aboutsummaryrefslogtreecommitdiffstats
path: root/1.2-netsec/db1-ast/hash/hash_page.c
diff options
context:
space:
mode:
Diffstat (limited to '1.2-netsec/db1-ast/hash/hash_page.c')
-rw-r--r--1.2-netsec/db1-ast/hash/hash_page.c944
1 files changed, 0 insertions, 944 deletions
diff --git a/1.2-netsec/db1-ast/hash/hash_page.c b/1.2-netsec/db1-ast/hash/hash_page.c
deleted file mode 100644
index 1429dd6c3..000000000
--- a/1.2-netsec/db1-ast/hash/hash_page.c
+++ /dev/null
@@ -1,944 +0,0 @@
-/*-
- * 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_page.c 8.7 (Berkeley) 8/16/94";
-#endif /* LIBC_SCCS and not lint */
-
-/*
- * PACKAGE: hashing
- *
- * DESCRIPTION:
- * Page manipulation for hashing package.
- *
- * ROUTINES:
- *
- * External
- * __get_page
- * __add_ovflpage
- * Internal
- * overflow_page
- * open_temp
- */
-
-#include <sys/types.h>
-
-#include <errno.h>
-#include <fcntl.h>
-#include <signal.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 u_int32_t *fetch_bitmap __P((HTAB *, int));
-static u_int32_t first_free __P((u_int32_t));
-static int open_temp __P((HTAB *));
-static u_int16_t overflow_page __P((HTAB *));
-static void putpair __P((char *, const DBT *, const DBT *));
-static void squeeze_key __P((u_int16_t *, const DBT *, const DBT *));
-static int ugly_split
- __P((HTAB *, u_int32_t, BUFHEAD *, BUFHEAD *, int, int));
-
-#define PAGE_INIT(P) { \
- ((u_int16_t *)(P))[0] = 0; \
- ((u_int16_t *)(P))[1] = hashp->BSIZE - 3 * sizeof(u_int16_t); \
- ((u_int16_t *)(P))[2] = hashp->BSIZE; \
-}
-
-/*
- * This is called AFTER we have verified that there is room on the page for
- * the pair (PAIRFITS has returned true) so we go right ahead and start moving
- * stuff on.
- */
-static void
-putpair(p, key, val)
- char *p;
- const DBT *key, *val;
-{
- register u_int16_t *bp, n, off;
-
- bp = (u_int16_t *)p;
-
- /* Enter the key first. */
- n = bp[0];
-
- off = OFFSET(bp) - key->size;
- memmove(p + off, key->data, key->size);
- bp[++n] = off;
-
- /* Now the data. */
- off -= val->size;
- memmove(p + off, val->data, val->size);
- bp[++n] = off;
-
- /* Adjust page info. */
- bp[0] = n;
- bp[n + 1] = off - ((n + 3) * sizeof(u_int16_t));
- bp[n + 2] = off;
-}
-
-/*
- * Returns:
- * 0 OK
- * -1 error
- */
-extern int
-__delpair(hashp, bufp, ndx)
- HTAB *hashp;
- BUFHEAD *bufp;
- register int ndx;
-{
- register u_int16_t *bp, newoff;
- register int n;
- u_int16_t pairlen;
-
- bp = (u_int16_t *)bufp->page;
- n = bp[0];
-
- if (bp[ndx + 1] < REAL_KEY)
- return (__big_delete(hashp, bufp));
- if (ndx != 1)
- newoff = bp[ndx - 1];
- else
- newoff = hashp->BSIZE;
- pairlen = newoff - bp[ndx + 1];
-
- if (ndx != (n - 1)) {
- /* Hard Case -- need to shuffle keys */
- register int i;
- register char *src = bufp->page + (int)OFFSET(bp);
- register char *dst = src + (int)pairlen;
- memmove(dst, src, bp[ndx + 1] - OFFSET(bp));
-
- /* Now adjust the pointers */
