/* $NetBSD: hash.c,v 1.16 2002/01/12 11:26:13 aymeric 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. 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. */ #include #if defined(LIBC_SCCS) && !defined(lint) #if 0 static char sccsid[] = "@(#)hash.c 8.9 (Berkeley) 6/16/94"; #else __RCSID("$NetBSD: hash.c,v 1.16 2002/01/12 11:26:13 aymeric Exp $"); #endif #endif /* LIBC_SCCS and not lint */ #include "namespace.h" #include #include #include #include #include #include #include #include #ifdef DEBUG #include #endif #include #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 *, const HASHINFO *)); static int init_htab __P((HTAB *, size_t)); #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 */ /* ARGSUSED */ extern DB * __hash_open(file, flags, mode, info, dflags) const char *file; int flags; mode_t mode; const HASHINFO *info; /* Special directives for create */ int dflags; { HTAB *hashp; struct stat statbuf; DB *dbp; int bpages, hdrsize, new_table, nsegs, save_errno; if ((flags & O_ACCMODE) == O_WRONLY) { errno = EINVAL; return (NULL); } if (!(hashp = (HTAB *)calloc(1, sizeof(HTAB)))) return (NULL); hashp->fp = -1; /* * Even if user wants write only, we need to be able to read * the actual file, so we need to open it read/write. But, the * field in the hashp structure needs to be accurate so that * we can check accesses. */ hashp->flags = flags; 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, 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] + (unsigned int)(hashp->BSIZE << BYTE_SHIFT) - 1) >> (hashp->BSHIFT + BYTE_SHIFT); hashp->nmaps = bpages; (void)memset(&hashp->mapp[0], 0, bpages * sizeof(u_int32_t *)); } /* Initialize Buffer Manager */ if (info && info->cachesize) __buf_init(hashp, info->cachesize); else __buf_init(hashp, DEF_BUFSIZE); hashp->new_file = new_table; hashp->save_file = file && (hashp->flags & O_RDWR); hashp->cbucket = -1; if (!(dbp = (DB *)malloc(sizeof(DB)))) { save_errno = errno; hdestroy(hashp); errno = save_errno; return (NULL); } dbp->internal = hashp; dbp->close = hash_close; dbp->del = hash_delete; dbp->fd = hash_fd; dbp->get = hash_get; dbp->put = hash_put; dbp->seq = hash_seq; dbp->sync = hash_sync; dbp->type = DB_HASH; #ifdef DEBUG (void)fprintf(stderr, "%s\n%s%p\n%s%d\n%s%d\n%s%d\n%s%d\n%s%d\n%s%d\n%s%d\n%s%d\n%s%d\n%s%x\n%s%x\n%s%d\n%s%d\n", "init_htab:", "TABLE POINTER ", hashp, "BUCKET SIZE ", hashp->BSIZE, "BUCKET SHIFT ", hashp->BSHIFT, "DIRECTORY SIZE ", hashp->DSIZE, "SEGMENT SIZE ", hashp->SGSIZE, "SEGMENT SHIFT ", hashp->SSHIFT, "FILL FACTOR ", hashp->FFACTOR, "MAX BUCKET ", hashp->MAX_BUCKET, "OVFL POINT ", hashp->OVFL_POINT, "LAST FREED ", hashp->LAST_FREED, "HIGH MASK ", hashp->HIGH_MASK, "LOW MASK ", hashp->LOW_MASK, "NSEGS ", hashp->nsegs, "NKEYS ", hashp->NKEYS); #endif #ifdef HASH_STATISTICS hash_overflows = hash_accesses = hash_collisions = hash_expansions = 0; #endif return (dbp); error1: if (hashp != NULL) (void)close(hashp->fp); error0: free(hashp); errno = save_errno; return (NULL); } static int hash_close(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; const HASHINFO *info; { struct stat statbuf; int nelem; nelem = 1; hashp->NKEYS = 0; hashp->LORDER = BYTE_ORDER; hashp->BSIZE = DEF_BUCKET_SIZE; hashp->BSHIFT = DEF_BUCKET_SHIFT; hashp->SGSIZE = DEF_SEGSIZE; hashp->SSHIFT = DEF_SEGSIZE_SHIFT; hashp->DSIZE = DEF_DIRSIZE; hashp->FFACTOR = DEF_FFACTOR; hashp->hash = __default_hash; memset(hashp->SPARES, 0, sizeof(hashp->SPARES)); memset(hashp->BITMAPS, 0, sizeof (hashp->BITMAPS)); /* Fix bucket size to be optimal for file system */ if (file != NULL) { if (stat(file, &statbuf)) return (NULL); hashp->BSIZE = statbuf.st_blksize; hashp->BSHIFT = __log2((u_int32_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(hashp, nelem) HTAB *hashp; size_t nelem; { register int nbuckets; u_int32_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; 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, (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 > 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(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 ((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(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->err = errno = EINVAL; return (ERROR); } /* LINTED const castaway */ 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->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, (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->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, 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_t 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, (int)size), NULL, 0); if (!rbufp) return (ERROR); save_bufp = rbufp; /* Pin the bucket chain */ rbufp->flags |= BUF_PIN; for (bp = (u_int16_t *)(void *)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, (u_int32_t)*bp, rbufp, 0); if (!rbufp) { save_bufp->flags &= ~BUF_PIN; return (ERROR); } /* FOR LOOP INIT */ bp = (u_int16_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, (u_int32_t)pageno, bufp, 0); if (!rbufp) { save_bufp->flags &= ~BUF_PIN; return (ERROR); } /* FOR LOOP INIT */ bp = (u_int16_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 = (u_int16_t *)(void *)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->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 <= 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 *)(void *)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 *)(void *)hashp->cpage->page; #ifdef DEBUG assert(bp); assert(bufp); #endif while (bp[hashp->cndx + 1] == OVFLPAGE) { bufp = hashp->cpage = __get_buf(hashp, (u_int32_t)bp[hashp->cndx], bufp, 0); if (!bufp) return (ERROR); bp = (u_int16_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 { 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((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((u_int32_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 > 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((size_t)newsize)) != NULL) { memmove(p, *p_ptr, (size_t)oldsize); memset((char *)p + oldsize, 0, (size_t)(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, (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(hashp, nsegs) HTAB *hashp; int nsegs; { register int i; register SEGMENT store; int save_errno; if ((hashp->dir = (SEGMENT *)calloc((size_t)hashp->DSIZE, sizeof(SEGMENT *))) == NULL) { save_errno = errno; (void)hdestroy(hashp); errno = save_errno; return (-1); } /* Allocate segments */ if ((store = (SEGMENT)calloc((size_t)(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