};
	47
d9d8d8de	48	static void hfreeentries();
d9d8d8de	49
8d063cd8	50	STR *
a687059c	51	hfetch(tb,key,klen,lval)
8d063cd8	52	register HASH *tb;
8d063cd8	53	char *key;
d9d8d8de	54	unsigned int klen;
a687059c	55	int lval;
8d063cd8	56	{
	57	register char *s;
	58	register int i;
	59	register int hash;
	60	register HENT *entry;
a687059c	61	register int maxi;
	62	STR *str;
	63	#ifdef SOME_DBM
	64	datum dkey,dcontent;
	65	#endif
8d063cd8	66
8d063cd8	67	if (!tb)
d9d8d8de	68	return &str_undef;
6eb13c3b	69	if (!tb->tbl_array) {
	70	if (lval)
	71	Newz(503,tb->tbl_array, tb->tbl_max + 1, HENT*);
	72	else
d9d8d8de	73	return &str_undef;
6eb13c3b	74	}
a687059c	75
	76	/* The hash function we use on symbols has to be equal to the first
	77	* character when taken modulo 128, so that str_reset() can be implemented
	78	* efficiently. We throw in the second character and the last character
	79	* (times 128) so that long chains of identifiers starting with the
	80	* same letter don't have to be strEQ'ed within hfetch(), since it
	81	* compares hash values before trying strEQ().
	82	*/
	83	if (!tb->tbl_coeffsize)
	84	hash = key + 128 key[1] + 128 * key[klen-1]; /* assuming klen > 0 */
	85	else { /* use normal coefficients */
	86	if (klen < tb->tbl_coeffsize)
	87	maxi = klen;
	88	else
	89	maxi = tb->tbl_coeffsize;
	90	for (s=key, i=0, hash = 0;
	91	i < maxi;
	92	s++, i++, hash *= 5) {
	93	hash += s coeff[i];
	94	}
8d063cd8	95	}
a687059c	96
8d063cd8	97	entry = tb->tbl_array[hash & tb->tbl_max];
	98	for (; entry; entry = entry->hent_next) {
	99	if (entry->hent_hash != hash) /* strings can't be equal */
	100	continue;
a687059c	101	if (entry->hent_klen != klen)
	102	continue;
	103	if (bcmp(entry->hent_key,key,klen)) /* is this it? */
8d063cd8	104	continue;
	105	return entry->hent_val;
	106	}
a687059c	107	#ifdef SOME_DBM
	108	if (tb->tbl_dbm) {
	109	dkey.dptr = key;
	110	dkey.dsize = klen;
	111	dcontent = dbm_fetch(tb->tbl_dbm,dkey);
	112	if (dcontent.dptr) { /* found one */
	113	str = Str_new(60,dcontent.dsize);
	114	str_nset(str,dcontent.dptr,dcontent.dsize);
	115	hstore(tb,key,klen,str,hash); /* cache it */
	116	return str;
	117	}
	118	}
	119	#endif
	120	if (lval) { /* gonna assign to this, so it better be there */
	121	str = Str_new(61,0);
	122	hstore(tb,key,klen,str,hash);
	123	return str;
	124	}
d9d8d8de	125	return &str_undef;
8d063cd8	126	}
	127
	128	bool
a687059c	129	hstore(tb,key,klen,val,hash)
8d063cd8	130	register HASH *tb;
8d063cd8	131	char *key;
d9d8d8de	132	unsigned int klen;
8d063cd8	133	STR *val;
a687059c	134	register int hash;
8d063cd8	135	{
	136	register char *s;
	137	register int i;
8d063cd8	138	register HENT *entry;
8d063cd8	139	register HENT **oentry;
a687059c	140	register int maxi;
8d063cd8	141
	142	if (!tb)
	143	return FALSE;
a687059c	144
	145	if (hash)
	146	;
	147	else if (!tb->tbl_coeffsize)
	148	hash = key + 128 key[1] + 128 * key[klen-1];
	149	else { /* use normal coefficients */
	150	if (klen < tb->tbl_coeffsize)
	151	maxi = klen;
	152	else
	153	maxi = tb->tbl_coeffsize;
	154	for (s=key, i=0, hash = 0;
	155	i < maxi;
