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/* $MidnightBSD$ */ |
| 2 |
/*- |
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* Copyright (c) 1990, 1993, 1994 |
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* The Regents of the University of California. All rights reserved. |
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* |
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* This code is derived from software contributed to Berkeley by |
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* Margo Seltzer. |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in the |
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* documentation and/or other materials provided with the distribution. |
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* 4. Neither the name of the University nor the names of its contributors |
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* may be used to endorse or promote products derived from this software |
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* without specific prior written permission. |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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* SUCH DAMAGE. |
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*/ |
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|
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#if defined(LIBC_SCCS) && !defined(lint) |
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static char sccsid[] = "@(#)hash.c 8.9 (Berkeley) 6/16/94"; |
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#endif /* LIBC_SCCS and not lint */ |
| 37 |
#include <sys/cdefs.h> |
| 38 |
__FBSDID("$FreeBSD: stable/10/lib/libc/db/hash/hash.c 309485 2016-12-03 17:17:42Z ngie $"); |
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|
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#include "namespace.h" |
| 41 |
#include <sys/param.h> |
| 42 |
#include <sys/stat.h> |
| 43 |
|
| 44 |
#include <errno.h> |
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#include <fcntl.h> |
| 46 |
#include <stdio.h> |
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#include <stdlib.h> |
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#include <string.h> |
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#include <unistd.h> |
| 50 |
#ifdef DEBUG |
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#include <assert.h> |
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#endif |
| 53 |
#include "un-namespace.h" |
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|
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#include <db.h> |
| 56 |
#include "hash.h" |
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#include "page.h" |
| 58 |
#include "extern.h" |
| 59 |
|
| 60 |
static int alloc_segs(HTAB *, int); |
| 61 |
static int flush_meta(HTAB *); |
| 62 |
static int hash_access(HTAB *, ACTION, DBT *, DBT *); |
| 63 |
static int hash_close(DB *); |
| 64 |
static int hash_delete(const DB *, const DBT *, u_int32_t); |
| 65 |
static int hash_fd(const DB *); |
| 66 |
static int hash_get(const DB *, const DBT *, DBT *, u_int32_t); |
| 67 |
static int hash_put(const DB *, DBT *, const DBT *, u_int32_t); |
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static void *hash_realloc(SEGMENT **, int, int); |
| 69 |
static int hash_seq(const DB *, DBT *, DBT *, u_int32_t); |
| 70 |
static int hash_sync(const DB *, u_int32_t); |
| 71 |
static int hdestroy(HTAB *); |
| 72 |
static HTAB *init_hash(HTAB *, const char *, const HASHINFO *); |
| 73 |
static int init_htab(HTAB *, int); |
| 74 |
#if BYTE_ORDER == LITTLE_ENDIAN |
| 75 |
static void swap_header(HTAB *); |
| 76 |
static void swap_header_copy(HASHHDR *, HASHHDR *); |
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#endif |
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|
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/* Fast arithmetic, relying on powers of 2, */ |
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#define MOD(x, y) ((x) & ((y) - 1)) |
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|
| 82 |
#define RETURN_ERROR(ERR, LOC) { save_errno = ERR; goto LOC; } |
| 83 |
|
| 84 |
/* Return values */ |
| 85 |
#define SUCCESS (0) |
| 86 |
#define ERROR (-1) |
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#define ABNORMAL (1) |
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|
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#ifdef HASH_STATISTICS |
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int hash_accesses, hash_collisions, hash_expansions, hash_overflows; |
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#endif |
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|
