text: /*
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
   *
   * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
   *
   * THE BSD LICENSE
   *
   * Redistribution and use in source and binary forms, with or without 
   * modification, are permitted provided that the following conditions are met:
   *
   * Redistributions of source code must retain the above copyright notice, this
   * list of conditions and the following disclaimer. 
   * 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. 
   *
   * Neither the name of the  nor the names of its contributors may be
   * used to endorse or promote products derived from this software without 
   * specific prior written permission. 
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 
   * 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.
   */
  
  /*-
   * Copyright (c) 1990, 1993, 1994
   *	The Regents of the University of California.  All rights reserved.
   *
   * This code is derived from software contributed to Berkeley by
   * Margo Seltzer.
   *
   * 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.
   * 3. All advertising materials mentioning features or use of this software
   *    must display the following acknowledgement:
   *	This product includes software developed by the University of
   *	California, Berkeley and its contributors.
   * 4. Neither the name of the University nor the names of its contributors
   *    may be used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
   */
  
  #if defined(LIBC_SCCS) && !defined(lint)
  static char sccsid[] = "@(#)hash.c	8.9 (Berkeley) 6/16/94";
  #endif /* LIBC_SCCS and not lint */
  
  #if !defined(_WIN32) && !defined(_WINDOWS) && !defined(macintosh)
  #include <sys/param.h>
  #endif
  
  #if !defined(macintosh)
  #include <sys/stat.h>
  #endif
  
  #include <errno.h>
  #ifdef macintosh
  #include <unix.h>
  #else
  #include <fcntl.h>
  #endif
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  
  #if !defined(_WIN32) && !defined(_WINDOWS) && !defined(macintosh)
  #include <unistd.h>
  #endif
  
  #ifdef DEBUG
  #include <assert.h>
  #endif
  
  #include "mcom_db.h"
  #include "hash.h"
  #include "page.h"
  
  #if defined(__sony) || defined(NECSVR4)
  # include <sys/byteorder.h>
  #endif /* __sony */
  #if defined(AIX)
  #include <sys/machine.h>      /* For BYTE_ORDER definition */
  #endif
  
  /*
  #include "extern.h"
  */
  static int   alloc_segs __P((HTAB *, int));
  static int   flush_meta __P((HTAB *));
  static int   hash_access __P((HTAB *, ACTION, DBT *, DBT *));
  static int   hash_close __P((DB *));
  static int   hash_delete __P((const DB *, const DBT *, uint));
  static int   hash_fd __P((const DB *));
  static int   hash_get __P((const DB *, const DBT *, DBT *, uint));
  static int   hash_put __P((const DB *, DBT *, const DBT *, uint));
  static void *hash_realloc __P((SEGMENT **, int, int));
  static int   hash_seq __P((const DB *, DBT *, DBT *, uint));
  static int   hash_sync __P((const DB *, uint));
  static int   hdestroy __P((HTAB *));
  static HTAB *init_hash __P((HTAB *, const char *, HASHINFO *));
  static int   init_htab __P((HTAB *, int));
  #if BYTE_ORDER == LITTLE_ENDIAN
  static void  swap_header __P((HTAB *));
  static void  swap_header_copy __P((HASHHDR *, HASHHDR *));
  #endif
  
  /* Fast arithmetic, relying on powers of 2, */
  #define MOD(x, y)		((x) & ((y) - 1))
  
  #define RETURN_ERROR(ERR, LOC)	{ save_errno = ERR; goto LOC; }
  
  /* Return values */
  #define	SUCCESS	 (0)
  #define	ERROR	(-1)
  #define	ABNORMAL (1)
  
  #ifdef HASH_STATISTICS
  int hash_accesses, hash_collisions, hash_expansions, hash_overflows;
  #endif
  
  /* A new Lou (montulli@mozilla.com) routine.
   *
   * The database is screwed.  Delete it by 
   * making it a zero length file
   *
   * This zero's hashp so that the
   * database can't be accessed any more
   */
  static void
  __remove_database(DB *dbp)
  {
  	HTAB *hashp = (HTAB *)dbp->internal;
  	if (!hashp)
  		return;
  
  	if(hashp->fp != NO_FILE)
  		close(hashp->fp);
  	if(hashp->filename)
  		unlink(hashp->filename);
  	dbp->internal = NULL; /* zero the internal stuff */
  
  }
  
  /************************** INTERFACE ROUTINES ***************************/
  /* OPEN/CLOSE */
  
  
  extern DB *
  __hash_open(const char *file, int flags, int mode, const HASHINFO *info, int dflags)
  {
  	HTAB *hashp = 0;
  	struct stat statbuf;
  	DB *dbp;
  	int bpages, hdrsize, new_table, nsegs, save_errno;
  	int lock;
  
  	if ((flags & O_ACCMODE) == O_WRONLY) {
  		errno = EINVAL;
  		RETURN_ERROR(ENOMEM, error0);
  	}
  
  	/* zero the statbuffer so that
  	 * we can check it for a non-zero
  	 * date to see if stat succeeded
  	 */
  	memset(&statbuf, 0, sizeof(struct stat));
  
  	if (!(hashp = (HTAB *)calloc(1, sizeof(HTAB))))
  		RETURN_ERROR(ENOMEM, error0);
  	hashp->fp = NO_FILE;
  	if(file)
  		hashp->filename = strdup(file);
  
  	/*
  	 * Even if user wants write only, we need to be able to read
  	 * the actual file, so we need to open it read/write. But, the
  	 * field in the hashp structure needs to be accurate so that
  	 * we can check accesses.
  	 */
  	hashp->flags = flags;
  