	156	s++, i++, hash *= 5) {
	157	hash += s coeff[i];
	158	}
8d063cd8	159	}
8d063cd8	160
6eb13c3b	161	if (!tb->tbl_array)
	162	Newz(505,tb->tbl_array, tb->tbl_max + 1, HENT*);
	163
8d063cd8	164	oentry = &(tb->tbl_array[hash & tb->tbl_max]);
	165	i = 1;
	166
	167	for (entry = *oentry; entry; i=0, entry = entry->hent_next) {
	168	if (entry->hent_hash != hash) /* strings can't be equal */
	169	continue;
a687059c	170	if (entry->hent_klen != klen)
	171	continue;
	172	if (bcmp(entry->hent_key,key,klen)) /* is this it? */
8d063cd8	173	continue;
a687059c	174	Safefree(entry->hent_val);
8d063cd8	175	entry->hent_val = val;
	176	return TRUE;
	177	}
a687059c	178	New(501,entry, 1, HENT);
8d063cd8	179
a687059c	180	entry->hent_klen = klen;
a687059c	181	entry->hent_key = nsavestr(key,klen);
8d063cd8	182	entry->hent_val = val;
	183	entry->hent_hash = hash;
	184	entry->hent_next = *oentry;
	185	*oentry = entry;
	186
a687059c	187	/* hdbmstore not necessary here because it's called from stabset() */
a687059c	188
8d063cd8	189	if (i) { /* initial entry? */
8d063cd8	190	tb->tbl_fill++;
a687059c	191	#ifdef SOME_DBM
	192	if (tb->tbl_dbm && tb->tbl_max >= DBM_CACHE_MAX)
	193	return FALSE;
	194	#endif
	195	if (tb->tbl_fill > tb->tbl_dosplit)
8d063cd8	196	hsplit(tb);
8d063cd8	197	}
a687059c	198	#ifdef SOME_DBM
a687059c	199	else if (tb->tbl_dbm) { /* is this just a cache for dbm file? */
b1248f16	200	void hentdelayfree();
b1248f16	201
a687059c	202	entry = tb->tbl_array[hash & tb->tbl_max];
	203	oentry = &entry->hent_next;
	204	entry = *oentry;
	205	while (entry) { /* trim chain down to 1 entry */
	206	*oentry = entry->hent_next;
b1248f16	207	hentdelayfree(entry); /* no doubt they'll want this next. */
a687059c	208	entry = *oentry;
	209	}
	210	}
	211	#endif
8d063cd8	212
	213	return FALSE;
	214	}
	215
378cc40b	216	STR *
a687059c	217	hdelete(tb,key,klen)
8d063cd8	218	register HASH *tb;
8d063cd8	219	char *key;
d9d8d8de	220	unsigned int klen;
8d063cd8	221	{
	222	register char *s;
	223	register int i;
	224	register int hash;
	225	register HENT *entry;
	226	register HENT **oentry;
378cc40b	227	STR *str;
a687059c	228	int maxi;
	229	#ifdef SOME_DBM
	230	datum dkey;
	231	#endif
8d063cd8	232
6eb13c3b	233	if (!tb \|\| !tb->tbl_array)
378cc40b	234	return Nullstr;
a687059c	235	if (!tb->tbl_coeffsize)
	236	hash = key + 128 key[1] + 128 * key[klen-1];
	237	else { /* use normal coefficients */
	238	if (klen < tb->tbl_coeffsize)
	239	maxi = klen;
	240	else
	241	maxi = tb->tbl_coeffsize;
	242	for (s=key, i=0, hash = 0;
	243	i < maxi;
	244	s++, i++, hash *= 5) {
	245	hash += s coeff[i];
	246	}
8d063cd8	247	}
	248
	249	oentry = &(tb->tbl_array[hash & tb->tbl_max]);
	250	entry = *oentry;
	251	i = 1;
378cc40b	252	for (; entry; i=0, oentry = &entry->hent_next, entry = *oentry) {
8d063cd8	253	if (entry->hent_hash != hash) /* strings can't be equal */
8d063cd8	254	continue;
a687059c	255	if (entry->hent_klen != klen)
	256	continue;
	257	if (bcmp(entry->hent_key,key,klen)) /* is this it? */
8d063cd8	258	continue;
8d063cd8	259	*oentry = entry->hent_next;