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/************************** INTERFACE ROUTINES ***************************/ |
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/* OPEN/CLOSE */ |
| 95 |
|
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/* ARGSUSED */ |
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DB * |
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__hash_open(const char *file, int flags, int mode, |
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const HASHINFO *info, /* Special directives for create */ |
| 100 |
int dflags) |
| 101 |
{ |
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HTAB *hashp; |
| 103 |
struct stat statbuf; |
| 104 |
DB *dbp; |
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int bpages, hdrsize, new_table, nsegs, save_errno; |
| 106 |
|
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if ((flags & O_ACCMODE) == O_WRONLY) { |
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errno = EINVAL; |
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return (NULL); |
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} |
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|
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if (!(hashp = (HTAB *)calloc(1, sizeof(HTAB)))) |
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return (NULL); |
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hashp->fp = -1; |
| 115 |
|
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/* |
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* Even if user wants write only, we need to be able to read |
| 118 |
* the actual file, so we need to open it read/write. But, the |
| 119 |
* field in the hashp structure needs to be accurate so that |
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* we can check accesses. |
| 121 |
*/ |
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hashp->flags = flags; |
| 123 |
|
| 124 |
if (file) { |
| 125 |
if ((hashp->fp = _open(file, flags | O_CLOEXEC, mode)) == -1) |
| 126 |
RETURN_ERROR(errno, error0); |
| 127 |
new_table = _fstat(hashp->fp, &statbuf) == 0 && |
| 128 |
statbuf.st_size == 0 && (flags & O_ACCMODE) != O_RDONLY; |
| 129 |
} else |
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new_table = 1; |
| 131 |
|
| 132 |
if (new_table) { |
| 133 |
if (!(hashp = init_hash(hashp, file, info))) |
| 134 |
RETURN_ERROR(errno, error1); |
| 135 |
} else { |
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/* Table already exists */ |
| 137 |
if (info && info->hash) |
| 138 |
hashp->hash = info->hash; |
| 139 |
else |
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hashp->hash = __default_hash; |
| 141 |
|
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hdrsize = _read(hashp->fp, &hashp->hdr, sizeof(HASHHDR)); |
| 143 |
#if BYTE_ORDER == LITTLE_ENDIAN |
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swap_header(hashp); |
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#endif |
| 146 |
if (hdrsize == -1) |
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RETURN_ERROR(errno, error1); |
| 148 |
if (hdrsize != sizeof(HASHHDR)) |
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RETURN_ERROR(EFTYPE, error1); |
| 150 |
/* Verify file type, versions and hash function */ |
| 151 |
if (hashp->MAGIC != HASHMAGIC) |
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RETURN_ERROR(EFTYPE, error1); |
| 153 |
#define OLDHASHVERSION 1 |
| 154 |
if (hashp->VERSION != HASHVERSION && |
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hashp->VERSION != OLDHASHVERSION) |
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RETURN_ERROR(EFTYPE, error1); |
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if ((int32_t)hashp->hash(CHARKEY, sizeof(CHARKEY)) != hashp->H_CHARKEY) |
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RETURN_ERROR(EFTYPE, error1); |
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/* |
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* Figure out how many segments we need. Max_Bucket is the |
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* maximum bucket number, so the number of buckets is |
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* max_bucket + 1. |
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*/ |
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nsegs = (hashp->MAX_BUCKET + 1 + hashp->SGSIZE - 1) / |
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hashp->SGSIZE; |
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if (alloc_segs(hashp, nsegs)) |
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/* |
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* If alloc_segs fails, table will have been destroyed |
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* and errno will have been set. |
| 170 |
*/ |
