/* DBM module using dictionary interface */

#include "Python.h"

#include <sys/types.h>

#include <sys/stat.h>

#include <fcntl.h>

/* Some Linux systems install gdbm/ndbm.h, but not ndbm.h. This supports

* whichever configure was able to locate.

*/

#if defined(HAVE_NDBM_H)

#include <ndbm.h>

static char *which_dbm = "ndbm";

#elif defined(HAVE_DB1_NDBM_H)

#include <db1/ndbm.h>

static char *which_dbm = "BSD db";

#elif defined(HAVE_GDBM_NDBM_H)

#include <gdbm/ndbm.h>

static char *which_dbm = "GNU gdbm";

#else

#error "No ndbm.h available!"

#endif

typedef struct {

PyObject_HEAD

int di_size; /* -1 means recompute */

DBM *di_dbm;

} dbmobject;

staticforward PyTypeObject Dbmtype;

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

#define check_dbmobject_open(v) if ((v)->di_dbm == NULL) \

{ PyErr_SetString(DbmError, "DBM object has already been closed"); \

return NULL; }

static PyObject *DbmError;

static PyObject *

newdbmobject(char *file, int flags, int mode)

{

dbmobject *dp;

dp = PyObject_New(dbmobject, &Dbmtype);

if (dp == NULL)

return NULL;

dp->di_size = -1;

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

PyErr_SetFromErrno(DbmError);

Py_DECREF(dp);

return NULL;

}

return (PyObject *)dp;

}

/* Methods */

static void

dbm_dealloc(register dbmobject *dp)

{

if ( dp->di_dbm )

dbm_close(dp->di_dbm);

PyObject_Del(dp);

}

static int

dbm_length(dbmobject *dp)

{

if (dp->di_dbm == NULL) {

PyErr_SetString(DbmError, "DBM object has already been closed");

return -1;

}

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 PyObject *

dbm_subscript(dbmobject *dp, register PyObject *key)

{

datum drec, krec;

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

return NULL;

check_dbmobject_open(dp);

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

if ( drec.dptr == 0 ) {

PyErr_SetString(PyExc_KeyError,

PyString_AS_STRING((PyStringObject *)key));

return NULL;

}

if ( dbm_error(dp->di_dbm) ) {

dbm_clearerr(dp->di_dbm);

PyErr_SetString(DbmError, "");

return NULL;

}

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

}

static int

dbm_ass_sub(dbmobject *dp, PyObject *v, PyObject *w)

{

datum krec, drec;

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

PyErr_SetString(PyExc_TypeError,

"dbm mappings have string indices only");

return -1;

}

if (dp->di_dbm == NULL) {

PyErr_SetString(DbmError, "DBM object has already been closed");

return -1;

}

dp->di_size = -1;

if (w == NULL) {

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

dbm_clearerr(dp->di_dbm);

PyErr_SetString(PyExc_KeyError,

PyString_AS_STRING((PyStringObject *)v));

return -1;

}

} else {

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

PyErr_SetString(PyExc_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);

PyErr_SetString(DbmError,

"Cannot add item to database");

return -1;

}

}

if ( dbm_error(dp->di_dbm) ) {

dbm_clearerr(dp->di_dbm);

PyErr_SetString(DbmError, "");

return -1;

}

return 0;

}

static PyMappingMethods dbm_as_mapping = {

(inquiry)dbm_length, /*mp_length*/

(binaryfunc)dbm_subscript, /*mp_subscript*/

(objobjargproc)dbm_ass_sub, /*mp_ass_subscript*/

};

static PyObject *

dbm__close(register dbmobject *dp, PyObject *args)

{

if (!PyArg_ParseTuple(args, ":close"))

return NULL;

if (dp->di_dbm)

dbm_close(dp->di_dbm);

dp->di_dbm = NULL;

Py_INCREF(Py_None);

return Py_None;

}

static PyObject *

dbm_keys(register dbmobject *dp, PyObject *args)

{

register PyObject *v, *item;

datum key;

int err;

if (!PyArg_ParseTuple(args, ":keys"))

return NULL;

check_dbmobject_open(dp);

v = PyList_New(0);

if (v == NULL)

return NULL;

