--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nss/lib/dbm/src/h_bigkey.c	Tue Aug 05 18:32:02 2014 +0200
@@ -0,0 +1,709 @@
+/*-
+ * 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. ***REMOVED*** - see 
+ *    ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change
+ * 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_bigkey.c	8.3 (Berkeley) 5/31/94";
+#endif /* LIBC_SCCS and not lint */
+
+/*
+ * PACKAGE: hash
+ * DESCRIPTION:
+ *	Big key/data handling for the hashing package.
+ *
+ * ROUTINES:
+ * External
+ *	__big_keydata
+ *	__big_split
+ *	__big_insert
+ *	__big_return
+ *	__big_delete
+ *	__find_last_page
+ * Internal
+ *	collect_key
+ *	collect_data
+ */
+
+#if !defined(_WIN32) && !defined(_WINDOWS) && !defined(macintosh)
+#include <sys/param.h>
+#endif
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifdef DEBUG
+#include <assert.h>
+#endif
+
+#include "mcom_db.h"
+#include "hash.h"
+#include "page.h"
+/* #include "extern.h" */
+
+static int collect_key __P((HTAB *, BUFHEAD *, int, DBT *, int));
+static int collect_data __P((HTAB *, BUFHEAD *, int, int));
+
+/*
+ * Big_insert
+ *
+ * You need to do an insert and the key/data pair is too big
+ *
+ * Returns:
+ * 0 ==> OK
+ *-1 ==> ERROR
+ */
+extern int
+__big_insert(HTAB *hashp, BUFHEAD *bufp, const DBT *key, const DBT *val)
+{
+	register uint16 *p;
+	uint key_size, n, val_size;
+	uint16 space, move_bytes, off;
+	char *cp, *key_data, *val_data;
+
+	cp = bufp->page;		/* Character pointer of p. */
+	p = (uint16 *)cp;
+
+	key_data = (char *)key->data;
+	key_size = key->size;
+	val_data = (char *)val->data;
+	val_size = val->size;
+
+	/* First move the Key */
+	for (space = FREESPACE(p) - BIGOVERHEAD; key_size;
+	    space = FREESPACE(p) - BIGOVERHEAD) {
+		move_bytes = PR_MIN(space, key_size);
+		off = OFFSET(p) - move_bytes;
+		memmove(cp + off, key_data, move_bytes);
+		key_size -= move_bytes;
+		key_data += move_bytes;
+		n = p[0];
+		p[++n] = off;
+		p[0] = ++n;
+		FREESPACE(p) = off - PAGE_META(n);
+		OFFSET(p) = off;
+		p[n] = PARTIAL_KEY;
+		bufp = __add_ovflpage(hashp, bufp);
+		if (!bufp)
+			return (-1);
+		n = p[0];
+		if (!key_size) {
+			if (FREESPACE(p)) {
+				move_bytes = PR_MIN(FREESPACE(p), val_size);
+				off = OFFSET(p) - move_bytes;
+				p[n] = off;
+				memmove(cp + off, val_data, move_bytes);
+				val_data += move_bytes;
+				val_size -= move_bytes;
+				p[n - 2] = FULL_KEY_DATA;
+				FREESPACE(p) = FREESPACE(p) - move_bytes;
+				OFFSET(p) = off;
+			} else
+				p[n - 2] = FULL_KEY;
+		}
+		p = (uint16 *)bufp->page;
+		cp = bufp->page;
+		bufp->flags |= BUF_MOD;
+	}
+
+	/* Now move the data */
+	for (space = FREESPACE(p) - BIGOVERHEAD; val_size;
+	    space = FREESPACE(p) - BIGOVERHEAD) {
+		move_bytes = PR_MIN(space, val_size);
+		/*
+		 * Here's the hack to make sure that if the data ends on the
+		 * same page as the key ends, FREESPACE is at least one.
+		 */
+		if (space == val_size && val_size == val->size)
+			move_bytes--;
+		off = OFFSET(p) - move_bytes;
+		memmove(cp + off, val_data, move_bytes);
+		val_size -= move_bytes;
+		val_data += move_bytes;
+		n = p[0];
+		p[++n] = off;
+		p[0] = ++n;
+		FREESPACE(p) = off - PAGE_META(n);
+		OFFSET(p) = off;
+		if (val_size) {
+			p[n] = FULL_KEY;
+			bufp = __add_ovflpage(hashp, bufp);
+			if (!bufp)
+				return (-1);
+			cp = bufp->page;
+			p = (uint16 *)cp;
+		} else
+			p[n] = FULL_KEY_DATA;
+		bufp->flags |= BUF_MOD;
+	}
+	return (0);
+}
+
+/*
+ * Called when bufp's page  contains a partial key (index should be 1)
+ *
+ * All pages in the big key/data pair except bufp are freed.  We cannot
+ * free bufp because the page pointing to it is lost and we can't get rid
+ * of its pointer.
