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-rw-r--r--utils/db1-ast/hash/hash_bigkey.c668
1 files changed, 668 insertions, 0 deletions
diff --git a/utils/db1-ast/hash/hash_bigkey.c b/utils/db1-ast/hash/hash_bigkey.c
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+++ b/utils/db1-ast/hash/hash_bigkey.c
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+/*-
+ * 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_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
+ */
+
+#include <sys/param.h>
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifdef DEBUG
+#include <assert.h>
+#endif
+
+#include "../include/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(hashp, bufp, key, val)
+ HTAB *hashp;
+ BUFHEAD *bufp;
+ const DBT *key, *val;
+{
+ register u_int16_t *p;
+ int key_size, n, val_size;
+ u_int16_t space, move_bytes, off;
+ char *cp, *key_data, *val_data;
+
+ cp = bufp->page; /* Character pointer of p. */
+ p = (u_int16_t *)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 = 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 = 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 = (u_int16_t *)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 = 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 ((int) space == val_size && (size_t) 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 = (u_int16_t *)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(hashp, bufp)
+ HTAB *hashp;
+ BUFHEAD *bufp;
+{
+ register BUFHEAD *last_bfp, *rbufp;
+ u_int16_t *bp, pageno;
+ int key_done, n;
+
+ rbufp = bufp;
+ last_bfp = NULL;
+ bp = (u_int16_t *)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 = (u_int16_t *)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 = (u_int16_t *)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 && 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(hashp, bufp, ndx, key, size)
+ HTAB *hashp;
+ BUFHEAD *bufp;
+ int ndx;
+ char *key;
+ int size;
+{
+ register u_int16_t *bp;
+ register char *p;
+ int ksize;
+ u_int16_t bytes;
+ char *kkey;
+
+ bp = (u_int16_t *)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 = (u_int16_t *)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 u_int16_t
+__find_last_page(hashp, bpp)
+ HTAB *hashp;
+ BUFHEAD **bpp;
+{
+ BUFHEAD *bufp;
+ u_int16_t *bp, pageno;
+ int n;
+
+ bufp = *bpp;
+ bp = (u_int16_t *)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;
+
+ pageno = bp[n - 1];
+ bufp = __get_buf(hashp, pageno, bufp, 0);
+ if (!bufp)
+ return (0); /* Need to indicate an error! */
+ bp = (u_int16_t *)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(hashp, bufp, ndx, val, set_current)
+ HTAB *hashp;
+ BUFHEAD *bufp;
+ int ndx;
+ DBT *val;
+ int set_current;
+{
+ BUFHEAD *save_p;
+ u_int16_t *bp, len, off, save_addr;
+ char *tp;
+
+ bp = (u_int16_t *)bufp->page;
+ while (bp[ndx + 1] == PARTIAL_KEY) {
+ bufp = __get_buf(hashp, bp[bp[0] - 1], bufp, 0);
+ if (!bufp)
+ return (-1);
+ bp = (u_int16_t *)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 = (u_int16_t *)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 = (u_int16_t *)bufp->page;
+ } else {
+ /* The data is all on one page. */
+ tp = (char *)bp;
+ off = bp[bp[0]];
+ val->data = (u_char *)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 (!((u_int16_t *)
+ hashp->cpage->page)[0]) {
+ hashp->cbucket++;
+ hashp->cpage = NULL;
+ }
+ }
+ }
+ return (0);
+ }
+
+ val->size = collect_data(hashp, bufp, (int)len, set_current);
+ 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 = (u_char *)hashp->tmp_buf;
+ return (0);
+}
+/*
+ * Count how big the total datasize is by recursing through the pages. Then
+ * allocate a buffer and copy the data as you recurse up.
+ */
+static int
+collect_data(hashp, bufp, len, set)
+ HTAB *hashp;
+ BUFHEAD *bufp;
+ int len, set;
+{
+ register u_int16_t *bp;
+ register char *p;
+ BUFHEAD *xbp;
+ u_int16_t save_addr;
+ int mylen, totlen;
+
+ p = bufp->page;
+ bp = (u_int16_t *)p;
+ mylen = hashp->BSIZE - bp[1];
+ save_addr = bufp->addr;
+
+ if (bp[2] == FULL_KEY_DATA) { /* End of Data */
+ totlen = len + mylen;
+ if (hashp->tmp_buf)
+ free(hashp->tmp_buf);
+ if ((hashp->tmp_buf = (char *)malloc(totlen)) == NULL)
+ return (-1);
+ 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 (!((u_int16_t *)hashp->cpage->page)[0]) {
+ hashp->cbucket++;
+ hashp->cpage = NULL;
+ }
+ }
+ }
+ } else {
+ xbp = __get_buf(hashp, bp[bp[0] - 1], bufp, 0);
+ if (!xbp || ((totlen =
+ collect_data(hashp, xbp, len + mylen, set)) < 1))
+ return (-1);
+ }
+ if (bufp->addr != save_addr) {
+ errno = EINVAL; /* Out of buffers. */
+ return (-1);
+ }
+ memmove(&hashp->tmp_buf[len], (bufp->page) + bp[1], mylen);
+ return (totlen);
+}
+
+/*
+ * Fill in the key and data for this big pair.
+ */
+extern int
+__big_keydata(hashp, bufp, key, val, set)
+ HTAB *hashp;
+ BUFHEAD *bufp;
+ DBT *key, *val;
+ int set;
+{
+ key->size = collect_key(hashp, bufp, 0, val, set);
+ if (key->size == (size_t) -1)
+ return (-1);
+ key->data = (u_char *)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(hashp, bufp, len, val, set)
+ HTAB *hashp;
+ BUFHEAD *bufp;
+ int len;
+ DBT *val;
+ int set;
+{
+ BUFHEAD *xbp;
+ char *p;
+ int mylen, totlen;
+ u_int16_t *bp, save_addr;
+
+ p = bufp->page;
+ bp = (u_int16_t *)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(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], mylen);
+ return (totlen);
+}
+
+/*
+ * Returns:
+ * 0 => OK
+ * -1 => error
+ */
+extern int
+__big_split(hashp, op, np, big_keyp, addr, obucket, ret)
+ 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;
+ int addr; /* Address of big_keyp */
+ u_int32_t obucket;/* Old Bucket */
+ SPLIT_RETURN *ret;
+{
+ register BUFHEAD *tmpp;
+ register u_int16_t *tp;
+ BUFHEAD *bp;
+ DBT key, val;
+ u_int32_t change;
+ u_int16_t 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, 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 = (u_int16_t *)tmpp->page;
+#ifdef DEBUG
+ assert(FREESPACE(tp) >= OVFLSIZE);
+#endif
+ n = tp[0];
+ off = OFFSET(tp);
+ free_space = FREESPACE(tp);
+ tp[++n] = (u_int16_t)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 = (u_int16_t *)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);
+}