1
2 /* DBM module using dictionary interface */
3
4
5 #define PY_SSIZE_T_CLEAN
6 #include "Python.h"
7
8 #include <sys/types.h>
9 #include <sys/stat.h>
10 #include <fcntl.h>
11
12 /* Some Linux systems install gdbm/ndbm.h, but not ndbm.h. This supports
13 * whichever configure was able to locate.
14 */
15 #if defined(HAVE_NDBM_H)
16 #include <ndbm.h>
17 static const char which_dbm[] = "GNU gdbm"; /* EMX port of GDBM */
18 #elif defined(HAVE_GDBM_NDBM_H)
19 #include <gdbm/ndbm.h>
20 static const char which_dbm[] = "GNU gdbm";
21 #elif defined(HAVE_GDBM_DASH_NDBM_H)
22 #include <gdbm-ndbm.h>
23 static const char which_dbm[] = "GNU gdbm";
24 #elif defined(HAVE_BERKDB_H)
25 #include <db.h>
26 static const char which_dbm[] = "Berkeley DB";
27 #else
28 #error "No ndbm.h available!"
29 #endif
30
31 /*[clinic input]
32 module _dbm
33 class _dbm.dbm "dbmobject *" "&Dbmtype"
34 [clinic start generated code]*/
35 /*[clinic end generated code: output=da39a3ee5e6b4b0d input=9b1aa8756d16150e]*/
36
37 typedef struct {
38 PyObject_HEAD
39 int di_size; /* -1 means recompute */
40 DBM *di_dbm;
41 } dbmobject;
42
43 #include "clinic/_dbmmodule.c.h"
44
45 static PyTypeObject Dbmtype;
46
47 #define is_dbmobject(v) (Py_TYPE(v) == &Dbmtype)
48 #define check_dbmobject_open(v) if ((v)->di_dbm == NULL) \
49 { PyErr_SetString(DbmError, "DBM object has already been closed"); \
50 return NULL; }
51
52 static PyObject *DbmError;
53
54 static PyObject *
newdbmobject(const char * file,int flags,int mode)55 newdbmobject(const char *file, int flags, int mode)
56 {
57 dbmobject *dp;
58
59 dp = PyObject_New(dbmobject, &Dbmtype);
60 if (dp == NULL)
61 return NULL;
62 dp->di_size = -1;
63 /* See issue #19296 */
64 if ( (dp->di_dbm = dbm_open((char *)file, flags, mode)) == 0 ) {
65 PyErr_SetFromErrno(DbmError);
66 Py_DECREF(dp);
67 return NULL;
68 }
69 return (PyObject *)dp;
70 }
71
72 /* Methods */
73
74 static void
dbm_dealloc(dbmobject * dp)75 dbm_dealloc(dbmobject *dp)
76 {
77 if ( dp->di_dbm )
78 dbm_close(dp->di_dbm);
79 PyObject_Del(dp);
80 }
81
82 static Py_ssize_t
dbm_length(dbmobject * dp)83 dbm_length(dbmobject *dp)
84 {
85 if (dp->di_dbm == NULL) {
86 PyErr_SetString(DbmError, "DBM object has already been closed");
87 return -1;
88 }
89 if ( dp->di_size < 0 ) {
90 datum key;
91 int size;
92
93 size = 0;
94 for ( key=dbm_firstkey(dp->di_dbm); key.dptr;
95 key = dbm_nextkey(dp->di_dbm))
96 size++;
97 dp->di_size = size;
98 }
99 return dp->di_size;
100 }
101
102 static PyObject *
dbm_subscript(dbmobject * dp,PyObject * key)103 dbm_subscript(dbmobject *dp, PyObject *key)
104 {
105 datum drec, krec;
106 Py_ssize_t tmp_size;
107
108 if (!PyArg_Parse(key, "s#", &krec.dptr, &tmp_size) )
109 return NULL;
110
111 krec.dsize = tmp_size;
112 check_dbmobject_open(dp);
113 drec = dbm_fetch(dp->di_dbm, krec);
114 if ( drec.dptr == 0 ) {
115 PyErr_SetObject(PyExc_KeyError, key);
116 return NULL;
117 }
118 if ( dbm_error(dp->di_dbm) ) {
119 dbm_clearerr(dp->di_dbm);
120 PyErr_SetString(DbmError, "");
121 return NULL;
122 }
123 return PyBytes_FromStringAndSize(drec.dptr, drec.dsize);
124 }
125
126 static int
dbm_ass_sub(dbmobject * dp,PyObject * v,PyObject * w)127 dbm_ass_sub(dbmobject *dp, PyObject *v, PyObject *w)
128 {
129 datum krec, drec;
130 Py_ssize_t tmp_size;
131
132 if ( !PyArg_Parse(v, "s#", &krec.dptr, &tmp_size) ) {
133 PyErr_SetString(PyExc_TypeError,
134 "dbm mappings have bytes or string keys only");
135 return -1;
136 }
137 krec.dsize = tmp_size;
138 if (dp->di_dbm == NULL) {