+ *
+ * Returns:
+ * 0 => OK
+ *-1 => ERROR
+ */
+extern int
+__big_delete(HTAB *hashp, BUFHEAD *bufp)
+{
+	register BUFHEAD *last_bfp, *rbufp;
+	uint16 *bp, pageno;
+	int key_done, n;
+
+	rbufp = bufp;
+	last_bfp = NULL;
+	bp = (uint16 *)bufp->page;
+	pageno = 0;
+	key_done = 0;
+
+	while (!key_done || (bp[2] != FULL_KEY_DATA)) {
+		if (bp[2] == FULL_KEY || bp[2] == FULL_KEY_DATA)
+			key_done = 1;
+
+		/*
+		 * If there is freespace left on a FULL_KEY_DATA page, then
+		 * the data is short and fits entirely on this page, and this
+		 * is the last page.
+		 */
+		if (bp[2] == FULL_KEY_DATA && FREESPACE(bp))
+			break;
+		pageno = bp[bp[0] - 1];
+		rbufp->flags |= BUF_MOD;
+		rbufp = __get_buf(hashp, pageno, rbufp, 0);
+		if (last_bfp)
+			__free_ovflpage(hashp, last_bfp);
+		last_bfp = rbufp;
+		if (!rbufp)
+			return (-1);		/* Error. */
+		bp = (uint16 *)rbufp->page;
+	}
+
+	/*
+	 * If we get here then rbufp points to the last page of the big
+	 * key/data pair.  Bufp points to the first one -- it should now be
+	 * empty pointing to the next page after this pair.  Can't free it
+	 * because we don't have the page pointing to it.
+	 */
+
+	/* This is information from the last page of the pair. */
+	n = bp[0];
+	pageno = bp[n - 1];
+
+	/* Now, bp is the first page of the pair. */
+	bp = (uint16 *)bufp->page;
+	if (n > 2) {
+		/* There is an overflow page. */
+		bp[1] = pageno;
+		bp[2] = OVFLPAGE;
+		bufp->ovfl = rbufp->ovfl;
+	} else
+		/* This is the last page. */
+		bufp->ovfl = NULL;
+	n -= 2;
+	bp[0] = n;
+	FREESPACE(bp) = hashp->BSIZE - PAGE_META(n);
+	OFFSET(bp) = hashp->BSIZE - 1;
+
+	bufp->flags |= BUF_MOD;
+	if (rbufp)
+		__free_ovflpage(hashp, rbufp);
+	if (last_bfp != rbufp)
+		__free_ovflpage(hashp, last_bfp);
+
+	hashp->NKEYS--;
+	return (0);
+}
+/*
+ * Returns:
+ *  0 = key not found
+ * -1 = get next overflow page
+ * -2 means key not found and this is big key/data
+ * -3 error
+ */
+extern int
+__find_bigpair(HTAB *hashp, BUFHEAD *bufp, int ndx, char *key, int size)
+{
+	register uint16 *bp;
+	register char *p;
+	int ksize;
+	uint16 bytes;
+	char *kkey;
+
+	bp = (uint16 *)bufp->page;
+	p = bufp->page;
+	ksize = size;
+	kkey = key;
+
+	for (bytes = hashp->BSIZE - bp[ndx];
+	    bytes <= size && bp[ndx + 1] == PARTIAL_KEY;
+	    bytes = hashp->BSIZE - bp[ndx]) {
+		if (memcmp(p + bp[ndx], kkey, bytes))
+			return (-2);
+		kkey += bytes;
+		ksize -= bytes;
+		bufp = __get_buf(hashp, bp[ndx + 2], bufp, 0);
+		if (!bufp)
+			return (-3);
+		p = bufp->page;
+		bp = (uint16 *)p;
+		ndx = 1;
+	}
+
+	if (bytes != ksize || memcmp(p + bp[ndx], kkey, bytes)) {
+#ifdef HASH_STATISTICS
+		++hash_collisions;
+#endif
+		return (-2);
+	} else
+		return (ndx);
+}
+
+/*
+ * Given the buffer pointer of the first overflow page of a big pair,
+ * find the end of the big pair
+ *
+ * This will set bpp to the buffer header of the last page of the big pair.
