cpython/Modules/_dbmmodule.c

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/* DBM module using dictionary interface */
#define PY_SSIZE_T_CLEAN
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#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 = "GNU gdbm"; /* EMX port of GDBM */
#elif defined(HAVE_GDBM_NDBM_H)
#include <gdbm/ndbm.h>
static char *which_dbm = "GNU gdbm";
#elif defined(HAVE_GDBM_DASH_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) (Py_TYPE(v) == &Dbmtype)
#define check_dbmobject_open(v) if ((v)->di_dbm == NULL) \
{ PyErr_SetString(DbmError, "DBM object has already been closed"); \
return NULL; }
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static PyObject *DbmError;
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static PyObject *
newdbmobject(const 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(dbmobject *dp)
{
if ( dp->di_dbm )
dbm_close(dp->di_dbm);
PyObject_Del(dp);
}
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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;
}
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static PyObject *
dbm_subscript(dbmobject *dp, PyObject *key)
{
datum drec, krec;
Py_ssize_t 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_SetObject(PyExc_KeyError, key);
return NULL;
}
if ( dbm_error(dp->di_dbm) ) {
dbm_clearerr(dp->di_dbm);
PyErr_SetString(DbmError, "");
return NULL;
}
return PyBytes_FromStringAndSize(drec.dptr, drec.dsize);
}
static int
dbm_ass_sub(dbmobject *dp, PyObject *v, PyObject *w)
{
datum krec, drec;
Py_ssize_t tmp_size;
if ( !PyArg_Parse(v, "s#", &krec.dptr, &tmp_size) ) {
PyErr_SetString(PyExc_TypeError,
"dbm mappings have bytes or string keys 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_SetObject(PyExc_KeyError, v);
return -1;
}
} else {
if ( !PyArg_Parse(w, "s#", &drec.dptr, &tmp_size) ) {
PyErr_SetString(PyExc_TypeError,
"dbm mappings have byte or 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;
}
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static PyMappingMethods dbm_as_mapping = {
(lenfunc)dbm_length, /*mp_length*/
(binaryfunc)dbm_subscript, /*mp_subscript*/
(objobjargproc)dbm_ass_sub, /*mp_ass_subscript*/
};
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static PyObject *
dbm__close(dbmobject *dp, PyObject *unused)
{
if (dp->di_dbm)
dbm_close(dp->di_dbm);
dp->di_dbm = NULL;
Py_INCREF(Py_None);
return Py_None;
}
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static PyObject *
dbm_keys(dbmobject *dp, PyObject *unused)
{
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 = PyBytes_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 int
dbm_contains(PyObject *self, PyObject *arg)
{
dbmobject *dp = (dbmobject *)self;
datum key, val;
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Py_ssize_t size;
if ((dp)->di_dbm == NULL) {
PyErr_SetString(DbmError,
"DBM object has already been closed");
return -1;
}
if (PyUnicode_Check(arg)) {
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key.dptr = PyUnicode_AsUTF8AndSize(arg, &size);
key.dsize = size;
if (key.dptr == NULL)
return -1;
}
else if (!PyBytes_Check(arg)) {
PyErr_Format(PyExc_TypeError,
"dbm key must be bytes or string, not %.100s",
arg->ob_type->tp_name);
return -1;
}
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else {
key.dptr = PyBytes_AS_STRING(arg);
key.dsize = PyBytes_GET_SIZE(arg);
}
val = dbm_fetch(dp->di_dbm, key);
return val.dptr != NULL;
}
static PySequenceMethods dbm_as_sequence = {
0, /* sq_length */
0, /* sq_concat */
0, /* sq_repeat */
0, /* sq_item */
0, /* sq_slice */
0, /* sq_ass_item */
0, /* sq_ass_slice */
dbm_contains, /* sq_contains */
0, /* sq_inplace_concat */
0, /* sq_inplace_repeat */
};
static PyObject *
dbm_get(dbmobject *dp, PyObject *args)
{
datum key, val;
PyObject *defvalue = Py_None;
char *tmp_ptr;
Py_ssize_t tmp_size;
if (!PyArg_ParseTuple(args, "s#|O:get",
&tmp_ptr, &tmp_size, &defvalue))
return NULL;
key.dptr = tmp_ptr;
key.dsize = tmp_size;
check_dbmobject_open(dp);
val = dbm_fetch(dp->di_dbm, key);
if (val.dptr != NULL)
return PyBytes_FromStringAndSize(val.dptr, val.dsize);
else {
Py_INCREF(defvalue);
return defvalue;
}
}
static PyObject *
dbm_setdefault(dbmobject *dp, PyObject *args)
{
datum key, val;
PyObject *defvalue = NULL;
