ssize_t rsize;
int rsize;
static uint32	*fetch_bitmap __P((HTAB *, uint32));static uint32	 first_free __P((uint32));static int	 open_temp __P((HTAB *));static uint16	 overflow_page __P((HTAB *));static void	 squeeze_key __P((uint16 *, const DBT *, const DBT *));static int	 ugly_split		    __P((HTAB *, uint32, BUFHEAD *, BUFHEAD *, int, int));#define	PAGE_INIT(P) { \	((uint16 *)(P))[0] = 0; \	((uint16 *)(P))[1] = hashp->BSIZE - 3 * sizeof(uint16); \	((uint16 *)(P))[2] = hashp->BSIZE; \}/* implement a new lseek using lseek that * writes zero's when extending a file * beyond the end. */long new_lseek(int fd, long offset, int origin){ 	long cur_pos=0;	long end_pos=0;	long seek_pos=0;	if(origin == SEEK_CUR)      {	      	if(offset < 1)							  	    	return(lseek(fd, offset, SEEK_CUR));		cur_pos = lseek(fd, 0, SEEK_CUR);		if(cur_pos < 0)			return(cur_pos);	  }										 	end_pos = lseek(fd, 0, SEEK_END);	if(end_pos < 0)		return(end_pos);	if(origin == SEEK_SET)		seek_pos = offset;	else if(origin == SEEK_CUR)		seek_pos = cur_pos + offset;	else if(origin == SEEK_END)		seek_pos = end_pos + offset; 	else	  {	  	assert(0);		return(-1);	  } 	/* the seek position desired is before the	 * end of the file.  We don't need	 * to do anything special except the seek.	 */ 	if(seek_pos <= end_pos) 		return(lseek(fd, seek_pos, SEEK_SET)); 		 	  /* the seek position is beyond the end of the 	   * file.  Write zero's to the end. 	   *	   * we are already at the end of the file so	   * we just need to "write()" zeros for the	   * difference between seek_pos-end_pos and	   * then seek to the position to finish	   * the call 	   */ 	  {  	 	char buffer[1024];	   	long len = seek_pos-end_pos;	   	memset(&buffer, 0, 1024);	   	while(len > 0)	      {	        write(fd, (char*)&buffer, (size_t)(1024 > len ? len : 1024));		    len -= 1024;		  }		return(lseek(fd, seek_pos, SEEK_SET));	  }		}/* * This is called AFTER we have verified that there is room on the page for * the pair (PAIRFITS has returned true) so we go right ahead and start moving * stuff on. */static voidputpair(char *p, const DBT *key, DBT * val){	register uint16 *bp, n, off;	bp = (uint16 *)p;	/* Enter the key first. */	n = bp[0];	off = OFFSET(bp) - key->size;	memmove(p + off, key->data, key->size);	bp[++n] = off;	/* Now the data. */	off -= val->size;	memmove(p + off, val->data, val->size);	bp[++n] = off;	/* Adjust page info. */	bp[0] = n;	bp[n + 1] = off - ((n + 3) * sizeof(uint16));	bp[n + 2] = off;}/* * Returns: *	 0 OK *	-1 error */extern int__delpair(HTAB *hashp, BUFHEAD *bufp, int ndx){	register uint16 *bp, newoff;	register int n;	uint16 pairlen;	bp = (uint16 *)bufp->page;	n = bp[0];	if (bp[ndx + 1] < REAL_KEY)		return (__big_delete(hashp, bufp));	if (ndx != 1)		newoff = bp[ndx - 1];	else		newoff = hashp->BSIZE;	pairlen = newoff - bp[ndx + 1];	if (ndx != (n - 1)) {		/* Hard Case -- need to shuffle keys */		register int i;		register char *src = bufp->page + (int)OFFSET(bp);		uint32 dst_offset = (uint32)OFFSET(bp) + (uint32)pairlen;		register char *dst = bufp->page + dst_offset;		uint32 length = bp[ndx + 1] - OFFSET(bp);		/*		 * +-----------+XXX+---------+XXX+---------+---------> +infinity		 * |           |             |             |		 * 0           src_offset    dst_offset    BSIZE		 *		 * Dst_offset is > src_offset, so if src_offset were bad, dst_offset		 * would be too, therefore we check only dst_offset.		 *		 * If dst_offset is >= BSIZE, either OFFSET(bp), or pairlen, or both		 * is corrupted.		 *		 * Once we know dst_offset is < BSIZE, we can subtract it from BSIZE		 * to get an upper bound on length.		 */		if(dst_offset > (uint32)hashp->BSIZE)			return(DATABASE_CORRUPTED_ERROR);		if(length > (uint32)(hashp->BSIZE - dst_offset))			return(DATABASE_CORRUPTED_ERROR);		memmove(dst, src, length);		/* Now adjust the pointers */		for (i = ndx + 2; i <= n; i += 2) {			if (bp[i + 1] == OVFLPAGE) {				bp[i - 2] = bp[i];				bp[i - 1] = bp[i + 1];			} else {				bp[i - 2] = bp[i] + pairlen;				bp[i - 1] = bp[i + 1] + pairlen;			}		}	}	/* Finally adjust the page data */	bp[n] = OFFSET(bp) + pairlen;	bp[n - 1] = bp[n + 1] + pairlen + 2 * sizeof(uint16);	bp[0] = n - 2;	hashp->NKEYS--;	bufp->flags |= BUF_MOD;	return (0);}/* * Returns: *	 0 ==> OK *	-1 ==> Error */extern int__split_page(HTAB *hashp, uint32 obucket, uint32 nbucket){	register BUFHEAD *new_bufp, *old_bufp;	register uint16 *ino;	register uint16 *tmp_uint16_array;	register char *np;	DBT key, val;    uint16 n, ndx;	int retval;	uint16 copyto, diff, moved;	size_t off;	char *op;	copyto = (uint16)hashp->BSIZE;	off = (uint16)hashp->BSIZE;	old_bufp = __get_buf(hashp, obucket, NULL, 0);	if (old_bufp == NULL)		return (-1);	new_bufp = __get_buf(hashp, nbucket, NULL, 0);	if (new_bufp == NULL)		return (-1);	old_bufp->flags |= (BUF_MOD | BUF_PIN);	new_bufp->flags |= (BUF_MOD | BUF_PIN);	ino = (uint16 *)(op = old_bufp->page);	np = new_bufp->page;	moved = 0;	for (n = 1, ndx = 1; n < ino[0]; n += 2) {		if (ino[n + 1] < REAL_KEY) {			retval = ugly_split(hashp, obucket, old_bufp, new_bufp,			    (int)copyto, (int)moved);			old_bufp->flags &= ~BUF_PIN;			new_bufp->flags &= ~BUF_PIN;			return (retval);		}		key.data = (uint8 *)op + ino[n];		/* check here for ino[n] being greater than		 * off.  If it is then the database has		 * been corrupted.		 */		if(ino[n] > off)			return(DATABASE_CORRUPTED_ERROR);		key.size = off - ino[n];#ifdef DEBUG		/* make sure the size is positive */		assert(((int)key.size) > -1);#endif		if (__call_hash(hashp, (char *)key.data, key.size) == obucket) {			/* Don't switch page */			diff = copyto - off;			if (diff) {				copyto = ino[n + 1] + diff;				memmove(op + copyto, op + ino[n + 1],				    off - ino[n + 1]);				ino[ndx] = copyto + ino[n] - ino[n + 1];				ino[ndx + 1] = copyto;			} else				copyto = ino[n + 1];			ndx += 2;		} else {			/* Switch page */			val.data = (uint8 *)op + ino[n + 1];			val.size = ino[n] - ino[n + 1];			/* if the pair doesn't fit something is horribly			 * wrong.  LJM			 */			tmp_uint16_array = (uint16*)np;			if(!PAIRFITS(tmp_uint16_array, &key, &val))				return(DATABASE_CORRUPTED_ERROR);			putpair(np, &key, &val);			moved += 2;		}		off = ino[n + 1];	}	/* Now clean up the page */	ino[0] -= moved;	FREESPACE(ino) = copyto - sizeof(uint16) * (ino[0] + 3);	OFFSET(ino) = copyto;#ifdef DEBUG3	(void)fprintf(stderr, "split %d/%d\n",	    ((uint16 *)np)[0] / 2,	    ((uint16 *)op)[0] / 2);#endif	/* unpin both pages */	old_bufp->flags &= ~BUF_PIN;	new_bufp->flags &= ~BUF_PIN;	return (0);}/* * Called when we encounter an overflow or big key/data page during split * handling.  