+ * It will return the pageno of the overflow page following the last page
+ * of the pair; 0 if there isn't any (i.e. big pair is the last key in the
+ * bucket)
+ */
+extern uint16
+__find_last_page(HTAB *hashp, BUFHEAD **bpp)
+{
+	BUFHEAD *bufp;
+	uint16 *bp, pageno;
+	uint n;
+
+	bufp = *bpp;
+	bp = (uint16 *)bufp->page;
+	for (;;) {
+		n = bp[0];
+
+		/*
+		 * This is the last page if: the tag is FULL_KEY_DATA and
+		 * either only 2 entries OVFLPAGE marker is explicit there
+		 * is freespace on the page.
+		 */
+		if (bp[2] == FULL_KEY_DATA &&
+		    ((n == 2) || (bp[n] == OVFLPAGE) || (FREESPACE(bp))))
+			break;
+
+		/* LJM bound the size of n to reasonable limits
+		 */
+		if(n > hashp->BSIZE/sizeof(uint16))
+			return(0);
+
+		pageno = bp[n - 1];
+		bufp = __get_buf(hashp, pageno, bufp, 0);
+		if (!bufp)
+			return (0);	/* Need to indicate an error! */
+		bp = (uint16 *)bufp->page;
+	}
+
+	*bpp = bufp;
+	if (bp[0] > 2)
+		return (bp[3]);
+	else
+		return (0);
+}
+
+/*
+ * Return the data for the key/data pair that begins on this page at this
+ * index (index should always be 1).
+ */
+extern int
+__big_return(
+	HTAB *hashp,
+	BUFHEAD *bufp,
+	int ndx,
+	DBT *val,
+	int set_current)
+{
+	BUFHEAD *save_p;
+	uint16 *bp, len, off, save_addr;
+	char *tp;
+	int save_flags;
+
+	bp = (uint16 *)bufp->page;
+	while (bp[ndx + 1] == PARTIAL_KEY) {
+		bufp = __get_buf(hashp, bp[bp[0] - 1], bufp, 0);
+		if (!bufp)
+			return (-1);
+		bp = (uint16 *)bufp->page;
+		ndx = 1;
+	}
+
+	if (bp[ndx + 1] == FULL_KEY) {
+		bufp = __get_buf(hashp, bp[bp[0] - 1], bufp, 0);
+		if (!bufp)
+			return (-1);
+		bp = (uint16 *)bufp->page;
+		save_p = bufp;
+		save_addr = save_p->addr;
+		off = bp[1];
+		len = 0;
+	} else
+		if (!FREESPACE(bp)) {
+			/*
+			 * This is a hack.  We can't distinguish between
+			 * FULL_KEY_DATA that contains complete data or
+			 * incomplete data, so we require that if the data
+			 * is complete, there is at least 1 byte of free
+			 * space left.
+			 */
+			off = bp[bp[0]];
+			len = bp[1] - off;
+			save_p = bufp;
+			save_addr = bufp->addr;
+			bufp = __get_buf(hashp, bp[bp[0] - 1], bufp, 0);
+			if (!bufp)
+				return (-1);
+			bp = (uint16 *)bufp->page;
+		} else {
+			/* The data is all on one page. */
+			tp = (char *)bp;
+			off = bp[bp[0]];
+			val->data = (uint8 *)tp + off;
+			val->size = bp[1] - off;
+			if (set_current) {
+				if (bp[0] == 2) {	/* No more buckets in
+							 * chain */
+					hashp->cpage = NULL;
+					hashp->cbucket++;
+					hashp->cndx = 1;
+				} else {
+					hashp->cpage = __get_buf(hashp,
+					    bp[bp[0] - 1], bufp, 0);
+					if (!hashp->cpage)
+						return (-1);
+					hashp->cndx = 1;
+					if (!((uint16 *)
+					    hashp->cpage->page)[0]) {
+						hashp->cbucket++;
+						hashp->cpage = NULL;
+					}
+				}
+			}
+			return (0);
+		}
+
+	/* pin our saved buf so that we don't lose if 
+	 * we run out of buffers */
+ 	save_flags = save_p->flags;
+	save_p->flags |= BUF_PIN;
+	val->size = collect_data(hashp, bufp, (int)len, set_current);
+	save_p->flags = save_flags;
+	if (val->size == (size_t)-1)
+		return (-1);
+	if (save_p->addr != save_addr) {
+		/* We are pretty short on buffers. */
+		errno = EINVAL;			/* OUT OF BUFFERS */
+		return (-1);
+	}
+	memmove(hashp->tmp_buf, (save_p->page) + off, len);
+	val->data = (uint8 *)hashp->tmp_buf;
+	return (0);
+}
+
+
+/*
+ * Count how big the total datasize is by looping through the pages.  Then
+ * allocate a buffer and copy the data in the second loop. NOTE: Our caller
+ * may already have a bp which it is holding onto. The caller is
+ * responsible for copying that bp into our temp buffer. 'len' is how much
+ * space to reserve for that buffer.
