source: trunk/essentials/dev-lang/python/Modules/dbmmodule.c@ 3300

Last change on this file since 3300 was 3225, checked in by bird, 19 years ago

Python 2.5
File size: 8.7 KB
Line 
1
2/* DBM module using dictionary interface */
3
4
5#include "Python.h"
6
7#include <sys/types.h>
8#include <sys/stat.h>
9#include <fcntl.h>
10
11/* Some Linux systems install gdbm/ndbm.h, but not ndbm.h. This supports
12 * whichever configure was able to locate.
13 */
14#if defined(HAVE_NDBM_H)
15#include <ndbm.h>
16#if defined(PYOS_OS2) && !defined(PYCC_GCC)
17static char *which_dbm = "ndbm";
18#else
19static char *which_dbm = "GNU gdbm"; /* EMX port of GDBM */
20#endif
21#elif defined(HAVE_GDBM_NDBM_H)
22#include <gdbm/ndbm.h>
23static char *which_dbm = "GNU gdbm";
24#elif defined(HAVE_BERKDB_H)
25#include <db.h>
26static char *which_dbm = "Berkeley DB";
27#else
28#error "No ndbm.h available!"
29#endif
30
31typedef struct {
32 PyObject_HEAD
33 int di_size; /* -1 means recompute */
34 DBM *di_dbm;
35} dbmobject;
36
37static PyTypeObject Dbmtype;
38
39#define is_dbmobject(v) ((v)->ob_type == &Dbmtype)
40#define check_dbmobject_open(v) if ((v)->di_dbm == NULL) \
41 { PyErr_SetString(DbmError, "DBM object has already been closed"); \
42 return NULL; }
43
44static PyObject *DbmError;
45
46static PyObject *
47newdbmobject(char *file, int flags, int mode)
48{
49 dbmobject *dp;
50
51 dp = PyObject_New(dbmobject, &Dbmtype);
52 if (dp == NULL)
53 return NULL;
54 dp->di_size = -1;
55 if ( (dp->di_dbm = dbm_open(file, flags, mode)) == 0 ) {
56 PyErr_SetFromErrno(DbmError);
57 Py_DECREF(dp);
58 return NULL;
59 }
60 return (PyObject *)dp;
61}
62
63/* Methods */
64
65static void
66dbm_dealloc(register dbmobject *dp)
67{
68 if ( dp->di_dbm )
69 dbm_close(dp->di_dbm);
70 PyObject_Del(dp);
71}
72
73static Py_ssize_t
74dbm_length(dbmobject *dp)
75{
76 if (dp->di_dbm == NULL) {
77 PyErr_SetString(DbmError, "DBM object has already been closed");
78 return -1;
79 }
80 if ( dp->di_size < 0 ) {
81 datum key;
82 int size;
83
84 size = 0;
85 for ( key=dbm_firstkey(dp->di_dbm); key.dptr;
86 key = dbm_nextkey(dp->di_dbm))
87 size++;
88 dp->di_size = size;
89 }
90 return dp->di_size;
91}
92
93static PyObject *
94dbm_subscript(dbmobject *dp, register PyObject *key)
95{
96 datum drec, krec;
97 int tmp_size;
98
99 if (!PyArg_Parse(key, "s#", &krec.dptr, &tmp_size) )
100 return NULL;
101
102 krec.dsize = tmp_size;
103 check_dbmobject_open(dp);
104 drec = dbm_fetch(dp->di_dbm, krec);
105 if ( drec.dptr == 0 ) {
106 PyErr_SetString(PyExc_KeyError,
107 PyString_AS_STRING((PyStringObject *)key));
108 return NULL;
109 }
110 if ( dbm_error(dp->di_dbm) ) {
111 dbm_clearerr(dp->di_dbm);
112 PyErr_SetString(DbmError, "");
113 return NULL;
114 }
115 return PyString_FromStringAndSize(drec.dptr, drec.dsize);
116}
117
118static int
119dbm_ass_sub(dbmobject *dp, PyObject *v, PyObject *w)
120{
121 datum krec, drec;
122 int tmp_size;
123
124 if ( !PyArg_Parse(v, "s#", &krec.dptr, &tmp_size) ) {
125 PyErr_SetString(PyExc_TypeError,