- for (i = ndx + 2; i <= n; i += 2) {
- if (bp[i + 1] == OVFLPAGE) {
- bp[i - 2] = bp[i];
- bp[i - 1] = bp[i + 1];
- } else {
- bp[i - 2] = bp[i] + pairlen;
- bp[i - 1] = bp[i + 1] + pairlen;
- }
- }
- }
- /* Finally adjust the page data */
- bp[n] = OFFSET(bp) + pairlen;
- bp[n - 1] = bp[n + 1] + pairlen + 2 * sizeof(u_int16_t);
- bp[0] = n - 2;
- hashp->NKEYS--;
-
- bufp->flags |= BUF_MOD;
- return (0);
-}
-/*
- * Returns:
- * 0 ==> OK
- * -1 ==> Error
- */
-extern int
-__split_page(hashp, obucket, nbucket)
- HTAB *hashp;
- u_int32_t obucket, nbucket;
-{
- register BUFHEAD *new_bufp, *old_bufp;
- register u_int16_t *ino;
- register char *np;
- DBT key, val;
- int n, ndx, retval;
- u_int16_t copyto, diff, off, moved;
- char *op;
-
- copyto = (u_int16_t)hashp->BSIZE;
- off = (u_int16_t)hashp->BSIZE;
- old_bufp = __get_buf(hashp, obucket, NULL, 0);
- if (old_bufp == NULL)
- return (-1);
- new_bufp = __get_buf(hashp, nbucket, NULL, 0);
- if (new_bufp == NULL)
- return (-1);
-
- old_bufp->flags |= (BUF_MOD | BUF_PIN);
- new_bufp->flags |= (BUF_MOD | BUF_PIN);
-
- ino = (u_int16_t *)(op = old_bufp->page);
- np = new_bufp->page;
-
- moved = 0;
-
- for (n = 1, ndx = 1; n < ino[0]; n += 2) {
- if (ino[n + 1] < REAL_KEY) {
- retval = ugly_split(hashp, obucket, old_bufp, new_bufp,
- (int)copyto, (int)moved);
- old_bufp->flags &= ~BUF_PIN;
- new_bufp->flags &= ~BUF_PIN;
- return (retval);
-
- }
- key.data = (u_char *)op + ino[n];
- key.size = off - ino[n];
-
- if (__call_hash(hashp, key.data, key.size) == obucket) {
- /* Don't switch page */
- diff = copyto - off;
- if (diff) {
- copyto = ino[n + 1] + diff;
- memmove(op + copyto, op + ino[n + 1],
- off - ino[n + 1]);
- ino[ndx] = copyto + ino[n] - ino[n + 1];
- ino[ndx + 1] = copyto;
- } else
- copyto = ino[n + 1];
- ndx += 2;
- } else {
- /* Switch page */
- val.data = (u_char *)op + ino[n + 1];
- val.size = ino[n] - ino[n + 1];
- putpair(np, &key, &val);
- moved += 2;
- }
-
- off = ino[n + 1];
- }
-
- /* Now clean up the page */
- ino[0] -= moved;
- FREESPACE(ino) = copyto - sizeof(u_int16_t) * (ino[0] + 3);
- OFFSET(ino) = copyto;
-
-#ifdef DEBUG3
- (void)fprintf(stderr, "split %d/%d\n",
- ((u_int16_t *)np)[0] / 2,
- ((u_int16_t *)op)[0] / 2);
-#endif
- /* unpin both pages */
- old_bufp->flags &= ~BUF_PIN;
- new_bufp->flags &= ~BUF_PIN;
- return (0);
-}
-
-/*
- * Called when we encounter an overflow or big key/data page during split
- * handling. This is special cased since we have to begin checking whether
- * the key/data pairs fit on their respective pages and because we may need
- * overflow pages for both the old and new pages.
- *
- * The first page might be a page with regular key/data pairs in which case
- * we have a regular overflow condition and just need to go on to the next
- * page or it might be a big key/data pair in which case we need to fix the
- * big key/data pair.
