diff options
Diffstat (limited to 'db/hash/hash.c')
| -rw-r--r-- | db/hash/hash.c | 999 |
1 files changed, 0 insertions, 999 deletions
diff --git a/db/hash/hash.c b/db/hash/hash.c deleted file mode 100644 index 99592ea..0000000 --- a/db/hash/hash.c +++ /dev/null @@ -1,999 +0,0 @@ -/*- - * Copyright (c) 1990, 1993, 1994 - * The Regents of the University of California. All rights reserved. - * - * This code is derived from software contributed to Berkeley by - * Margo Seltzer. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * 3. All advertising materials mentioning features or use of this software - * must display the following acknowledgement: - * This product includes software developed by the University of - * California, Berkeley and its contributors. - * 4. Neither the name of the University nor the names of its contributors - * may be used to endorse or promote products derived from this software - * without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND - * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE - * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL - * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS - * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) - * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT - * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY - * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - * SUCH DAMAGE. - */ - -#if defined(LIBC_SCCS) && !defined(lint) -static char sccsid[] = "@(#)hash.c 8.9 (Berkeley) 6/16/94"; -#endif /* LIBC_SCCS and not lint */ - -#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 <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); - (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)) - != (u_int32_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] + - (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_ACCMODE) != O_RDONLY; - 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; -{ -#ifdef _STATBUF_ST_BLKSIZE - struct stat statbuf; -#endif - 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 */ -#ifdef _STATBUF_ST_BLKSIZE - if (file != NULL) { - if (stat(file, &statbuf)) - return (NULL); - hashp->BSIZE = statbuf.st_blksize; - hashp->BSHIFT = __hash_log2(hashp->BSIZE); - } -#endif - - if (info) { - if (info->bsize) { - /* Round pagesize up to power of 2 */ - hashp->BSHIFT = __hash_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 = __hash_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 << __hash_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->errnum = 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->errnum = 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->errnum = errno = EINVAL; - return (ERROR); - } - if ((hashp->flags & O_ACCMODE) == O_RDONLY) { - hashp->errnum = 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->errnum = errno = EINVAL; - return (ERROR); - } - if ((hashp->flags & O_ACCMODE) == O_RDONLY) { - hashp->errnum = 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->errnum = 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 <= (u_int32_t) 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 = __hash_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 > (u_int32_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(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 |