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Viewing changes to Modules/_dbmmodule.c

  • Committer: Bazaar Package Importer
  • Author(s): Matthias Klose
  • Date: 2009-03-23 00:01:27 UTC
  • Revision ID: james.westby@ubuntu.com-20090323000127-5fstfxju4ufrhthq
Tags: upstream-3.1~a1+20090322
Import upstream version 3.1~a1+20090322

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Modules/_dbmmodule.c
 
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
#if defined(PYOS_OS2) && !defined(PYCC_GCC)
 
18
static char *which_dbm = "ndbm";
 
19
#else
 
20
static char *which_dbm = "GNU gdbm";  /* EMX port of GDBM */
 
21
#endif
 
22
#elif defined(HAVE_GDBM_NDBM_H)
 
23
#include <gdbm/ndbm.h>
 
24
static char *which_dbm = "GNU gdbm";
 
25
#elif defined(HAVE_GDBM_DASH_NDBM_H)
 
26
#include <gdbm-ndbm.h>
 
27
static char *which_dbm = "GNU gdbm";
 
28
#elif defined(HAVE_BERKDB_H)
 
29
#include <db.h>
 
30
static char *which_dbm = "Berkeley DB";
 
31
#else
 
32
#error "No ndbm.h available!"
 
33
#endif
 
34
 
 
35
typedef struct {
 
36
        PyObject_HEAD
 
37
        int di_size;    /* -1 means recompute */
 
38
        DBM *di_dbm;
 
39
} dbmobject;
 
40
 
 
41
static PyTypeObject Dbmtype;
 
42
 
 
43
#define is_dbmobject(v) (Py_TYPE(v) == &Dbmtype)
 
44
#define check_dbmobject_open(v) if ((v)->di_dbm == NULL) \
 
45
               { PyErr_SetString(DbmError, "DBM object has already been closed"); \
 
46
                 return NULL; }
 
47
 
 
48
static PyObject *DbmError;
 
49
 
 
50
static PyObject *
 
51
newdbmobject(char *file, int flags, int mode)
 
52
{
 
53
        dbmobject *dp;
 
54
 
 
55
        dp = PyObject_New(dbmobject, &Dbmtype);
 
56
        if (dp == NULL)
 
57
                return NULL;
 
58
        dp->di_size = -1;
 
59
        if ( (dp->di_dbm = dbm_open(file, flags, mode)) == 0 ) {
 
60
                PyErr_SetFromErrno(DbmError);
 
61
                Py_DECREF(dp);
 
62
                return NULL;
 
63
        }
 
64
        return (PyObject *)dp;
 
65
}
 
66
 
 
67
/* Methods */
 
68
 
 
69
static void
 
70
dbm_dealloc(register dbmobject *dp)
 
71
{
 
72
        if ( dp->di_dbm )
 
73
                dbm_close(dp->di_dbm);
 
74
        PyObject_Del(dp);
 
75
}
 
76
 
 
77
static Py_ssize_t
 
78
dbm_length(dbmobject *dp)
 
79
{
 
80
        if (dp->di_dbm == NULL) {
 
81
                 PyErr_SetString(DbmError, "DBM object has already been closed"); 
 
82
                 return -1; 
 
83
        }
 
84
        if ( dp->di_size < 0 ) {
 
85
                datum key;
 
86
                int size;
 
87
 
 
88
                size = 0;
 
89
                for ( key=dbm_firstkey(dp->di_dbm); key.dptr;
 
90
                      key = dbm_nextkey(dp->di_dbm))
 
91
                        size++;
 
92
                dp->di_size = size;
 
93
        }
 
94
        return dp->di_size;
 
95
}
 
96
 
 
97
static PyObject *
 
98
dbm_subscript(dbmobject *dp, register PyObject *key)
 
99
{
 
100
        datum drec, krec;
 
101
        Py_ssize_t tmp_size;
 
102
        
 
103
        if (!PyArg_Parse(key, "s#", &krec.dptr, &tmp_size) )
 
104
                return NULL;
 
105
        
 
106
        krec.dsize = tmp_size;
 
107
        check_dbmobject_open(dp);
 
108
        drec = dbm_fetch(dp->di_dbm, krec);
 
109
        if ( drec.dptr == 0 ) {
 
110
                PyErr_SetObject(PyExc_KeyError, key);
 
111
                return NULL;
 
112
        }
 
113
        if ( dbm_error(dp->di_dbm) ) {
 
114
                dbm_clearerr(dp->di_dbm);
 
115
                PyErr_SetString(DbmError, "");
 
116
                return NULL;
 
117
        }
 
118
        return PyBytes_FromStringAndSize(drec.dptr, drec.dsize);
 