- *
- * Returns:
- * 0 ==> success
- * -1 ==> failure
- */
-static int
-ugly_split(hashp, obucket, old_bufp, new_bufp, copyto, moved)
- HTAB *hashp;
- u_int32_t obucket; /* Same as __split_page. */
- BUFHEAD *old_bufp, *new_bufp;
- int copyto; /* First byte on page which contains key/data values. */
- int moved; /* Number of pairs moved to new page. */
-{
- register BUFHEAD *bufp; /* Buffer header for ino */
- register u_int16_t *ino; /* Page keys come off of */
- register u_int16_t *np; /* New page */
- register u_int16_t *op; /* Page keys go on to if they aren't moving */
-
- BUFHEAD *last_bfp; /* Last buf header OVFL needing to be freed */
- DBT key, val;
- SPLIT_RETURN ret;
- u_int16_t n, off, ov_addr, scopyto;
- char *cino; /* Character value of ino */
-
- bufp = old_bufp;
- ino = (u_int16_t *)old_bufp->page;
- np = (u_int16_t *)new_bufp->page;
- op = (u_int16_t *)old_bufp->page;
- last_bfp = NULL;
- scopyto = (u_int16_t)copyto; /* ANSI */
-
- n = ino[0] - 1;
- while (n < ino[0]) {
- if (ino[2] < REAL_KEY && ino[2] != OVFLPAGE) {
- if (__big_split(hashp, old_bufp,
- new_bufp, bufp, bufp->addr, obucket, &ret))
- return (-1);
- old_bufp = ret.oldp;
- if (!old_bufp)
- return (-1);
- op = (u_int16_t *)old_bufp->page;
- new_bufp = ret.newp;
- if (!new_bufp)
- return (-1);
- np = (u_int16_t *)new_bufp->page;
- bufp = ret.nextp;
- if (!bufp)
- return (0);
- cino = (char *)bufp->page;
- ino = (u_int16_t *)cino;
- last_bfp = ret.nextp;
- } else if (ino[n + 1] == OVFLPAGE) {
- ov_addr = ino[n];
- /*
- * Fix up the old page -- the extra 2 are the fields
- * which contained the overflow information.
- */
- ino[0] -= (moved + 2);
- FREESPACE(ino) =
- scopyto - sizeof(u_int16_t) * (ino[0] + 3);
- OFFSET(ino) = scopyto;
-
- bufp = __get_buf(hashp, ov_addr, bufp, 0);
- if (!bufp)
- return (-1);
-
- ino = (u_int16_t *)bufp->page;
- n = 1;
- scopyto = hashp->BSIZE;
- moved = 0;
-
- if (last_bfp)
- __free_ovflpage(hashp, last_bfp);
- last_bfp = bufp;
- }
- /* Move regular sized pairs of there are any */
- off = hashp->BSIZE;
- for (n = 1; (n < ino[0]) && (ino[n + 1] >= REAL_KEY); n += 2) {
- cino = (char *)ino;
- key.data = (u_char *)cino + ino[n];
- key.size = off - ino[n];
- val.data = (u_char *)cino + ino[n + 1];
- val.size = ino[n] - ino[n + 1];
- off = ino[n + 1];
-
- if (__call_hash(hashp, key.data, key.size) == obucket) {
- /* Keep on old page */
- if (PAIRFITS(op, (&key), (&val)))
- putpair((char *)op, &key, &val);
- else {
- old_bufp =
- __add_ovflpage(hashp, old_bufp);
- if (!old_bufp)
- return (-1);
- op = (u_int16_t *)old_bufp->page;
- putpair((char *)op, &key, &val);
- }
- old_bufp->flags |= BUF_MOD;
- } else {
- /* Move to new page */
- if (PAIRFITS(np, (&key), (&val)))
- putpair((char *)np, &key, &val);
- else {
- new_bufp =
- __add_ovflpage(hashp, new_bufp);
