#include "sdbm.h"
#include "sdbm_tune.h"
#include "sdbm_pair.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#ifdef WIN32
#else
#include <unistd.h>
#endif
static int getdbit proto((DBM *, long));
static int setdbit proto((DBM *, long));
static int getpage proto((DBM *, long));
static datum getnext proto((DBM *));
static int makroom proto((DBM *, long, int));
#define bad(x) ((x).dptr == NULL || (x).dsize <= 0)
#define exhash(item) sdbm_hash((item).dptr, (item).dsize)
#define ioerr(db) ((db)->flags |= DBM_IOERR)
#define OFF_PAG(off) (long) (off) * PBLKSIZ
#define OFF_DIR(off) (long) (off) * DBLKSIZ
static long masks[] = {
000000000000, 000000000001, 000000000003, 000000000007,
000000000017, 000000000037, 000000000077, 000000000177,
000000000377, 000000000777, 000000001777, 000000003777,
000000007777, 000000017777, 000000037777, 000000077777,
000000177777, 000000377777, 000000777777, 000001777777,
000003777777, 000007777777, 000017777777, 000037777777,
000077777777, 000177777777, 000377777777, 000777777777,
001777777777, 003777777777, 007777777777, 017777777777
};
datum nullitem = {NULL, 0};
DBM *
sdbm_open(file, flags, mode)
register char *file;
register int flags;
register int mode;
{
register DBM *db;
register char *dirname;
register char *pagname;
register int n;
if (file == NULL || !*file)
return errno = EINVAL, (DBM *) NULL;
n = strlen(file) * 2 + strlen(DIRFEXT) + strlen(PAGFEXT) + 2;
if ((dirname = malloc((unsigned) n)) == NULL)
return errno = ENOMEM, (DBM *) NULL;
dirname = strcat(strcpy(dirname, file), DIRFEXT);
pagname = strcpy(dirname + strlen(dirname) + 1, file);
pagname = strcat(pagname, PAGFEXT);
db = sdbm_prep(dirname, pagname, flags, mode);
free((char *) dirname);
return db;
}
DBM *
sdbm_prep(dirname, pagname, flags, mode)
char *dirname;
char *pagname;
int flags;
int mode;
{
register DBM *db;
struct stat dstat;
if ((db = (DBM *) malloc(sizeof(DBM))) == NULL)
return errno = ENOMEM, (DBM *) NULL;
db->flags = 0;
db->hmask = 0;
db->blkptr = 0;
db->keyptr = 0;
if (flags & O_WRONLY)
flags = (flags & ~O_WRONLY) | O_RDWR;
else if ((flags & 03) == O_RDONLY)
db->flags = DBM_RDONLY;
#if defined(OS2) || defined(MSDOS) || defined(WIN32)
flags |= O_BINARY;
#endif
if ((db->pagf = open(pagname, flags, mode)) > -1) {
if ( sdbm_fd_lock(db->pagf, sdbm_rdonly(db)) > -1 ) {
if ((db->dirf = open(dirname, flags, mode)) > -1) {
if (fstat(db->dirf, &dstat) == 0) {
db->dirbno = (!dstat.st_size) ? 0 : -1;
db->pagbno = -1;
db->maxbno = dstat.st_size * BYTESIZ;
(void) memset(db->pagbuf, 0, PBLKSIZ);
(void) memset(db->dirbuf, 0, DBLKSIZ);
return db;
}
(void) close(db->dirf);
}
(void) sdbm_fd_unlock(db->pagf);
}
(void) close(db->pagf);
}
free((char *) db);
return (DBM *) NULL;
}
void
sdbm_close(db)
register DBM *db;
{
if (db == NULL)
errno = EINVAL;
else {
(void) close(db->dirf);
(void) sdbm_fd_unlock(db->pagf);
(void) close(db->pagf);
free((char *) db);
}
}
datum
sdbm_fetch(db, key)
register DBM *db;
datum key;
{
if (db == NULL || bad(key))
return errno = EINVAL, nullitem;
if (getpage(db, exhash(key)))
return getpair(db->pagbuf, key);
return ioerr(db), nullitem;
}
int
sdbm_delete(db, key)
register DBM *db;
datum key;
{
if (db == NULL || bad(key))
return errno = EINVAL, -1;
if (sdbm_rdonly(db))
return errno = EPERM, -1;
if (getpage(db, exhash(key))) {
if (!delpair(db->pagbuf, key))
return -1;
if (lseek(db->pagf, OFF_PAG(db->pagbno), SEEK_SET) < 0
|| write(db->pagf, db->pagbuf, PBLKSIZ) < 0)
return ioerr(db), -1;
return 0;
}
return ioerr(db), -1;
}
int
sdbm_store(db, key, val, flags)
register DBM *db;
datum key;
datum val;
int flags;
{
int need;
register long hash;
if (db == NULL || bad(key))
return errno = EINVAL, -1;
if (sdbm_rdonly(db))
return errno = EPERM, -1;
need = key.dsize + val.dsize;
if (need < 0 || need > PAIRMAX)