119
}
 
120
 
 
121
static int
 
122
dbm_ass_sub(dbmobject *dp, PyObject *v, PyObject *w)
 
123
{
 
124
        datum krec, drec;
 
125
        Py_ssize_t tmp_size;
 
126
        
 
127
        if ( !PyArg_Parse(v, "s#", &krec.dptr, &tmp_size) ) {
 
128
                PyErr_SetString(PyExc_TypeError,
 
129
                                "dbm mappings have bytes or string keys only");
 
130
                return -1;
 
131
        }
 
132
        krec.dsize = tmp_size;
 
133
        if (dp->di_dbm == NULL) {
 
134
                 PyErr_SetString(DbmError, "DBM object has already been closed"); 
 
135
                 return -1;
 
136
        }
 
137
        dp->di_size = -1;
 
138
        if (w == NULL) {
 
139
                if ( dbm_delete(dp->di_dbm, krec) < 0 ) {
 
140
                        dbm_clearerr(dp->di_dbm);
 
141
                        PyErr_SetObject(PyExc_KeyError, v);
 
142
                        return -1;
 
143
                }
 
144
        } else {
 
145
                if ( !PyArg_Parse(w, "s#", &drec.dptr, &tmp_size) ) {
 
146
                        PyErr_SetString(PyExc_TypeError,
 
147
                             "dbm mappings have byte or string elements only");
 
148
                        return -1;
 
149
                }
 
150
                drec.dsize = tmp_size;
 
151
                if ( dbm_store(dp->di_dbm, krec, drec, DBM_REPLACE) < 0 ) {
 
152
                        dbm_clearerr(dp->di_dbm);
 
153
                        PyErr_SetString(DbmError,
 
154
                                        "cannot add item to database");
 
155
                        return -1;
 
156
                }
 
157
        }
 
158
        if ( dbm_error(dp->di_dbm) ) {
 
159
                dbm_clearerr(dp->di_dbm);
 
160
                PyErr_SetString(DbmError, "");
 
161
                return -1;
 
162
        }
 
163
        return 0;
 
164
}
 
165
 
 
166
static PyMappingMethods dbm_as_mapping = {
 
167
        (lenfunc)dbm_length,            /*mp_length*/
 
168
        (binaryfunc)dbm_subscript,      /*mp_subscript*/
 
169
        (objobjargproc)dbm_ass_sub,     /*mp_ass_subscript*/
 
170
};
 
171
 
 
172
static PyObject *
 
173
dbm__close(register dbmobject *dp, PyObject *unused)
 
174
{
 
175
        if (dp->di_dbm)
 
176
                dbm_close(dp->di_dbm);
 
177
        dp->di_dbm = NULL;
 
178
        Py_INCREF(Py_None);
 
179
        return Py_None;
 
180
}
 
181
 
 
182
static PyObject *
 
183
dbm_keys(register dbmobject *dp, PyObject *unused)
 
184
{
 
185
        register PyObject *v, *item;
 
186
        datum key;
 
187
        int err;
 
188
 
 
189
        check_dbmobject_open(dp);
 
190
        v = PyList_New(0);
 
191
        if (v == NULL)
 
192
                return NULL;
 
193
        for (key = dbm_firstkey(dp->di_dbm); key.dptr;
 
194
             key = dbm_nextkey(dp->di_dbm)) {
 
195
                item = PyBytes_FromStringAndSize(key.dptr, key.dsize);
 
196
                if (item == NULL) {
 
197
                        Py_DECREF(v);
 
198
                        return NULL;
 
199
                }
 
200
                err = PyList_Append(v, item);
 
201
                Py_DECREF(item);
 
202
                if (err != 0) {
 
203
                        Py_DECREF(v);
 
204
                        return NULL;
 
205
                }
 
206
        }
 
207
        return v;
 
208
}
 
209
 
 
210
static int
 
211
dbm_contains(PyObject *self, PyObject *arg)
 
212
{
 
213
        dbmobject *dp = (dbmobject *)self;
 
214
        datum key, val;
 
215
 
 
216
        if ((dp)->di_dbm == NULL) {
 
217
                PyErr_SetString(DbmError,
 
218
                                "DBM object has already been closed");
 
219
                 return -1;
 
220
        }
 
221
        if (PyUnicode_Check(arg)) {
 
222
                arg = _PyUnicode_AsDefaultEncodedString(arg, NULL);
 
223
                if (arg == NULL)
 
224
                        return -1;
 
225
        }
 
226
        if (!PyBytes_Check(arg)) {
 
227
                PyErr_Format(PyExc_TypeError,
 
228
                             "dbm key must be string, not %.100s",
 
229
                             arg->ob_type->tp_name);
 
230
                return -1;
 