- if (!new_bufp)
- return (-1);
- np = (u_int16_t *)new_bufp->page;
- putpair((char *)np, &key, &val);
- }
- new_bufp->flags |= BUF_MOD;
- }
- }
- }
- if (last_bfp)
- __free_ovflpage(hashp, last_bfp);
- return (0);
-}
-
-/*
- * Add the given pair to the page
- *
- * Returns:
- * 0 ==> OK
- * 1 ==> failure
- */
-extern int
-__addel(hashp, bufp, key, val)
- HTAB *hashp;
- BUFHEAD *bufp;
- const DBT *key, *val;
-{
- register u_int16_t *bp, *sop;
- int do_expand;
-
- bp = (u_int16_t *)bufp->page;
- do_expand = 0;
- while (bp[0] && (bp[2] < REAL_KEY || bp[bp[0]] < REAL_KEY))
- /* Exception case */
- if (bp[2] == FULL_KEY_DATA && bp[0] == 2)
- /* This is the last page of a big key/data pair
- and we need to add another page */
- break;
- else if (bp[2] < REAL_KEY && bp[bp[0]] != OVFLPAGE) {
- bufp = __get_buf(hashp, bp[bp[0] - 1], bufp, 0);
- if (!bufp)
- return (-1);
- bp = (u_int16_t *)bufp->page;
- } else
- /* Try to squeeze key on this page */
- if (FREESPACE(bp) > PAIRSIZE(key, val)) {
- squeeze_key(bp, key, val);
- return (0);
- } else {
- bufp = __get_buf(hashp, bp[bp[0] - 1], bufp, 0);
- if (!bufp)
- return (-1);
- bp = (u_int16_t *)bufp->page;
- }
-
- if (PAIRFITS(bp, key, val))
- putpair(bufp->page, key, val);
- else {
- do_expand = 1;
- bufp = __add_ovflpage(hashp, bufp);
- if (!bufp)
- return (-1);
- sop = (u_int16_t *)bufp->page;
-
- if (PAIRFITS(sop, key, val))
- putpair((char *)sop, key, val);
- else
- if (__big_insert(hashp, bufp, key, val))
- return (-1);
- }
- bufp->flags |= BUF_MOD;
- /*
- * If the average number of keys per bucket exceeds the fill factor,
- * expand the table.
- */
- hashp->NKEYS++;
- if (do_expand ||
- (hashp->NKEYS / (hashp->MAX_BUCKET + 1) > hashp->FFACTOR))
- return (__expand_table(hashp));
- return (0);
-}
-
-/*
- *
- * Returns:
- * pointer on success
- * NULL on error
- */
-extern BUFHEAD *
-__add_ovflpage(hashp, bufp)
- HTAB *hashp;
- BUFHEAD *bufp;
-{
- register u_int16_t *sp;
- u_int16_t ndx, ovfl_num;
-#ifdef DEBUG1
- int tmp1, tmp2;
-#endif
- sp = (u_int16_t *)bufp->page;
-
- /* Check if we are dynamically determining the fill factor */
- if (hashp->FFACTOR == DEF_FFACTOR) {
- hashp->FFACTOR = sp[0] >> 1;
- if (hashp->FFACTOR < MIN_FFACTOR)
- hashp->FFACTOR = MIN_FFACTOR;
- }
- bufp->flags |= BUF_MOD;
- ovfl_num = overflow_page(hashp);
-#ifdef DEBUG1
- tmp1 = bufp->addr;
- tmp2 = bufp->ovfl ? bufp->ovfl->addr : 0;
-#endif
- if (!ovfl_num || !(bufp->ovfl = __get_buf(hashp, ovfl_num, bufp, 1)))
- return (NULL);
- bufp->ovfl->flags |= BUF_MOD;
-#ifdef DEBUG1
- (void)fprintf(stderr, "ADDOVFLPAGE: %d->ovfl was %d is now %d\n",
- tmp1, tmp2, bufp->ovfl->addr);
-#endif
- ndx = sp[0];
- /*
- * Since a pair is allocated on a page only if there's room to add
- * an overflow page, we know that the OVFL information will fit on
- * the page.
