/*
* 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 > hashp->DSIZE)
hashp->DSIZE = nsegs;
return (alloc_segs(hashp, (int)nsegs));
}
/* ARGSUSED */
DB *
__hash_open(const char *file, int flags, int 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;
if (file) {
if ((hashp->fp = _open(file, flags | O_CLOEXEC, mode)) == -1)
RETURN_ERROR(errno, error0);
new_table = _fstat(hashp->fp, &statbuf) == 0 &&
statbuf.st_size == 0 && (flags & O_ACCMODE) != O_RDONLY;
} else
new_table = 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 ((int32_t)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;
if (alloc_segs(hashp, nsegs))
/*
* If alloc_segs fails, table will have been destroyed
* and errno will have been set.
*/
return (NULL);
/* Read in bitmaps */
bpages = (hashp->SPARES[hashp->OVFL_POINT] +
(hashp->BSIZE << BYTE_SHIFT) - 1) >>
(hashp->BSHIFT + BYTE_SHIFT);
hashp->nmaps = bpages;
(void)memset(&hashp->mapp[0], 0, bpages * sizeof(u_int32_t *));
}
/* Initialize Buffer Manager */
if (info && info->cachesize)
__buf_init(hashp, info->cachesize);
else
__buf_init(hashp, DEF_BUFSIZE);
hashp->new_file = new_table;
hashp->save_file = file && (hashp->flags & O_RDWR);
hashp->cbucket = -1;
if (!(dbp = (DB *)malloc(sizeof(DB)))) {
save_errno = errno;
hdestroy(hashp);
errno = save_errno;
return (NULL);
}
dbp->internal = hashp;
dbp->close = hash_close;
dbp->del = hash_delete;
dbp->fd = hash_fd;
dbp->get = hash_get;
dbp->put = hash_put;
dbp->seq = hash_seq;
dbp->sync = hash_sync;
dbp->type = DB_HASH;
#ifdef DEBUG
(void)fprintf(stderr,
"%s\n%s%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);
}
extern DB *
__hash_open(const char *file, int flags, int mode, const HASHINFO *info, int dflags)
{
HTAB *hashp=NULL;
struct stat statbuf;
DB *dbp;
int bpages, hdrsize, new_table, nsegs, save_errno;
if ((flags & O_ACCMODE) == O_WRONLY) {
errno = EINVAL;
return NULL;
}
/* zero the statbuffer so that
* we can check it for a non-zero
* date to see if stat succeeded
*/
memset(&statbuf, 0, sizeof(struct stat));
if (!(hashp = (HTAB *)calloc(1, sizeof(HTAB)))) {
errno = ENOMEM;
return NULL;
}
hashp->fp = NO_FILE;
if(file)
hashp->filename = strdup(file);
/*
* 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;
}
else if(statbuf.st_mtime && statbuf.st_size == 0)
{
/* check for a zero length file and delete it
* if it exists
*/
new_table = 1;
}
hashp->file_size = statbuf.st_size;
if (file) {
#if defined(_WIN32) || defined(_WINDOWS) || defined (macintosh) || defined(XP_OS2)
if ((hashp->fp = DBFILE_OPEN(file, flags | O_BINARY, mode)) == -1)
RETURN_ERROR(errno, error1);
#else
if ((hashp->fp = open(file, flags, mode)) == -1)
RETURN_ERROR(errno, error1);
(void)fcntl(hashp->fp, F_SETFD, 1);
#endif
}
if (new_table) {
if (!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, (char *)&hashp->hdr, sizeof(HASHHDR));
if (hdrsize == -1)
RETURN_ERROR(errno, error1);
if (hdrsize != sizeof(HASHHDR))
RETURN_ERROR(EFTYPE, error1);
#if BYTE_ORDER == LITTLE_ENDIAN
swap_header(hashp);
#endif
/* 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);
if (hashp->NKEYS < 0) /* Old bad database. */
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, errno will have been set. */
RETURN_ERROR(errno, error1);
/* 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(uint32 *));
}
/* Initialize Buffer Manager */
if (info && info->cachesize)
__buf_init(hashp, (int32) info->cachesize);
else
__buf_init(hashp, DEF_BUFSIZE);
hashp->new_file = new_table;
#ifdef macintosh
hashp->save_file = file && !(hashp->flags & O_RDONLY);
#else
hashp->save_file = file && (hashp->flags & O_RDWR);
#endif
hashp->cbucket = -1;
if (!(dbp = (DB *)malloc(sizeof(DB)))) {
RETURN_ERROR(ENOMEM, error1);
}
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 HASH_STATISTICS
hash_overflows = hash_accesses = hash_collisions = hash_expansions = 0;
#endif
return (dbp);
error1:
hdestroy(hashp);
errno = save_errno;
return (NULL);
}