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return (NULL); |
| 172 |
/* Read in bitmaps */ |
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bpages = (hashp->SPARES[hashp->OVFL_POINT] + |
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(hashp->BSIZE << BYTE_SHIFT) - 1) >> |
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(hashp->BSHIFT + BYTE_SHIFT); |
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|
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hashp->nmaps = bpages; |
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(void)memset(&hashp->mapp[0], 0, bpages * sizeof(u_int32_t *)); |
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} |
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|
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/* Initialize Buffer Manager */ |
| 182 |
if (info && info->cachesize) |
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__buf_init(hashp, info->cachesize); |
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else |
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__buf_init(hashp, DEF_BUFSIZE); |
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|
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hashp->new_file = new_table; |
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hashp->save_file = file && (hashp->flags & O_RDWR); |
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hashp->cbucket = -1; |
| 190 |
if (!(dbp = (DB *)malloc(sizeof(DB)))) { |
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save_errno = errno; |
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hdestroy(hashp); |
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errno = save_errno; |
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return (NULL); |
| 195 |
} |
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dbp->internal = hashp; |
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dbp->close = hash_close; |
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dbp->del = hash_delete; |
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dbp->fd = hash_fd; |
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dbp->get = hash_get; |
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dbp->put = hash_put; |
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dbp->seq = hash_seq; |
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dbp->sync = hash_sync; |
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dbp->type = DB_HASH; |
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|
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#ifdef DEBUG |
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(void)fprintf(stderr, |
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"%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", |
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"init_htab:", |
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"TABLE POINTER ", hashp, |
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"BUCKET SIZE ", hashp->BSIZE, |
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"BUCKET SHIFT ", hashp->BSHIFT, |
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"DIRECTORY SIZE ", hashp->DSIZE, |
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"SEGMENT SIZE ", hashp->SGSIZE, |
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"SEGMENT SHIFT ", hashp->SSHIFT, |
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"FILL FACTOR ", hashp->FFACTOR, |
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"MAX BUCKET ", hashp->MAX_BUCKET, |
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"OVFL POINT ", hashp->OVFL_POINT, |
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"LAST FREED ", hashp->LAST_FREED, |
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"HIGH MASK ", hashp->HIGH_MASK, |
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"LOW MASK ", hashp->LOW_MASK, |
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"NSEGS ", hashp->nsegs, |
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"NKEYS ", hashp->NKEYS); |
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#endif |
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#ifdef HASH_STATISTICS |
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hash_overflows = hash_accesses = hash_collisions = hash_expansions = 0; |
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#endif |
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return (dbp); |
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|
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error1: |
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if (hashp != NULL) |
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(void)_close(hashp->fp); |
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|