return errno = EINVAL, -1;
if (getpage(db, (hash = exhash(key)))) {
if (flags == DBM_REPLACE)
(void) delpair(db->pagbuf, key);
#ifdef SEEDUPS
else if (duppair(db->pagbuf, key))
return 1;
#endif
if (!fitpair(db->pagbuf, need))
if (!makroom(db, hash, need))
return ioerr(db), -1;
(void) putpair(db->pagbuf, key, val);
if (lseek(db->pagf, OFF_PAG(db->pagbno), SEEK_SET) < 0
|| write(db->pagf, db->pagbuf, PBLKSIZ) < 0)
return ioerr(db), -1;
return 0;
}
return ioerr(db), -1;
}
static int
makroom(db, hash, need)
register DBM *db;
long hash;
int need;
{
long newp;
char twin[PBLKSIZ];
char *pag = db->pagbuf;
char *new = twin;
register int smax = SPLTMAX;
do {
(void) splpage(pag, new, db->hmask + 1);
newp = (hash & db->hmask) | (db->hmask + 1);
if (hash & (db->hmask + 1)) {
if (lseek(db->pagf, OFF_PAG(db->pagbno), SEEK_SET) < 0
|| write(db->pagf, db->pagbuf, PBLKSIZ) < 0)
return 0;
db->pagbno = newp;
(void) memcpy(pag, new, PBLKSIZ);
}
else if (lseek(db->pagf, OFF_PAG(newp), SEEK_SET) < 0
|| write(db->pagf, new, PBLKSIZ) < 0)
return 0;
if (!setdbit(db, db->curbit))
return 0;
if (fitpair(pag, need))
return 1;
db->curbit = 2 * db->curbit +
((hash & (db->hmask + 1)) ? 2 : 1);
db->hmask |= db->hmask + 1;
if (lseek(db->pagf, OFF_PAG(db->pagbno), SEEK_SET) < 0
|| write(db->pagf, db->pagbuf, PBLKSIZ) < 0)
return 0;
} while (--smax);
#ifdef BADMESS
(void) write(2, "sdbm: cannot insert after SPLTMAX attempts.\n", 44);
#endif
return 0;
}
datum
sdbm_firstkey(db)
register DBM *db;
{
if (db == NULL)
return errno = EINVAL, nullitem;
if (lseek(db->pagf, OFF_PAG(0), SEEK_SET) < 0
|| read(db->pagf, db->pagbuf, PBLKSIZ) < 0)
return ioerr(db), nullitem;
db->pagbno = 0;
db->blkptr = 0;
db->keyptr = 0;
return getnext(db);
}
datum
sdbm_nextkey(db)
register DBM *db;
{
if (db == NULL)
return errno = EINVAL, nullitem;
return getnext(db);
}
static int
getpage(db, hash)
register DBM *db;
register long hash;
{
register int hbit;
register long dbit;
register long pagb;
dbit = 0;
hbit = 0;
while (dbit < db->maxbno && getdbit(db, dbit))
dbit = 2 * dbit + ((hash & (1 << hbit++)) ? 2 : 1);
debug(("dbit: %d...", dbit));
db->curbit = dbit;
db->hmask = masks[hbit];
pagb = hash & db->hmask;
if (pagb != db->pagbno) {
if (lseek(db->pagf, OFF_PAG(pagb), SEEK_SET) < 0
|| read(db->pagf, db->pagbuf, PBLKSIZ) < 0)
return 0;
if (!chkpage(db->pagbuf))
return 0;
db->pagbno = pagb;
debug(("pag read: %d\n", pagb));
}
return 1;
}
static int
getdbit(db, dbit)
register DBM *db;
register long dbit;
{
register long c;
register long dirb;
c = dbit / BYTESIZ;
dirb = c / DBLKSIZ;
if (dirb != db->dirbno) {
if (lseek(db->dirf, OFF_DIR(dirb), SEEK_SET) < 0
|| read(db->dirf, db->dirbuf, DBLKSIZ) < 0)
return 0;
db->dirbno = dirb;
debug(("dir read: %d\n", dirb));
}
return db->dirbuf[c % DBLKSIZ] & (1 << dbit % BYTESIZ);
}
static int
setdbit(db, dbit)
register DBM *db;
register long dbit;
{
register long c;
register long dirb;
c = dbit / BYTESIZ;
dirb = c / DBLKSIZ;
if (dirb != db->dirbno) {
if (lseek(db->dirf, OFF_DIR(dirb), SEEK_SET) < 0
|| read(db->dirf, db->dirbuf, DBLKSIZ) < 0)
return 0;
db->dirbno = dirb;
debug(("dir read: %d\n", dirb));
}
db->dirbuf[c % DBLKSIZ] |= (1 << dbit % BYTESIZ);
if (dbit >= db->maxbno)
db->maxbno += DBLKSIZ * BYTESIZ;
if (lseek(db->dirf, OFF_DIR(dirb), SEEK_SET) < 0
|| write(db->dirf, db->dirbuf, DBLKSIZ) < 0)
return 0;
return 1;
}
static datum
getnext(db)
register DBM *db;
{
datum key;
for (;;) {
db->keyptr++;
key = getnkey(db->pagbuf, db->keyptr);
if (key.dptr != NULL)
return key;
db->keyptr = 0;
if (db->pagbno != db->blkptr++)
if (lseek(db->pagf, OFF_PAG(db->blkptr), SEEK_SET) < 0)
break;
db->pagbno = db->blkptr;
if (read(db->pagf, db->pagbuf, PBLKSIZ) <= 0)
break;
if (!chkpage(db->pagbuf))
break;
}
return ioerr(db), nullitem;
}