378cc40b	260	str = str_static(entry->hent_val);
378cc40b	261	hentfree(entry);
8d063cd8	262	if (i)
8d063cd8	263	tb->tbl_fill--;
a687059c	264	#ifdef SOME_DBM
	265	do_dbm_delete:
	266	if (tb->tbl_dbm) {
	267	dkey.dptr = key;
	268	dkey.dsize = klen;
	269	dbm_delete(tb->tbl_dbm,dkey);
	270	}
	271	#endif
378cc40b	272	return str;
8d063cd8	273	}
a687059c	274	#ifdef SOME_DBM
	275	str = Nullstr;
	276	goto do_dbm_delete;
	277	#else
378cc40b	278	return Nullstr;
a687059c	279	#endif
8d063cd8	280	}
8d063cd8	281
	282	hsplit(tb)
	283	HASH *tb;
	284	{
	285	int oldsize = tb->tbl_max + 1;
	286	register int newsize = oldsize * 2;
	287	register int i;
	288	register HENT **a;
	289	register HENT **b;
	290	register HENT *entry;
	291	register HENT **oentry;
	292
a687059c	293	a = tb->tbl_array;
	294	Renew(a, newsize, HENT*);
	295	Zero(&a[oldsize], oldsize, HENT); / zero 2nd half*/
8d063cd8	296	tb->tbl_max = --newsize;
a687059c	297	tb->tbl_dosplit = tb->tbl_max * FILLPCT / 100;
8d063cd8	298	tb->tbl_array = a;
	299
	300	for (i=0; i<oldsize; i++,a++) {
	301	if (!a) / non-existent */
	302	continue;
	303	b = a+oldsize;
	304	for (oentry = a, entry = a; entry; entry = oentry) {
	305	if ((entry->hent_hash & newsize) != i) {
	306	*oentry = entry->hent_next;
	307	entry->hent_next = *b;
	308	if (!*b)
	309	tb->tbl_fill++;
	310	*b = entry;
	311	continue;
	312	}
	313	else
	314	oentry = &entry->hent_next;
	315	}
	316	if (!a) / everything moved */
	317	tb->tbl_fill--;
	318	}
	319	}
	320
	321	HASH *
a687059c	322	hnew(lookat)
a687059c	323	unsigned int lookat;
8d063cd8	324	{
a687059c	325	register HASH *tb;
8d063cd8	326
a687059c	327	Newz(502,tb, 1, HASH);
	328	if (lookat) {
	329	tb->tbl_coeffsize = lookat;
	330	tb->tbl_max = 7; /* it's a normal associative array */
	331	tb->tbl_dosplit = tb->tbl_max * FILLPCT / 100;
	332	}
	333	else {
	334	tb->tbl_max = 127; /* it's a symbol table */
	335	tb->tbl_dosplit = 128; /* so never split */
	336	}
8d063cd8	337	tb->tbl_fill = 0;
a687059c	338	#ifdef SOME_DBM
	339	tb->tbl_dbm = 0;
	340	#endif
	341	(void)hiterinit(tb); /* so each() will start off right */
8d063cd8	342	return tb;
	343	}
	344
378cc40b	345	void
	346	hentfree(hent)
	347	register HENT *hent;
	348	{
	349	if (!hent)
	350	return;
	351	str_free(hent->hent_val);
a687059c	352	Safefree(hent->hent_key);
a687059c	353	Safefree(hent);
378cc40b	354	}
	355
	356	void
b1248f16	357	hentdelayfree(hent)
	358	register HENT *hent;
	359	{
	360	if (!hent)
	361	return;
	362	str_2static(hent->hent_val); /* free between statements */
	363	Safefree(hent->hent_key);
	364	Safefree(hent);
	365	}
	366
	367	void
d9d8d8de	368	hclear(tb,dodbm)
	369	register HASH *tb;
	370	int dodbm;
	371	{
	372	if (!tb)
	373	return;
	374	hfreeentries(tb,dodbm);
	375	tb->tbl_fill = 0;
	376	#ifndef lint
	377	if (tb->tbl_array)
	378	(void)bzero((char)tb->tbl_array, (tb->tbl_max + 1) sizeof(HENT*));
	379	#endif
	380	}
	381
	382	static void
	383	hfreeentries(tb,dodbm)
378cc40b	384	register HASH *tb;
d9d8d8de	385	int dodbm;
378cc40b	386	{
	387	register HENT *hent;
	388	register HENT ohent = Null(HENT);
d9d8d8de	389	#ifdef SOME_DBM