126 "dbm mappings have string indices only");
127 return -1;
128 }
129 krec.dsize = tmp_size;
130 if (dp->di_dbm == NULL) {
131 PyErr_SetString(DbmError, "DBM object has already been closed");
132 return -1;
133 }
134 dp->di_size = -1;
135 if (w == NULL) {
136 if ( dbm_delete(dp->di_dbm, krec) < 0 ) {
137 dbm_clearerr(dp->di_dbm);
138 PyErr_SetString(PyExc_KeyError,
139 PyString_AS_STRING((PyStringObject *)v));
140 return -1;
141 }
142 } else {
143 if ( !PyArg_Parse(w, "s#", &drec.dptr, &tmp_size) ) {
144 PyErr_SetString(PyExc_TypeError,
145 "dbm mappings have string elements only");
146 return -1;
147 }
148 drec.dsize = tmp_size;
149 if ( dbm_store(dp->di_dbm, krec, drec, DBM_REPLACE) < 0 ) {
150 dbm_clearerr(dp->di_dbm);
151 PyErr_SetString(DbmError,
152 "cannot add item to database");
153 return -1;
154 }
155 }
156 if ( dbm_error(dp->di_dbm) ) {
157 dbm_clearerr(dp->di_dbm);
158 PyErr_SetString(DbmError, "");
159 return -1;
160 }
161 return 0;
162}
163
164static PyMappingMethods dbm_as_mapping = {
165 (lenfunc)dbm_length, /*mp_length*/
166 (binaryfunc)dbm_subscript, /*mp_subscript*/
167 (objobjargproc)dbm_ass_sub, /*mp_ass_subscript*/
168};
169
170static PyObject *
171dbm__close(register dbmobject *dp, PyObject *unused)
172{
173 if (dp->di_dbm)
174 dbm_close(dp->di_dbm);
175 dp->di_dbm = NULL;
176 Py_INCREF(Py_None);
177 return Py_None;
178}
179
180static PyObject *
181dbm_keys(register dbmobject *dp, PyObject *unused)
182{
183 register PyObject *v, *item;
184 datum key;
185 int err;
186
187 check_dbmobject_open(dp);
188 v = PyList_New(0);
189 if (v == NULL)
190 return NULL;
191 for (key = dbm_firstkey(dp->di_dbm); key.dptr;
192 key = dbm_nextkey(dp->di_dbm)) {
193 item = PyString_FromStringAndSize(key.dptr, key.dsize);
194 if (item == NULL) {
195 Py_DECREF(v);
196 return NULL;
197 }
198 err = PyList_Append(v, item);
199 Py_DECREF(item);
200 if (err != 0) {
201 Py_DECREF(v);
202 return NULL;
203 }
204 }
205 return v;
206}
207
208static PyObject *
209dbm_has_key(register dbmobject *dp, PyObject *args)
210{
211 datum key, val;
212 int tmp_size;
213
214 if (!PyArg_ParseTuple(args, "s#:has_key", &key.dptr, &tmp_size))
215 return NULL;
216 key.dsize = tmp_size;
217 check_dbmobject_open(dp);
218 val = dbm_fetch(dp->di_dbm, key);
219 return PyInt_FromLong(val.dptr != NULL);
220}
221
222static PyObject *
223dbm_get(register dbmobject *dp, PyObject *args)
224{
225 datum key, val;
226 PyObject *defvalue = Py_None;
227 int tmp_size;
228
229 if (!PyArg_ParseTuple(args, "s#|O:get",
230 &key.dptr, &tmp_size, &defvalue))
231 return NULL;
232 key.dsize = tmp_size;
233 check_dbmobject_open(dp);
234 val = dbm_fetch(dp->di_dbm, key);
235 if (val.dptr != NULL)
236 return PyString_FromStringAndSize(val.dptr, val.dsize);
237 else {
238 Py_INCREF(defvalue);
239 return defvalue;
240 }
241}
242
243static PyObject *
244dbm_setdefault(register dbmobject *dp, PyObject *args)
245{
246 datum key, val;
247 PyObject *defvalue = NULL;
248 int tmp_size;
249
250 if (!PyArg_ParseTuple(args, "s#|S:setdefault",