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error0: |
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free(hashp); |
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errno = save_errno; |
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return (NULL); |
| 238 |
} |
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|
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static int |
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hash_close(DB *dbp) |
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{ |
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HTAB *hashp; |
| 244 |
int retval; |
| 245 |
|
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if (!dbp) |
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return (ERROR); |
| 248 |
|
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hashp = (HTAB *)dbp->internal; |
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retval = hdestroy(hashp); |
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free(dbp); |
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return (retval); |
| 253 |
} |
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|
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static int |
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hash_fd(const DB *dbp) |
| 257 |
{ |
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HTAB *hashp; |
| 259 |
|
| 260 |
if (!dbp) |
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return (ERROR); |
| 262 |
|
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hashp = (HTAB *)dbp->internal; |
| 264 |
if (hashp->fp == -1) { |
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errno = ENOENT; |
| 266 |
return (-1); |
| 267 |
} |
| 268 |
return (hashp->fp); |
| 269 |
} |
| 270 |
|
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/************************** LOCAL CREATION ROUTINES **********************/ |
| 272 |
static HTAB * |
| 273 |
init_hash(HTAB *hashp, const char *file, const HASHINFO *info) |
| 274 |
{ |
| 275 |
struct stat statbuf; |
| 276 |
int nelem; |
| 277 |
|
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nelem = 1; |
| 279 |
hashp->NKEYS = 0; |
| 280 |
hashp->LORDER = BYTE_ORDER; |
| 281 |
hashp->BSIZE = DEF_BUCKET_SIZE; |
| 282 |
hashp->BSHIFT = DEF_BUCKET_SHIFT; |
| 283 |
hashp->SGSIZE = DEF_SEGSIZE; |
| 284 |
hashp->SSHIFT = DEF_SEGSIZE_SHIFT; |
| 285 |
hashp->DSIZE = DEF_DIRSIZE; |
| 286 |
hashp->FFACTOR = DEF_FFACTOR; |
| 287 |
hashp->hash = __default_hash; |
| 288 |
memset(hashp->SPARES, 0, sizeof(hashp->SPARES)); |
| 289 |
memset(hashp->BITMAPS, 0, sizeof (hashp->BITMAPS)); |
| 290 |
|
| 291 |
/* Fix bucket size to be optimal for file system */ |
| 292 |
if (file != NULL) { |
| 293 |
if (stat(file, &statbuf)) |
| 294 |
return (NULL); |
| 295 |
hashp->BSIZE = statbuf.st_blksize; |
| 296 |
if (hashp->BSIZE > MAX_BSIZE) |
| 297 |
hashp->BSIZE = MAX_BSIZE; |
| 298 |
hashp->BSHIFT = __log2(hashp->BSIZE); |
| 299 |
} |
| 300 |
|
| 301 |
if (info) { |
| 302 |
if (info->bsize) { |
| 303 |
/* Round pagesize up to power of 2 */ |
| 304 |
hashp->BSHIFT = __log2(info->bsize); |
| 305 |
hashp->BSIZE = 1 << hashp->BSHIFT; |
| 306 |
if (hashp->BSIZE > MAX_BSIZE) { |
| 307 |
errno = EINVAL; |
| 308 |
return (NULL); |
| 309 |
} |
| 310 |
} |
| 311 |
if (info->ffactor) |
| 312 |
hashp->FFACTOR = info->ffactor; |
| 313 |
if (info->hash) |
| 314 |
hashp->hash = info->hash; |
| 315 |
if (info->nelem) |
| 316 |
nelem = info->nelem; |
| 317 |
if (info->lorder) { |
| 318 |
if (info->lorder != BIG_ENDIAN && |
| 319 |
info->lorder != LITTLE_ENDIAN) { |
| 320 |
errno = EINVAL; |
| 321 |
return (NULL); |
| 322 |
} |
| 323 |
hashp->LORDER = info->lorder; |
| 324 |
} |
| 325 |
} |
| 326 |
/* init_htab should destroy the table and set errno if it fails */ |
| 327 |
if (init_htab(hashp, nelem)) |
| 328 |
return (NULL); |
| 329 |
else |
| 330 |
return (hashp); |
| 331 |
} |
| 332 |
/* |
| 333 |
* This calls alloc_segs which may run out of memory. Alloc_segs will destroy |
| 334 |
* the table and set errno, so we just pass the error information along. |
| 335 |
* |
| 336 |
* Returns 0 on No Error |
| 337 |
*/ |
| 338 |
static int |
| 339 |
init_htab(HTAB *hashp, int nelem) |
| 340 |
{ |
| 341 |
int nbuckets, nsegs, l2; |
| 342 |
|
| 343 |
/* |
| 344 |
* Divide number of elements by the fill factor and determine a |
| 345 |
* desired number of buckets. Allocate space for the next greater |
| 346 |
* power of two number of buckets. |
| 347 |
*/ |
| 348 |
nelem = (nelem - 1) / hashp->FFACTOR + 1; |
| 349 |
|
| 350 |
l2 = __log2(MAX(nelem, 2)); |
| 351 |
nbuckets = 1 << l2; |
| 352 |
|
| 353 |
hashp->SPARES[l2] = l2 + 1; |
| 354 |
hashp->SPARES[l2 + 1] = l2 + 1; |
| 355 |
hashp->OVFL_POINT = l2; |
| 356 |