  	/* Initialize the dflags field */
  	hashp->flags |= dflags;
  	if (dflags & DB_LOCK) {
  	    if ((flags & O_ACCMODE) == O_RDONLY)
  		lock = HASH_SHARED_LOCK;
  	    else
  		lock = HASH_EXCLUSIVE_LOCK;
  	}
  	else {
  		lock = 0;
  	}
  
  	new_table = 0;
  	if (!file || (flags & O_TRUNC) 	|| (stat(file, &statbuf)  && (errno == ENOENT))) 
  	{
  		if (errno == ENOENT)
  			errno = 0; /* Just in case someone looks at errno */
  		new_table = 1;
  	}
  	else if(statbuf.st_mtime && statbuf.st_size == 0)
  	{
  		/* check for a zero length file and delete it
  	 	 * if it exists
  	 	 */
  		new_table = 1;
  	}
  
  	if (file) {				 
  
  #if defined(_WIN32) || defined(_WINDOWS) || defined (macintosh)
  		if ((hashp->fp = DBFILE_OPEN(file, flags | O_BINARY, mode)) == -1)
  			RETURN_ERROR(errno, error0);
  #else
   	if ((hashp->fp = open(file, flags, mode)) == -1)
  		RETURN_ERROR(errno, error0);
  	(void)fcntl(hashp->fp, F_SETFD, 1);
  /* We can't use fcntl because of NFS bugs. SIGH */
  #if 0
      {
  	struct flock fl;
  	memset(&fl, 0, sizeof(fl));
  	fl.l_type = F_WRLCK;
  	if (fcntl(hashp->fp, F_SETLK, &fl) < 0) {
  #ifdef DEBUG
  	    fprintf(stderr, "unable to open %s because it's locked (flags=0x%x)\n", file, flags);
  #endif
  	    RETURN_ERROR(EACCES, error1);
  	}
      }
  #endif
  
  #endif
  	}
  	/* Lock the other processes/threads out before proceeding further */
  	__hash_lock(hashp, lock);
          
  	if (new_table) {
  		if (!init_hash(hashp, file, (HASHINFO *)info))
  			RETURN_ERROR(errno, error1);
  	} else {
  		/* Table already exists */
  		if (info && info->hash)
  			hashp->hash = info->hash;
  		else
  			hashp->hash = __default_hash;
  
  		hdrsize = read(hashp->fp, (char *)&hashp->hdr, sizeof(HASHHDR));
  #if BYTE_ORDER == LITTLE_ENDIAN
  		swap_header(hashp);
  #endif
  		if (hdrsize == -1)
  			RETURN_ERROR(errno, error1);
  		if (hdrsize != sizeof(HASHHDR))
  			RETURN_ERROR(EFTYPE, error1);
  		/* Verify file type, versions and hash function */
  		if (hashp->MAGIC != HASHMAGIC)
  			RETURN_ERROR(EFTYPE, error1);
  #define	OLDHASHVERSION	1
  		if (hashp->VERSION != HASHVERSION &&
  		    hashp->VERSION != OLDHASHVERSION)
  			RETURN_ERROR(EFTYPE, error1);
  		if (hashp->hash(CHARKEY, sizeof(CHARKEY)) != hashp->H_CHARKEY)
  			RETURN_ERROR(EFTYPE, error1);
  		if (hashp->NKEYS < 0) {
  		    /*
  		    ** OOPS. Old bad database from previously busted
  		    ** code. Blow it away.
  		    */
  		    __hash_unlock(hashp);
  		    close(hashp->fp);
  		    if (remove(file) < 0) {
  #if defined(DEBUG) && defined(XP_UNIX)
  			fprintf(stderr,
  				"WARNING: You have an old bad cache.db file"
  				" '%s', and I couldn't remove it!\n", file);
  #endif
  		    } else {
  #if defined(DEBUG) && defined(XP_UNIX)
  			fprintf(stderr,
  				"WARNING: I blew away your %s file because"
  				" it was bad due to a recently fixed bug\n",
  				file);
  #endif
  		    }
  		    RETURN_ERROR(ENOENT, error0);
  		}
  
  		/*
  		 * Figure out how many segments we need.  Max_Bucket is the
  		 * maximum bucket number, so the number of buckets is
  		 * max_bucket + 1.
  		 */
  		nsegs = (hashp->MAX_BUCKET + 1 + hashp->SGSIZE - 1) /
  			 hashp->SGSIZE;
  		hashp->nsegs = 0;
  		if (alloc_segs(hashp, nsegs))
  			/*
  			 * If alloc_segs fails, table will have been destroyed
  			 * and errno will have been set.
  			 */
  			RETURN_ERROR(ENOMEM, error0);
  		/* Read in bitmaps */
  		bpages = (hashp->SPARES[hashp->OVFL_POINT] +
  		    (hashp->BSIZE << BYTE_SHIFT) - 1) >>
  		    (hashp->BSHIFT + BYTE_SHIFT);
  
  		hashp->nmaps = bpages;
  		(void)memset(&hashp->mapp[0], 0, bpages * sizeof(PRUint32 *));
  	}
  
