minix/lib/nbsd_libc/db/hash/hash.c
Evgeniy Ivanov ef0a265086 New stat structure.
* VFS and installed MFSes must be in sync before and after this change *

Use struct stat from NetBSD. It requires adding new STAT, FSTAT and LSTAT
syscalls. Libc modification is both backward and forward compatible.

Also new struct stat uses modern field sizes to avoid ABI
incompatibility, when we update uid_t, gid_t and company.
Exceptions are ino_t and off_t in old libc (though paddings added).
2011-07-12 16:39:55 +02:00

981 lines
24 KiB
C

/* $NetBSD: hash.c,v 1.31 2009/02/12 06:35:54 lukem Exp $ */
/*-
* 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. 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 HAVE_NBTOOL_CONFIG_H
#include "nbtool_config.h"
#endif
#include <sys/cdefs.h>
__RCSID("$NetBSD: hash.c,v 1.31 2009/02/12 06:35:54 lukem 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>
#include <assert.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 *, uint32_t);
static int hash_fd(const DB *);
static int hash_get(const DB *, const DBT *, DBT *, uint32_t);
static int hash_put(const DB *, DBT *, const DBT *, uint32_t);
static void *hash_realloc(SEGMENT **, size_t, size_t);
static int hash_seq(const DB *, DBT *, DBT *, uint32_t);
static int hash_sync(const DB *, uint32_t);
static int hdestroy(HTAB *);
static HTAB *init_hash(HTAB *, const char *, const HASHINFO *);
static int init_htab(HTAB *, size_t);
#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, mode_t mode, const HASHINFO *info,
int dflags)
{
HTAB *hashp;
struct stat statbuf;
DB *dbp;
int bpages, new_table, nsegs, save_errno;
ssize_t hdrsize;
if ((flags & O_ACCMODE) == O_WRONLY) {
errno = EINVAL;
return (NULL);
}
if (!(hashp = 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 (fcntl(hashp->fp, F_SETFD, FD_CLOEXEC) == -1)
RETURN_ERROR(errno, error1);
if (fstat(hashp->fp, &statbuf) == -1)
RETURN_ERROR(errno, error1);
new_table |= statbuf.st_size == 0;
}
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 (hashp->hash(CHARKEY, sizeof(CHARKEY)) !=
(uint32_t)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] +
(unsigned int)(hashp->BSIZE << BYTE_SHIFT) - 1) >>
(hashp->BSHIFT + BYTE_SHIFT);
hashp->nmaps = bpages;
(void)memset(&hashp->mapp[0], 0, bpages * sizeof(uint32_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 = 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 = dbp->internal;
retval = hdestroy(hashp);
free(dbp);
return (retval);
}
static int
hash_fd(const DB *dbp)
{
HTAB *hashp;
if (!dbp)
return (ERROR);
hashp = 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);
#ifdef __minix
if (statbuf.st_blksize == 0) {
/* 0 in 2 cases: upgrade from old to new struct stat or
* there is a bug in underlying fs.
*/
hashp->BSIZE = MIN(MINIX_ST_BLKSIZE, MAX_BSIZE);
} else
#endif
hashp->BSIZE = MIN(statbuf.st_blksize, MAX_BSIZE);
hashp->BSHIFT = __log2((uint32_t)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, (size_t)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, size_t nelem)
{
int nbuckets;
uint32_t 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;
_DBFIT(nelem, uint32_t);
l2 = __log2(MAX((uint32_t)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, (int)OADDR_OF(l2, 1), l2 + 1, 0))
return (-1);
hashp->MAX_BUCKET = hashp->LOW_MASK = nbuckets - 1;
hashp->HIGH_MASK = (nbuckets << 1) - 1;
/* LINTED constant in conditional context */
hashp->HDRPAGES = ((MAX(sizeof(HASHHDR), MINHDRSIZE) - 1) >>
hashp->BSHIFT) + 1;
nsegs = (nbuckets - 1) / hashp->SGSIZE + 1;
nsegs = 1 << __log2(nsegs);
if (nsegs > (uint32_t)hashp->DSIZE)
hashp->DSIZE = nsegs;
return (alloc_segs(hashp, (int)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 %d collisions %d\n",
hash_accesses, hash_collisions);
(void)fprintf(stderr, "hdestroy: expansions %d\n",
hash_expansions);
(void)fprintf(stderr, "hdestroy: overflows %d\n",
hash_overflows);
(void)fprintf(stderr, "keys %d 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(const DB *dbp, uint32_t flags)
{
HTAB *hashp;
if (flags != 0) {
errno = EINVAL;
return (ERROR);
}
if (!dbp)
return (ERROR);
hashp = 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;
ssize_t 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->err = errno;
return (-1);
}
for (i = 0; i < NCACHED; i++)
if (hashp->mapp[i])
if (__put_page(hashp, (char *)(void *)hashp->mapp[i],
(u_int)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, uint32_t flag)
{
HTAB *hashp;
