summaryrefslogtreecommitdiffstats
path: root/Modules/dbmmodule.c
blob: ee5a7f01c22dbde280120ee352befe6299e62e3b (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

/* DBM module using dictionary interface */


#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>
#if defined(PYOS_OS2) && !defined(PYCC_GCC)
static char *which_dbm = "ndbm";
#else
static char *which_dbm = "GNU gdbm";  /* EMX port of GDBM */
#endif
#elif defined(HAVE_GDBM_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) ((v)->ob_type == &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(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(register 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, register PyObject *key)
{
	datum drec, krec;
	int 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_SetString(PyExc_KeyError,
				PyString_AS_STRING((PyStringObject *)key));
		return NULL;
	}
	if ( dbm_error(dp->di_dbm) ) {
		dbm_clearerr(dp->di_dbm);
		PyErr_SetString(DbmError, "");
		return NULL;
	}
	return PyString_FromStringAndSize(drec.dptr, drec.dsize);
}

static int
dbm_ass_sub(dbmobject *dp, PyObject *v, PyObject *w)
{
        datum krec, drec;
	int tmp_size;
	
        if ( !PyArg_Parse(v, "s#", &krec.dptr, &tmp_size) ) {
		PyErr_SetString(PyExc_TypeError,
				"dbm mappings have string indices 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_SetString(PyExc_KeyError,
				      PyString_AS_STRING((PyStringObject *)v));
			return -1;
		}
	} else {
		if ( !PyArg_Parse(w, "s#", &drec.dptr, &tmp_size) ) {
			PyErr_SetString(PyExc_TypeError,
				     "dbm mappings have 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*/
};

static PyObject *
dbm__close(register dbmobject *dp, PyObject *unused)
{
        if (dp->di_dbm)
		dbm_close(dp->di_dbm);
	dp->di_dbm = NULL;
	Py_INCREF(Py_None);
	return Py_None;
}

static PyObject *
dbm_keys(register dbmobject *dp, PyObject *unused)
{
	register 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 = PyString_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;

	if ((dp)->di_dbm == NULL) {
		PyErr_SetString(DbmError,
				"DBM object has already been closed");
                 return -1;
	}
	if (!PyString_Check(arg)) {
		PyErr_Format(PyExc_TypeError,
			     "dbm key must be string, not %.100s",
			     arg->ob_type->tp_name);
		return -1;
	}
	key.dptr = PyString_AS_STRING(arg);
	key.dsize = PyString_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(register dbmobject *dp, PyObject *args)
{
	datum key, val;
	PyObject *defvalue = Py_None;
	int tmp_size;

	if (!PyArg_ParseTuple(args, "s#|O:get",
                              &key.dptr, &tmp_size, &defvalue))
		return NULL;
	key.dsize = tmp_size;
        check_dbmobject_open(dp);
	val = dbm_fetch(dp->di_dbm, key);
	if (val.dptr != NULL)
		return PyString_FromStringAndSize(val.dptr, val.dsize);
	else {
		Py_INCREF(defvalue);
		return defvalue;
	}
}

static PyObject *
dbm_setdefault(register dbmobject *dp, PyObject *args)
{
	datum key, val;
	PyObject *defvalue = NULL;
	int tmp_size;

	if (!PyArg_ParseTuple(args, "s#|S:setdefault",
                              &key.dptr, &tmp_size, &defvalue))
		return NULL;
	key.dsize = tmp_size;
        check_dbmobject_open(dp);
	val = dbm_fetch(dp->di_dbm, key);
	if (val.dptr != NULL)
		return PyString_FromStringAndSize(val.dptr, val.dsize);
	if (defvalue == NULL) {
		defvalue = PyString_FromStringAndSize(NULL, 0);
		if (defvalue == NULL)
			return NULL;
	}
	else
		Py_INCREF(defvalue);
	val.dptr = PyString_AS_STRING(defvalue);
	val.dsize = PyString_GET_SIZE(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");
		return NULL;
	}
	return defvalue;
}

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."},
	{NULL,		NULL}		/* sentinel */
};

static PyObject *
dbm_getattr(dbmobject *dp, char *name)
{
	return Py_FindMethod(dbm_methods, (PyObject *)dp, name);
}

static PyTypeObject Dbmtype = {
	PyObject_HEAD_INIT(NULL)
	0,
	"dbm.dbm",
	sizeof(dbmobject),
	0,
	(destructor)dbm_dealloc,  /*tp_dealloc*/
	0,			  /*tp_print*/
	(getattrfunc)dbm_getattr, /*tp_getattr*/
	0,			  /*tp_setattr*/
	0,			  /*tp_compare*/
	0,			  /*tp_repr*/
	0,			  /*tp_as_number*/
	&dbm_as_sequence,	  /*tp_as_sequence*/
	&dbm_as_mapping,	  /*tp_as_mapping*/
};

/* ----------------------------------------------------------------- */

static PyObject *
dbmopen(PyObject *self, PyObject *args)
{
	char *name;
	char *flags = "r";
	int iflags;
	int mode = 0666;

        if ( !PyArg_ParseTuple(args, "s|si:open", &name, &flags, &mode) )
		return NULL;
	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(name, iflags, mode);
}

static PyMethodDef dbmmodule_methods[] = {
	{ "open", (PyCFunction)dbmopen, METH_VARARGS,
	  "open(path[, flag[, mode]]) -> mapping\n"
	  "Return a database object."},
	{ 0, 0 },
};

PyMODINIT_FUNC
initdbm(void) {
	PyObject *m, *d, *s;

	if (PyType_Ready(&Dbmtype) < 0)
		return;
	m = Py_InitModule("dbm", dbmmodule_methods);
	if (m == NULL)
		return;
	d = PyModule_GetDict(m);
	if (DbmError == NULL)
		DbmError = PyErr_NewException("dbm.error", NULL, NULL);
	s = PyString_FromString(which_dbm);
	if (s != NULL) {
		PyDict_SetItemString(d, "library", s);
		Py_DECREF(s);
	}
	if (DbmError != NULL)
		PyDict_SetItemString(d, "error", DbmError);
}