  	/* Initialize Buffer Manager */
  	if (info && info->cachesize)
  		__buf_init(hashp, (PRInt32) info->cachesize);
  	else
  		__buf_init(hashp, DEF_BUFSIZE);
  
  	hashp->new_file = new_table;
  #ifdef macintosh
  	hashp->save_file = file && !(hashp->flags & O_RDONLY);
  #else
  	hashp->save_file = file && (hashp->flags & O_RDWR);
  #endif
  	hashp->cbucket = -1;
  	if (!(dbp = (DB *)malloc(sizeof(DB)))) {
  		save_errno = errno;
  		hdestroy(hashp);
  		errno = save_errno;
  		RETURN_ERROR(ENOMEM, error0);
  	}
  	dbp->internal = hashp;
  	dbp->close = hash_close;
  	dbp->del = hash_delete;
  	dbp->fd = hash_fd;
  	dbp->get = hash_get;
  	dbp->put = hash_put;
  	dbp->seq = hash_seq;
  	dbp->sync = hash_sync;
  	dbp->type = DB_HASH;
  
  #if 0
  #if defined(DEBUG) && !defined(_WINDOWS)
  {
  extern int MKLib_trace_flag;
  
    if(MKLib_trace_flag)
  	(void)fprintf(stderr,
  "%s\n%s%lx\n%s%d\n%s%d\n%s%d\n%s%d\n%s%d\n%s%d\n%s%d\n%s%d\n%s%d\n%s%x\n%s%x\n%s%d\n%s%d\n",
  	    "init_htab:",
  	    "TABLE POINTER   ", (unsigned long) hashp,
  	    "BUCKET SIZE     ", hashp->BSIZE,
  	    "BUCKET SHIFT    ", hashp->BSHIFT,
  	    "DIRECTORY SIZE  ", hashp->DSIZE,
  	    "SEGMENT SIZE    ", hashp->SGSIZE,
  	    "SEGMENT SHIFT   ", hashp->SSHIFT,
  	    "FILL FACTOR     ", hashp->FFACTOR,
  	    "MAX BUCKET      ", hashp->MAX_BUCKET,
  	    "OVFL POINT	     ", hashp->OVFL_POINT,
  	    "LAST FREED      ", hashp->LAST_FREED,
  	    "HIGH MASK       ", hashp->HIGH_MASK,
  	    "LOW  MASK       ", hashp->LOW_MASK,
  	    "NSEGS           ", hashp->nsegs,
  	    "NKEYS           ", hashp->NKEYS);
  }
  #endif
  #endif /* 0 */
  #ifdef HASH_STATISTICS
  	hash_overflows = hash_accesses = hash_collisions = hash_expansions = 0;
  #endif
  	return (dbp);
  
  error1:
  	if (hashp != NULL) {
  		__hash_unlock(hashp);
  		(void)close(hashp->fp);
  	}
  
  error0:
          if (hashp != NULL && hashp->filename != NULL)
              free(hashp->filename);
  	free(hashp);
  	errno = save_errno;
  	return (NULL);
  }
  
  static int
  hash_close(DB *dbp)
  {
  	HTAB *hashp;
  	int retval;
  
  	if (!dbp)
  		return (ERROR);
  
  	hashp = (HTAB *)dbp->internal;
  	if(!hashp)
  		return (ERROR);
  
  	retval = hdestroy(hashp);
  	free(dbp);
  	return (retval);
  }
  
  static int hash_fd(const DB *dbp)
  {
  	HTAB *hashp;
  
  	if (!dbp)
  		return (ERROR);
  
  	hashp = (HTAB *)dbp->internal;
  	if(!hashp)
  		return (ERROR);
  
  	if (hashp->fp == -1) {
  		errno = ENOENT;
  		return (-1);
  	}
  	return (hashp->fp);
  }
  
  /************************** LOCAL CREATION ROUTINES **********************/
  static HTAB *
  init_hash(HTAB *hashp, const char *file, HASHINFO *info)
  {
  	struct stat statbuf;
  	int nelem;
  
  	nelem = 1;
  	hashp->NKEYS = 0;
  	hashp->LORDER = BYTE_ORDER;
  	hashp->BSIZE = DEF_BUCKET_SIZE;
  	hashp->BSHIFT = DEF_BUCKET_SHIFT;
  	hashp->SGSIZE = DEF_SEGSIZE;
  	hashp->SSHIFT = DEF_SEGSIZE_SHIFT;
  	hashp->DSIZE = DEF_DIRSIZE;
  	hashp->FFACTOR = DEF_FFACTOR;
  	hashp->hash = __default_hash;
  	memset(hashp->SPARES, 0, sizeof(hashp->SPARES));
  	memset(hashp->BITMAPS, 0, sizeof (hashp->BITMAPS));
  
  	/* Fix bucket size to be optimal for file system */
  	if (file != NULL) {
  		if (stat(file, &statbuf))
  			return (NULL);
  
  #if !defined(_WIN32) && !defined(_WINDOWS) && !defined(macintosh)
  		hashp->BSIZE = statbuf.st_blksize;
  
         	/* new code added by Lou to reduce block
         	 * size down below MAX_BSIZE
         	 */
         	if (hashp->BSIZE > MAX_BSIZE)
         		hashp->BSIZE = MAX_BSIZE;
  #endif
  		hashp->BSHIFT = __log2(hashp->BSIZE);
  	}
  
  	if (info) {
  		if (info->bsize) {
  			/* Round pagesize up to power of 2 */
  			hashp->BSHIFT = __log2(info->bsize);
  			hashp->BSIZE = 1 << hashp->BSHIFT;
  			if (hashp->BSIZE > MAX_BSIZE) {
  				errno = EINVAL;
  				return (NULL);
  			}
  		}
   	 	else {
                    if (hashp->BSIZE < DEF_BUCKET_SIZE) {
                         /* since info->bsize == 0, we can hard code the bsize to
                            be the default.  We only do this if the default is
                            more than the current bsize value.  This was to
                            fix bug 29102 until a real fix is found. */
  #ifdef DEBUG
                         assert(__log2(DEF_BUCKET_SIZE) == DEF_BUCKET_SHIFT);
  #endif
                         hashp->BSIZE = DEF_BUCKET_SIZE;
                         hashp->BSHIFT = DEF_BUCKET_SHIFT;
                     }
                  }
  
