/*
 * CDE - Common Desktop Environment
 *
 * Copyright (c) 1993-2012, The Open Group. All rights reserved.
 *
 * These libraries and programs are free software; you can
 * redistribute them and/or modify them under the terms of the GNU
 * Lesser General Public License as published by the Free Software
 * Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 * These libraries and programs are distributed in the hope that
 * they will be useful, but WITHOUT ANY WARRANTY; without even the
 * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 * PURPOSE. See the GNU Lesser General Public License for more
 * details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with these libraries and programs; if not, write
 * to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
 * Floor, Boston, MA 02110-1301 USA
 */
/* Quarks.c 1.1 - Fujitsu source for CDEnext    95/11/06 20:31:17 	*/
/* $XConsortium: _falQuarks.c /main/2 1996/09/09 13:20:21 rswiston $ */

/***********************************************************
Copyright 1987, 1988, 1990 by Digital Equipment Corporation, Maynard,

                        All Rights Reserved

Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted,
provided that the above copyright notice appear in all copies and that
both that copyright notice and this permission notice appear in
supporting documentation, and that the name Digital not be
used in advertising or publicity pertaining to distribution of the
software without specific, written prior permission.

DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
DIGITAL BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
SOFTWARE.

******************************************************************/
/*

Copyright (c) 1987, 1988, 1990  X Consortium

Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE X CONSORTIUM BE LIABLE FOR ANY CLAIM, DAMAGES OR
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

Except as contained in this notice, the name of the X Consortium shall
not be used in advertising or otherwise to promote the sale, use or
other dealings in this Software without prior written authorization
from the X Consortium.

*/

#include "_fallibint.h"
#include <X11/Xresource.h>

/* Not cost effective, at least for vanilla MIT clients */
/* #define PERMQ */

typedef unsigned long Signature;
typedef unsigned long Entry;
#ifdef PERMQ
typedef unsigned char Bits;
#endif

static XrmQuark nextQuark = 1;	/* next available quark number */
static unsigned long quarkMask = 0;
static Entry zero = 0;
static Entry *quarkTable = &zero; /* crock */
static unsigned long quarkRehash;
static XrmString **stringTable = NULL;
#ifdef PERMQ
static Bits **permTable = NULL;
#endif
static XrmQuark nextUniq = -1;	/* next quark from falrmUniqueQuark */

#define QUANTUMSHIFT	8
#define QUANTUMMASK	((1 << QUANTUMSHIFT) - 1)
#define CHUNKPER	8
#define CHUNKMASK	((CHUNKPER << QUANTUMSHIFT) - 1)

#define LARGEQUARK	((Entry)0x80000000L)
#define QUARKSHIFT	18
#define QUARKMASK	((LARGEQUARK - 1) >> QUARKSHIFT)
#define XSIGMASK	((1L << QUARKSHIFT) - 1)

#define STRQUANTSIZE	(sizeof(XrmString) * (QUANTUMMASK + 1))
#ifdef PERMQ
#define QUANTSIZE	(STRQUANTSIZE + \
			 (sizeof(Bits) * ((QUANTUMMASK + 1) >> 3))
#else
#define QUANTSIZE	STRQUANTSIZE
#endif

#define HASH(sig) ((sig) & quarkMask)
#define REHASHVAL(sig) ((((sig) % quarkRehash) + 2) | 1)
#define REHASH(idx,rehash) ((idx + rehash) & quarkMask)
#define NAME(q) stringTable[(q) >> QUANTUMSHIFT][(q) & QUANTUMMASK]
#ifdef PERMQ
#define BYTEREF(q) permTable[(q) >> QUANTUMSHIFT][((q) & QUANTUMMASK) >> 3]
#define ISPERM(q) (BYTEREF(q) & (1 << ((q) & 7)))
#define SETPERM(q) BYTEREF(q) |= (1 << ((q) & 7))
#define CLEARPERM(q) BYTEREF(q) &= ~(1 << ((q) & 7))
#endif

/* Permanent memory allocation */

#define WALIGN sizeof(unsigned long)
#define DALIGN sizeof(double)

#define NEVERFREETABLESIZE ((8192-12) & ~(DALIGN-1))
static char *neverFreeTable = NULL;
static int  neverFreeTableSize = 0;

static char *permalloc(unsigned int length)
{
    char *ret;

    if (neverFreeTableSize < length) {
	if (length >= NEVERFREETABLESIZE)
	    return Xmalloc(length);
	if (! (ret = Xmalloc(NEVERFREETABLESIZE)))
	    return (char *) NULL;
	neverFreeTableSize = NEVERFREETABLESIZE;
	neverFreeTable = ret;
    }
    ret = neverFreeTable;
    neverFreeTable += length;
    neverFreeTableSize -= length;
    return(ret);
}

typedef struct {char a; double b;} TestType1;
typedef struct {char a; unsigned long b;} TestType2;