231
        }
 
232
        key.dptr = PyBytes_AS_STRING(arg);
 
233
        key.dsize = PyBytes_GET_SIZE(arg);
 
234
        val = dbm_fetch(dp->di_dbm, key);
 
235
        return val.dptr != NULL;
 
236
}
 
237
 
 
238
static PySequenceMethods dbm_as_sequence = {
 
239
        0,                      /* sq_length */
 
240
        0,                      /* sq_concat */
 
241
        0,                      /* sq_repeat */
 
242
        0,                      /* sq_item */
 
243
        0,                      /* sq_slice */
 
244
        0,                      /* sq_ass_item */
 
245
        0,                      /* sq_ass_slice */
 
246
        dbm_contains,           /* sq_contains */
 
247
        0,                      /* sq_inplace_concat */
 
248
        0,                      /* sq_inplace_repeat */
 
249
};
 
250
 
 
251
static PyObject *
 
252
dbm_get(register dbmobject *dp, PyObject *args)
 
253
{
 
254
        datum key, val;
 
255
        PyObject *defvalue = Py_None;
 
256
        char *tmp_ptr;
 
257
        Py_ssize_t tmp_size;
 
258
 
 
259
        if (!PyArg_ParseTuple(args, "s#|O:get",
 
260
                              &tmp_ptr, &tmp_size, &defvalue))
 
261
                return NULL;
 
262
        key.dptr = tmp_ptr;
 
263
        key.dsize = tmp_size;
 
264
        check_dbmobject_open(dp);
 
265
        val = dbm_fetch(dp->di_dbm, key);
 
266
        if (val.dptr != NULL)
 
267
                return PyBytes_FromStringAndSize(val.dptr, val.dsize);
 
268
        else {
 
269
                Py_INCREF(defvalue);
 
270
                return defvalue;
 
271
        }
 
272
}
 
273
 
 
274
static PyObject *
 
275
dbm_setdefault(register dbmobject *dp, PyObject *args)
 
276
{
 
277
        datum key, val;
 
278
        PyObject *defvalue = NULL;
 
279
        char *tmp_ptr;
 
280
        Py_ssize_t tmp_size;
 
281
 
 
282
        if (!PyArg_ParseTuple(args, "s#|O:setdefault",
 
283
                              &tmp_ptr, &tmp_size, &defvalue))
 
284
                return NULL;
 
285
        key.dptr = tmp_ptr;
 
286
        key.dsize = tmp_size;
 
287
        check_dbmobject_open(dp);
 
288
        val = dbm_fetch(dp->di_dbm, key);
 
289
        if (val.dptr != NULL)
 
290
                return PyBytes_FromStringAndSize(val.dptr, val.dsize);
 
291
        if (defvalue == NULL) {
 
292
                defvalue = PyBytes_FromStringAndSize(NULL, 0);
 
293
                if (defvalue == NULL)
 
294
                        return NULL;
 
295
                val.dptr = NULL;
 
296
                val.dsize = 0;
 
297
        }
 
298
        else {
 
299
                if ( !PyArg_Parse(defvalue, "s#", &val.dptr, &tmp_size) ) {
 
300
                        PyErr_SetString(PyExc_TypeError,
 
301
                                "dbm mappings have byte string elements only");
 
302
                        return NULL;
 
303
                }
 
304
                val.dsize = tmp_size;
 
305
                Py_INCREF(defvalue);
 
306
        }
 
307
        if (dbm_store(dp->di_dbm, key, val, DBM_INSERT) < 0) {
 
308
                dbm_clearerr(dp->di_dbm);
 
309
                PyErr_SetString(DbmError, "cannot add item to database");
 
310
                Py_DECREF(defvalue);
 
311
                return NULL;
 
312
        }
 
313
        return defvalue;
 
314
}
 
315
 
 
316
static PyMethodDef dbm_methods[] = {
 
317
        {"close",       (PyCFunction)dbm__close,        METH_NOARGS,
 
318
         "close()\nClose the database."},
 
319
        {"keys",        (PyCFunction)dbm_keys,          METH_NOARGS,
 
320
         "keys() -> list\nReturn a list of all keys in the database."},
 
321
        {"get",         (PyCFunction)dbm_get,           METH_VARARGS,
 
322
         "get(key[, default]) -> value\n"
 
323
         "Return the value for key if present, otherwise default."},
 
324
        {"setdefault",  (PyCFunction)dbm_setdefault,    METH_VARARGS,
 
325
         "setdefault(key[, default]) -> value\n"
 
326
         "Return the value for key if present, otherwise default.  If key\n"
 
327
         "is not in the database, it is inserted with default as the value."},
 
328
        {NULL,          NULL}           /* sentinel */
 
329
};
 