- */
- sp[ndx + 4] = OFFSET(sp);
- sp[ndx + 3] = FREESPACE(sp) - OVFLSIZE;
- sp[ndx + 1] = ovfl_num;
- sp[ndx + 2] = OVFLPAGE;
- sp[0] = ndx + 2;
-#ifdef HASH_STATISTICS
- hash_overflows++;
-#endif
- return (bufp->ovfl);
-}
-
-/*
- * Returns:
- * 0 indicates SUCCESS
- * -1 indicates FAILURE
- */
-extern int
-__get_page(hashp, p, bucket, is_bucket, is_disk, is_bitmap)
- HTAB *hashp;
- char *p;
- u_int32_t bucket;
- int is_bucket, is_disk, is_bitmap;
-{
- register int fd, page, size;
- int rsize;
- u_int16_t *bp;
-
- fd = hashp->fp;
- size = hashp->BSIZE;
-
- if ((fd == -1) || !is_disk) {
- PAGE_INIT(p);
- return (0);
- }
- if (is_bucket)
- page = BUCKET_TO_PAGE(bucket);
- else
- page = OADDR_TO_PAGE(bucket);
- if ((lseek(fd, (off_t)page << hashp->BSHIFT, SEEK_SET) == -1) ||
- ((rsize = read(fd, p, size)) == -1))
- return (-1);
- bp = (u_int16_t *)p;
- if (!rsize)
- bp[0] = 0; /* We hit the EOF, so initialize a new page */
- else
- if (rsize != size) {
- errno = EFTYPE;
- return (-1);
- }
- if (!is_bitmap && !bp[0]) {
- PAGE_INIT(p);
- } else
- if (hashp->LORDER != BYTE_ORDER) {
- register int i, max;
-
- if (is_bitmap) {
- max = hashp->BSIZE >> 2; /* divide by 4 */
- for (i = 0; i < max; i++)
- M_32_SWAP(((int *)p)[i]);
- } else {
- M_16_SWAP(bp[0]);
- max = bp[0] + 2;
- for (i = 1; i <= max; i++)
- M_16_SWAP(bp[i]);
- }
- }
- return (0);
-}
-
-/*
- * Write page p to disk
- *
- * Returns:
- * 0 ==> OK
- * -1 ==>failure
- */
-extern int
-__put_page(hashp, p, bucket, is_bucket, is_bitmap)
- HTAB *hashp;
- char *p;
- u_int32_t bucket;
- int is_bucket, is_bitmap;
-{
- register int fd, page, size;
- int wsize;
-
- size = hashp->BSIZE;
- if ((hashp->fp == -1) && open_temp(hashp))
- return (-1);
- fd = hashp->fp;
-
- if (hashp->LORDER != BYTE_ORDER) {
- register int i;
- register int max;
-
- if (is_bitmap) {
- max = hashp->BSIZE >> 2; /* divide by 4 */
- for (i = 0; i < max; i++)
- M_32_SWAP(((int *)p)[i]);
- } else {
- max = ((u_int16_t *)p)[0] + 2;
- for (i = 0; i <= max; i++)
- M_16_SWAP(((u_int16_t *)p)[i]);
- }
- }
- if (is_bucket)
- page = BUCKET_TO_PAGE(bucket);
- else
- page = OADDR_TO_PAGE(bucket);
- if ((lseek(fd, (off_t)page << hashp->BSHIFT, SEEK_SET) == -1) ||
- ((wsize = write(fd, p, size)) == -1))
- /* Errno is set */
- return (-1);
- if (wsize != size) {
- errno = EFTYPE;
- return (-1);
- }
- return (0);
-}
-
-#define BYTE_MASK ((1 << INT_BYTE_SHIFT) -1)
-/*
- * Initialize a new bitmap page. Bitmap pages are left in memory
- * once they are read in.