139 PyErr_SetString(DbmError, "DBM object has already been closed");
140 return -1;
141 }
142 dp->di_size = -1;
143 if (w == NULL) {
144 if ( dbm_delete(dp->di_dbm, krec) < 0 ) {
145 dbm_clearerr(dp->di_dbm);
146 PyErr_SetObject(PyExc_KeyError, v);
147 return -1;
148 }
149 } else {
150 if ( !PyArg_Parse(w, "s#", &drec.dptr, &tmp_size) ) {
151 PyErr_SetString(PyExc_TypeError,
152 "dbm mappings have byte or string elements only");
153 return -1;
154 }
155 drec.dsize = tmp_size;
156 if ( dbm_store(dp->di_dbm, krec, drec, DBM_REPLACE) < 0 ) {
157 dbm_clearerr(dp->di_dbm);
158 PyErr_SetString(DbmError,
159 "cannot add item to database");
160 return -1;
161 }
162 }
163 if ( dbm_error(dp->di_dbm) ) {
164 dbm_clearerr(dp->di_dbm);
165 PyErr_SetString(DbmError, "");
166 return -1;
167 }
168 return 0;
169 }
170
171 static PyMappingMethods dbm_as_mapping = {
172 (lenfunc)dbm_length, /*mp_length*/
173 (binaryfunc)dbm_subscript, /*mp_subscript*/
174 (objobjargproc)dbm_ass_sub, /*mp_ass_subscript*/
175 };
176
177 /*[clinic input]
178 _dbm.dbm.close
179
180 Close the database.
181 [clinic start generated code]*/
182
183 static PyObject *
_dbm_dbm_close_impl(dbmobject * self)184 _dbm_dbm_close_impl(dbmobject *self)
185 /*[clinic end generated code: output=c8dc5b6709600b86 input=046db72377d51be8]*/
186 {
187 if (self->di_dbm)
188 dbm_close(self->di_dbm);
189 self->di_dbm = NULL;
190 Py_INCREF(Py_None);
191 return Py_None;
192 }
193
194 /*[clinic input]
195 _dbm.dbm.keys
196
197 Return a list of all keys in the database.
198 [clinic start generated code]*/
199
200 static PyObject *
_dbm_dbm_keys_impl(dbmobject * self)201 _dbm_dbm_keys_impl(dbmobject *self)
202 /*[clinic end generated code: output=434549f7c121b33c input=d210ba778cd9c68a]*/
203 {
204 PyObject *v, *item;
205 datum key;
206 int err;
207
208 check_dbmobject_open(self);
209 v = PyList_New(0);
210 if (v == NULL)
211 return NULL;
212 for (key = dbm_firstkey(self->di_dbm); key.dptr;
213 key = dbm_nextkey(self->di_dbm)) {
214 item = PyBytes_FromStringAndSize(key.dptr, key.dsize);
215 if (item == NULL) {
216 Py_DECREF(v);
217 return NULL;
218 }
219 err = PyList_Append(v, item);
220 Py_DECREF(item);
221 if (err != 0) {
222 Py_DECREF(v);
223 return NULL;
224 }
225 }
226 return v;
227 }
228
229 static int
dbm_contains(PyObject * self,PyObject * arg)230 dbm_contains(PyObject *self, PyObject *arg)
231 {
232 dbmobject *dp = (dbmobject *)self;
233 datum key, val;
234 Py_ssize_t size;
235
236 if ((dp)->di_dbm == NULL) {
237 PyErr_SetString(DbmError,
238 "DBM object has already been closed");
239 return -1;
240 }
241 if (PyUnicode_Check(arg)) {
242 key.dptr = PyUnicode_AsUTF8AndSize(arg, &size);
243 key.dsize = size;
244 if (key.dptr == NULL)
245 return -1;
246 }
247 else if (!PyBytes_Check(arg)) {
248 PyErr_Format(PyExc_TypeError,
249 "dbm key must be bytes or string, not %.100s",
250 arg->ob_type->tp_name);
251 return -1;
252 }
253 else {
254 key.dptr = PyBytes_AS_STRING(arg);
255 key.dsize = PyBytes_GET_SIZE(arg);
256 }
257 val = dbm_fetch(dp->di_dbm, key);
258 return val.dptr != NULL;
259 }
260
261 static PySequenceMethods dbm_as_sequence = {
262 0, /* sq_length */
263 0, /* sq_concat */
264 0, /* sq_repeat */
265 0, /* sq_item */
266 0, /* sq_slice */
267 0, /* sq_ass_item */
268 0, /* sq_ass_slice */
269 dbm_contains, /* sq_contains */
270 0, /* sq_inplace_concat */
271 0, /* sq_inplace_repeat */
272 };
273
274 /*[clinic input]
275 _dbm.dbm.get
276
277 key: str(accept={str, robuffer}, zeroes=True)
278 default: object(c_default="NULL") = b''