  
  		if (info->ffactor)
  			hashp->FFACTOR = info->ffactor;
  		if (info->hash)
  			hashp->hash = info->hash;
  		if (info->nelem)
  			nelem = info->nelem;
  		if (info->lorder) {
  			if (info->lorder != BIG_ENDIAN &&
  			    info->lorder != LITTLE_ENDIAN) {
  				errno = EINVAL;
  				return (NULL);
  			}
  			hashp->LORDER = info->lorder;
  		}
  	}
  	else {
  		if (hashp->BSIZE < DEF_BUCKET_SIZE) {
                         /* since info == null, we can hard code the bsize to
                            be the default.  We only do this if the default is
                            more than the current bsize value.  This was to
                            fix bug 29102 until a real fix is found. */
  #ifdef DEBUG
                         	assert(__log2(DEF_BUCKET_SIZE) == DEF_BUCKET_SHIFT);
  #endif
                          hashp->BSIZE = DEF_BUCKET_SIZE;
                 		hashp->BSHIFT = DEF_BUCKET_SHIFT;
                 	}
         	}
  
  #ifdef HASH_SHOW_MORE_INFO
  	fprintf(stderr, "NUMBER OF ELEMENTS :\t%d\n",nelem);
  	fprintf(stderr, "FILL FACTOR:\t%d\n",hashp->FFACTOR);
  	fprintf(stderr, "PAGE SIZE:\t%d\n",hashp->BSIZE);
  #endif
  
  	/* init_htab should destroy the table and set errno if it fails */
  	if (init_htab(hashp, nelem))
  		return (NULL);
  	else
  		return (hashp);
  }
  /*
   * This calls alloc_segs which may run out of memory.  Alloc_segs will destroy
   * the table and set errno, so we just pass the error information along.
   *
   * Returns 0 on No Error
   */
  static int
  init_htab(HTAB *hashp, int nelem)
  {
  	register int nbuckets, nsegs;
  	int l2;
  
  	/*
  	 * Divide number of elements by the fill factor and determine a
  	 * desired number of buckets.  Allocate space for the next greater
  	 * power of two number of buckets.
  	 */
  	nelem = (nelem - 1) / hashp->FFACTOR + 1;
  
  	l2 = __log2(MAX(nelem, 2));
  	nbuckets = 1 << l2;
  
  	hashp->SPARES[l2] = l2 + 1;
  	hashp->SPARES[l2 + 1] = l2 + 1;
  	hashp->OVFL_POINT = l2;
  	hashp->LAST_FREED = 2;
  
  	/* First bitmap page is at: splitpoint l2 page offset 1 */
  	if (__ibitmap(hashp, OADDR_OF(l2, 1), l2 + 1, 0))
  		return (-1);
  
  	hashp->MAX_BUCKET = hashp->LOW_MASK = nbuckets - 1;
  	hashp->HIGH_MASK = (nbuckets << 1) - 1;
  	hashp->HDRPAGES = ((MAX(sizeof(HASHHDR), MINHDRSIZE) - 1) >>
  	    hashp->BSHIFT) + 1;
  
  	nsegs = (nbuckets - 1) / hashp->SGSIZE + 1;
  	nsegs = 1 << __log2(nsegs);
  
  	if (nsegs > hashp->DSIZE)
  		hashp->DSIZE = nsegs;
  	return (alloc_segs(hashp, nsegs));
  }
  
  /********************** DESTROY/CLOSE ROUTINES ************************/
  
  /*
   * Flushes any changes to the file if necessary and destroys the hashp
   * structure, freeing all allocated space.
   */
  static int
  hdestroy(HTAB *hashp)
  {
  	int i, save_errno;
  
  	save_errno = 0;
  
  #ifdef HASH_STATISTICS
  	(void)fprintf(stderr, "hdestroy: accesses %ld collisions %ld\n",
  	    hash_accesses, hash_collisions);
  	(void)fprintf(stderr, "hdestroy: expansions %ld\n",
  	    hash_expansions);
  	(void)fprintf(stderr, "hdestroy: overflows %ld\n",
  	    hash_overflows);
  	(void)fprintf(stderr, "keys %ld maxp %d segmentcount %d\n",
  	    hashp->NKEYS, hashp->MAX_BUCKET, hashp->nsegs);
  
  	for (i = 0; i < NCACHED; i++)
  		(void)fprintf(stderr,
  		    "spares[%d] = %d\n", i, hashp->SPARES[i]);
  #endif
  	/*
  	 * Call on buffer manager to free buffers, and if required,
  	 * write them to disk.
  	 */
  	if (__buf_free(hashp, 1, hashp->save_file))
  		save_errno = errno;
  	if (hashp->dir) {
  		free(*hashp->dir);	/* Free initial segments */
  		/* Free extra segments */
  		while (hashp->exsegs--)
  			free(hashp->dir[--hashp->nsegs]);
  		free(hashp->dir);
  	}
  	if (flush_meta(hashp) && !save_errno)
  		save_errno = errno;
  	/* Free Bigmaps */
  	for (i = 0; i < hashp->nmaps; i++)
  		if (hashp->mapp[i])
  			free(hashp->mapp[i]);
  