+ */
+static int
+collect_data(
+	HTAB *hashp,
+	BUFHEAD *bufp,
+	int len, int set)
+{
+	register uint16 *bp;
+	BUFHEAD *save_bufp;
+	int save_flags;
+	int mylen, totlen;
+
+	/*
+	 * save the input buf head because we need to walk the list twice.
+	 * pin it to make sure it doesn't leave the buffer pool. 
+	 * This has the effect of growing the buffer pool if necessary.
+	 */
+	save_bufp = bufp;
+	save_flags = save_bufp->flags;
+	save_bufp->flags |= BUF_PIN;
+
+	/* read the length of the buffer */
+	for (totlen = len; bufp ; bufp = __get_buf(hashp, bp[bp[0]-1], bufp, 0)) {
+		bp = (uint16 *)bufp->page;
+		mylen = hashp->BSIZE - bp[1];
+
+		/* if mylen ever goes negative it means that the
+		 * page is screwed up.
+		 */
+		if (mylen < 0) {
+			save_bufp->flags = save_flags;
+			return (-1);
+ 		}
+		totlen += mylen;
+		if (bp[2] == FULL_KEY_DATA) {		/* End of Data */
+			break;
+		}
+	}
+
+ 	if (!bufp) {
+		save_bufp->flags = save_flags;
+		return (-1);
+	}
+
+	/* allocate a temp buf */
+	if (hashp->tmp_buf)
+		free(hashp->tmp_buf);
+	if ((hashp->tmp_buf = (char *)malloc((size_t)totlen)) == NULL) {
+		save_bufp->flags = save_flags;
+		return (-1);
+ 	}
+
+	/* copy the buffers back into temp buf */
+	for (bufp = save_bufp; bufp ;
+				bufp = __get_buf(hashp, bp[bp[0]-1], bufp, 0)) {
+		bp = (uint16 *)bufp->page;
+		mylen = hashp->BSIZE - bp[1];
+		memmove(&hashp->tmp_buf[len], (bufp->page) + bp[1], (size_t)mylen);
+		len += mylen;
+		if (bp[2] == FULL_KEY_DATA) {
+			break;
+		}
+	}
+
+	/* 'clear' the pin flags */
+	save_bufp->flags = save_flags;
+
+	/* update the database cursor */
+	if (set) {
+		hashp->cndx = 1;
+		if (bp[0] == 2) {	/* No more buckets in chain */
+			hashp->cpage = NULL;
+			hashp->cbucket++;
+		} else {
+			hashp->cpage = __get_buf(hashp, bp[bp[0] - 1], bufp, 0);
+			if (!hashp->cpage)
+				return (-1);
+			else if (!((uint16 *)hashp->cpage->page)[0]) {
+				hashp->cbucket++;
+				hashp->cpage = NULL;
+			}
+		}
+	}
+	return (totlen);
+}
+
+/*
+ * Fill in the key and data for this big pair.
+ */
+extern int
+__big_keydata(
+	HTAB *hashp, 
+	BUFHEAD *bufp, 
+	DBT *key, DBT *val,
+	int set)
+{
+	key->size = collect_key(hashp, bufp, 0, val, set);
+	if (key->size == (size_t)-1)
+		return (-1);
+	key->data = (uint8 *)hashp->tmp_key;
+	return (0);
+}
+
+/*
+ * Count how big the total key size is by recursing through the pages.  Then
+ * collect the data, allocate a buffer and copy the key as you recurse up.
