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 const char which_dbm[] = "GNU gdbm"; /* EMX port of GDBM */
#elif defined(HAVE_GDBM_NDBM_H)
#include <gdbm/ndbm.h>
static const char which_dbm[] = "GNU gdbm";
#elif defined(HAVE_GDBM_DASH_NDBM_H)
#include <gdbm-ndbm.h>
static const char which_dbm[] = "GNU gdbm";
#elif defined(HAVE_BERKDB_H)
#include <db.h>
static const char which_dbm[] = "Berkeley DB";
#else
#error "No ndbm.h available!"
#endif
/*[clinic input]
module _dbm
class _dbm.dbm "dbmobject *" "&Dbmtype"
[clinic start generated code]*/
/*[clinic end generated code: output=da39a3ee5e6b4b0d input=9b1aa8756d16150e]*/
typedef struct {
PyObject_HEAD
int flags;
int di_size; /* -1 means recompute */
DBM *di_dbm;
} dbmobject;
#include "clinic/_dbmmodule.c.h"
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;
dp->flags = flags;
/* See issue #19296 */
if ( (dp->di_dbm = dbm_open((char *)file, flags, mode)) == 0 ) {
PyErr_SetFromErrnoWithFilename(DbmError, file);
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);
/* we might get a failure for reasons like file corrupted,
but we are not able to distinguish it */
if (dp->flags & O_RDWR) {
PyErr_SetObject(PyExc_KeyError, v);
}
else {
PyErr_SetString(DbmError, "cannot delete item from database");
}
return -1;
}
} else {
if ( !PyArg_Parse(w, "s#", &drec.dptr, &tmp_size) ) {
PyErr_SetString(PyExc_TypeError,
"dbm mappings have bytes 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*/
};
/*[clinic input]
_dbm.dbm.close
Close the database.
[clinic start generated code]*/
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static PyObject *
_dbm_dbm_close_impl(dbmobject *self)
/*[clinic end generated code: output=c8dc5b6709600b86 input=046db72377d51be8]*/
{
if (self->di_dbm)
dbm_close(self->di_dbm);
self->di_dbm = NULL;
Py_RETURN_NONE;
}
/*[clinic input]
_dbm.dbm.keys
Return a list of all keys in the database.
[clinic start generated code]*/
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static PyObject *
_dbm_dbm_keys_impl(dbmobject *self)
/*[clinic end generated code: output=434549f7c121b33c input=d210ba778cd9c68a]*/
{
PyObject *v, *item;
datum key;
int err;
check_dbmobject_open(self);
v = PyList_New(0);
if (v == NULL)
return NULL;
for (key = dbm_firstkey(self->di_dbm); key.dptr;
key = dbm_nextkey(self->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)) {
key.dptr = (char *)PyUnicode_AsUTF8AndSize(arg, &size);
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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 */
};
/*[clinic input]
_dbm.dbm.get
key: str(accept={str, robuffer}, zeroes=True)
default: object = None
/
Return the value for key if present, otherwise default.
[clinic start generated code]*/
static PyObject *
_dbm_dbm_get_impl(dbmobject *self, const char *key,
Py_ssize_clean_t key_length, PyObject *default_value)
/*[clinic end generated code: output=b44f95eba8203d93 input=b788eba0ffad2e91]*/
/*[clinic end generated code: output=4f5c0e523eaf1251 input=9402c0af8582dc69]*/
{
datum dbm_key, val;
dbm_key.dptr = (char *)key;
dbm_key.dsize = key_length;
check_dbmobject_open(self);
val = dbm_fetch(self->di_dbm, dbm_key);
if (val.dptr != NULL)
return PyBytes_FromStringAndSize(val.dptr, val.dsize);
Py_INCREF(default_value);
return default_value;
}
/*[clinic input]
_dbm.dbm.setdefault
key: str(accept={str, robuffer}, zeroes=True)
default: object(c_default="NULL") = b''
/
Return the value for key if present, otherwise default.
If key is not in the database, it is inserted with default as the value.
[clinic start generated code]*/
static PyObject *
_dbm_dbm_setdefault_impl(dbmobject *self, const char *key,
Py_ssize_clean_t key_length,
PyObject *default_value)
/*[clinic end generated code: output=52545886cf272161 input=bf40c48edaca01d6]*/
{
datum dbm_key, val;
Py_ssize_t tmp_size;
dbm_key.dptr = (char *)key;
dbm_key.dsize = key_length;
check_dbmobject_open(self);
val = dbm_fetch(self->di_dbm, dbm_key);
if (val.dptr != NULL)
return PyBytes_FromStringAndSize(val.dptr, val.dsize);
if (default_value == NULL) {
default_value = PyBytes_FromStringAndSize(NULL, 0);
if (default_value == NULL)
return NULL;
val.dptr = NULL;
val.dsize = 0;
}
else {
if ( !PyArg_Parse(default_value, "s#", &val.dptr, &tmp_size) ) {
PyErr_SetString(PyExc_TypeError,
"dbm mappings have bytes or string elements only");
return NULL;
}
val.dsize = tmp_size;
Py_INCREF(default_value);
}
if (dbm_store(self->di_dbm, dbm_key, val, DBM_INSERT) < 0) {
dbm_clearerr(self->di_dbm);
PyErr_SetString(DbmError, "cannot add item to database");
Py_DECREF(default_value);
return NULL;
}
return default_value;
}
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_CallMethodIdNoArgs(self, &PyId_close);
}
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static PyMethodDef dbm_methods[] = {
_DBM_DBM_CLOSE_METHODDEF
_DBM_DBM_KEYS_METHODDEF
_DBM_DBM_GET_METHODDEF
_DBM_DBM_SETDEFAULT_METHODDEF
{"__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_vectorcall_offset*/
0, /*tp_getattr*/
0, /*tp_setattr*/
0, /*tp_as_async*/
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 input]
_dbm.open as dbmopen
filename: unicode
The filename to open.
flags: str="r"
How to open the file. "r" for reading, "w" for writing, etc.
mode: int(py_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 start generated code]*/
static PyObject *
dbmopen_impl(PyObject *module, PyObject *filename, const char *flags,
int mode)
/*[clinic end generated code: output=9527750f5df90764 input=376a9d903a50df59]*/
{
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;
}
PyObject *filenamebytes = PyUnicode_EncodeFSDefault(filename);
if (filenamebytes == NULL) {
return NULL;
}
const char *name = PyBytes_AS_STRING(filenamebytes);
if (strlen(name) != (size_t)PyBytes_GET_SIZE(filenamebytes)) {
Py_DECREF(filenamebytes);
PyErr_SetString(PyExc_ValueError, "embedded null character");
return NULL;
}
PyObject *self = newdbmobject(name, iflags, mode);
Py_DECREF(filenamebytes);
return self;
}
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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_OSError, 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;
}