279 /
280
281 Return the value for key if present, otherwise default.
282 [clinic start generated code]*/
283
284 static PyObject *
_dbm_dbm_get_impl(dbmobject * self,const char * key,Py_ssize_clean_t key_length,PyObject * default_value)285 _dbm_dbm_get_impl(dbmobject *self, const char *key,
286 Py_ssize_clean_t key_length, PyObject *default_value)
287 /*[clinic end generated code: output=b44f95eba8203d93 input=a3a279957f85eb6d]*/
288 /*[clinic end generated code: output=4f5c0e523eaf1251 input=9402c0af8582dc69]*/
289 {
290 datum dbm_key, val;
291
292 dbm_key.dptr = (char *)key;
293 dbm_key.dsize = key_length;
294 check_dbmobject_open(self);
295 val = dbm_fetch(self->di_dbm, dbm_key);
296 if (val.dptr != NULL)
297 return PyBytes_FromStringAndSize(val.dptr, val.dsize);
298
299 Py_INCREF(default_value);
300 return default_value;
301 }
302
303 /*[clinic input]
304 _dbm.dbm.setdefault
305 key: str(accept={str, robuffer}, zeroes=True)
306 default: object(c_default="NULL") = b''
307 /
308
309 Return the value for key if present, otherwise default.
310
311 If key is not in the database, it is inserted with default as the value.
312 [clinic start generated code]*/
313
314 static PyObject *
_dbm_dbm_setdefault_impl(dbmobject * self,const char * key,Py_ssize_clean_t key_length,PyObject * default_value)315 _dbm_dbm_setdefault_impl(dbmobject *self, const char *key,
316 Py_ssize_clean_t key_length,
317 PyObject *default_value)
318 /*[clinic end generated code: output=52545886cf272161 input=bf40c48edaca01d6]*/
319 {
320 datum dbm_key, val;
321 Py_ssize_t tmp_size;
322
323 dbm_key.dptr = (char *)key;
324 dbm_key.dsize = key_length;
325 check_dbmobject_open(self);
326 val = dbm_fetch(self->di_dbm, dbm_key);
327 if (val.dptr != NULL)
328 return PyBytes_FromStringAndSize(val.dptr, val.dsize);
329 if (default_value == NULL) {
330 default_value = PyBytes_FromStringAndSize(NULL, 0);
331 if (default_value == NULL)
332 return NULL;
333 val.dptr = NULL;
334 val.dsize = 0;
335 }
336 else {
337 if ( !PyArg_Parse(default_value, "s#", &val.dptr, &tmp_size) ) {
338 PyErr_SetString(PyExc_TypeError,
339 "dbm mappings have byte string elements only");
340 return NULL;
341 }
342 val.dsize = tmp_size;
343 Py_INCREF(default_value);
344 }
345 if (dbm_store(self->di_dbm, dbm_key, val, DBM_INSERT) < 0) {
346 dbm_clearerr(self->di_dbm);
347 PyErr_SetString(DbmError, "cannot add item to database");
348 Py_DECREF(default_value);
349 return NULL;
350 }
351 return default_value;
352 }
353
354 static PyObject *
dbm__enter__(PyObject * self,PyObject * args)355 dbm__enter__(PyObject *self, PyObject *args)
356 {
357 Py_INCREF(self);
358 return self;
359 }
360
361 static PyObject *
dbm__exit__(PyObject * self,PyObject * args)362 dbm__exit__(PyObject *self, PyObject *args)
363 {
364 _Py_IDENTIFIER(close);
365 return _PyObject_CallMethodId(self, &PyId_close, NULL);
366 }
367
368
369 static PyMethodDef dbm_methods[] = {
370 _DBM_DBM_CLOSE_METHODDEF
371 _DBM_DBM_KEYS_METHODDEF
372 _DBM_DBM_GET_METHODDEF
373 _DBM_DBM_SETDEFAULT_METHODDEF
374 {"__enter__", dbm__enter__, METH_NOARGS, NULL},
