/***********************************************************

Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam,

The Netherlands.

All Rights Reserved

Permission to use, copy, modify, and distribute this software and its

documentation for any purpose and without fee is hereby granted,

provided that the above copyright notice appear in all copies and that

both that copyright notice and this permission notice appear in

supporting documentation, and that the names of Stichting Mathematisch

Centrum or CWI not be used in advertising or publicity pertaining to

distribution of the software without specific, written prior permission.

STICHTING MATHEMATISCH CENTRUM DISCLAIMS ALL WARRANTIES WITH REGARD TO

THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND

FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH CENTRUM BE LIABLE

FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES

WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN

ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT

OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

******************************************************************/

/* DBM module using dictionary interface */

#include "allobjects.h"

#include "modsupport.h"

#include <sys/types.h>

#include <sys/stat.h>

#include <fcntl.h>

#include <ndbm.h>

typedef struct {

OB_HEAD

int di_size; /* -1 means recompute */

DBM *di_dbm;

} dbmobject;

staticforward typeobject Dbmtype;

#define is_dbmobject(v) ((v)->ob_type == &Dbmtype)

static object *DbmError;

static object *

newdbmobject(file, flags, mode)

char *file;

int flags;

int mode;

{

dbmobject *dp;

dp = NEWOBJ(dbmobject, &Dbmtype);

if (dp == NULL)

return NULL;

dp->di_size = -1;

if ( (dp->di_dbm = dbm_open(file, flags, mode)) == 0 ) {

err_errno(DbmError);

DECREF(dp);

return NULL;

}

return (object *)dp;

}

/* Methods */

static void

dbm_dealloc(dp)

register dbmobject *dp;

{

if ( dp->di_dbm )

dbm_close(dp->di_dbm);

DEL(dp);

}

static int

dbm_length(dp)

dbmobject *dp;

{

if ( dp->di_size < 0 ) {

datum key;

int size;

size = 0;

for ( key=dbm_firstkey(dp->di_dbm); key.dptr;

key = dbm_nextkey(dp->di_dbm))

size++;

dp->di_size = size;

}

return dp->di_size;

}

static object *

dbm_subscript(dp, key)

dbmobject *dp;

register object *key;

{

object *v;

datum drec, krec;

if (!getargs(key, "s#", &krec.dptr, &krec.dsize) )

return NULL;

drec = dbm_fetch(dp->di_dbm, krec);

if ( drec.dptr == 0 ) {

err_setstr(KeyError, GETSTRINGVALUE((stringobject *)key));

return NULL;

}

if ( dbm_error(dp->di_dbm) ) {

dbm_clearerr(dp->di_dbm);

err_setstr(DbmError, "");

return NULL;

}

return newsizedstringobject(drec.dptr, drec.dsize);

}

static int

dbm_ass_sub(dp, v, w)

dbmobject *dp;

object *v, *w;

{

datum krec, drec;

if ( !getargs(v, "s#", &krec.dptr, &krec.dsize) ) {

err_setstr(TypeError, "dbm mappings have string indices only");

return -1;

}

dp->di_size = -1;

if (w == NULL) {

if ( dbm_delete(dp->di_dbm, krec) < 0 ) {

dbm_clearerr(dp->di_dbm);

err_setstr(KeyError, GETSTRINGVALUE((stringobject *)v));

return -1;

}

} else {

if ( !getargs(w, "s#", &drec.dptr, &drec.dsize) ) {

err_setstr(TypeError,

"dbm mappings have string elements only");

return -1;

}

if ( dbm_store(dp->di_dbm, krec, drec, DBM_REPLACE) < 0 ) {

dbm_clearerr(dp->di_dbm);

err_setstr(DbmError, "Cannot add item to database");

return -1;

}

}

if ( dbm_error(dp->di_dbm) ) {

dbm_clearerr(dp->di_dbm);

err_setstr(DbmError, "");

return -1;

}

return 0;

}

static mapping_methods dbm_as_mapping = {

(inquiry)dbm_length, /*mp_length*/

(binaryfunc)dbm_subscript, /*mp_subscript*/

(objobjargproc)dbm_ass_sub, /*mp_ass_subscript*/

};

static object *

dbm__close(dp, args)

register dbmobject *dp;

object *args;

{

if ( !getnoarg(args) )

return NULL;

if ( dp->di_dbm )

dbm_close(dp->di_dbm);

dp->di_dbm = NULL;

INCREF(None);

return None;

}

static object *

dbm_keys(dp, args)

register dbmobject *dp;

object *args;

{

register object *v, *item;

datum key;

int err;

if (!getnoarg(args))

return NULL;

v = newlistobject(0);

if (v == NULL)

return NULL;

for (key = dbm_firstkey(dp->di_dbm); key.dptr;

key = dbm_nextkey(dp->di_dbm)) {

item = newsizedstringobject(key.dptr, key.dsize);

if (item == NULL) {

DECREF(v);

return NULL;

}

err = addlistitem(v, item);

DECREF(item);

if (err != 0) {

DECREF(v);

return NULL;

}

}

return v;

}

static object *

dbm_has_key(dp, args)

register dbmobject *dp;

object *args;

{

datum key, val;

if (!getargs(args, "s#", &key.dptr, &key.dsize))

return NULL;

val = dbm_fetch(dp->di_dbm, key);

return newintobject(val.dptr != NULL);

}

static struct methodlist dbm_methods[] = {

{"close", (method)dbm__close},

{"keys", (method)dbm_keys},

{"has_key", (method)dbm_has_key},

{NULL, NULL} /* sentinel */

};

static object *

dbm_getattr(dp, name)

dbmobject *dp;

char *name;

{

return findmethod(dbm_methods, (object *)dp, name);

}

static typeobject Dbmtype = {

OB_HEAD_INIT(&Typetype)

0,

"dbm",

sizeof(dbmobject),

0,

(destructor)dbm_dealloc, /*tp_dealloc*/

0, /*tp_print*/

(getattrfunc)dbm_getattr, /*tp_getattr*/

0, /*tp_setattr*/

0, /*tp_compare*/

0, /*tp_repr*/

0, /*tp_as_number*/

0, /*tp_as_sequence*/

&dbm_as_mapping, /*tp_as_mapping*/

};

/* ----------------------------------------------------------------- */

static object *

dbmopen(self, args)

object *self;

object *args;

{

char *name;

char *flags = "r";

int iflags;

int mode = 0666;

if ( !newgetargs(args, "s|si", &name, &flags, &mode) )

return NULL;

if ( strcmp(flags, "r") == 0 )

iflags = O_RDONLY;

else if ( strcmp(flags, "w") == 0 )

iflags = O_RDWR;

else if ( strcmp(flags, "rw") == 0 ) /* B/W compat */

iflags = O_RDWR|O_CREAT;

else if ( strcmp(flags, "c") == 0 )

iflags = O_RDWR|O_CREAT;

else if ( strcmp(flags, "n") == 0 )

iflags = O_RDWR|O_CREAT|O_TRUNC;

else {

err_setstr(DbmError,

"Flags should be one of 'r', 'w', 'c' or 'n'");

return NULL;

}

return newdbmobject(name, iflags, mode);

}

static struct methodlist dbmmodule_methods[] = {

{ "open", (method)dbmopen, 1 },

{ 0, 0 },

};

void

initdbm() {

object *m, *d;

m = initmodule("dbm", dbmmodule_methods);

d = getmoduledict(m);

DbmError = newstringobject("dbm.error");

if ( DbmError == NULL || dictinsert(d, "error", DbmError) )

fatal("can't define dbm.error");

}