- */
-extern int
-__ibitmap(hashp, pnum, nbits, ndx)
- HTAB *hashp;
- int pnum, nbits, ndx;
-{
- u_int32_t *ip;
- int clearbytes, clearints;
-
- if ((ip = (u_int32_t *)malloc(hashp->BSIZE)) == NULL)
- return (1);
- hashp->nmaps++;
- clearints = ((nbits - 1) >> INT_BYTE_SHIFT) + 1;
- clearbytes = clearints << INT_TO_BYTE;
- (void)memset((char *)ip, 0, clearbytes);
- (void)memset(((char *)ip) + clearbytes, 0xFF,
- hashp->BSIZE - clearbytes);
- ip[clearints - 1] = ALL_SET << (nbits & BYTE_MASK);
- SETBIT(ip, 0);
- hashp->BITMAPS[ndx] = (u_int16_t)pnum;
- hashp->mapp[ndx] = ip;
- return (0);
-}
-
-static u_int32_t
-first_free(map)
- u_int32_t map;
-{
- register u_int32_t i, mask;
-
- mask = 0x1;
- for (i = 0; i < BITS_PER_MAP; i++) {
- if (!(mask & map))
- return (i);
- mask = mask << 1;
- }
- return (i);
-}
-
-static u_int16_t
-overflow_page(hashp)
- HTAB *hashp;
-{
- register u_int32_t *freep = 0;
- register int max_free, offset, splitnum;
- u_int16_t addr;
- int bit, first_page, free_bit, free_page, i, in_use_bits, j;
-#ifdef DEBUG2
- int tmp1, tmp2;
-#endif
- splitnum = hashp->OVFL_POINT;
- max_free = hashp->SPARES[splitnum];
-
- free_page = (max_free - 1) >> (hashp->BSHIFT + BYTE_SHIFT);
- free_bit = (max_free - 1) & ((hashp->BSIZE << BYTE_SHIFT) - 1);
-
- /* Look through all the free maps to find the first free block */
- first_page = hashp->LAST_FREED >>(hashp->BSHIFT + BYTE_SHIFT);
- for ( i = first_page; i <= free_page; i++ ) {
- if (!(freep = (u_int32_t *)hashp->mapp[i]) &&
- !(freep = fetch_bitmap(hashp, i)))
- return (0);
- if (i == free_page)
- in_use_bits = free_bit;
- else
- in_use_bits = (hashp->BSIZE << BYTE_SHIFT) - 1;
-
- if (i == first_page) {
- bit = hashp->LAST_FREED &
- ((hashp->BSIZE << BYTE_SHIFT) - 1);
- j = bit / BITS_PER_MAP;
- bit = bit & ~(BITS_PER_MAP - 1);
- } else {
- bit = 0;
- j = 0;
- }
- for (; bit <= in_use_bits; j++, bit += BITS_PER_MAP)
- if (freep[j] != ALL_SET)
- goto found;
- }
-
- /* No Free Page Found */
- hashp->LAST_FREED = hashp->SPARES[splitnum];
- hashp->SPARES[splitnum]++;
- offset = hashp->SPARES[splitnum] -
- (splitnum ? hashp->SPARES[splitnum - 1] : 0);
-
-#define OVMSG "HASH: Out of overflow pages. Increase page size\n"
- if (offset > SPLITMASK) {
- if (++splitnum >= NCACHED) {
- (void)write(STDERR_FILENO, OVMSG, sizeof(OVMSG) - 1);
- return (0);
- }
- hashp->OVFL_POINT = splitnum;
- hashp->SPARES[splitnum] = hashp->SPARES[splitnum-1];
- hashp->SPARES[splitnum-1]--;
- offset = 1;
- }
-
- /* Check if we need to allocate a new bitmap page */
- if (free_bit == (hashp->BSIZE << BYTE_SHIFT) - 1) {
- free_page++;
- if (free_page >= NCACHED) {
- (void)write(STDERR_FILENO, OVMSG, sizeof(OVMSG) - 1);
- return (0);
- }
- /*
- * This is tricky. The 1 indicates that you want the new page
- * allocated with 1 clear bit. Actually, you are going to
- * allocate 2 pages from this map. The first is going to be
- * the map page, the second is the overflow page we were
- * looking for. The init_bitmap routine automatically, sets
- * the first bit of itself to indicate that the bitmap itself
- * is in use. We would explicitly set the second bit, but
- * don't have to if we tell init_bitmap not to leave it clear
- * in the first place.