hashp = dbp->internal;
if (flag) {
hashp->err = errno = EINVAL;
return (ERROR);
}
return (hash_access(hashp, HASH_GET, __UNCONST(key), data));
}
static int
hash_put(const DB *dbp, DBT *key, const DBT *data, uint32_t flag)
{
HTAB *hashp;
hashp = dbp->internal;
if (flag && flag != R_NOOVERWRITE) {
hashp->err = errno = EINVAL;
return (ERROR);
}
if ((hashp->flags & O_ACCMODE) == O_RDONLY) {
hashp->err = errno = EPERM;
return (ERROR);
}
/* LINTED const castaway */
return (hash_access(hashp, flag == R_NOOVERWRITE ?
HASH_PUTNEW : HASH_PUT, __UNCONST(key), __UNCONST(data)));
}
static int
hash_delete(const DB *dbp, const DBT *key, uint32_t flag)
{
HTAB *hashp;
hashp = dbp->internal;
if (flag && flag != R_CURSOR) {
hashp->err = errno = EINVAL;
return (ERROR);
}
if ((hashp->flags & O_ACCMODE) == O_RDONLY) {
hashp->err = errno = EPERM;
return (ERROR);
}
return hash_access(hashp, HASH_DELETE, __UNCONST(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;
uint16_t *bp;
int n, ndx, off;
size_t size;
char *kp;
uint16_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, (int)size), NULL, 0);
if (!rbufp)
return (ERROR);
save_bufp = rbufp;
/* Pin the bucket chain */
rbufp->flags |= BUF_PIN;
for (bp = (uint16_t *)(void *)rbufp->page, n = *bp++, ndx = 1; ndx < n;)
if (bp[1] >= REAL_KEY) {
/* Real key/data pair */
if (size == (size_t)(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, (uint32_t)*bp, rbufp, 0);
if (!rbufp) {
save_bufp->flags &= ~BUF_PIN;
return (ERROR);
}
/* FOR LOOP INIT */
bp = (uint16_t *)(void *)rbufp->page;
n = *bp++;
ndx = 1;
off = hashp->BSIZE;
} else if (bp[1] < REAL_KEY) {
if ((ndx =
__find_bigpair(hashp, rbufp, ndx, kp, (int)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, (uint32_t)pageno,
bufp, 0);
if (!rbufp) {
save_bufp->flags &= ~BUF_PIN;
return (ERROR);
}
/* FOR LOOP INIT */
bp = (uint16_t *)(void *)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 = (uint16_t *)(void *)rbufp->page;
if (bp[ndx + 1] < REAL_KEY) {
if (__big_return(hashp, rbufp, ndx, val, 0))
return (ERROR);
} else {
val->data = (uint8_t *)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, uint32_t flag)
{
uint32_t bucket;
BUFHEAD *bufp = NULL; /* XXX: gcc */
HTAB *hashp;
uint16_t *bp, ndx;
hashp = dbp->internal;
if (flag && flag != R_FIRST && flag != R_NEXT) {
hashp->err = 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 <= (uint32_t)hashp->MAX_BUCKET;
bucket++, hashp->cndx = 1) {
bufp = __get_buf(hashp, bucket, NULL, 0);
if (!bufp)
return (ERROR);
hashp->cpage = bufp;
bp = (uint16_t *)(void *)bufp->page;
if (bp[0])
break;
}
hashp->cbucket = bucket;
if (hashp->cbucket > hashp->MAX_BUCKET) {
hashp->cbucket = -1;
return (ABNORMAL);
}
} else
bp = (uint16_t *)(void *)hashp->cpage->page;
_DIAGASSERT(bp != NULL);
_DIAGASSERT(bufp != NULL);
while (bp[hashp->cndx + 1] == OVFLPAGE) {
bufp = hashp->cpage =
__get_buf(hashp, (uint32_t)bp[hashp->cndx], bufp,
0);
if (!bufp)
return (ERROR);
bp = (uint16_t *)(void *)(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 == NULL)
return (ERROR);
key->data = (uint8_t *)hashp->cpage->page + bp[ndx];
key->size = (ndx > 1 ? bp[ndx - 1] : hashp->BSIZE) - bp[ndx];
data->data = (uint8_t *)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
*/
int
__expand_table(HTAB *hashp)
{
uint32_t old_bucket, new_bucket;
int new_segnum, spare_ndx;
size_t dirsize;
#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] =
calloc((size_t)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((uint32_t)(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 > (uint32_t)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, size_t oldsize, size_t newsize)
{
void *p;
if ((p = malloc(newsize)) != NULL) {
memmove(p, *p_ptr, oldsize);
memset((char *)p + oldsize, 0, newsize - oldsize);
free(*p_ptr);
*p_ptr = p;
}
return (p);
}
uint32_t
__call_hash(HTAB *hashp, char *k, int len)
{
int n, bucket;
n = hashp->hash(k, (size_t)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;
hashp->dir = calloc((size_t)hashp->DSIZE, sizeof(SEGMENT *));
if (hashp->dir == NULL) {
save_errno = errno;
(void)hdestroy(hashp);
errno = save_errno;
return (-1);
}
hashp->nsegs = nsegs;
if (nsegs == 0)
return 0;
/* Allocate segments */
store = calloc((size_t)(nsegs << hashp->SSHIFT), sizeof(SEGMENT));
if (store == 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)
{
size_t 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;
size_t 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