This is special cased since we have to begin checking whether * the key/data pairs fit on their respective pages and because we may need * overflow pages for both the old and new pages. * * The first page might be a page with regular key/data pairs in which case * we have a regular overflow condition and just need to go on to the next * page or it might be a big key/data pair in which case we need to fix the * big key/data pair. * * Returns: *	 0 ==> success *	-1 ==> failure *//* the maximum number of loops we will allow UGLY split to chew * on before we assume the database is corrupted and throw it * away. */#define MAX_UGLY_SPLIT_LOOPS 10000static intugly_split(HTAB *hashp, uint32 obucket, BUFHEAD *old_bufp, BUFHEAD *new_bufp,/* Same as __split_page. */ int copyto, int moved)	/* int copyto;	 First byte on page which contains key/data values. */	/* int moved;	 Number of pairs moved to new page. */{	register BUFHEAD *bufp;	/* Buffer header for ino */	register uint16 *ino;	/* Page keys come off of */	register uint16 *np;	/* New page */	register uint16 *op;	/* Page keys go on to if they aren't moving */    uint32 loop_detection=0;	BUFHEAD *last_bfp;	/* Last buf header OVFL needing to be freed */	DBT key, val;	SPLIT_RETURN ret;	uint16 n, off, ov_addr, scopyto;	char *cino;		/* Character value of ino */	int status;	bufp = old_bufp;	ino = (uint16 *)old_bufp->page;	np = (uint16 *)new_bufp->page;	op = (uint16 *)old_bufp->page;	last_bfp = NULL;	scopyto = (uint16)copyto;	/* ANSI */	n = ino[0] - 1;	while (n < ino[0]) {        /* this function goes nuts sometimes and never returns.          * I havent found the problem yet but I need a solution         * so if we loop too often we assume a database curruption error         * :LJM         */        loop_detection++;        if(loop_detection > MAX_UGLY_SPLIT_LOOPS)            return DATABASE_CORRUPTED_ERROR;		if (ino[2] < REAL_KEY && ino[2] != OVFLPAGE) {			if ((status = __big_split(hashp, old_bufp,			    new_bufp, bufp, bufp->addr, obucket, &ret)))				return (status);			old_bufp = ret.oldp;			if (!old_bufp)				return (-1);			op = (uint16 *)old_bufp->page;			new_bufp = ret.newp;			if (!new_bufp)				return (-1);			np = (uint16 *)new_bufp->page;			bufp = ret.nextp;			if (!bufp)				return (0);			cino = (char *)bufp->page;			ino = (uint16 *)cino;			last_bfp = ret.nextp;		} else if (ino[n + 1] == OVFLPAGE) {			ov_addr = ino[n];			/*			 * Fix up the old page -- the extra 2 are the fields			 * which contained the overflow information.			 */			ino[0] -= (moved + 2);			FREESPACE(ino) =			    scopyto - sizeof(uint16) * (ino[0] + 3);			OFFSET(ino) = scopyto;			bufp = __get_buf(hashp, ov_addr, bufp, 0);			if (!bufp)				return (-1);			ino = (uint16 *)bufp->page;			n = 1;			scopyto = hashp->BSIZE;			moved = 0;			if (last_bfp)				__free_ovflpage(hashp, last_bfp);			last_bfp = bufp;		}		/* Move regular sized pairs of there are any */		off = hashp->BSIZE;		for (n = 1; (n < ino[0]) && (ino[n + 1] >= REAL_KEY); n += 2) {			cino = (char *)ino;			key.data = (uint8 *)cino + ino[n];			key.size = off - ino[n];			val.data = (uint8 *)cino + ino[n + 1];			val.size = ino[n] - ino[n + 1];			off = ino[n + 1];			if (__call_hash(hashp, (char*)key.data, key.size) == obucket) {				/* Keep on old page */				if (PAIRFITS(op, (&key), (&val)))					putpair((char *)op, &key, &val);				else {					old_bufp =					    __add_ovflpage(hashp, old_bufp);					if (!old_bufp)						return (-1);					op = (uint16 *)old_bufp->page;					putpair((char *)op, &key, &val);				}				old_bufp->flags |= BUF_MOD;			} else {				/* Move to new page */				if (PAIRFITS(np, (&key), (&val)))					putpair((char *)np, &key, &val);				else {					new_bufp =					    __add_ovflpage(hashp, new_bufp);					if (!new_bufp)						return (-1);					np = (uint16 *)new_bufp->page;					putpair((char *)np, &key, &val);				}				new_bufp->flags |= BUF_MOD;			}		}	}	if (last_bfp)		__free_ovflpage(hashp, last_bfp);	return (0);}/* * Add the given pair to the page * * Returns: *	0 ==> OK *	1 ==> failure */extern int__addel(HTAB *hashp, BUFHEAD *bufp, const DBT *key, const DBT * val){	register uint16 *bp, *sop;	int do_expand;	bp = (uint16 *)bufp->page;	do_expand = 0;	while (bp[0] && (bp[2] < REAL_KEY || bp[bp[0]] < REAL_KEY))		/* Exception case */		if (bp[2] == FULL_KEY_DATA && bp[0] == 2)			/* This is the last page of a big key/data pair			   and we need to add another page */			break;		else if (bp[2] < REAL_KEY && bp[bp[0]] != OVFLPAGE) {			bufp = __get_buf(hashp, bp[bp[0] - 1], bufp, 0);			if (!bufp)			  {#ifdef DEBUG				assert(0);#endif				return (-1);			  }			bp = (uint16 *)bufp->page;		} else			/* Try to squeeze key on this page */			if (FREESPACE(bp) > PAIRSIZE(key, val)) {			  {				squeeze_key(bp, key, val);				/* LJM: I added this because I think it was				 * left out on accident.				 * if this isn't incremented nkeys will not				 * be the actual number of keys in the db.				 */				hashp->NKEYS++;				return (0);			  }			} else {				bufp = __get_buf(hashp, bp[bp[0] - 1], bufp, 0);				if (!bufp)			      {#ifdef DEBUG				    assert(0);#endif					return (-1);				  }				bp = (uint16 *)bufp->page;			}	if (PAIRFITS(bp, key, val))		putpair(bufp->page, key, (DBT *)val);	else {		do_expand = 1;		bufp = __add_ovflpage(hashp, bufp);		if (!bufp)	      {#ifdef DEBUG		    assert(0);#endif			return (-1);		  }		sop = (uint16 *)bufp->page;		if (PAIRFITS(sop, key, val))			putpair((char *)sop, key, (DBT *)val);		else			if (__big_insert(hashp, bufp, key, val))	          {#ifdef DEBUG		        assert(0);#endif			    return (-1);		      }	}	bufp->flags |= BUF_MOD;	/*	 * If the average number of keys per bucket exceeds the fill factor,	 * expand the table.	 */	hashp->NKEYS++;	if (do_expand ||	    (hashp->NKEYS / (hashp->MAX_BUCKET + 1) > hashp->FFACTOR))		return (__expand_table(hashp));	return (0);}/* * * Returns: *	pointer on success *	NULL on error */extern BUFHEAD *__add_ovflpage(HTAB *hashp, BUFHEAD *bufp){	register uint16 *sp;	uint16 ndx, ovfl_num;#ifdef DEBUG1	int tmp1, tmp2;#endif	sp = (uint16 *)bufp->page;	/* Check if we are dynamically determining the fill factor */	if (hashp->FFACTOR == DEF_FFACTOR) {		hashp->FFACTOR = sp[0] >> 1;		if (hashp->FFACTOR < MIN_FFACTOR)			hashp->FFACTOR = MIN_FFACTOR;	}	bufp->flags |= BUF_MOD;	ovfl_num = overflow_page(hashp);#ifdef DEBUG1	tmp1 = bufp->addr;	tmp2 = bufp->ovfl ? bufp->ovfl->addr : 0;#endif	if (!ovfl_num || !