         __hash_unlock(hashp);
  
  	if (hashp->fp != -1)
  		(void)close(hashp->fp);
  
  	if(hashp->filename)
  		free(hashp->filename);
  
  	free(hashp);
  
  	if (save_errno) {
  		errno = save_errno;
  		return (ERROR);
  	}
  	return (SUCCESS);
  }
  /*
   * Write modified pages to disk
   *
   * Returns:
   *	 0 == OK
   *	-1 ERROR
   */
  static int
  hash_sync(const DB *dbp, uint flags)
  {
  	HTAB *hashp;
  
  	if (flags != 0) {
  		errno = EINVAL;
  		return (ERROR);
  	}
  
  	if (!dbp)
  		return (ERROR);
  
  	hashp = (HTAB *)dbp->internal;
  	if(!hashp)
  		return (ERROR);
  
  	if (!hashp->save_file)
  		return (0);
  	__hash_lock(hashp, HASH_EXCLUSIVE_LOCK);
  
  	if (__buf_free(hashp, 0, 1) || flush_meta(hashp)) {
  		__hash_unlock(hashp);
  		return (ERROR);
  	}
  
  	__hash_unlock(hashp);
  
  	hashp->new_file = 0;
  	return (0);
  }
  
  /*
   * Returns:
   *	 0 == OK
   *	-1 indicates that errno should be set
   */
  static int
  flush_meta(HTAB *hashp)
  {
  	HASHHDR *whdrp;
  #if BYTE_ORDER == LITTLE_ENDIAN
  	HASHHDR whdr;
  #endif
  	int fp, i, wsize;
  
  	if (!hashp->save_file)
  		return (0);
  	hashp->MAGIC = HASHMAGIC;
  	hashp->VERSION = HASHVERSION;
  	hashp->H_CHARKEY = hashp->hash(CHARKEY, sizeof(CHARKEY));
  
  	fp = hashp->fp;
  	whdrp = &hashp->hdr;
  #if BYTE_ORDER == LITTLE_ENDIAN
  	whdrp = &whdr;
  	swap_header_copy(&hashp->hdr, whdrp);
  #endif
  	if ((lseek(fp, (off_t)0, SEEK_SET) == -1) ||
  	    ((wsize = write(fp, (char*)whdrp, sizeof(HASHHDR))) == -1))
  		return (-1);
  	else
  		if (wsize != sizeof(HASHHDR)) {
  			errno = EFTYPE;
  			hashp->dbmerrno = errno;
  			return (-1);
  		}
  	for (i = 0; i < NCACHED; i++)
  		if (hashp->mapp[i])
  			if (__put_page(hashp, (char *)hashp->mapp[i],
  				hashp->BITMAPS[i], 0, 1))
  				return (-1);
  	return (0);
  }
  
  /*******************************SEARCH ROUTINES *****************************/
  /*
   * All the access routines return
   *
   * Returns:
   *	 0 on SUCCESS
   *	 1 to indicate an external ERROR (i.e. key not found, etc)
   *	-1 to indicate an internal ERROR (i.e. out of memory, etc)
   */
  static int
  hash_get(
  	const DB *dbp,
  	const DBT *key,
  	DBT *data,
  	uint flag)
  {
  	HTAB *hashp;
  	int rv;
  
  	hashp = (HTAB *)dbp->internal;
  	if (!hashp)
  		return (ERROR);
  
  	if (flag) {
  		hashp->dbmerrno = errno = EINVAL;
  		return (ERROR);
  	}
  
  	__hash_lock(hashp, HASH_SHARED_LOCK);
  
  	rv = hash_access(hashp, HASH_GET, (DBT *)key, data);
  
  	__hash_unlock(hashp);
  
  	if(rv == DATABASE_CORRUPTED_ERROR)
  	  {
  #if defined(unix) && defined(DEBUG)
  		printf("\n\nDBM Database has been corrupted, tell Lou...\n\n");
  #endif
  	  	__remove_database((DB *)dbp);
  	  }
  
  	return(rv);
  }
  
  static int
  hash_put(
  	const DB *dbp,
  	DBT *key,
  	const DBT *data,
  	uint flag)
  {
  	HTAB *hashp;
  	int rv;
  
  
  	hashp = (HTAB *)dbp->internal;
  	if (!hashp)
  		return (ERROR);
  
  	if (flag && flag != R_NOOVERWRITE) {
  		hashp->dbmerrno = errno = EINVAL;
  		return (ERROR);
  	}
  	if ((hashp->flags & O_ACCMODE) == O_RDONLY) {
  		hashp->dbmerrno = errno = EPERM;
  		return (ERROR);
  	}
  
  	__hash_lock(hashp, HASH_EXCLUSIVE_LOCK);
  
  	rv =  hash_access(hashp, flag == R_NOOVERWRITE ?
  	    HASH_PUTNEW : HASH_PUT, (DBT *)key, (DBT *)data);
  
  	__hash_unlock(hashp);
  
  	if(rv == DATABASE_CORRUPTED_ERROR)
  	  {
  #if defined(unix) && defined(DEBUG)
  		printf("\n\nDBM Database has been corrupted, tell Lou...\n\n");
  #endif
  	  	__remove_database((DB *)dbp);
  	  }
  
  	return(rv);
  }
  
  static int
  hash_delete(
  	const DB *dbp,
  	const DBT *key,
  	uint flag)		/* Ignored */
  {
  	HTAB *hashp;
  	int rv;
  
  
  	hashp = (HTAB *)dbp->internal;
  	if (!hashp)
  		return (ERROR);
  
  	if (flag && flag != R_CURSOR) {
  		hashp->dbmerrno = errno = EINVAL;
  		return (ERROR);
  	}
  	if ((hashp->flags & O_ACCMODE) == O_RDONLY) {
  		hashp->dbmerrno = errno = EPERM;
  		return (ERROR);
  	}
  	__hash_lock(hashp, HASH_EXCLUSIVE_LOCK);
  
  	rv = hash_access(hashp, HASH_DELETE, (DBT *)key, NULL);
  