330
 
 
331
static PyTypeObject Dbmtype = {
 
332
        PyVarObject_HEAD_INIT(NULL, 0)
 
333
        "_dbm.dbm",
 
334
        sizeof(dbmobject),
 
335
        0,
 
336
        (destructor)dbm_dealloc,  /*tp_dealloc*/
 
337
        0,                        /*tp_print*/
 
338
        0,                        /*tp_getattr*/
 
339
        0,                        /*tp_setattr*/
 
340
        0,                        /*tp_reserved*/
 
341
        0,                        /*tp_repr*/
 
342
        0,                        /*tp_as_number*/
 
343
        &dbm_as_sequence,         /*tp_as_sequence*/
 
344
        &dbm_as_mapping,          /*tp_as_mapping*/
 
345
        0,                    /*tp_hash*/
 
346
        0,                    /*tp_call*/
 
347
        0,                    /*tp_str*/
 
348
        0,                    /*tp_getattro*/
 
349
        0,                    /*tp_setattro*/
 
350
        0,                    /*tp_as_buffer*/
 
351
        Py_TPFLAGS_DEFAULT,   /*tp_flags*/
 
352
        0,                    /*tp_doc*/
 
353
        0,                    /*tp_traverse*/
 
354
        0,                    /*tp_clear*/
 
355
        0,                    /*tp_richcompare*/
 
356
        0,                    /*tp_weaklistoffset*/
 
357
        0,                    /*tp_iter*/
 
358
        0,                    /*tp_iternext*/
 
359
        dbm_methods,          /*tp_methods*/
 
360
};
 
361
 
 
362
/* ----------------------------------------------------------------- */
 
363
 
 
364
static PyObject *
 
365
dbmopen(PyObject *self, PyObject *args)
 
366
{
 
367
        char *name;
 
368
        char *flags = "r";
 
369
        int iflags;
 
370
        int mode = 0666;
 
371
 
 
372
        if ( !PyArg_ParseTuple(args, "s|si:open", &name, &flags, &mode) )
 
373
                return NULL;
 
374
        if ( strcmp(flags, "r") == 0 )
 
375
                iflags = O_RDONLY;
 
376
        else if ( strcmp(flags, "w") == 0 )
 
377
                iflags = O_RDWR;
 
378
        else if ( strcmp(flags, "rw") == 0 ) /* B/W compat */
 
379
                iflags = O_RDWR|O_CREAT; 
 
380
        else if ( strcmp(flags, "c") == 0 )
 
381
                iflags = O_RDWR|O_CREAT;
 
382
        else if ( strcmp(flags, "n") == 0 )
 
383
                iflags = O_RDWR|O_CREAT|O_TRUNC;
 
384
        else {
 
385
                PyErr_SetString(DbmError,
 
386
                                "arg 2 to open should be 'r', 'w', 'c', or 'n'");
 
387
                return NULL;
 
388
        }
 
389
        return newdbmobject(name, iflags, mode);
 
390
}
 
391
 
 
392
static PyMethodDef dbmmodule_methods[] = {
 
393
        { "open", (PyCFunction)dbmopen, METH_VARARGS,
 
394
          "open(path[, flag[, mode]]) -> mapping\n"
 
395
          "Return a database object."},
 
396
        { 0, 0 },
 
397
};
 
398
 
 
399
 
 
400
static struct PyModuleDef _dbmmodule = {
 
401
        PyModuleDef_HEAD_INIT,
 
402
        "_dbm",
 
403
        NULL,
 
404
        -1,
 
405
        dbmmodule_methods,
 
406
        NULL,
 
407
        NULL,
 
408
        NULL,
 
409
        NULL
 
410
};
 
411
 
 
412
PyMODINIT_FUNC
 
413
PyInit__dbm(void) {
 
414
        PyObject *m, *d, *s;
 
415
 
 
416
        if (PyType_Ready(&Dbmtype) < 0)
 
417
                return NULL;
 
418
        m = PyModule_Create(&_dbmmodule);
 
419
        if (m == NULL)
 
420
                return NULL;
 
421
        d = PyModule_GetDict(m);
 
422
        if (DbmError == NULL)
 
423
                DbmError = PyErr_NewException("_dbm.error",
 
424
                                              PyExc_IOError, NULL);
 
425
        s = PyUnicode_FromString(which_dbm);
 
426
        if (s != NULL) {
 
427
                PyDict_SetItemString(d, "library", s);
 
428
                Py_DECREF(s);
 
429
        }
 
430
        if (DbmError != NULL)
 
431
                PyDict_SetItemString(d, "error", DbmError);
 
432
        if (PyErr_Occurred()) {
 
433
                Py_DECREF(m);
 
434
                m = NULL;
 
435
        }
 
436
        return m;
 
437
}