(bufp->ovfl = __get_buf(hashp, ovfl_num, bufp, 1)))		return (NULL);	bufp->ovfl->flags |= BUF_MOD;#ifdef DEBUG1	(void)fprintf(stderr, "ADDOVFLPAGE: %d->ovfl was %d is now %d\n",	    tmp1, tmp2, bufp->ovfl->addr);#endif	ndx = sp[0];	/*	 * Since a pair is allocated on a page only if there's room to add	 * an overflow page, we know that the OVFL information will fit on	 * the page.	 */	sp[ndx + 4] = OFFSET(sp);	sp[ndx + 3] = FREESPACE(sp) - OVFLSIZE;	sp[ndx + 1] = ovfl_num;	sp[ndx + 2] = OVFLPAGE;	sp[0] = ndx + 2;#ifdef HASH_STATISTICS	hash_overflows++;#endif	return (bufp->ovfl);}/* * Returns: *	 0 indicates SUCCESS *	-1 indicates FAILURE */extern int__get_page(HTAB *hashp,	char * p,	uint32 bucket, 	int is_bucket, 	int is_disk, 	int is_bitmap){	register int fd, page;	size_t size;	ssize_t rsize;	uint16 *bp;	fd = hashp->fp;	size = hashp->BSIZE;	if ((fd == -1) || !is_disk) {		PAGE_INIT(p);		return (0);	}	if (is_bucket)		page = BUCKET_TO_PAGE(bucket);	else		page = OADDR_TO_PAGE(bucket);	if ((MY_LSEEK(fd, (off_t)page << hashp->BSHIFT, SEEK_SET) == -1) ||	    ((rsize = read(fd, p, size)) == -1))		return (-1);	bp = (uint16 *)p;	if (!rsize)		bp[0] = 0;	/* We hit the EOF, so initialize a new page */	else		if (rsize != size) {			errno = EFTYPE;			return (-1);		}	if (!is_bitmap && !bp[0]) {		PAGE_INIT(p);	} else {#ifdef DEBUG		if(BYTE_ORDER == LITTLE_ENDIAN)		  {			int is_little_endian;			is_little_endian = BYTE_ORDER;		  }		else if(BYTE_ORDER == BIG_ENDIAN)		  {			int is_big_endian;			is_big_endian = BYTE_ORDER;		  }		else		  {			assert(0);		  }#endif		if (hashp->LORDER != BYTE_ORDER) {			register int i, max;			if (is_bitmap) {				max = hashp->BSIZE >> 2; /* divide by 4 */				for (i = 0; i < max; i++)					M_32_SWAP(((int *)p)[i]);			} else {				M_16_SWAP(bp[0]);				max = bp[0] + 2;	    		/* bound the size of max by	     		 * the maximum number of entries	     		 * in the array	     		 */				if(max > (size / sizeof(uint16)))					return(DATABASE_CORRUPTED_ERROR);				/* do the byte order swap				 */				for (i = 1; i <= max; i++)					M_16_SWAP(bp[i]);			}		}		/* check the validity of the page here		 * (after doing byte order swaping if necessary)		 */		if(!is_bitmap && bp[0] != 0)		  {			uint16 num_keys = bp[0];			uint16 offset;			uint16 i;			/* bp[0] is supposed to be the number of			 * entries currently in the page.  If			 * bp[0] is too large (larger than the whole			 * page) then the page is corrupted			 */			if(bp[0] > (size / sizeof(uint16)))				return(DATABASE_CORRUPTED_ERROR);						/* bound free space */			if(FREESPACE(bp) > size)				return(DATABASE_CORRUPTED_ERROR);					/* check each key and data offset to make 			 * sure they are all within bounds they 			 * should all be less than the previous 			 * offset as well. 			 */			offset = size;			for(i=1 ; i <= num_keys; i+=2)  			  {				/* ignore overflow pages etc. */				if(bp[i+1] >= REAL_KEY)	  			  {											if(bp[i] > offset || bp[i+1] > bp[i])									return(DATABASE_CORRUPTED_ERROR);								offset = bp[i+1];	  			  }				else	  			  {					/* there are no other valid keys after		 			 * seeing a non REAL_KEY		 			 */					break;	  			  }  			  }		}	}	return (0);}/* * Write page p to disk * * Returns: *	 0 ==> OK *	-1 ==>failure */extern int__put_page(HTAB *hashp, char *p, uint32 bucket, int is_bucket, int is_bitmap){	register int fd, page;	size_t size;	ssize_t wsize;	size = hashp->BSIZE;	if ((hashp->fp == -1) && open_temp(hashp))		return (-1);	fd = hashp->fp;	if (hashp->LORDER != BYTE_ORDER) {		register int i;		register int max;		if (is_bitmap) {			max = hashp->BSIZE >> 2;	/* divide by 4 */			for (i = 0; i < max; i++)				M_32_SWAP(((int *)p)[i]);		} else {			max = ((uint16 *)p)[0] + 2;            /* bound the size of max by             * the maximum number of entries             * in the array             */            if(max > (size / sizeof(uint16)))                return(DATABASE_CORRUPTED_ERROR);			for (i = 0; i <= max; i++)				M_16_SWAP(((uint16 *)p)[i]);		}	}	if (is_bucket)		page = BUCKET_TO_PAGE(bucket);	else		page = OADDR_TO_PAGE(bucket);	if ((MY_LSEEK(fd, (off_t)page << hashp->BSHIFT, SEEK_SET) == -1) ||	    ((wsize = write(fd, p, size)) == -1))		/* Errno is set */		return (-1);	if (wsize != size) {		errno = EFTYPE;		return (-1);	}	/* put the page back the way it was so that it isn't byteswapped	 * if it remains in memory - LJM	 */	if (hashp->LORDER != BYTE_ORDER) {		register int i;		register int max;		if (is_bitmap) {			max = hashp->BSIZE >> 2;	/* divide by 4 */			for (i = 0; i < max; i++)				M_32_SWAP(((int *)p)[i]);		} else {    		uint16 *bp = (uint16 *)p;			M_16_SWAP(bp[0]);			max = bp[0] + 2;			/* no need to bound the size if max again			 * since it was done already above			 */			/* do the byte order re-swap			 */			for (i = 1; i <= max; i++)				M_16_SWAP(bp[i]);		}	}	return (0);}#define BYTE_MASK	((1 << INT_BYTE_SHIFT) -1)/* * Initialize a new bitmap page.  Bitmap pages are left in memory * once they are read in. */extern int__ibitmap(HTAB *hashp, int pnum, int nbits, int ndx){	uint32 *ip;	size_t clearbytes, clearints;	if ((ip = (uint32 *)malloc((size_t)hashp->BSIZE)) == NULL)		return (1);	hashp->nmaps++;	clearints = ((nbits - 1) >> INT_BYTE_SHIFT) + 1;	clearbytes = clearints << INT_TO_BYTE;	(void)memset((char *)ip, 0, clearbytes);	(void)memset(((char *)ip) + clearbytes, 0xFF,	    hashp->BSIZE - clearbytes);	ip[clearints - 1] = ALL_SET << (nbits & BYTE_MASK);	SETBIT(ip, 0);	hashp->BITMAPS[ndx] = (uint16)pnum;	hashp->mapp[ndx] = ip;	return (0);}static uint32first_free(uint32 map){	register uint32 i, mask;	mask = 0x1;	for (i = 0; i < BITS_PER_MAP; i++) {		if (!(mask & map))			return (i);		mask = mask << 1;	}	return (i);}static uint16overflow_page(HTAB *hashp){	register uint32 *freep=NULL;	register int max_free, offset, splitnum;	uint16 addr;	uint32 i;	int bit, first_page, free_bit, free_page, in_use_bits, j;#ifdef DEBUG2	int tmp1, tmp2;#endif	splitnum = hashp->OVFL_POINT;	max_free = hashp->SPARES[splitnum];	free_page = (max_free - 1) >> (hashp->BSHIFT + BYTE_SHIFT);	free_bit = (max_free - 1) & ((hashp->BSIZE << BYTE_SHIFT) - 1);	/* Look through all the free maps to find the first free block */	first_page = hashp->LAST_FREED >>(hashp->BSHIFT + BYTE_SHIFT);	for ( i = first_page; i <= free_page; i++ ) {		if (!