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-rw-r--r--db/hash/hash.c994
1 files changed, 994 insertions, 0 deletions
diff --git a/db/hash/hash.c b/db/hash/hash.c
new file mode 100644
index 0000000000..4b7b732a8f
--- /dev/null
+++ b/db/hash/hash.c
@@ -0,0 +1,994 @@
+/*-
+ * 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 */
+
+#include <sys/param.h>
+#include <sys/stat.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#ifdef DEBUG
+#include <assert.h>
+#endif
+
+#include <db.h>
+#include "hash.h"
+#include "page.h"
+#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 *, u_int32_t));
+static int   hash_fd __P((const DB *));
+static int   hash_get __P((const DB *, const DBT *, DBT *, u_int32_t));
+static int   hash_put __P((const DB *, DBT *, const DBT *, u_int32_t));
+static void *hash_realloc __P((SEGMENT **, int, int));
+static int   hash_seq __P((const DB *, DBT *, DBT *, u_int32_t));
+static int   hash_sync __P((const DB *, u_int32_t));
+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
+
+/************************** INTERFACE ROUTINES ***************************/
+/* OPEN/CLOSE */
+
+extern DB *
+__hash_open(file, flags, mode, info, dflags)
+	const char *file;
+	int flags, mode, dflags;
+	const HASHINFO *info;	/* Special directives for create */
+{
+	HTAB *hashp;
+	struct stat statbuf;
+	DB *dbp;
+	int bpages, hdrsize, new_table, nsegs, save_errno;
+
+	if ((flags & O_ACCMODE) == O_WRONLY) {
+		errno = EINVAL;
+		return (NULL);
+	}
+
+	if (!(hashp = (HTAB *)calloc(1, sizeof(HTAB))))
+		return (NULL);
+	hashp->fp = -1;
+
+	/*
+	 * 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;
+
+	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;
+	}
+	if (file) {
+		if ((hashp->fp = open(file, flags, mode)) == -1)
+			RETURN_ERROR(errno, error0);
+		(void)fcntl(hashp->fp, F_SETFD, 1);
+	}
+	if (new_table) {
+		if (!(hashp = 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, &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);
+		/*
+		 * 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 (NULL);
+		/* 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(u_int32_t *));
+	}
+
+	/* Initialize Buffer Manager */
+	if (info && info->cachesize)
+		__buf_init(hashp, info->cachesize);
+	else
+		__buf_init(hashp, DEF_BUFSIZE);
+
+	hashp->new_file = new_table;
+	hashp->save_file = file && (hashp->flags & O_RDWR);
+	hashp->cbucket = -1;
+	if (!(dbp = (DB *)malloc(sizeof(DB)))) {
+		save_errno = errno;
+		hdestroy(hashp);
+		errno = save_errno;
+		return (NULL);
+	}
+	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;
+
+#ifdef DEBUG
+	(void)fprintf(stderr,
+"%s\n%s%x\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   ", 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
+#ifdef HASH_STATISTICS
+	hash_overflows = hash_accesses = hash_collisions = hash_expansions = 0;
+#endif
+	return (dbp);
+
+error1:
+	if (hashp != NULL)
+		(void)close(hashp->fp);
+
+error0:
+	free(hashp);
+	errno = save_errno;
+	return (NULL);
+}
+
+static int
+hash_close(dbp)
+	DB *dbp;
+{
+	HTAB *hashp;
+	int retval;
+
+	if (!dbp)
+		return (ERROR);
+
+	hashp = (HTAB *)dbp->internal;
+	retval = hdestroy(hashp);
+	free(dbp);
+	return (retval);
+}
+
+static int
+hash_fd(dbp)
+	const DB *dbp;
+{
+	HTAB *hashp;
+
+	if (!dbp)
+		return (ERROR);
+
+	hashp = (HTAB *)dbp->internal;
+	if (hashp->fp == -1) {
+		errno = ENOENT;
+		return (-1);
+	}
+	return (hashp->fp);
+}
+
+/************************** LOCAL CREATION ROUTINES **********************/
+static HTAB *
+init_hash(hashp, file, info)
+	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);
+		hashp->BSIZE = statbuf.st_blksize;
+		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);
+			}
+		}
+		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;
+		}
+	}
+	/* 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(hashp, nelem)
+	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(hashp)
+	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]);
+
+	if (hashp->fp != -1)
+		(void)close(hashp->fp);
+
+	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(dbp, flags)
+	const DB *dbp;
+	u_int32_t flags;
+{
+	HTAB *hashp;
+
+	if (flags != 0) {
+		errno = EINVAL;
+		return (ERROR);
+	}
+
+	if (!dbp)
+		return (ERROR);
+
+	hashp = (HTAB *)dbp->internal;
+	if (!hashp->save_file)
+		return (0);
+	if (__buf_free(hashp, 0, 1) || flush_meta(hashp))
+		return (ERROR);
+	hashp->new_file = 0;
+	return (0);
+}
+
+/*
+ * Returns:
+ *	 0 == OK
+ *	-1 indicates that errno should be set
+ */
+static int
+flush_meta(hashp)
+	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, whdrp, sizeof(HASHHDR))) == -1))
+		return (-1);
+	else
+		if (wsize != sizeof(HASHHDR)) {
+			errno = EFTYPE;
+			hashp->errno = 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(dbp, key, data, flag)
+	const DB *dbp;
+	const DBT *key;
+	DBT *data;
+	u_int32_t flag;
+{
+	HTAB *hashp;
+
+	hashp = (HTAB *)dbp->internal;
+	if (flag) {
+		hashp->errno = errno = EINVAL;
+		return (ERROR);
+	}
+	return (hash_access(hashp, HASH_GET, (DBT *)key, data));
+}
+
+static int
+hash_put(dbp, key, data, flag)
+	const DB *dbp;
+	DBT *key;
+	const DBT *data;
+	u_int32_t flag;
+{
+	HTAB *hashp;
+
+	hashp = (HTAB *)dbp->internal;
+	if (flag && flag != R_NOOVERWRITE) {
+		hashp->errno = errno = EINVAL;
+		return (ERROR);
+	}
+	if ((hashp->flags & O_ACCMODE) == O_RDONLY) {
+		hashp->errno = errno = EPERM;
+		return (ERROR);
+	}
+	return (hash_access(hashp, flag == R_NOOVERWRITE ?