+ */
+static int
+collect_key(
+	HTAB *hashp,
+	BUFHEAD *bufp,
+	int len,
+	DBT *val,
+	int set)
+{
+	BUFHEAD *xbp;
+	char *p;
+	int mylen, totlen;
+	uint16 *bp, save_addr;
+
+	p = bufp->page;
+	bp = (uint16 *)p;
+	mylen = hashp->BSIZE - bp[1];
+
+	save_addr = bufp->addr;
+	totlen = len + mylen;
+	if (bp[2] == FULL_KEY || bp[2] == FULL_KEY_DATA) {    /* End of Key. */
+		if (hashp->tmp_key != NULL)
+			free(hashp->tmp_key);
+		if ((hashp->tmp_key = (char *)malloc((size_t)totlen)) == NULL)
+			return (-1);
+		if (__big_return(hashp, bufp, 1, val, set))
+			return (-1);
+	} else {
+		xbp = __get_buf(hashp, bp[bp[0] - 1], bufp, 0);
+		if (!xbp || ((totlen =
+		    collect_key(hashp, xbp, totlen, val, set)) < 1))
+			return (-1);
+	}
+	if (bufp->addr != save_addr) {
+		errno = EINVAL;		/* MIS -- OUT OF BUFFERS */
+		return (-1);
+	}
+	memmove(&hashp->tmp_key[len], (bufp->page) + bp[1], (size_t)mylen);
+	return (totlen);
+}
+
+/*
+ * Returns:
+ *  0 => OK
+ * -1 => error
+ */
+extern int
+__big_split(
+	HTAB *hashp,
+	BUFHEAD *op,	/* Pointer to where to put keys that go in old bucket */
+	BUFHEAD *np,	/* Pointer to new bucket page */
+			/* Pointer to first page containing the big key/data */
+	BUFHEAD *big_keyp,
+	uint32 addr,	/* Address of big_keyp */
+	uint32   obucket,/* Old Bucket */
+	SPLIT_RETURN *ret)
+{
+	register BUFHEAD *tmpp;
+	register uint16 *tp;
+	BUFHEAD *bp;
+	DBT key, val;
+	uint32 change;
+	uint16 free_space, n, off;
+
+	bp = big_keyp;
+
+	/* Now figure out where the big key/data goes */
+	if (__big_keydata(hashp, big_keyp, &key, &val, 0))
+		return (-1);
+	change = (__call_hash(hashp,(char*) key.data, key.size) != obucket);
+
+	if ((ret->next_addr = __find_last_page(hashp, &big_keyp))) {
+		if (!(ret->nextp =
+		    __get_buf(hashp, ret->next_addr, big_keyp, 0)))
+			return (-1);;
+	} else
+		ret->nextp = NULL;
+
+	/* Now make one of np/op point to the big key/data pair */
+#ifdef DEBUG
+	assert(np->ovfl == NULL);
+#endif
+	if (change)
+		tmpp = np;
+	else
+		tmpp = op;
+
+	tmpp->flags |= BUF_MOD;
+#ifdef DEBUG1
+	(void)fprintf(stderr,
+	    "BIG_SPLIT: %d->ovfl was %d is now %d\n", tmpp->addr,
+	    (tmpp->ovfl ? tmpp->ovfl->addr : 0), (bp ? bp->addr : 0));
+#endif
+	tmpp->ovfl = bp;	/* one of op/np point to big_keyp */
+	tp = (uint16 *)tmpp->page;
+
+
+#if 0  /* this get's tripped on database corrupted error */
+	assert(FREESPACE(tp) >= OVFLSIZE);
+#endif
+	if(FREESPACE(tp) < OVFLSIZE)
+		return(DATABASE_CORRUPTED_ERROR);
+
+	n = tp[0];
+	off = OFFSET(tp);
+	free_space = FREESPACE(tp);
+	tp[++n] = (uint16)addr;
+	tp[++n] = OVFLPAGE;
+	tp[0] = n;
+	OFFSET(tp) = off;
+	FREESPACE(tp) = free_space - OVFLSIZE;
+
+	/*
+	 * Finally, set the new and old return values. BIG_KEYP contains a
+	 * pointer to the last page of the big key_data pair. Make sure that
+	 * big_keyp has no following page (2 elements) or create an empty
+	 * following page.
+	 */
+
+	ret->newp = np;
+	ret->oldp = op;
+
+	tp = (uint16 *)big_keyp->page;
+	big_keyp->flags |= BUF_MOD;
+	if (tp[0] > 2) {
+		/*
+		 * There may be either one or two offsets on this page.  If
+		 * there is one, then the overflow page is linked on normally
+		 * and tp[4] is OVFLPAGE.  If there are two, tp[4] contains
+		 * the second offset and needs to get stuffed in after the
+		 * next overflow page is added.
+		 */
+		n = tp[4];
+		free_space = FREESPACE(tp);
+		off = OFFSET(tp);
+		tp[0] -= 2;
+		FREESPACE(tp) = free_space + OVFLSIZE;
+		OFFSET(tp) = off;
+		tmpp = __add_ovflpage(hashp, big_keyp);
+		if (!tmpp)
+			return (-1);
+		tp[4] = n;
+	} else
+		tmpp = big_keyp;
+
+	if (change)
+		ret->newp = tmpp;
+	else
+		ret->oldp = tmpp;
+	return (0);
+}