251 &key.dptr, &tmp_size, &defvalue))
252 return NULL;
253 key.dsize = tmp_size;
254 check_dbmobject_open(dp);
255 val = dbm_fetch(dp->di_dbm, key);
256 if (val.dptr != NULL)
257 return PyString_FromStringAndSize(val.dptr, val.dsize);
258 if (defvalue == NULL) {
259 defvalue = PyString_FromStringAndSize(NULL, 0);
260 if (defvalue == NULL)
261 return NULL;
262 }
263 else
264 Py_INCREF(defvalue);
265 val.dptr = PyString_AS_STRING(defvalue);
266 val.dsize = PyString_GET_SIZE(defvalue);
267 if (dbm_store(dp->di_dbm, key, val, DBM_INSERT) < 0) {
268 dbm_clearerr(dp->di_dbm);
269 PyErr_SetString(DbmError, "cannot add item to database");
270 return NULL;
271 }
272 return defvalue;
273}
274
275static PyMethodDef dbm_methods[] = {
276 {"close", (PyCFunction)dbm__close, METH_NOARGS,
277 "close()\nClose the database."},
278 {"keys", (PyCFunction)dbm_keys, METH_NOARGS,
279 "keys() -> list\nReturn a list of all keys in the database."},
280 {"has_key", (PyCFunction)dbm_has_key, METH_VARARGS,
281 "has_key(key} -> boolean\nReturn true iff key is in the database."},
282 {"get", (PyCFunction)dbm_get, METH_VARARGS,
283 "get(key[, default]) -> value\n"
284 "Return the value for key if present, otherwise default."},
285 {"setdefault", (PyCFunction)dbm_setdefault, METH_VARARGS,
286 "setdefault(key[, default]) -> value\n"
287 "Return the value for key if present, otherwise default. If key\n"
288 "is not in the database, it is inserted with default as the value."},
289 {NULL, NULL} /* sentinel */
290};
291
292static PyObject *
293dbm_getattr(dbmobject *dp, char *name)
294{
295 return Py_FindMethod(dbm_methods, (PyObject *)dp, name);
296}
297
298static PyTypeObject Dbmtype = {
299 PyObject_HEAD_INIT(NULL)
300 0,
301 "dbm.dbm",
302 sizeof(dbmobject),
303 0,
304 (destructor)dbm_dealloc, /*tp_dealloc*/
305 0, /*tp_print*/
306 (getattrfunc)dbm_getattr, /*tp_getattr*/
307 0, /*tp_setattr*/
308 0, /*tp_compare*/
309 0, /*tp_repr*/
310 0, /*tp_as_number*/
311 0, /*tp_as_sequence*/
312 &dbm_as_mapping, /*tp_as_mapping*/
313};
314
315/* ----------------------------------------------------------------- */
316
317static PyObject *
318dbmopen(PyObject *self, PyObject *args)
319{
320 char *name;
321 char *flags = "r";
322 int iflags;
323 int mode = 0666;
324
325 if ( !PyArg_ParseTuple(args, "s|si:open", &name, &flags, &mode) )
326 return NULL;
327 if ( strcmp(flags, "r") == 0 )
328 iflags = O_RDONLY;
329 else if ( strcmp(flags, "w") == 0 )
330 iflags = O_RDWR;
331 else if ( strcmp(flags, "rw") == 0 ) /* B/W compat */
332 iflags = O_RDWR|O_CREAT;
333 else if ( strcmp(flags, "c") == 0 )
334 iflags = O_RDWR|O_CREAT;
335 else if ( strcmp(flags, "n") == 0 )
336 iflags = O_RDWR|O_CREAT|O_TRUNC;
337 else {
338 PyErr_SetString(DbmError,
339 "arg 2 to open should be 'r', 'w', 'c', or 'n'");
340 return NULL;
341 }
342 return newdbmobject(name, iflags, mode);
343}
344
345static PyMethodDef dbmmodule_methods[] = {
346 { "open", (PyCFunction)dbmopen, METH_VARARGS,
347 "open(path[, flag[, mode]]) -> mapping\n"
348 "Return a database object."},