(freep = (uint32 *)hashp->mapp[i]) &&		    !(freep = fetch_bitmap(hashp, i)))			return (0);		if (i == free_page)			in_use_bits = free_bit;		else			in_use_bits = (hashp->BSIZE << BYTE_SHIFT) - 1;				if (i == first_page) {			bit = hashp->LAST_FREED &			    ((hashp->BSIZE << BYTE_SHIFT) - 1);			j = bit / BITS_PER_MAP;			bit = bit & ~(BITS_PER_MAP - 1);		} else {			bit = 0;			j = 0;		}		for (; bit <= in_use_bits; j++, bit += BITS_PER_MAP)			if (freep[j] != ALL_SET)				goto found;	}	/* No Free Page Found */	hashp->LAST_FREED = hashp->SPARES[splitnum];	hashp->SPARES[splitnum]++;	offset = hashp->SPARES[splitnum] -	    (splitnum ? hashp->SPARES[splitnum - 1] : 0);#define	OVMSG	"HASH: Out of overflow pages.  Increase page size\n"	if (offset > SPLITMASK) {		if (++splitnum >= NCACHED) {#ifndef macintosh			(void)write(STDERR_FILENO, OVMSG, sizeof(OVMSG) - 1);#endif			return (0);		}		hashp->OVFL_POINT = splitnum;		hashp->SPARES[splitnum] = hashp->SPARES[splitnum-1];		hashp->SPARES[splitnum-1]--;		offset = 1;	}	/* Check if we need to allocate a new bitmap page */	if (free_bit == (hashp->BSIZE << BYTE_SHIFT) - 1) {		free_page++;		if (free_page >= NCACHED) {#ifndef macintosh			(void)write(STDERR_FILENO, OVMSG, sizeof(OVMSG) - 1);#endif			return (0);		}		/*		 * This is tricky.  The 1 indicates that you want the new page		 * allocated with 1 clear bit.  Actually, you are going to		 * allocate 2 pages from this map.  The first is going to be		 * the map page, the second is the overflow page we were		 * looking for.  The init_bitmap routine automatically, sets		 * the first bit of itself to indicate that the bitmap itself		 * is in use.  We would explicitly set the second bit, but		 * don't have to if we tell init_bitmap not to leave it clear		 * in the first place.		 */		if (__ibitmap(hashp,		    (int)OADDR_OF(splitnum, offset), 1, free_page))			return (0);		hashp->SPARES[splitnum]++;#ifdef DEBUG2		free_bit = 2;#endif		offset++;		if (offset > SPLITMASK) {			if (++splitnum >= NCACHED) {#ifndef macintosh				(void)write(STDERR_FILENO, OVMSG,				    sizeof(OVMSG) - 1);#endif				return (0);			}			hashp->OVFL_POINT = splitnum;			hashp->SPARES[splitnum] = hashp->SPARES[splitnum-1];			hashp->SPARES[splitnum-1]--;			offset = 0;		}	} else {		/*		 * Free_bit addresses the last used bit.  Bump it to address		 * the first available bit.		 */		free_bit++;		SETBIT(freep, free_bit);	}	/* Calculate address of the new overflow page */	addr = OADDR_OF(splitnum, offset);#ifdef DEBUG2	(void)fprintf(stderr, "OVERFLOW_PAGE: ADDR: %d BIT: %d PAGE %d\n",	    addr, free_bit, free_page);#endif	return (addr);found:	bit = bit + first_free(freep[j]);	SETBIT(freep, bit);#ifdef DEBUG2	tmp1 = bit;	tmp2 = i;#endif	/*	 * Bits are addressed starting with 0, but overflow pages are addressed	 * beginning at 1. Bit is a bit addressnumber, so we need to increment	 * it to convert it to a page number.	 */	bit = 1 + bit + (i * (hashp->BSIZE << BYTE_SHIFT));	if (bit >= hashp->LAST_FREED)		hashp->LAST_FREED = bit - 1;	/* Calculate the split number for this page */	for (i = 0; (i < splitnum) && (bit > hashp->SPARES[i]); i++) {}	offset = (i ? bit - hashp->SPARES[i - 1] : bit);	if (offset >= SPLITMASK)		return (0);	/* Out of overflow pages */	addr = OADDR_OF(i, offset);#ifdef DEBUG2	(void)fprintf(stderr, "OVERFLOW_PAGE: ADDR: %d BIT: %d PAGE %d\n",	    addr, tmp1, tmp2);#endif	/* Allocate and return the overflow page */	return (addr);}/* * Mark this overflow page as free. */extern void__free_ovflpage(HTAB *hashp, BUFHEAD *obufp){	uint16 addr;	uint32 *freep;	uint32 bit_address, free_page, free_bit;	uint16 ndx;	if(!obufp || !obufp->addr)	    return;	addr = obufp->addr;#ifdef DEBUG1	(void)fprintf(stderr, "Freeing %d\n", addr);#endif	ndx = (((uint16)addr) >> SPLITSHIFT);	bit_address =	    (ndx ? hashp->SPARES[ndx - 1] : 0) + (addr & SPLITMASK) - 1;	 if (bit_address < hashp->LAST_FREED)		hashp->LAST_FREED = bit_address;	free_page = (bit_address >> (hashp->BSHIFT + BYTE_SHIFT));	free_bit = bit_address & ((hashp->BSIZE << BYTE_SHIFT) - 1);	if (!(freep = hashp->mapp[free_page])) 		freep = fetch_bitmap(hashp, free_page);#ifdef DEBUG	/*	 * This had better never happen.  It means we tried to read a bitmap	 * that has already had overflow pages allocated off it, and we	 * failed to read it from the file.	 */	if (!freep)	  {		assert(0);		return;	  }#endif	CLRBIT(freep, free_bit);#ifdef DEBUG2	(void)fprintf(stderr, "FREE_OVFLPAGE: ADDR: %d BIT: %d PAGE %d\n",	    obufp->addr, free_bit, free_page);#endif	__reclaim_buf(hashp, obufp);}/* * Returns: *	 0 success *	-1 failure */static intopen_temp(HTAB *hashp){#if !defined(_WIN32) && !defined(_WINDOWS) && !defined(macintosh)	sigset_t set, oset;#endif	static char namestr[] = "_hashXXXXXX";#if !defined(_WIN32) && !defined(_WINDOWS) && !defined(macintosh)	/* Block signals; make sure file goes away at process exit. */	(void)sigfillset(&set);	(void)sigprocmask(SIG_BLOCK, &set, &oset);#endif	if ((hashp->fp = mkstemp(namestr)) != -1) {		(void)unlink(namestr);#if !defined(_WIN32) && !defined(_WINDOWS) && !defined(macintosh)		(void)fcntl(hashp->fp, F_SETFD, 1);#endif									  	}#if !defined(_WIN32) && !defined(_WINDOWS) && !defined(macintosh) 	(void)sigprocmask(SIG_SETMASK, &oset, (sigset_t *)NULL);#endif	return (hashp->fp != -1 ? 0 : -1);}/* * We have to know that the key will fit, but the last entry on the page is * an overflow pair, so we need to shift things. */static voidsqueeze_key(uint16 *sp, const DBT * key, const DBT * val){	register char *p;	uint16 free_space, n, off, pageno;	p = (char *)sp;	n = sp[0];	free_space = FREESPACE(sp);	off = OFFSET(sp);	pageno = sp[n - 1];	off -= key->size;	sp[n - 1] = off;	memmove(p + off, key->data, key->size);	off -= val->size;	sp[n] = off;	memmove(p + off, val->data, val->size);	sp[0] = n + 2;	sp[n + 1] = pageno;	sp[n + 2] = OVFLPAGE;	FREESPACE(sp) = free_space - PAIRSIZE(key, val);	OFFSET(sp) = off;}static uint32 *fetch_bitmap(HTAB *hashp, uint32 ndx){	if (ndx >= hashp->nmaps)		return (NULL);	if ((hashp->mapp[ndx] = (uint32 *)malloc((size_t)hashp->BSIZE)) == NULL)		return (NULL);	if (__get_page(hashp,	    (char *)hashp->mapp[ndx], hashp->BITMAPS[ndx], 0, 1, 1)) {		free(hashp->mapp[ndx]);		hashp->mapp[ndx] = NULL; /* NEW: 9-11-95 */		return (NULL);	}                 	return (hashp->mapp[ndx]);}