hashp->LAST_FREED = 2; |
| 357 |
|
| 358 |
/* First bitmap page is at: splitpoint l2 page offset 1 */ |
| 359 |
if (__ibitmap(hashp, OADDR_OF(l2, 1), l2 + 1, 0)) |
| 360 |
return (-1); |
| 361 |
|
| 362 |
hashp->MAX_BUCKET = hashp->LOW_MASK = nbuckets - 1; |
| 363 |
hashp->HIGH_MASK = (nbuckets << 1) - 1; |
| 364 |
hashp->HDRPAGES = ((MAX(sizeof(HASHHDR), MINHDRSIZE) - 1) >> |
| 365 |
hashp->BSHIFT) + 1; |
| 366 |
|
| 367 |
nsegs = (nbuckets - 1) / hashp->SGSIZE + 1; |
| 368 |
nsegs = 1 << __log2(nsegs); |
| 369 |
|
| 370 |
if (nsegs > hashp->DSIZE) |
| 371 |
hashp->DSIZE = nsegs; |
| 372 |
return (alloc_segs(hashp, nsegs)); |
| 373 |
} |
| 374 |
|
| 375 |
/********************** DESTROY/CLOSE ROUTINES ************************/ |
| 376 |
|
| 377 |
/* |
| 378 |
* Flushes any changes to the file if necessary and destroys the hashp |
| 379 |
* structure, freeing all allocated space. |
| 380 |
*/ |
| 381 |
static int |
| 382 |
hdestroy(HTAB *hashp) |
| 383 |
{ |
| 384 |
int i, save_errno; |
| 385 |
|
| 386 |
save_errno = 0; |
| 387 |
|
| 388 |
#ifdef HASH_STATISTICS |
| 389 |
(void)fprintf(stderr, "hdestroy: accesses %ld collisions %ld\n", |
| 390 |
hash_accesses, hash_collisions); |
| 391 |
(void)fprintf(stderr, "hdestroy: expansions %ld\n", |
| 392 |
hash_expansions); |
| 393 |
(void)fprintf(stderr, "hdestroy: overflows %ld\n", |
| 394 |
hash_overflows); |
| 395 |
(void)fprintf(stderr, "keys %ld maxp %d segmentcount %d\n", |
| 396 |
hashp->NKEYS, hashp->MAX_BUCKET, hashp->nsegs); |
| 397 |
|
| 398 |
for (i = 0; i < NCACHED; i++) |
| 399 |
(void)fprintf(stderr, |
| 400 |
"spares[%d] = %d\n", i, hashp->SPARES[i]); |
| 401 |
#endif |
| 402 |
/* |
| 403 |
* Call on buffer manager to free buffers, and if required, |
| 404 |
* write them to disk. |
| 405 |
*/ |
| 406 |
if (__buf_free(hashp, 1, hashp->save_file)) |
| 407 |
save_errno = errno; |
| 408 |
if (hashp->dir) { |
| 409 |
free(*hashp->dir); /* Free initial segments */ |
| 410 |
/* Free extra segments */ |
| 411 |
while (hashp->exsegs--) |
| 412 |
free(hashp->dir[--hashp->nsegs]); |
| 413 |
free(hashp->dir); |
| 414 |
} |
| 415 |
if (flush_meta(hashp) && !save_errno) |
| 416 |
save_errno = errno; |
| 417 |
/* Free Bigmaps */ |
| 418 |
for (i = 0; i < hashp->nmaps; i++) |
| 419 |
if (hashp->mapp[i]) |
| 420 |
free(hashp->mapp[i]); |
| 421 |
if (hashp->tmp_key) |
| 422 |
free(hashp->tmp_key); |
| 423 |
if (hashp->tmp_buf) |
| 424 |
free(hashp->tmp_buf); |
| 425 |
|
| 426 |
if (hashp->fp != -1) { |
| 427 |
if (hashp->save_file) |
| 428 |
(void)_fsync(hashp->fp); |
| 429 |
(void)_close(hashp->fp); |
| 430 |
} |
| 431 |
|
| 432 |
free(hashp); |
| 433 |
|
| 434 |
if (save_errno) { |
| 435 |
errno = save_errno; |
| 436 |
return (ERROR); |
| 437 |
} |
| 438 |
return (SUCCESS); |
| 439 |
} |
| 440 |
/* |
| 441 |
* Write modified pages to disk |
| 442 |
* |
| 443 |
* Returns: |
| 444 |
* 0 == OK |
| 445 |
* -1 ERROR |
| 446 |
*/ |
| 447 |
static int |
| 448 |
hash_sync(const DB *dbp, u_int32_t flags) |
| 449 |
{ |
| 450 |
HTAB *hashp; |
| 451 |
|
| 452 |
if (flags != 0) { |
| 453 |
errno = EINVAL; |
| 454 |
return (ERROR); |
| 455 |
} |
| 456 |
|
| 457 |
if (!dbp) |
| 458 |
return (ERROR); |
| 459 |
|
| 460 |
hashp = (HTAB *)dbp->internal; |
| 461 |
if (!hashp->save_file) |
| 462 |
return (0); |
| 463 |
if (__buf_free(hashp, 0, 1) || flush_meta(hashp)) |
| 464 |
return (ERROR); |
| 465 |
if (hashp->fp != -1 && _fsync(hashp->fp) != 0) |
| 466 |
return (ERROR); |
| 467 |
hashp->new_file = 0; |
| 468 |
return (0); |
| 469 |
} |
| 470 |
|
| 471 |
/* |
| 472 |
* Returns: |
| 473 |
* 0 == OK |
| 474 |
* -1 indicates that errno should be set |
| 475 |
*/ |
| 476 |
static int |
| 477 |
flush_meta(HTAB *hashp) |
| 478 |
{ |
| 479 |
HASHHDR *whdrp; |
| 480 |
#if BYTE_ORDER == LITTLE_ENDIAN |
| 481 |
HASHHDR whdr; |
| 482 |
#endif |
| 483 |
int fp, i, wsize; |
| 484 |
|
| 485 |
if (!hashp->save_file) |
| 486 |
return (0); |
| 487 |
hashp->MAGIC = HASHMAGIC; |
| 488 |
hashp->VERSION = HASHVERSION; |
| 489 |
hashp->H_CHARKEY = hashp->hash(CHARKEY, sizeof(CHARKEY)); |
| 490 |
|
| 491 |
fp = hashp->fp; |
| 492 |
whdrp = &hashp->hdr; |
| 493 |
#if BYTE_ORDER == LITTLE_ENDIAN |
| 494 |
whdrp = &whdr; |
| 495 |
swap_header_copy(&hashp->hdr, whdrp); |
| 496 |
#endif |
| 497 |
if ((wsize = pwrite(fp, whdrp, sizeof(HASHHDR), (off_t)0)) == -1) |
| 498 |
return (-1); |
| 499 |
else |
| 500 |
if (wsize != sizeof(HASHHDR)) { |
| 501 |
errno = EFTYPE; |
| 502 |
hashp->error = errno; |
| 503 |
return (-1); |
| 504 |
} |
| 505 |
for (i = 0; i < NCACHED; i++) |
| 506 |
if (hashp->mapp[i]) |
| 507 |
if (__put_page(hashp, (char *)hashp->mapp[i], |
| 508 |
hashp->BITMAPS[i], 0, 1)) |
| 509 |
return (-1); |
| 510 |
return (0); |
| 511 |
} |
| 512 |
|
| 513 |
