freebsd-skq/lib/libc/db/hash/hash.c
Daniel Eischen d201fe46e3 Remove _THREAD_SAFE and make libc thread-safe by default by
adding (weak definitions to) stubs for some of the pthread
functions.  If the threads library is linked in, the real
pthread functions will pulled in.

Use the following convention for system calls wrapped by the
threads library:
	__sys_foo - actual system call
	_foo - weak definition to __sys_foo
	foo - weak definition to __sys_foo

Change all libc uses of system calls wrapped by the threads
library from foo to _foo.  In order to define the prototypes
for _foo(), we introduce namespace.h and un-namespace.h
(suggested by bde).  All files that need to reference these
system calls, should include namespace.h before any standard
includes, then include un-namespace.h after the standard
includes and before any local includes.  <db.h> is an exception
and shouldn't be included in between namespace.h and
un-namespace.h  namespace.h will define foo to _foo, and
un-namespace.h will undefine foo.

Try to eliminate some of the recursive calls to MT-safe
functions in libc/stdio in preparation for adding a mutex
to FILE.  We have recursive mutexes, but would like to avoid
using them if possible.

Remove uneeded includes of <errno.h> from a few files.

Add $FreeBSD$ to a few files in order to pass commitprep.

Approved by:	-arch
2001-01-24 13:01:12 +00:00

1007 lines
24 KiB
C

/*-
* 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.
*
* $FreeBSD$
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)hash.c 8.9 (Berkeley) 6/16/94";
#endif /* LIBC_SCCS and not lint */
#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 __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);
/* if the .db file is empty, and we had permission to create
a new .db file, then reinitialize the database */
if ((flags & O_CREAT) &&
_fstat(hashp->fp, &statbuf) == 0 && statbuf.st_size == 0)
new_table = 1;
(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->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(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->error = 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->error = EINVAL;
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(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->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(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->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;
}
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