  	__hash_unlock(hashp);
  
  	if(rv == DATABASE_CORRUPTED_ERROR)
  	  {
  #if defined(unix) && defined(DEBUG)
  		printf("\n\nDBM Database has been corrupted, tell Lou...\n\n");
  #endif
  	  	__remove_database((DB *)dbp);
  	  }
  
  	return(rv);
  }
  
  /*
   * Assume that hashp has been set in wrapper routine.
   */
  static int
  hash_access(
  	HTAB *hashp,
  	ACTION action,
  	DBT *key, DBT *val)
  {
  	register BUFHEAD *rbufp;
  	BUFHEAD *bufp, *save_bufp;
  	register uint16 *bp;
  	register long n, ndx, off, size;
  	register char *kp;
  	uint16 pageno;
  
  #ifdef HASH_STATISTICS
  	hash_accesses++;
  #endif 
  
  #ifdef HASH_SHOW_MORE_INFO
  	switch (action) {
  		case HASH_PUT:
  			fprintf(stderr, "HASH_PUT");
  			break;
  		case HASH_PUTNEW:
  			fprintf(stderr, "HASH_PUTNEW");
  			break;
  		case HASH_DELETE:
  			fprintf(stderr, "HASH_DELETE");
  			break;
  		case HASH_FIRST:
  			fprintf(stderr, "HASH_FIRST");
  			break;
  		case HASH_NEXT:
  			fprintf(stderr, "HASH_NEXT");
  			break;
  		case HASH_GET:
  			fprintf(stderr, "HASH_GET");
  			break;
  		default:
  			fprintf(stderr, "<unknown>");
  			break;
  	}
  
          if (key == NULL) {
                  fprintf(stderr, "(key size = NULL)\n");
          }
          else {
                  fprintf(stderr, "(key size = %d)\n", key->size);
          }
   
          if (val == NULL) {
                  fprintf(stderr, "(data size = NULL)\n(data = NULL)\n");
          }
          else {
                  fprintf(stderr, "(data size = %d)\n", val->size);
          }
  #endif
  
  	off = hashp->BSIZE;
  	size = key->size;
  	kp = (char *)key->data;
  	rbufp = __get_buf(hashp, __call_hash(hashp, kp, size), NULL, 0);
  	if (!rbufp)
  		return (DATABASE_CORRUPTED_ERROR);
  	save_bufp = rbufp;
  
  	/* Pin the bucket chain */
  	rbufp->flags |= BUF_PIN;
  	for (bp = (uint16 *)rbufp->page, n = *bp++, ndx = 1; ndx < n;)
  		if (bp[1] >= REAL_KEY) {
  			/* Real key/data pair */
  			if (size == off - *bp &&
  			    memcmp(kp, rbufp->page + *bp, size) == 0)
  				goto found;
  			off = bp[1];
  #ifdef HASH_STATISTICS
  			hash_collisions++;
  #endif
  			bp += 2;
  			ndx += 2;
  		} else if (bp[1] == OVFLPAGE) {
  			rbufp = __get_buf(hashp, *bp, rbufp, 0);
  			if (!rbufp) {
  				save_bufp->flags &= ~BUF_PIN;
  				return (ERROR);
  			}
  			/* FOR LOOP INIT */
  			bp = (uint16 *)rbufp->page;
  			n = *bp++;
  			ndx = 1;
  			off = hashp->BSIZE;
  		} else if (bp[1] < REAL_KEY) {
  			if ((ndx =
  			    __find_bigpair(hashp, rbufp, ndx, kp, size)) > 0)
  				goto found;
  			if (ndx == -2) {
  				bufp = rbufp;
  				if (!(pageno =
  				    __find_last_page(hashp, &bufp))) {
  					ndx = 0;
  					rbufp = bufp;
  					break;	/* FOR */
  				}
  				rbufp = __get_buf(hashp, pageno, bufp, 0);
  				if (!rbufp) {
  					save_bufp->flags &= ~BUF_PIN;
  					return (ERROR);
  				}
  				/* FOR LOOP INIT */
  				bp = (uint16 *)rbufp->page;
  				n = *bp++;
  				ndx = 1;
  				off = hashp->BSIZE;
  			} else {
  				save_bufp->flags &= ~BUF_PIN;
  				return (ERROR);
  			}
  		}
  
  	/* Not found */
  	switch (action) {
  	case HASH_PUT:
  	case HASH_PUTNEW:
  		if (__addel(hashp, rbufp, key, val)) {
  			save_bufp->flags &= ~BUF_PIN;
  			return (ERROR);
  		} else {
  			save_bufp->flags &= ~BUF_PIN;
  			return (SUCCESS);
  		}
  	case HASH_GET:
  	case HASH_DELETE:
  	default:
  		save_bufp->flags &= ~BUF_PIN;
  		return (ABNORMAL);
  	}
  