375 {"__exit__", dbm__exit__, METH_VARARGS, NULL},
376 {NULL, NULL} /* sentinel */
377 };
378
379 static PyTypeObject Dbmtype = {
380 PyVarObject_HEAD_INIT(NULL, 0)
381 "_dbm.dbm",
382 sizeof(dbmobject),
383 0,
384 (destructor)dbm_dealloc, /*tp_dealloc*/
385 0, /*tp_print*/
386 0, /*tp_getattr*/
387 0, /*tp_setattr*/
388 0, /*tp_reserved*/
389 0, /*tp_repr*/
390 0, /*tp_as_number*/
391 &dbm_as_sequence, /*tp_as_sequence*/
392 &dbm_as_mapping, /*tp_as_mapping*/
393 0, /*tp_hash*/
394 0, /*tp_call*/
395 0, /*tp_str*/
396 0, /*tp_getattro*/
397 0, /*tp_setattro*/
398 0, /*tp_as_buffer*/
399 Py_TPFLAGS_DEFAULT, /*tp_flags*/
400 0, /*tp_doc*/
401 0, /*tp_traverse*/
402 0, /*tp_clear*/
403 0, /*tp_richcompare*/
404 0, /*tp_weaklistoffset*/
405 0, /*tp_iter*/
406 0, /*tp_iternext*/
407 dbm_methods, /*tp_methods*/
408 };
409
410 /* ----------------------------------------------------------------- */
411
412 /*[clinic input]
413
414 _dbm.open as dbmopen
415
416 filename: str
417 The filename to open.
418
419 flags: str="r"
420 How to open the file. "r" for reading, "w" for writing, etc.
421
422 mode: int(py_default="0o666") = 0o666
423 If creating a new file, the mode bits for the new file
424 (e.g. os.O_RDWR).
425
426 /
427
428 Return a database object.
429
430 [clinic start generated code]*/
431
432 static PyObject *
dbmopen_impl(PyObject * module,const char * filename,const char * flags,int mode)433 dbmopen_impl(PyObject *module, const char *filename, const char *flags,
434 int mode)
435 /*[clinic end generated code: output=5fade8cf16e0755f input=226334bade5764e6]*/
436 {
437 int iflags;
438
439 if ( strcmp(flags, "r") == 0 )
440 iflags = O_RDONLY;
441 else if ( strcmp(flags, "w") == 0 )
442 iflags = O_RDWR;
443 else if ( strcmp(flags, "rw") == 0 ) /* B/W compat */
444 iflags = O_RDWR|O_CREAT;
445 else if ( strcmp(flags, "c") == 0 )
446 iflags = O_RDWR|O_CREAT;
447 else if ( strcmp(flags, "n") == 0 )
448 iflags = O_RDWR|O_CREAT|O_TRUNC;
449 else {
450 PyErr_SetString(DbmError,
451 "arg 2 to open should be 'r', 'w', 'c', or 'n'");
452 return NULL;
453 }
454 return newdbmobject(filename, iflags, mode);
455 }
456
457 static PyMethodDef dbmmodule_methods[] = {
458 DBMOPEN_METHODDEF
459 { 0, 0 },
460 };
461
462
463 static struct PyModuleDef _dbmmodule = {
464 PyModuleDef_HEAD_INIT,
465 "_dbm",
466 NULL,
467 -1,
468 dbmmodule_methods,
469 NULL,
470 NULL,
471 NULL,
472 NULL
473 };
474
475 PyMODINIT_FUNC
PyInit__dbm(void)476 PyInit__dbm(void) {
477 PyObject *m, *d, *s;
478
479 if (PyType_Ready(&Dbmtype) < 0)
480 return NULL;
481 m = PyModule_Create(&_dbmmodule);
482 if (m == NULL)
483 return NULL;
484 d = PyModule_GetDict(m);
485 if (DbmError == NULL)
486 DbmError = PyErr_NewException("_dbm.error",
487 PyExc_IOError, NULL);
488 s = PyUnicode_FromString(which_dbm);
489 if (s != NULL) {
490 PyDict_SetItemString(d, "library", s);
491 Py_DECREF(s);
492 }
493 if (DbmError != NULL)
494 PyDict_SetItemString(d, "error", DbmError);
495 if (PyErr_Occurred()) {
496 Py_DECREF(m);
497 m = NULL;
498 }
499 return m;
500 }
501