ref: a70b93a356662355214f5405edda066786f6dd03
dir: /sys/src/cmd/python/Modules/dbmmodule.c/
/* 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>
#if defined(PYOS_OS2) && !defined(PYCC_GCC)
static char *which_dbm = "ndbm";
#else
static char *which_dbm = "GNU gdbm"; /* EMX port of GDBM */
#endif
#elif defined(HAVE_GDBM_NDBM_H)
#include <gdbm/ndbm.h>
static char *which_dbm = "GNU gdbm";
#elif defined(HAVE_BERKDB_H)
#include <db.h>
static char *which_dbm = "Berkeley DB";
#else
#error "No ndbm.h available!"
#endif
typedef struct {
PyObject_HEAD
int di_size; /* -1 means recompute */
DBM *di_dbm;
} dbmobject;
static 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 Py_ssize_t
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;
int tmp_size;
if (!PyArg_Parse(key, "s#", &krec.dptr, &tmp_size) )
return NULL;
krec.dsize = tmp_size;
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;
int tmp_size;
if ( !PyArg_Parse(v, "s#", &krec.dptr, &tmp_size) ) {
PyErr_SetString(PyExc_TypeError,
"dbm mappings have string indices only");
return -1;
}
krec.dsize = tmp_size;
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, &tmp_size) ) {
PyErr_SetString(PyExc_TypeError,
"dbm mappings have string elements only");
return -1;
}
drec.dsize = tmp_size;
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 = {
(lenfunc)dbm_length, /*mp_length*/
(binaryfunc)dbm_subscript, /*mp_subscript*/
(objobjargproc)dbm_ass_sub, /*mp_ass_subscript*/
};
static PyObject *
dbm__close(register dbmobject *dp, PyObject *unused)
{
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 *unused)
{
register PyObject *v, *item;
datum key;
int err;
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;
int tmp_size;
if (!PyArg_ParseTuple(args, "s#:has_key", &key.dptr, &tmp_size))
return NULL;
key.dsize = tmp_size;
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;
int tmp_size;
if (!PyArg_ParseTuple(args, "s#|O:get",
&key.dptr, &tmp_size, &defvalue))
return NULL;
key.dsize = tmp_size;
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;
int tmp_size;
if (!PyArg_ParseTuple(args, "s#|S:setdefault",
&key.dptr, &tmp_size, &defvalue))
return NULL;
key.dsize = tmp_size;
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_NOARGS,
"close()\nClose the database."},
{"keys", (PyCFunction)dbm_keys, METH_NOARGS,
"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(NULL)
0,
"dbm.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,
"arg 2 to open should be '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 },
};
PyMODINIT_FUNC
initdbm(void) {
PyObject *m, *d, *s;
Dbmtype.ob_type = &PyType_Type;
m = Py_InitModule("dbm", dbmmodule_methods);
if (m == NULL)
return;
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);
}