char *tmp_ptr;
Py_ssize_t tmp_size;
if (!PyArg_ParseTuple(args, "s#|O:setdefault",
&tmp_ptr, &tmp_size, &defvalue))
return NULL;
key.dptr = tmp_ptr;
key.dsize = tmp_size;
check_dbmobject_open(dp);
val = dbm_fetch(dp->di_dbm, key);
if (val.dptr != NULL)
return PyBytes_FromStringAndSize(val.dptr, val.dsize);
if (defvalue == NULL) {
defvalue = PyBytes_FromStringAndSize(NULL, 0);
if (defvalue == NULL)
return NULL;
val.dptr = NULL;
val.dsize = 0;
}
else {
if ( !PyArg_Parse(defvalue, "s#", &val.dptr, &tmp_size) ) {
PyErr_SetString(PyExc_TypeError,
"dbm mappings have byte string elements only");
return NULL;
}
val.dsize = tmp_size;
Py_INCREF(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");
Py_DECREF(defvalue);
return NULL;
}
return defvalue;
}
static PyObject *
dbm__enter__(PyObject *self, PyObject *args)
{
Py_INCREF(self);
return self;
}
static PyObject *
dbm__exit__(PyObject *self, PyObject *args)
{
_Py_IDENTIFIER(close);
return _PyObject_CallMethodId(self, &PyId_close, NULL);
}
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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."},
{"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."},
{"__enter__", dbm__enter__, METH_NOARGS, NULL},
{"__exit__", dbm__exit__, METH_VARARGS, NULL},
{NULL, NULL} /* sentinel */
};
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static PyTypeObject Dbmtype = {
PyVarObject_HEAD_INIT(NULL, 0)
"_dbm.dbm",
sizeof(dbmobject),
0,
(destructor)dbm_dealloc, /*tp_dealloc*/
0, /*tp_print*/
0, /*tp_getattr*/
0, /*tp_setattr*/
0, /*tp_reserved*/
0, /*tp_repr*/
0, /*tp_as_number*/
&dbm_as_sequence, /*tp_as_sequence*/
&dbm_as_mapping, /*tp_as_mapping*/
0, /*tp_hash*/
0, /*tp_call*/
0, /*tp_str*/
0, /*tp_getattro*/
0, /*tp_setattro*/
0, /*tp_as_buffer*/
Py_TPFLAGS_DEFAULT, /*tp_flags*/
0, /*tp_doc*/
0, /*tp_traverse*/
0, /*tp_clear*/
0, /*tp_richcompare*/
0, /*tp_weaklistoffset*/
0, /*tp_iter*/
0, /*tp_iternext*/
dbm_methods, /*tp_methods*/
};
/* ----------------------------------------------------------------- */
/*[clinic]
module dbm
dbm.open as dbmopen
filename: str
The filename to open.
flags: str="r"
How to open the file. "r" for reading, "w" for writing, etc.
mode: int(doc_default="0o666") = 0o666
If creating a new file, the mode bits for the new file
(e.g. os.O_RDWR).
/
Return a database object.
[clinic]*/
PyDoc_STRVAR(dbmopen__doc__,
"Return a database object.\n"
"\n"
"dbm.open(filename, flags=\'r\', mode=0o666)\n"
" filename\n"
" The filename to open.\n"
" flags\n"
" How to open the file. \"r\" for reading, \"w\" for writing, etc.\n"
" mode\n"
" If creating a new file, the mode bits for the new file\n"
" (e.g. os.O_RDWR).");
#define DBMOPEN_METHODDEF \
{"open", (PyCFunction)dbmopen, METH_VARARGS, dbmopen__doc__},
static PyObject *
dbmopen_impl(PyObject *module, const char *filename, const char *flags, int mode);
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static PyObject *
dbmopen(PyObject *module, PyObject *args)
{
PyObject *return_value = NULL;
const char *filename;
const char *flags = "r";
int mode = 438;
if (!PyArg_ParseTuple(args,
"s|si:open",
&filename, &flags, &mode))
goto exit;
return_value = dbmopen_impl(module, filename, flags, mode);
exit:
return return_value;
}
static PyObject *
dbmopen_impl(PyObject *module, const char *filename, const char *flags, int mode)
/*[clinic checksum: 2b0ec9e3c6ecd19e06d16c9f0ba33848245cb1ab]*/
{
int iflags;
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(filename, iflags, mode);
}
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static PyMethodDef dbmmodule_methods[] = {
DBMOPEN_METHODDEF
{ 0, 0 },
};
static struct PyModuleDef _dbmmodule = {
PyModuleDef_HEAD_INIT,
"_dbm",
NULL,
-1,
dbmmodule_methods,
NULL,
NULL,
NULL,
NULL
};
PyMODINIT_FUNC
PyInit__dbm(void) {
PyObject *m, *d, *s;
if (PyType_Ready(&Dbmtype) < 0)
return NULL;
m = PyModule_Create(&_dbmmodule);
if (m == NULL)
return NULL;
d = PyModule_GetDict(m);
if (DbmError == NULL)
DbmError = PyErr_NewException("_dbm.error",
PyExc_IOError, NULL);
s = PyUnicode_FromString(which_dbm);
if (s != NULL) {
PyDict_SetItemString(d, "library", s);
Py_DECREF(s);
}
if (DbmError != NULL)
PyDict_SetItemString(d, "error", DbmError);
if (PyErr_Occurred()) {
Py_DECREF(m);
m = NULL;
}
return m;
}