+	    HASH_PUTNEW : HASH_PUT, (DBT *)key, (DBT *)data));
+}
+
+static int
+hash_delete(dbp, key, flag)
+	const DB *dbp;
+	const DBT *key;
+	u_int32_t flag;		/* Ignored */
+{
+	HTAB *hashp;
+
+	hashp = (HTAB *)dbp->internal;
+	if (flag && flag != R_CURSOR) {
+		hashp->errno = errno = EINVAL;
+		return (ERROR);
+	}
+	if ((hashp->flags & O_ACCMODE) == O_RDONLY) {
+		hashp->errno = errno = EPERM;
+		return (ERROR);
+	}
+	return (hash_access(hashp, HASH_DELETE, (DBT *)key, NULL));
+}
+
+/*
+ * Assume that hashp has been set in wrapper routine.
+ */
+static int
+hash_access(hashp, action, key, val)
+	HTAB *hashp;
+	ACTION action;
+	DBT *key, *val;
+{
+	register BUFHEAD *rbufp;
+	BUFHEAD *bufp, *save_bufp;
+	register u_int16_t *bp;
+	register int n, ndx, off, size;
+	register char *kp;
+	u_int16_t pageno;
+
+#ifdef HASH_STATISTICS
+	hash_accesses++;
+#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 (ERROR);
+	save_bufp = rbufp;
+
+	/* Pin the bucket chain */
+	rbufp->flags |= BUF_PIN;
+	for (bp = (u_int16_t *)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 = (u_int16_t *)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 = (u_int16_t *)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 = (u_int16_t *)rbufp->page;
+		if (bp[ndx + 1] < REAL_KEY) {
+			if (__big_return(hashp, rbufp, ndx, val, 0))
+				return (ERROR);
+		} else {
+			val->data = (u_char *)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(dbp, key, data, flag)
+	const DB *dbp;
+	DBT *key, *data;
+	u_int32_t flag;
+{
+	register u_int32_t bucket;
+	register BUFHEAD *bufp;
+	HTAB *hashp;
+	u_int16_t *bp, ndx;
+
+	hashp = (HTAB *)dbp->internal;
+	if (flag && flag != R_FIRST && flag != R_NEXT) {
+		hashp->errno = 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;
+	}
+
+	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)
+					return (ERROR);
+				hashp->cpage = bufp;
+				bp = (u_int16_t *)bufp->page;
+				if (bp[0])
+					break;
+			}
+			hashp->cbucket = bucket;
+			if (hashp->cbucket > hashp->MAX_BUCKET) {
+				hashp->cbucket = -1;
+				return (ABNORMAL);
+			}
+		} else
+			bp = (u_int16_t *)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)
+				return (ERROR);
+			bp = (u_int16_t *)(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))
+			return (ERROR);
+	} else {
+		key->data = (u_char *)hashp->cpage->page + bp[ndx];
+		key->size = (ndx > 1 ? bp[ndx - 1] : hashp->BSIZE) - bp[ndx];
+		data->data = (u_char *)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;
+	}
+	return (SUCCESS);
+}
+
+/********************************* UTILITIES ************************/
+
+/*
+ * Returns:
+ *	 0 ==> OK
+ *	-1 ==> Error
+ */
+extern int
+__expand_table(hashp)
+	HTAB *hashp;
+{
+	u_int32_t 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(p_ptr, oldsize, newsize)
+	SEGMENT **p_ptr;
+	int oldsize, 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 = p;
+	}
+	return (p);
+}
+
+extern u_int32_t
+__call_hash(hashp, k, len)
+	HTAB *hashp;
+	char *k;
+	int len;
+{
+	int 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(hashp, nsegs)
+	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(srcp, destp)
+	HASHHDR *srcp, *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(hashp)
+	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