/*******************************SEARCH ROUTINES *****************************/ |
| 514 |
/* |
| 515 |
* All the access routines return |
| 516 |
* |
| 517 |
* Returns: |
| 518 |
* 0 on SUCCESS |
| 519 |
* 1 to indicate an external ERROR (i.e. key not found, etc) |
| 520 |
* -1 to indicate an internal ERROR (i.e. out of memory, etc) |
| 521 |
*/ |
| 522 |
static int |
| 523 |
hash_get(const DB *dbp, const DBT *key, DBT *data, u_int32_t flag) |
| 524 |
{ |
| 525 |
HTAB *hashp; |
| 526 |
|
| 527 |
hashp = (HTAB *)dbp->internal; |
| 528 |
if (flag) { |
| 529 |
hashp->error = errno = EINVAL; |
| 530 |
return (ERROR); |
| 531 |
} |
| 532 |
return (hash_access(hashp, HASH_GET, (DBT *)key, data)); |
| 533 |
} |
| 534 |
|
| 535 |
static int |
| 536 |
hash_put(const DB *dbp, DBT *key, const DBT *data, u_int32_t flag) |
| 537 |
{ |
| 538 |
HTAB *hashp; |
| 539 |
|
| 540 |
hashp = (HTAB *)dbp->internal; |
| 541 |
if (flag && flag != R_NOOVERWRITE) { |
| 542 |
hashp->error = errno = EINVAL; |
| 543 |
return (ERROR); |
| 544 |
} |
| 545 |
if ((hashp->flags & O_ACCMODE) == O_RDONLY) { |
| 546 |
hashp->error = errno = EPERM; |
| 547 |
return (ERROR); |
| 548 |
} |
| 549 |
return (hash_access(hashp, flag == R_NOOVERWRITE ? |
| 550 |
HASH_PUTNEW : HASH_PUT, (DBT *)key, (DBT *)data)); |
| 551 |
} |
| 552 |
|
| 553 |
static int |
| 554 |
hash_delete(const DB *dbp, const DBT *key, |
| 555 |
u_int32_t flag) /* Ignored */ |
| 556 |
{ |
| 557 |
HTAB *hashp; |
| 558 |
|
| 559 |
hashp = (HTAB *)dbp->internal; |
| 560 |
if (flag && flag != R_CURSOR) { |
| 561 |
hashp->error = errno = EINVAL; |
| 562 |
return (ERROR); |
| 563 |
} |
| 564 |
if ((hashp->flags & O_ACCMODE) == O_RDONLY) { |
| 565 |
hashp->error = errno = EPERM; |
| 566 |
return (ERROR); |
| 567 |
} |
| 568 |
return (hash_access(hashp, HASH_DELETE, (DBT *)key, NULL)); |
| 569 |
} |
| 570 |
|
| 571 |
/* |
| 572 |
* Assume that hashp has been set in wrapper routine. |
| 573 |
*/ |
| 574 |
static int |
| 575 |
hash_access(HTAB *hashp, ACTION action, DBT *key, DBT *val) |
| 576 |
{ |
| 577 |
BUFHEAD *rbufp; |
| 578 |
BUFHEAD *bufp, *save_bufp; |
| 579 |
u_int16_t *bp; |
| 580 |
int n, ndx, off, size; |
| 581 |
char *kp; |
| 582 |
u_int16_t pageno; |
| 583 |
|
| 584 |
#ifdef HASH_STATISTICS |
| 585 |
hash_accesses++; |
| 586 |
#endif |
| 587 |
|
| 588 |
off = hashp->BSIZE; |
| 589 |
size = key->size; |
| 590 |
kp = (char *)key->data; |
| 591 |
rbufp = __get_buf(hashp, __call_hash(hashp, kp, size), NULL, 0); |
| 592 |
if (!rbufp) |
| 593 |
return (ERROR); |
| 594 |
save_bufp = rbufp; |
| 595 |
|
| 596 |
/* Pin the bucket chain */ |
| 597 |
rbufp->flags |= BUF_PIN; |
| 598 |
for (bp = (u_int16_t *)rbufp->page, n = *bp++, ndx = 1; ndx < n;) |
| 599 |
if (bp[1] >= REAL_KEY) { |
| 600 |
/* Real key/data pair */ |
| 601 |
if (size == off - *bp && |
| 602 |
memcmp(kp, rbufp->page + *bp, size) == 0) |
| 603 |
goto found; |
| 604 |
off = bp[1]; |
| 605 |
#ifdef HASH_STATISTICS |
| 606 |
hash_collisions++; |
| 607 |
#endif |
| 608 |
bp += 2; |
| 609 |
ndx += 2; |
| 610 |
} else if (bp[1] == OVFLPAGE) { |
| 611 |
rbufp = __get_buf(hashp, *bp, rbufp, 0); |
| 612 |
if (!rbufp) { |
| 613 |
save_bufp->flags &= ~BUF_PIN; |
| 614 |
return (ERROR); |
| 615 |
} |
| 616 |
/* FOR LOOP INIT */ |
| 617 |
bp = (u_int16_t *)rbufp->page; |
| 618 |
n = *bp++; |
| 619 |
ndx = 1; |
| 620 |
off = hashp->BSIZE; |
| 621 |
} else if (bp[1] < REAL_KEY) { |
| 622 |
if ((ndx = |
| 623 |
__find_bigpair(hashp, rbufp, ndx, kp, size)) > 0) |
| 624 |
goto found; |
| 625 |
if (ndx == -2) { |
| 626 |
bufp = rbufp; |
| 627 |
if (!(pageno = |
| 628 |
__find_last_page(hashp, &bufp))) { |
| 629 |
ndx = 0; |
| 630 |
rbufp = bufp; |
| 631 |
break; /* FOR */ |
| 632 |
} |
| 633 |
rbufp = __get_buf(hashp, pageno, bufp, 0); |
| 634 |
if (!rbufp) { |
| 635 |
save_bufp->flags &= ~BUF_PIN; |
| 636 |
return (ERROR); |
| 637 |
} |
| 638 |
/* FOR LOOP INIT */ |
| 639 |
bp = (u_int16_t *)rbufp->page; |
| 640 |
n = *bp++; |
| 641 |
ndx = 1; |
| 642 |
off = hashp->BSIZE; |
| 643 |
} else { |
| 644 |
save_bufp->flags &= ~BUF_PIN; |
| 645 |
return (ERROR); |
| 646 |
} |
| 647 |
} |
| 648 |
|
| 649 |
/* Not found */ |
| 650 |
switch (action) { |
| 651 |
case HASH_PUT: |
| 652 |
case HASH_PUTNEW: |
| 653 |
if (__addel(hashp, rbufp, key, val)) { |
| 654 |
save_bufp->flags &= ~BUF_PIN; |
| 655 |
return (ERROR); |
| 656 |
} else { |
| 657 |
save_bufp->flags &= ~BUF_PIN; |
| 658 |
return (SUCCESS); |
| 659 |
} |
| 660 |
case HASH_GET: |
| 661 |
case HASH_DELETE: |
| 662 |
default: |
| 663 |
save_bufp->flags &= ~BUF_PIN; |
| 664 |
return (ABNORMAL); |
| 665 |
} |
| 666 |
|
| 667 |
found: |
| 668 |
switch (action) { |
| 669 |
case HASH_PUTNEW: |
| 670 |
save_bufp->flags &= ~BUF_PIN; |
| 671 |
return (ABNORMAL); |
| 672 |
case HASH_GET: |