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

key = dbm_nextkey(dp->di_dbm)) {

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

if (item == NULL) {

Py_DECREF(v);

return NULL;

}

err = PyList_Append(v, item);

Py_DECREF(item);

if (err != 0) {

Py_DECREF(v);

return NULL;

}

}

return v;

}

static PyObject *

dbm_has_key(register dbmobject *dp, PyObject *args)

{

datum key, val;

if (!PyArg_ParseTuple(args, "s#:has_key", &key.dptr, &key.dsize))

return NULL;

check_dbmobject_open(dp);

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

return PyInt_FromLong(val.dptr != NULL);

}

static PyObject *

dbm_get(register dbmobject *dp, PyObject *args)

{

datum key, val;

PyObject *defvalue = Py_None;

if (!PyArg_ParseTuple(args, "s#|O:get",

&key.dptr, &key.dsize, &defvalue))

return NULL;

check_dbmobject_open(dp);

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

if (val.dptr != NULL)

return PyString_FromStringAndSize(val.dptr, val.dsize);

else {

Py_INCREF(defvalue);

return defvalue;

}

}

static PyObject *

dbm_setdefault(register dbmobject *dp, PyObject *args)

{

datum key, val;

PyObject *defvalue = NULL;

if (!PyArg_ParseTuple(args, "s#|S:setdefault",

&key.dptr, &key.dsize, &defvalue))

return NULL;

check_dbmobject_open(dp);

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

if (val.dptr != NULL)

return PyString_FromStringAndSize(val.dptr, val.dsize);

if (defvalue == NULL) {

defvalue = PyString_FromStringAndSize(NULL, 0);

if (defvalue == NULL)

return NULL;

}

else

Py_INCREF(defvalue);

val.dptr = PyString_AS_STRING(defvalue);

val.dsize = PyString_GET_SIZE(defvalue);

if (dbm_store(dp->di_dbm, key, val, DBM_INSERT) < 0) {

dbm_clearerr(dp->di_dbm);

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

return NULL;

}

return defvalue;

}

static PyMethodDef dbm_methods[] = {

{"close", (PyCFunction)dbm__close, METH_VARARGS,

"close()\nClose the database."},

{"keys", (PyCFunction)dbm_keys, METH_VARARGS,

"keys() -> list\nReturn a list of all keys in the database."},

{"has_key", (PyCFunction)dbm_has_key, METH_VARARGS,

"has_key(key} -> boolean\nReturn true iff key is in the database."},

{"get", (PyCFunction)dbm_get, METH_VARARGS,

"get(key[, default]) -> value\n"

"Return the value for key if present, otherwise default."},

{"setdefault", (PyCFunction)dbm_setdefault, METH_VARARGS,

"setdefault(key[, default]) -> value\n"

"Return the value for key if present, otherwise default. If key\n"

"is not in the database, it is inserted with default as the value."},

{NULL, NULL} /* sentinel */

};

static PyObject *

dbm_getattr(dbmobject *dp, char *name)

{

return Py_FindMethod(dbm_methods, (PyObject *)dp, name);

}

static PyTypeObject Dbmtype = {

PyObject_HEAD_INIT(&PyType_Type)

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 PyObject *

dbmopen(PyObject *self, PyObject *args)

{

char *name;

char *flags = "r";

int iflags;

int mode = 0666;

if ( !PyArg_ParseTuple(args, "s|si:open", &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 {

PyErr_SetString(DbmError,

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

return NULL;

}

return newdbmobject(name, iflags, mode);

}

static PyMethodDef dbmmodule_methods[] = {

{ "open", (PyCFunction)dbmopen, METH_VARARGS,

"open(path[, flag[, mode]]) -> mapping\n"

"Return a database object."},

{ 0, 0 },

};

DL_EXPORT(void)

initdbm(void) {

PyObject *m, *d, *s;

m = Py_InitModule("dbm", dbmmodule_methods);

d = PyModule_GetDict(m);

if (DbmError == NULL)

DbmError = PyErr_NewException("dbm.error", NULL, NULL);

s = PyString_FromString(which_dbm);

if (s != NULL) {

PyDict_SetItemString(d, "library", s);

Py_DECREF(s);

}

if (DbmError != NULL)

PyDict_SetItemString(d, "error", DbmError);

}