	390	datum dkey;
	391	datum nextdkey;
	392	#ifdef NDBM
	393	DBM *old_dbm;
	394	#else
	395	int old_dbm;
	396	#endif
	397	#endif
378cc40b	398
6eb13c3b	399	if (!tb \|\| !tb->tbl_array)
378cc40b	400	return;
d9d8d8de	401	#ifdef SOME_DBM
	402	if ((old_dbm = tb->tbl_dbm) && dodbm) {
	403	while (dkey = dbm_firstkey(tb->tbl_dbm), dkey.dptr) {
	404	do {
	405	nextdkey = dbm_nextkey(tb->tbl_dbm, dkey);
	406	dbm_delete(tb->tbl_dbm,dkey);
	407	dkey = nextdkey;
	408	} while (dkey.dptr); /* one way or another, this works */
	409	}
	410	}
	411	tb->tbl_dbm = 0; /* now clear just cache */
	412	#endif
a687059c	413	(void)hiterinit(tb);
378cc40b	414	while (hent = hiternext(tb)) { /* concise but not very efficient */
	415	hentfree(ohent);
	416	ohent = hent;
	417	}
	418	hentfree(ohent);
d9d8d8de	419	#ifdef SOME_DBM
d9d8d8de	420	tb->tbl_dbm = old_dbm;
a687059c	421	#endif
378cc40b	422	}
378cc40b	423
378cc40b	424	void
d9d8d8de	425	hfree(tb,dodbm)
a687059c	426	register HASH *tb;
d9d8d8de	427	int dodbm;
378cc40b	428	{
378cc40b	429	if (!tb)
a687059c	430	return;
d9d8d8de	431	hfreeentries(tb,dodbm);
a687059c	432	Safefree(tb->tbl_array);
a687059c	433	Safefree(tb);
378cc40b	434	}
8d063cd8	435
a687059c	436	int
8d063cd8	437	hiterinit(tb)
	438	register HASH *tb;
	439	{
	440	tb->tbl_riter = -1;
	441	tb->tbl_eiter = Null(HENT*);
	442	return tb->tbl_fill;
	443	}
	444
	445	HENT *
	446	hiternext(tb)
	447	register HASH *tb;
	448	{
	449	register HENT *entry;
a687059c	450	#ifdef SOME_DBM
	451	datum key;
	452	#endif
8d063cd8	453
8d063cd8	454	entry = tb->tbl_eiter;
a687059c	455	#ifdef SOME_DBM
	456	if (tb->tbl_dbm) {
	457	if (entry) {
	458	#ifdef NDBM
	459	#ifdef _CX_UX
bf38876a	460	key.dptr = entry->hent_key;
bf38876a	461	key.dsize = entry->hent_klen;
a687059c	462	key = dbm_nextkey(tb->tbl_dbm, key);
	463	#else
	464	key = dbm_nextkey(tb->tbl_dbm);
	465	#endif /* _CX_UX */
	466	#else
	467	key.dptr = entry->hent_key;
	468	key.dsize = entry->hent_klen;
	469	key = nextkey(key);
	470	#endif
	471	}
	472	else {
	473	Newz(504,entry, 1, HENT);
	474	tb->tbl_eiter = entry;
	475	key = dbm_firstkey(tb->tbl_dbm);
	476	}
	477	entry->hent_key = key.dptr;
	478	entry->hent_klen = key.dsize;
	479	if (!key.dptr) {
	480	if (entry->hent_val)
	481	str_free(entry->hent_val);
	482	Safefree(entry);
	483	tb->tbl_eiter = Null(HENT*);
	484	return Null(HENT*);
	485	}
	486	return entry;
	487	}
	488	#endif
6eb13c3b	489	if (!tb->tbl_array)
6eb13c3b	490	Newz(506,tb->tbl_array, tb->tbl_max + 1, HENT*);
8d063cd8	491	do {
	492	if (entry)
	493	entry = entry->hent_next;
	494	if (!entry) {
	495	tb->tbl_riter++;
	496	if (tb->tbl_riter > tb->tbl_max) {
	497	tb->tbl_riter = -1;
	498	break;
	499	}
	500	entry = tb->tbl_array[tb->tbl_riter];
	501	}
	502	} while (!entry);
	503
	504	tb->tbl_eiter = entry;
	505	return entry;
	506	}
	507
	508	char *
a687059c	509	hiterkey(entry,retlen)
8d063cd8	510	register HENT *entry;
a687059c	511	int *retlen;
8d063cd8	512	{
a687059c	513	*retlen = entry->hent_klen;
8d063cd8	514	return entry->hent_key;
	515	}
	516
	517	STR *
a687059c	518	hiterval(tb,entry)
a687059c	519	register HASH *tb;
