--- /dev/null
+/*-
+ * 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.
+ * 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/cdefs.h>
+__FBSDID("$FreeBSD: src/lib/libc/db/hash/hash.c,v 1.21 2009/03/28 07:20:39 delphij Exp $");
+
+#include "namespace.h"
+#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 "un-namespace.h"
+
+#include <db.h>
+#include "hash.h"
+#include "page.h"
+#include "extern.h"
+
+static int alloc_segs(HTAB *, int);
+static int flush_meta(HTAB *);
+static int hash_access(HTAB *, ACTION, DBT *, DBT *);
+static int hash_close(DB *);
+static int hash_delete(const DB *, const DBT *, u_int32_t);
+static int hash_fd(const DB *);
+static int hash_get(const DB *, const DBT *, DBT *, u_int32_t);
+static int hash_put(const DB *, DBT *, const DBT *, u_int32_t);
+static void *hash_realloc(SEGMENT **, int, int);
+static int hash_seq(const DB *, DBT *, DBT *, u_int32_t);
+static int hash_sync(const DB *, u_int32_t);
+static int hdestroy(HTAB *);
+static HTAB *init_hash(HTAB *, const char *, const HASHINFO *);
+static int init_htab(HTAB *, int);
+#if BYTE_ORDER == LITTLE_ENDIAN
+static void swap_header(HTAB *);
+static void swap_header_copy(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 */
+
+/* ARGSUSED */
+DB *
+__hash_open(const char *file, int flags, int mode,
+ const HASHINFO *info, /* Special directives for create */
+ int dflags)
+{
+ 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;
+
+ if (file) {
+ if ((hashp->fp = _open(file, flags, mode)) == -1)
+ RETURN_ERROR(errno, error0);
+ (void)_fcntl(hashp->fp, F_SETFD, 1);
+ new_table = _fstat(hashp->fp, &statbuf) == 0 &&
+ statbuf.st_size == 0 &&
+ ((flags & O_ACCMODE) != O_RDONLY || (flags & O_CREAT) != 0);
+ } else
+ new_table = 1;
+
+ if (new_table) {
+ if (!(hashp = init_hash(hashp, file, 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 ((int32_t)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;
+ 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%p\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(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(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(HTAB *hashp, const char *file, const 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(HTAB *hashp, int nelem)
+{
+ int nbuckets, nsegs, 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]);
+ if (hashp->tmp_key)
+ free(hashp->tmp_key);
+ if (hashp->tmp_buf)
+ free(hashp->tmp_buf);
+
+ 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(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(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 ((wsize = pwrite(fp, whdrp, sizeof(HASHHDR), (off_t)0)) == -1)
+ return (-1);
+ else
+ if (wsize != sizeof(HASHHDR)) {
+ errno = EFTYPE;
+ hashp->error = 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, u_int32_t flag)
+{
+ HTAB *hashp;
+
+ hashp = (HTAB *)dbp->internal;
+ if (flag) {
+ hashp->error = errno = EINVAL;
+ return (ERROR);
+ }
+ return (hash_access(hashp, HASH_GET, (DBT *)key, data));
+}
+
+static int
+hash_put(const DB *dbp, DBT *key, const DBT *data, u_int32_t flag)
+{
+ HTAB *hashp;
+
+ hashp = (HTAB *)dbp->internal;
+ if (flag && flag != R_NOOVERWRITE) {
+ hashp->error = errno = EINVAL;
+ return (ERROR);
+ }
+ if ((hashp->flags & O_ACCMODE) == O_RDONLY) {
+ hashp->error = errno = EPERM;
+ return (ERROR);
+ }
+ return (hash_access(hashp, flag == R_NOOVERWRITE ?
+ HASH_PUTNEW : HASH_PUT, (DBT *)key, (DBT *)data));
+}
+
+static int
+hash_delete(const DB *dbp, const DBT *key,
+ u_int32_t flag) /* Ignored */
+{
+ HTAB *hashp;
+
+ hashp = (HTAB *)dbp->internal;
+ if (flag && flag != R_CURSOR) {
+ hashp->error = errno = EINVAL;
+ return (ERROR);
+ }
+ if ((hashp->flags & O_ACCMODE) == O_RDONLY) {
+ hashp->error = 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(HTAB *hashp, ACTION action, DBT *key, DBT *val)
+{
+ BUFHEAD *rbufp;
+ BUFHEAD *bufp, *save_bufp;
+ u_int16_t *bp;
+ int n, ndx, off, size;
+ 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(const DB *dbp, DBT *key, DBT *data, u_int32_t flag)
+{
+ u_int32_t bucket;
+ BUFHEAD *bufp;
+ HTAB *hashp;
+ u_int16_t *bp, ndx;
+
+ hashp = (HTAB *)dbp->internal;
+ if (flag && flag != R_FIRST && flag != R_NEXT) {
+ hashp->error = 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;
+ }
+ next_bucket:
+ 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 ((u_int32_t)hashp->cbucket > hashp->MAX_BUCKET) {
+ hashp->cbucket = -1;
+ return (ABNORMAL);
+ }
+ } else {
+ bp = (u_int16_t *)hashp->cpage->page;
+ if (flag == R_NEXT) {
+ hashp->cndx += 2;
+ if (hashp->cndx > bp[0]) {
+ hashp->cpage = NULL;
+ hashp->cbucket++;
+ hashp->cndx = 1;
+ goto next_bucket;
+ }
+ }
+ }
+
+#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 {
+ if (hashp->cpage == 0)
+ return (ERROR);
+ 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];
+ }
+ return (SUCCESS);
+}
+
+/********************************* UTILITIES ************************/
+
+/*
+ * Returns:
+ * 0 ==> OK
+ * -1 ==> Error
+ */
+int
+__expand_table(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(SEGMENT **p_ptr, int oldsize, int newsize)
+{
+ 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);
+}
+
+u_int32_t
+__call_hash(HTAB *hashp, char *k, int len)
+{
+ unsigned 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(HTAB *hashp, int nsegs)
+{
+ int i;
+ 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);
+ }
+ hashp->nsegs = nsegs;
+ if (nsegs == 0)
+ return (0);
+ /* 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->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
projects / apple / libc.git / commitdiff