#ifdef XTHREADS
static char *_falpermalloc();

char *falpermalloc(unsigned int length)
{
    char *p;

    _XLockMutex(_Xglobal_lock);
    p = _falpermalloc(length);
    _XUnlockMutex(_Xglobal_lock);
    return p;
}
#define falpermalloc _falpermalloc

static
#endif /* XTHREADS */
char *falpermalloc(unsigned int length)
{
    int i;

    if (neverFreeTableSize && length < NEVERFREETABLESIZE) {
	if ((sizeof(TestType1) !=
	     (sizeof(TestType2) - sizeof(unsigned long) + sizeof(double))) &&
	    !(length & (DALIGN-1)) &&
	    (i = (NEVERFREETABLESIZE - neverFreeTableSize) & (DALIGN-1))) {
	    neverFreeTableSize -= DALIGN - i;
	    neverFreeTable += DALIGN - i;
	} else
	    if (i = (NEVERFREETABLESIZE - neverFreeTableSize) & (WALIGN-1)) {
		neverFreeTableSize -= WALIGN - i;
		neverFreeTable += WALIGN - i;
	    }
    }
    return permalloc(length);
}

static Bool
ExpandQuarkTable(void)
{
    unsigned long oldmask, newmask;
    char c, *s;
    Entry *oldentries, *entries;
    Entry entry;
    int oldidx, newidx, rehash;
    Signature sig;
    XrmQuark q;

    oldentries = quarkTable;
    if (oldmask = quarkMask)
	newmask = (oldmask << 1) + 1;
    else {
	if (!stringTable) {
	    stringTable = (XrmString **)Xmalloc(sizeof(XrmString *) *
						CHUNKPER);
	    if (!stringTable)
		return False;
	    stringTable[0] = (XrmString *)NULL;
	}
#ifdef PERMQ
	if (!permTable)
	    permTable = (Bits **)Xmalloc(sizeof(Bits *) * CHUNKPER);
	if (!permTable)
	    return False;
#endif
	stringTable[0] = (XrmString *)falpermalloc(QUANTSIZE);
	if (!stringTable[0])
	    return False;
#ifdef PERMQ
	permTable[0] = (Bits *)((char *)stringTable[0] + STRQUANTSIZE);
#endif
	newmask = 0x1ff;
    }
    entries = (Entry *)Xmalloc(sizeof(Entry) * (newmask + 1));
    if (!entries)
	return False;
    bzero((char *)entries, sizeof(Entry) * (newmask + 1));
    quarkTable = entries;
    quarkMask = newmask;
    quarkRehash = quarkMask - 2;
    for (oldidx = 0; oldidx <= oldmask; oldidx++) {
	if (entry = oldentries[oldidx]) {
	    if (entry & LARGEQUARK)
		q = entry & (LARGEQUARK-1);
	    else
		q = (entry >> QUARKSHIFT) & QUARKMASK;
	    for (sig = 0, s = NAME(q); c = *s++; )
		sig = (sig << 1) + c;
	    newidx = HASH(sig);
	    if (entries[newidx]) {
		rehash = REHASHVAL(sig);
		do {
		    newidx = REHASH(newidx, rehash);
		} while (entries[newidx]);
	    }
	    entries[newidx] = entry;
	}
    }
    if (oldmask)
	Xfree((char *)oldentries);
    return True;
}

XrmQuark _falrmInternalStringToQuark(
    const char *name, int len, Signature sig, Bool permstring)
{
    XrmQuark q;
    Entry entry;
    int idx;
    int rehash = 0;
    int i;
    char *s1, *s2;
    char *new;