- */
- if (__ibitmap(hashp,
- (int)OADDR_OF(splitnum, offset), 1, free_page))
- return (0);
- hashp->SPARES[splitnum]++;
-#ifdef DEBUG2
- free_bit = 2;
-#endif
- offset++;
- if (offset > SPLITMASK) {
- if (++splitnum >= NCACHED) {
- (void)write(STDERR_FILENO, OVMSG,
- sizeof(OVMSG) - 1);
- return (0);
- }
- hashp->OVFL_POINT = splitnum;
- hashp->SPARES[splitnum] = hashp->SPARES[splitnum-1];
- hashp->SPARES[splitnum-1]--;
- offset = 0;
- }
- } else {
- /*
- * Free_bit addresses the last used bit. Bump it to address
- * the first available bit.
- */
- free_bit++;
- SETBIT(freep, free_bit);
- }
-
- /* Calculate address of the new overflow page */
- addr = OADDR_OF(splitnum, offset);
-#ifdef DEBUG2
- (void)fprintf(stderr, "OVERFLOW_PAGE: ADDR: %d BIT: %d PAGE %d\n",
- addr, free_bit, free_page);
-#endif
- return (addr);
-
-found:
- bit = bit + first_free(freep[j]);
- SETBIT(freep, bit);
-#ifdef DEBUG2
- tmp1 = bit;
- tmp2 = i;
-#endif
- /*
- * Bits are addressed starting with 0, but overflow pages are addressed
- * beginning at 1. Bit is a bit addressnumber, so we need to increment
- * it to convert it to a page number.
- */
- bit = 1 + bit + (i * (hashp->BSIZE << BYTE_SHIFT));
- if (bit >= hashp->LAST_FREED)
- hashp->LAST_FREED = bit - 1;
-
- /* Calculate the split number for this page */
- for (i = 0; (i < splitnum) && (bit > hashp->SPARES[i]); i++);
- offset = (i ? bit - hashp->SPARES[i - 1] : bit);
- if (offset >= SPLITMASK)
- return (0); /* Out of overflow pages */
- addr = OADDR_OF(i, offset);
-#ifdef DEBUG2
- (void)fprintf(stderr, "OVERFLOW_PAGE: ADDR: %d BIT: %d PAGE %d\n",
- addr, tmp1, tmp2);
-#endif
-
- /* Allocate and return the overflow page */
- return (addr);
-}
-
-/*
- * Mark this overflow page as free.
- */
-extern void
-__free_ovflpage(hashp, obufp)
- HTAB *hashp;
- BUFHEAD *obufp;
-{
- register u_int16_t addr;
- u_int32_t *freep;
- int bit_address, free_page, free_bit;
- u_int16_t ndx;
-
- addr = obufp->addr;
-#ifdef DEBUG1
- (void)fprintf(stderr, "Freeing %d\n", addr);
-#endif
- ndx = (((u_int16_t)addr) >> SPLITSHIFT);
- bit_address =
- (ndx ? hashp->SPARES[ndx - 1] : 0) + (addr & SPLITMASK) - 1;
- if (bit_address < hashp->LAST_FREED)
- hashp->LAST_FREED = bit_address;
- free_page = (bit_address >> (hashp->BSHIFT + BYTE_SHIFT));
- free_bit = bit_address & ((hashp->BSIZE << BYTE_SHIFT) - 1);
-
- if (!(freep = hashp->mapp[free_page]))
- freep = fetch_bitmap(hashp, free_page);
-#ifdef DEBUG
- /*
- * This had better never happen. It means we tried to read a bitmap
- * that has already had overflow pages allocated off it, and we
- * failed to read it from the file.