| 673 |
bp = (u_int16_t *)rbufp->page; |
| 674 |
if (bp[ndx + 1] < REAL_KEY) { |
| 675 |
if (__big_return(hashp, rbufp, ndx, val, 0)) |
| 676 |
return (ERROR); |
| 677 |
} else { |
| 678 |
val->data = (u_char *)rbufp->page + (int)bp[ndx + 1]; |
| 679 |
val->size = bp[ndx] - bp[ndx + 1]; |
| 680 |
} |
| 681 |
break; |
| 682 |
case HASH_PUT: |
| 683 |
if ((__delpair(hashp, rbufp, ndx)) || |
| 684 |
(__addel(hashp, rbufp, key, val))) { |
| 685 |
save_bufp->flags &= ~BUF_PIN; |
| 686 |
return (ERROR); |
| 687 |
} |
| 688 |
break; |
| 689 |
case HASH_DELETE: |
| 690 |
if (__delpair(hashp, rbufp, ndx)) |
| 691 |
return (ERROR); |
| 692 |
break; |
| 693 |
default: |
| 694 |
abort(); |
| 695 |
} |
| 696 |
save_bufp->flags &= ~BUF_PIN; |
| 697 |
return (SUCCESS); |
| 698 |
} |
| 699 |
|
| 700 |
static int |
| 701 |
hash_seq(const DB *dbp, DBT *key, DBT *data, u_int32_t flag) |
| 702 |
{ |
| 703 |
u_int32_t bucket; |
| 704 |
BUFHEAD *bufp; |
| 705 |
HTAB *hashp; |
| 706 |
u_int16_t *bp, ndx; |
| 707 |
|
| 708 |
hashp = (HTAB *)dbp->internal; |
| 709 |
if (flag && flag != R_FIRST && flag != R_NEXT) { |
| 710 |
hashp->error = errno = EINVAL; |
| 711 |
return (ERROR); |
| 712 |
} |
| 713 |
#ifdef HASH_STATISTICS |
| 714 |
hash_accesses++; |
| 715 |
#endif |
| 716 |
if ((hashp->cbucket < 0) || (flag == R_FIRST)) { |
| 717 |
hashp->cbucket = 0; |
| 718 |
hashp->cndx = 1; |
| 719 |
hashp->cpage = NULL; |
| 720 |
} |
| 721 |
next_bucket: |
| 722 |
for (bp = NULL; !bp || !bp[0]; ) { |
| 723 |
if (!(bufp = hashp->cpage)) { |
| 724 |
for (bucket = hashp->cbucket; |
| 725 |
bucket <= hashp->MAX_BUCKET; |
| 726 |
bucket++, hashp->cndx = 1) { |
| 727 |
bufp = __get_buf(hashp, bucket, NULL, 0); |
| 728 |
if (!bufp) |
| 729 |
return (ERROR); |
| 730 |
hashp->cpage = bufp; |
| 731 |
bp = (u_int16_t *)bufp->page; |
| 732 |
if (bp[0]) |
| 733 |
break; |
| 734 |
} |
| 735 |
hashp->cbucket = bucket; |
| 736 |
if ((u_int32_t)hashp->cbucket > hashp->MAX_BUCKET) { |
| 737 |
hashp->cbucket = -1; |
| 738 |
return (ABNORMAL); |
| 739 |
} |
| 740 |
} else { |
| 741 |
bp = (u_int16_t *)hashp->cpage->page; |
| 742 |
if (flag == R_NEXT || flag == 0) { |
| 743 |
hashp->cndx += 2; |
| 744 |
if (hashp->cndx > bp[0]) { |
| 745 |
hashp->cpage = NULL; |
| 746 |
hashp->cbucket++; |
| 747 |
hashp->cndx = 1; |
| 748 |
goto next_bucket; |
| 749 |
} |
| 750 |
} |
| 751 |
} |
| 752 |
|
| 753 |
#ifdef DEBUG |
| 754 |
assert(bp); |
| 755 |
assert(bufp); |
| 756 |
#endif |
| 757 |
while (bp[hashp->cndx + 1] == OVFLPAGE) { |
| 758 |
bufp = hashp->cpage = |
| 759 |
__get_buf(hashp, bp[hashp->cndx], bufp, 0); |
| 760 |
if (!bufp) |
| 761 |
return (ERROR); |
| 762 |
bp = (u_int16_t *)(bufp->page); |
| 763 |
hashp->cndx = 1; |
| 764 |
} |
| 765 |
if (!bp[0]) { |
| 766 |
hashp->cpage = NULL; |
| 767 |
++hashp->cbucket; |
| 768 |
} |
| 769 |
} |
| 770 |
ndx = hashp->cndx; |
| 771 |
if (bp[ndx + 1] < REAL_KEY) { |
| 772 |
if (__big_keydata(hashp, bufp, key, data, 1)) |
| 773 |
return (ERROR); |
| 774 |
} else { |
| 775 |
if (hashp->cpage == NULL) |
| 776 |
return (ERROR); |
| 777 |
key->data = (u_char *)hashp->cpage->page + bp[ndx]; |
| 778 |
key->size = (ndx > 1 ? bp[ndx - 1] : hashp->BSIZE) - bp[ndx]; |
| 779 |
data->data = (u_char *)hashp->cpage->page + bp[ndx + 1]; |
| 780 |
data->size = bp[ndx] - bp[ndx + 1]; |
| 781 |
} |
| 782 |
return (SUCCESS); |
| 783 |
} |
| 784 |
|
| 785 |
/********************************* UTILITIES ************************/ |
| 786 |
|
| 787 |
/* |
| 788 |
* Returns: |
| 789 |
* 0 ==> OK |
| 790 |
* -1 ==> Error |
| 791 |
*/ |
| 792 |
int |
| 793 |
__expand_table(HTAB *hashp) |
| 794 |
{ |
| 795 |
u_int32_t old_bucket, new_bucket; |
| 796 |
int dirsize, new_segnum, spare_ndx; |
| 797 |
|
| 798 |
#ifdef HASH_STATISTICS |
| 799 |
hash_expansions++; |
| 800 |
#endif |
| 801 |
new_bucket = ++hashp->MAX_BUCKET; |
| 802 |
old_bucket = (hashp->MAX_BUCKET & hashp->LOW_MASK); |
| 803 |
|
| 804 |
new_segnum = new_bucket >> hashp->SSHIFT; |
| 805 |
|
| 806 |
/* Check if we need a new segment */ |
| 807 |
if (new_segnum >= hashp->nsegs) { |
| 808 |
/* Check if we need to expand directory */ |
| 809 |
if (new_segnum >= hashp->DSIZE) { |
| 810 |
/* Reallocate directory */ |
| 811 |
dirsize = hashp->DSIZE * sizeof(SEGMENT *); |
| 812 |
if (!hash_realloc(&hashp->dir, dirsize, dirsize << 1)) |
| 813 |
return (-1); |
| 814 |
hashp->DSIZE = dirsize << 1; |
| 815 |
} |
| 816 |
if ((hashp->dir[new_segnum] = |
| 817 |
(SEGMENT)calloc(hashp->SGSIZE, sizeof(SEGMENT))) == NULL) |
| 818 |
return (-1); |
| 819 |
hashp->exsegs++; |
| 820 |
hashp->nsegs++; |
| 821 |
} |
| 822 |
/* |
| 823 |
* If the split point is increasing (MAX_BUCKET's log base 2 |
| 824 |
* * increases), we need to copy the current contents of the spare |
| 825 |