    idx = HASH(sig);
    _XLockMutex(_Xglobal_lock);
    while (entry = quarkTable[idx]) {
	if (entry & LARGEQUARK)
	    q = entry & (LARGEQUARK-1);
	else {
	    if ((entry - sig) & XSIGMASK){
	        if (!rehash)
                rehash = REHASHVAL(sig);
                idx = REHASH(idx, rehash);
                continue;
		}
	    q = (entry >> QUARKSHIFT) & QUARKMASK;
	}
	for (i = len, s1 = (char *)name, s2 = NAME(q); --i >= 0; ) {
	    if (*s1++ != *s2++){
	        if (!rehash)
                rehash = REHASHVAL(sig);
                idx = REHASH(idx, rehash);
                continue;
	    }
	}
	if (*s2) {
	    if (!rehash)
		rehash = REHASHVAL(sig);
	    idx = REHASH(idx, rehash);
	    continue;
	}
#ifdef PERMQ
	if (permstring && !ISPERM(q)) {
	    Xfree(NAME(q));
	    NAME(q) = (char *)name;
	    SETPERM(q);
	}
#endif
	_XUnlockMutex(_Xglobal_lock);
	return q;
    }
    if (nextUniq == nextQuark){
	_XUnlockMutex(_Xglobal_lock);
	return NULLQUARK;
    }
    if ((nextQuark + (nextQuark >> 2)) > quarkMask) {
	if (!ExpandQuarkTable()){
	    _XUnlockMutex(_Xglobal_lock);
	    return NULLQUARK;
	}
	_XUnlockMutex(_Xglobal_lock);
	return _falrmInternalStringToQuark(name, len, sig, permstring);
    }
    q = nextQuark;
    if (!(q & QUANTUMMASK)) {
	if (!(q & CHUNKMASK)) {
	    if (!(new = Xrealloc((char *)stringTable,
				 sizeof(XrmString *) *
				 ((q >> QUANTUMSHIFT) + CHUNKPER)))){
		_XUnlockMutex(_Xglobal_lock);
		return NULLQUARK;
	    }
	    stringTable = (XrmString **)new;
#ifdef PERMQ
	    if (!(new = Xrealloc((char *)permTable,
				 sizeof(Bits *) *
				 ((q >> QUANTUMSHIFT) + CHUNKPER)))){
		_XUnlockMutex(_Xglobal_lock);
		return NULLQUARK;
	    }
	    permTable = (Bits **)new;
#endif
	}
	new = falpermalloc(QUANTSIZE);
	if (!new){
	    _XUnlockMutex(_Xglobal_lock);
	    return NULLQUARK;
	}
	stringTable[q >> QUANTUMSHIFT] = (XrmString *)new;
#ifdef PERMQ
	permTable[q >> QUANTUMSHIFT] = (Bits *)(new + STRQUANTSIZE);
#endif
    }
    if (!permstring) {
	s2 = (char *)name;
#ifdef PERMQ
	name = Xmalloc(len+1);
#else
	name = permalloc(len+1);
#endif
	if (!name){
	    _XUnlockMutex(_Xglobal_lock);
	    return NULLQUARK;
	}
	for (i = len, s1 = (char *)name; --i >= 0; )
	    *s1++ = *s2++;
	*s1++ = '\0';
#ifdef PERMQ
	CLEARPERM(q);
    }
    else {
	SETPERM(q);
#endif
    }
    NAME(q) = (char *)name;
    if (q <= QUARKMASK)
	entry = (q << QUARKSHIFT) | (sig & XSIGMASK);
    else
	entry = q | LARGEQUARK;
    quarkTable[idx] = entry;
    nextQuark++;
    _XUnlockMutex(_Xglobal_lock);
    return q;
}

XrmQuark falrmStringToQuark(const char *name)
{
    char c, *tname;
    Signature sig = 0;

    if (!name)
	return (NULLQUARK);

    for (tname = (char *)name; c = *tname++; )
	sig = (sig << 1) + c;

    return _falrmInternalStringToQuark(name, tname-(char *)name-1, sig, False);
}

XrmQuark falrmPermStringToQuark(
    const char *name)
{
    char c, *tname;
    Signature sig = 0;

    if (!name)
	return (NULLQUARK);

    for (tname = (char *)name; c = *tname++; )
	sig = (sig << 1) + c;

    return _falrmInternalStringToQuark(name, tname-(char *)name-1, sig, True);
}

XrmQuark falrmUniqueQuark(void)
{
    XrmQuark q;

    _XLockMutex(_Xglobal_lock);
    if (nextUniq == nextQuark)
	q = NULLQUARK;
    else
	q = nextUniq--;
    _XUnlockMutex(_Xglobal_lock);
    return q;
}

XrmString falrmQuarkToString(XrmQuark quark)
{
    XrmString s;

    _XLockMutex(_Xglobal_lock);
    if (quark <= 0 || quark >= nextQuark)
	s = NULLSTRING;
    else {
#ifdef PERMQ
	/* We have to mark the quark as permanent, since the caller might hold
	 * onto the string pointer forver.
	 */
	SETPERM(quark);
#endif
	s = NAME(quark);
    }
    _XUnlockMutex(_Xglobal_lock);
    return s;
}