8d063cd8	520	register HENT *entry;
8d063cd8	521	{
a687059c	522	#ifdef SOME_DBM
	523	datum key, content;
	524
	525	if (tb->tbl_dbm) {
	526	key.dptr = entry->hent_key;
	527	key.dsize = entry->hent_klen;
	528	content = dbm_fetch(tb->tbl_dbm,key);
	529	if (!entry->hent_val)
	530	entry->hent_val = Str_new(62,0);
	531	str_nset(entry->hent_val,content.dptr,content.dsize);
	532	}
	533	#endif
8d063cd8	534	return entry->hent_val;
8d063cd8	535	}
a687059c	536
	537	#ifdef SOME_DBM
	538	#if defined(FCNTL) && ! defined(O_CREAT)
	539	#include <fcntl.h>
	540	#endif
	541
	542	#ifndef O_RDONLY
	543	#define O_RDONLY 0
	544	#endif
	545	#ifndef O_RDWR
	546	#define O_RDWR 2
	547	#endif
	548	#ifndef O_CREAT
	549	#define O_CREAT 01000
	550	#endif
	551
	552	#ifndef NDBM
	553	static int dbmrefcnt = 0;
	554	#endif
	555
	556	bool
	557	hdbmopen(tb,fname,mode)
	558	register HASH *tb;
	559	char *fname;
	560	int mode;
	561	{
	562	if (!tb)
	563	return FALSE;
	564	#ifndef NDBM
	565	if (tb->tbl_dbm) /* never really closed it */
	566	return TRUE;
	567	#endif
154e51a4	568	if (tb->tbl_dbm) {
a687059c	569	hdbmclose(tb);
154e51a4	570	tb->tbl_dbm = 0;
154e51a4	571	}
d9d8d8de	572	hclear(tb, FALSE); /* clear cache */
a687059c	573	#ifdef NDBM
154e51a4	574	if (mode >= 0)
	575	tb->tbl_dbm = dbm_open(fname, O_RDWR\|O_CREAT, mode);
	576	if (!tb->tbl_dbm)
	577	tb->tbl_dbm = dbm_open(fname, O_RDWR, mode);
d9d8d8de	578	if (!tb->tbl_dbm)
d9d8d8de	579	tb->tbl_dbm = dbm_open(fname, O_RDONLY, mode);
a687059c	580	#else
	581	if (dbmrefcnt++)
	582	fatal("Old dbm can only open one database");
	583	sprintf(buf,"%s.dir",fname);
	584	if (stat(buf, &statbuf) < 0) {
154e51a4	585	if (mode < 0 \|\| close(creat(buf,mode)) < 0)
a687059c	586	return FALSE;
	587	sprintf(buf,"%s.pag",fname);
	588	if (close(creat(buf,mode)) < 0)
	589	return FALSE;
	590	}
	591	tb->tbl_dbm = dbminit(fname) >= 0;
	592	#endif
d9d8d8de	593	if (!tb->tbl_array && tb->tbl_dbm != 0)
d9d8d8de	594	Newz(507,tb->tbl_array, tb->tbl_max + 1, HENT*);
a687059c	595	return tb->tbl_dbm != 0;
	596	}
	597
	598	void
	599	hdbmclose(tb)
	600	register HASH *tb;
	601	{
	602	if (tb && tb->tbl_dbm) {
	603	#ifdef NDBM
	604	dbm_close(tb->tbl_dbm);
	605	tb->tbl_dbm = 0;
	606	#else
	607	/* dbmrefcnt--; / / doesn't work, rats */
	608	#endif
	609	}
	610	else if (dowarn)
	611	warn("Close on unopened dbm file");
	612	}
	613
	614	bool
	615	hdbmstore(tb,key,klen,str)
	616	register HASH *tb;
	617	char *key;
d9d8d8de	618	unsigned int klen;
a687059c	619	register STR *str;
	620	{
	621	datum dkey, dcontent;
	622	int error;
	623
	624	if (!tb \|\| !tb->tbl_dbm)
	625	return FALSE;
	626	dkey.dptr = key;
	627	dkey.dsize = klen;
	628	dcontent.dptr = str_get(str);
	629	dcontent.dsize = str->str_cur;
	630	error = dbm_store(tb->tbl_dbm, dkey, dcontent, DBM_REPLACE);
	631	if (error) {
	632	if (errno == EPERM)
	633	fatal("No write permission to dbm file");
	634	warn("dbm store returned %d, errno %d, key \"%s\"",error,errno,key);
	635	#ifdef NDBM
	636	dbm_clearerr(tb->tbl_dbm);
	637	#endif
	638	}
	639	return !error;
	640	}
	641	#endif /* SOME_DBM */