* split bucket to the next bucket. |
| 826 |
*/ |
| 827 |
spare_ndx = __log2(hashp->MAX_BUCKET + 1); |
| 828 |
if (spare_ndx > hashp->OVFL_POINT) { |
| 829 |
hashp->SPARES[spare_ndx] = hashp->SPARES[hashp->OVFL_POINT]; |
| 830 |
hashp->OVFL_POINT = spare_ndx; |
| 831 |
} |
| 832 |
|
| 833 |
if (new_bucket > hashp->HIGH_MASK) { |
| 834 |
/* Starting a new doubling */ |
| 835 |
hashp->LOW_MASK = hashp->HIGH_MASK; |
| 836 |
hashp->HIGH_MASK = new_bucket | hashp->LOW_MASK; |
| 837 |
} |
| 838 |
/* Relocate records to the new bucket */ |
| 839 |
return (__split_page(hashp, old_bucket, new_bucket)); |
| 840 |
} |
| 841 |
|
| 842 |
/* |
| 843 |
* If realloc guarantees that the pointer is not destroyed if the realloc |
| 844 |
* fails, then this routine can go away. |
| 845 |
*/ |
| 846 |
static void * |
| 847 |
hash_realloc(SEGMENT **p_ptr, int oldsize, int newsize) |
| 848 |
{ |
| 849 |
void *p; |
| 850 |
|
| 851 |
if ( (p = malloc(newsize)) ) { |
| 852 |
memmove(p, *p_ptr, oldsize); |
| 853 |
memset((char *)p + oldsize, 0, newsize - oldsize); |
| 854 |
free(*p_ptr); |
| 855 |
*p_ptr = p; |
| 856 |
} |
| 857 |
return (p); |
| 858 |
} |
| 859 |
|
| 860 |
u_int32_t |
| 861 |
__call_hash(HTAB *hashp, char *k, int len) |
| 862 |
{ |
| 863 |
unsigned int n, bucket; |
| 864 |
|
| 865 |
n = hashp->hash(k, len); |
| 866 |
bucket = n & hashp->HIGH_MASK; |
| 867 |
if (bucket > hashp->MAX_BUCKET) |
| 868 |
bucket = bucket & hashp->LOW_MASK; |
| 869 |
return (bucket); |
| 870 |
} |
| 871 |
|
| 872 |
/* |
| 873 |
* Allocate segment table. On error, destroy the table and set errno. |
| 874 |
* |
| 875 |
* Returns 0 on success |
| 876 |
*/ |
| 877 |
static int |
| 878 |
alloc_segs(HTAB *hashp, int nsegs) |
| 879 |
{ |
| 880 |
int i; |
| 881 |
SEGMENT store; |
| 882 |
|
| 883 |
int save_errno; |
| 884 |
|
| 885 |
if ((hashp->dir = |
| 886 |
(SEGMENT *)calloc(hashp->DSIZE, sizeof(SEGMENT *))) == NULL) { |
| 887 |
save_errno = errno; |
| 888 |
(void)hdestroy(hashp); |
| 889 |
errno = save_errno; |
| 890 |
return (-1); |
| 891 |
} |
| 892 |
hashp->nsegs = nsegs; |
| 893 |
if (nsegs == 0) |
| 894 |
return (0); |
| 895 |
/* Allocate segments */ |
| 896 |
if ((store = (SEGMENT)calloc(nsegs << hashp->SSHIFT, |
| 897 |
sizeof(SEGMENT))) == NULL) { |
| 898 |
save_errno = errno; |
| 899 |
(void)hdestroy(hashp); |
| 900 |
errno = save_errno; |
| 901 |
return (-1); |
| 902 |
} |
| 903 |
for (i = 0; i < nsegs; i++) |
| 904 |
hashp->dir[i] = &store[i << hashp->SSHIFT]; |
| 905 |
return (0); |
| 906 |
} |
| 907 |
|
| 908 |
#if BYTE_ORDER == LITTLE_ENDIAN |
| 909 |
/* |
| 910 |
* Hashp->hdr needs to be byteswapped. |
| 911 |
*/ |
| 912 |
static void |
| 913 |
swap_header_copy(HASHHDR *srcp, HASHHDR *destp) |
| 914 |
{ |
| 915 |
int i; |
| 916 |
|
| 917 |
P_32_COPY(srcp->magic, destp->magic); |
| 918 |
P_32_COPY(srcp->version, destp->version); |
| 919 |
P_32_COPY(srcp->lorder, destp->lorder); |
| 920 |
P_32_COPY(srcp->bsize, destp->bsize); |
| 921 |
P_32_COPY(srcp->bshift, destp->bshift); |
| 922 |
P_32_COPY(srcp->dsize, destp->dsize); |
| 923 |
P_32_COPY(srcp->ssize, destp->ssize); |
| 924 |
P_32_COPY(srcp->sshift, destp->sshift); |
| 925 |
P_32_COPY(srcp->ovfl_point, destp->ovfl_point); |
| 926 |
P_32_COPY(srcp->last_freed, destp->last_freed); |
| 927 |
P_32_COPY(srcp->max_bucket, destp->max_bucket); |
| 928 |
P_32_COPY(srcp->high_mask, destp->high_mask); |
| 929 |
P_32_COPY(srcp->low_mask, destp->low_mask); |
| 930 |
P_32_COPY(srcp->ffactor, destp->ffactor); |
| 931 |
P_32_COPY(srcp->nkeys, destp->nkeys); |
| 932 |
P_32_COPY(srcp->hdrpages, destp->hdrpages); |
| 933 |
P_32_COPY(srcp->h_charkey, destp->h_charkey); |
| 934 |
for (i = 0; i < NCACHED; i++) { |
| 935 |
P_32_COPY(srcp->spares[i], destp->spares[i]); |
| 936 |
P_16_COPY(srcp->bitmaps[i], destp->bitmaps[i]); |
| 937 |
} |
| 938 |
} |
| 939 |
|
| 940 |
static void |
| 941 |
swap_header(HTAB *hashp) |
| 942 |
{ |
| 943 |
HASHHDR *hdrp; |
| 944 |
int i; |
| 945 |
|
| 946 |
hdrp = &hashp->hdr; |
| 947 |
|
| 948 |
M_32_SWAP(hdrp->magic); |
| 949 |
M_32_SWAP(hdrp->version); |
| 950 |
M_32_SWAP(hdrp->lorder); |
| 951 |
M_32_SWAP(hdrp->bsize); |
| 952 |
M_32_SWAP(hdrp->bshift); |
| 953 |
M_32_SWAP(hdrp->dsize); |
| 954 |
M_32_SWAP(hdrp->ssize); |
| 955 |
M_32_SWAP(hdrp->sshift); |
| 956 |
M_32_SWAP(hdrp->ovfl_point); |
| 957 |
M_32_SWAP(hdrp->last_freed); |
| 958 |
M_32_SWAP(hdrp->max_bucket); |
| 959 |
M_32_SWAP(hdrp->high_mask); |
| 960 |
M_32_SWAP(hdrp->low_mask); |
| 961 |
M_32_SWAP(hdrp->ffactor); |
| 962 |
M_32_SWAP(hdrp->nkeys); |
| 963 |
M_32_SWAP(hdrp->hdrpages); |
| 964 |
M_32_SWAP(hdrp->h_charkey); |
| 965 |
for (i = 0; i < NCACHED; i++) { |
| 966 |
M_32_SWAP(hdrp->spares[i]); |
| 967 |
M_16_SWAP(hdrp->bitmaps[i]); |
| 968 |
} |
| 969 |
} |
| 970 |
#endif |
