summaryrefslogtreecommitdiff
path: root/Modules/_dbmmodule.c
blob: 65761d83d380f71ef344ff136331b6a767c6dba9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512

/* DBM module using dictionary interface */


#define PY_SSIZE_T_CLEAN
#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 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; }

static PyObject *DbmError;

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;
    /* See issue #19296 */
    if ( (dp->di_dbm = dbm_open((char *)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);
}

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, 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;
}

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]*/

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]*/

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;
    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);
        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;
    }
    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 byte 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_CallMethodId(self, &PyId_close, NULL);
}


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 */
};

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 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;
}

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;
}