  found:
  	switch (action) {
  	case HASH_PUTNEW:
  		save_bufp->flags &= ~BUF_PIN;
  		return (ABNORMAL);
  	case HASH_GET:
  		bp = (uint16 *)rbufp->page;
  		if (bp[ndx + 1] < REAL_KEY) {
  			if (__big_return(hashp, rbufp, ndx, val, 0))
  				return (ERROR);
  		} else {
  			val->data = (uint8 *)rbufp->page + (int)bp[ndx + 1];
  			val->size = bp[ndx] - bp[ndx + 1];
  		}
  		break;
  	case HASH_PUT:
  		if ((__delpair(hashp, rbufp, ndx)) ||
  		    (__addel(hashp, rbufp, key, val))) {
  			save_bufp->flags &= ~BUF_PIN;
  			return (ERROR);
  		}
  		break;
  	case HASH_DELETE:
  		if (__delpair(hashp, rbufp, ndx))
  			return (ERROR);
  		break;
  	default:
  		abort();
  	}
  	save_bufp->flags &= ~BUF_PIN;
  	return (SUCCESS);
  }
  
  static int
  hash_seq(
  	const DB *dbp,
  	DBT *key, DBT *data,
  	uint flag)
  {
  	register PRUint32 bucket;
  	register BUFHEAD *bufp;
  	HTAB *hashp;
  	uint16 *bp, ndx;
  
  	hashp = (HTAB *)dbp->internal;
  	if (!hashp)
  		return (ERROR);
  
  	if (flag && flag != R_FIRST && flag != R_NEXT) {
  		hashp->dbmerrno = errno = EINVAL;
  		return (ERROR);
  	}
  #ifdef HASH_STATISTICS
  	hash_accesses++;
  #endif
  	if ((hashp->cbucket < 0) || (flag == R_FIRST)) {
  		hashp->cbucket = 0;
  		hashp->cndx = 1;
  		hashp->cpage = NULL;
  	}
  
  	__hash_lock(hashp, HASH_SHARED_LOCK);
  
  	for (bp = NULL; !bp || !bp[0]; ) {
  		if (!(bufp = hashp->cpage)) {
  			for (bucket = hashp->cbucket;
  			    bucket <= hashp->MAX_BUCKET;
  			    bucket++, hashp->cndx = 1) {
  				bufp = __get_buf(hashp, bucket, NULL, 0);
  				if (!bufp) {
   					__hash_unlock(hashp);
  					return (ERROR);
  				}
  				hashp->cpage = bufp;
  				bp = (uint16 *)bufp->page;
  				if (bp[0])
  					break;
  			}
  			hashp->cbucket = bucket;
  			if (hashp->cbucket > hashp->MAX_BUCKET) {
  				hashp->cbucket = -1;
  				__hash_unlock(hashp);
  				return (ABNORMAL);
  			}
  		} else
  			bp = (uint16 *)hashp->cpage->page;
  
  #ifdef DEBUG
  		assert(bp);
  		assert(bufp);
  #endif
  		while (bp[hashp->cndx + 1] == OVFLPAGE) {
  			bufp = hashp->cpage =
  			    __get_buf(hashp, bp[hashp->cndx], bufp, 0);
  			if (!bufp) {
  				__hash_unlock(hashp);
  				return (ERROR);
                          }
  			bp = (uint16 *)(bufp->page);
  			hashp->cndx = 1;
  		}
  		if (!bp[0]) {
  			hashp->cpage = NULL;
  			++hashp->cbucket;
  		}
  	}
  	ndx = hashp->cndx;
  	if (bp[ndx + 1] < REAL_KEY) {
  		if (__big_keydata(hashp, bufp, key, data, 1)) {
  			__hash_unlock(hashp);
  			return (ERROR);
  		}
  	} else {
  		key->data = (uint8 *)hashp->cpage->page + bp[ndx];
  		key->size = (ndx > 1 ? bp[ndx - 1] : hashp->BSIZE) - bp[ndx];
  		data->data = (uint8 *)hashp->cpage->page + bp[ndx + 1];
  		data->size = bp[ndx] - bp[ndx + 1];
  		ndx += 2;
  		if (ndx > bp[0]) {
  			hashp->cpage = NULL;
  			hashp->cbucket++;
  			hashp->cndx = 1;
  		} else
  			hashp->cndx = ndx;
  	}
  	__hash_unlock(hashp);
  	return (SUCCESS);
  }
  
  /********************************* UTILITIES ************************/
  
  /*
   * Returns:
   *	 0 ==> OK
   *	-1 ==> Error
   */
  extern int
  __expand_table(HTAB *hashp)
  {
  	PRUint32 old_bucket, new_bucket;
  	int dirsize, new_segnum, spare_ndx;
  
  #ifdef HASH_STATISTICS
  	hash_expansions++;
  #endif
  	new_bucket = ++hashp->MAX_BUCKET;
  	old_bucket = (hashp->MAX_BUCKET & hashp->LOW_MASK);
  
  	new_segnum = new_bucket >> hashp->SSHIFT;
  
  	/* Check if we need a new segment */
  	if (new_segnum >= hashp->nsegs) {
  		/* Check if we need to expand directory */
  		if (new_segnum >= hashp->DSIZE) {
  			/* Reallocate directory */
  			dirsize = hashp->DSIZE * sizeof(SEGMENT *);
  			if (!hash_realloc(&hashp->dir, dirsize, dirsize << 1))
  				return (-1);
  			hashp->DSIZE = dirsize << 1;
  		}
  		if ((hashp->dir[new_segnum] =
  		    (SEGMENT)calloc(hashp->SGSIZE, sizeof(SEGMENT))) == NULL)
  			return (-1);
  		hashp->exsegs++;
  		hashp->nsegs++;
  	}
  	/*
  	 * If the split point is increasing (MAX_BUCKET's log base 2
  	 * * increases), we need to copy the current contents of the spare
  	 * split bucket to the next bucket.
  	 */
  	spare_ndx = __log2(hashp->MAX_BUCKET + 1);
  	if (spare_ndx > hashp->OVFL_POINT) {
  		hashp->SPARES[spare_ndx] = hashp->SPARES[hashp->OVFL_POINT];
  		hashp->OVFL_POINT = spare_ndx;
  	}
  
  	if (new_bucket > hashp->HIGH_MASK) {
  		/* Starting a new doubling */
  		hashp->LOW_MASK = hashp->HIGH_MASK;
  		hashp->HIGH_MASK = new_bucket | hashp->LOW_MASK;
  	}
  	/* Relocate records to the new bucket */
  	return (__split_page(hashp, old_bucket, new_bucket));
  }
  