- */
- if (!freep)
- assert(0);
-#endif
- CLRBIT(freep, free_bit);
-#ifdef DEBUG2
- (void)fprintf(stderr, "FREE_OVFLPAGE: ADDR: %d BIT: %d PAGE %d\n",
- obufp->addr, free_bit, free_page);
-#endif
- __reclaim_buf(hashp, obufp);
-}
-
-/*
- * Returns:
- * 0 success
- * -1 failure
- */
-static int
-open_temp(hashp)
- HTAB *hashp;
-{
- sigset_t set, oset;
- static char namestr[] = "_hashXXXXXX";
-
- /* Block signals; make sure file goes away at process exit. */
- (void)sigfillset(&set);
- (void)sigprocmask(SIG_BLOCK, &set, &oset);
- if ((hashp->fp = mkstemp(namestr)) != -1) {
- (void)unlink(namestr);
- (void)fcntl(hashp->fp, F_SETFD, 1);
- }
- (void)sigprocmask(SIG_SETMASK, &oset, (sigset_t *)NULL);
- return (hashp->fp != -1 ? 0 : -1);
-}
-
-/*
- * We have to know that the key will fit, but the last entry on the page is
- * an overflow pair, so we need to shift things.
- */
-static void
-squeeze_key(sp, key, val)
- u_int16_t *sp;
- const DBT *key, *val;
-{
- register char *p;
- u_int16_t free_space, n, off, pageno;
-
- p = (char *)sp;
- n = sp[0];
- free_space = FREESPACE(sp);
- off = OFFSET(sp);
-
- pageno = sp[n - 1];
- off -= key->size;
- sp[n - 1] = off;
- memmove(p + off, key->data, key->size);
- off -= val->size;
- sp[n] = off;
- memmove(p + off, val->data, val->size);
- sp[0] = n + 2;
- sp[n + 1] = pageno;
- sp[n + 2] = OVFLPAGE;
- FREESPACE(sp) = free_space - PAIRSIZE(key, val);
- OFFSET(sp) = off;
-}
-
-static u_int32_t *
-fetch_bitmap(hashp, ndx)
- HTAB *hashp;
- int ndx;
-{
- if (ndx >= hashp->nmaps)
- return (NULL);
- if ((hashp->mapp[ndx] = (u_int32_t *)malloc(hashp->BSIZE)) == NULL)
- return (NULL);
- if (__get_page(hashp,
- (char *)hashp->mapp[ndx], hashp->BITMAPS[ndx], 0, 1, 1)) {
- free(hashp->mapp[ndx]);
- return (NULL);
- }
- return (hashp->mapp[ndx]);
-}
-
-#ifdef DEBUG4
-int
-print_chain(addr)
- int addr;
-{
- BUFHEAD *bufp;
- short *bp, oaddr;
-
- (void)fprintf(stderr, "%d ", addr);
- bufp = __get_buf(hashp, addr, NULL, 0);
- bp = (short *)bufp->page;
- while (bp[0] && ((bp[bp[0]] == OVFLPAGE) ||
- ((bp[0] > 2) && bp[2] < REAL_KEY))) {
- oaddr = bp[bp[0] - 1];
- (void)fprintf(stderr, "%d ", (int)oaddr);
- bufp = __get_buf(hashp, (int)oaddr, bufp, 0);
- bp = (short *)bufp->page;
- }
- (void)fprintf(stderr, "\n");
-}
-#endif