  /*
   * If realloc guarantees that the pointer is not destroyed if the realloc
   * fails, then this routine can go away.
   */
  static void *
  hash_realloc(
  	SEGMENT **p_ptr,
  	int oldsize, int newsize)
  {
  	register void *p;
  
  	if ((p = malloc(newsize))) {
  		memmove(p, *p_ptr, oldsize);
  		memset((char *)p + oldsize, 0, newsize - oldsize);
  		free(*p_ptr);
  		*p_ptr = (SEGMENT *)p;
  	}
  	return (p);
  }
  
  extern PRUint32
  __call_hash(HTAB *hashp, char *k, int len)
  {
  	PRUint32 n, bucket;
  
  	n = hashp->hash(k, len);
  	bucket = n & hashp->HIGH_MASK;
  	if (bucket > hashp->MAX_BUCKET)
  		bucket = bucket & hashp->LOW_MASK;
  	return (bucket);
  }
  
  /*
   * Allocate segment table.  On error, destroy the table and set errno.
   *
   * Returns 0 on success
   */
  static int
  alloc_segs(
  	HTAB *hashp,
  	int nsegs)
  {
  	register int i;
  	register SEGMENT store;
  
  	int save_errno;
  
  	if ((hashp->dir =
  	    (SEGMENT *)calloc(hashp->DSIZE, sizeof(SEGMENT *))) == NULL) {
  		save_errno = errno;
  		(void)hdestroy(hashp);
  		errno = save_errno;
  		return (-1);
  	}
  	/* Allocate segments */
  	if ((store =
  	    (SEGMENT)calloc(nsegs << hashp->SSHIFT, sizeof(SEGMENT))) == NULL) {
  		save_errno = errno;
  		(void)hdestroy(hashp);
  		errno = save_errno;
  		return (-1);
  	}
  	for (i = 0; i < nsegs; i++, hashp->nsegs++)
  		hashp->dir[i] = &store[i << hashp->SSHIFT];
  	return (0);
  }
  
  #if BYTE_ORDER == LITTLE_ENDIAN
  /*
   * Hashp->hdr needs to be byteswapped.
   */
  static void
  swap_header_copy(
  	HASHHDR *srcp, HASHHDR *destp)
  {
  	int i;
  
  	P_32_COPY(srcp->magic, destp->magic);
  	P_32_COPY(srcp->version, destp->version);
  	P_32_COPY(srcp->lorder, destp->lorder);
  	P_32_COPY(srcp->bsize, destp->bsize);
  	P_32_COPY(srcp->bshift, destp->bshift);
  	P_32_COPY(srcp->dsize, destp->dsize);
  	P_32_COPY(srcp->ssize, destp->ssize);
  	P_32_COPY(srcp->sshift, destp->sshift);
  	P_32_COPY(srcp->ovfl_point, destp->ovfl_point);
  	P_32_COPY(srcp->last_freed, destp->last_freed);
  	P_32_COPY(srcp->max_bucket, destp->max_bucket);
  	P_32_COPY(srcp->high_mask, destp->high_mask);
  	P_32_COPY(srcp->low_mask, destp->low_mask);
  	P_32_COPY(srcp->ffactor, destp->ffactor);
  	P_32_COPY(srcp->nkeys, destp->nkeys);
  	P_32_COPY(srcp->hdrpages, destp->hdrpages);
  	P_32_COPY(srcp->h_charkey, destp->h_charkey);
  	for (i = 0; i < NCACHED; i++) {
  		P_32_COPY(srcp->spares[i], destp->spares[i]);
  		P_16_COPY(srcp->bitmaps[i], destp->bitmaps[i]);
  	}
  }
  
  static void
  swap_header(HTAB *hashp)
  {
  	HASHHDR *hdrp;
  	int i;
  
  	hdrp = &hashp->hdr;
  
  	M_32_SWAP(hdrp->magic);
  	M_32_SWAP(hdrp->version);
  	M_32_SWAP(hdrp->lorder);
  	M_32_SWAP(hdrp->bsize);
  	M_32_SWAP(hdrp->bshift);
  	M_32_SWAP(hdrp->dsize);
  	M_32_SWAP(hdrp->ssize);
  	M_32_SWAP(hdrp->sshift);
  	M_32_SWAP(hdrp->ovfl_point);
  	M_32_SWAP(hdrp->last_freed);
  	M_32_SWAP(hdrp->max_bucket);
  	M_32_SWAP(hdrp->high_mask);
  	M_32_SWAP(hdrp->low_mask);
  	M_32_SWAP(hdrp->ffactor);
  	M_32_SWAP(hdrp->nkeys);
  	M_32_SWAP(hdrp->hdrpages);
  	M_32_SWAP(hdrp->h_charkey);
  	for (i = 0; i < NCACHED; i++) {
  		M_32_SWAP(hdrp->spares[i]);
  		M_16_SWAP(hdrp->bitmaps[i]);
  	}
  }
  #endif
  