/Modules/dbmmodule.c

http://unladen-swallow.googlecode.com/ · C · 417 lines · 367 code · 43 blank · 7 comment · 77 complexity · fdee1b50c0b8aa72143799ad9ac8443f MD5 · raw file

  1. /* DBM module using dictionary interface */
  2. #include "Python.h"
  3. #include <sys/types.h>
  4. #include <sys/stat.h>
  5. #include <fcntl.h>
  6. /* Some Linux systems install gdbm/ndbm.h, but not ndbm.h. This supports
  7. * whichever configure was able to locate.
  8. */
  9. #if defined(HAVE_NDBM_H)
  10. #include <ndbm.h>
  11. #if defined(PYOS_OS2) && !defined(PYCC_GCC)
  12. static char *which_dbm = "ndbm";
  13. #else
  14. static char *which_dbm = "GNU gdbm"; /* EMX port of GDBM */
  15. #endif
  16. #elif defined(HAVE_GDBM_NDBM_H)
  17. #include <gdbm/ndbm.h>
  18. static char *which_dbm = "GNU gdbm";
  19. #elif defined(HAVE_GDBM_DASH_NDBM_H)
  20. #include <gdbm-ndbm.h>
  21. static char *which_dbm = "GNU gdbm";
  22. #elif defined(HAVE_BERKDB_H)
  23. #include <db.h>
  24. static char *which_dbm = "Berkeley DB";
  25. #else
  26. #error "No ndbm.h available!"
  27. #endif
  28. typedef struct {
  29. PyObject_HEAD
  30. int di_size; /* -1 means recompute */
  31. DBM *di_dbm;
  32. } dbmobject;
  33. static PyTypeObject Dbmtype;
  34. #define is_dbmobject(v) (Py_TYPE(v) == &Dbmtype)
  35. #define check_dbmobject_open(v) if ((v)->di_dbm == NULL) \
  36. { PyErr_SetString(DbmError, "DBM object has already been closed"); \
  37. return NULL; }
  38. static PyObject *DbmError;
  39. static PyObject *
  40. newdbmobject(char *file, int flags, int mode)
  41. {
  42. dbmobject *dp;
  43. dp = PyObject_New(dbmobject, &Dbmtype);
  44. if (dp == NULL)
  45. return NULL;
  46. dp->di_size = -1;
  47. if ( (dp->di_dbm = dbm_open(file, flags, mode)) == 0 ) {
  48. PyErr_SetFromErrno(DbmError);
  49. Py_DECREF(dp);
  50. return NULL;
  51. }
  52. return (PyObject *)dp;
  53. }
  54. /* Methods */
  55. static void
  56. dbm_dealloc(register dbmobject *dp)
  57. {
  58. if ( dp->di_dbm )
  59. dbm_close(dp->di_dbm);
  60. PyObject_Del(dp);
  61. }
  62. static Py_ssize_t
  63. dbm_length(dbmobject *dp)
  64. {
  65. if (dp->di_dbm == NULL) {
  66. PyErr_SetString(DbmError, "DBM object has already been closed");
  67. return -1;
  68. }
  69. if ( dp->di_size < 0 ) {
  70. datum key;
  71. int size;
  72. size = 0;
  73. for ( key=dbm_firstkey(dp->di_dbm); key.dptr;
  74. key = dbm_nextkey(dp->di_dbm))
  75. size++;
  76. dp->di_size = size;
  77. }
  78. return dp->di_size;
  79. }
  80. static PyObject *
  81. dbm_subscript(dbmobject *dp, register PyObject *key)
  82. {
  83. datum drec, krec;
  84. int tmp_size;
  85. if (!PyArg_Parse(key, "s#", &krec.dptr, &tmp_size) )
  86. return NULL;
  87. krec.dsize = tmp_size;
  88. check_dbmobject_open(dp);
  89. drec = dbm_fetch(dp->di_dbm, krec);
  90. if ( drec.dptr == 0 ) {
  91. PyErr_SetString(PyExc_KeyError,
  92. PyString_AS_STRING((PyStringObject *)key));
  93. return NULL;
  94. }
  95. if ( dbm_error(dp->di_dbm) ) {
  96. dbm_clearerr(dp->di_dbm);
  97. PyErr_SetString(DbmError, "");
  98. return NULL;
  99. }
  100. return PyString_FromStringAndSize(drec.dptr, drec.dsize);
  101. }
  102. static int
  103. dbm_ass_sub(dbmobject *dp, PyObject *v, PyObject *w)
  104. {
  105. datum krec, drec;
  106. int tmp_size;
  107. if ( !PyArg_Parse(v, "s#", &krec.dptr, &tmp_size) ) {
  108. PyErr_SetString(PyExc_TypeError,
  109. "dbm mappings have string indices only");
  110. return -1;
  111. }
  112. krec.dsize = tmp_size;
  113. if (dp->di_dbm == NULL) {
  114. PyErr_SetString(DbmError, "DBM object has already been closed");
  115. return -1;
  116. }
  117. dp->di_size = -1;
  118. if (w == NULL) {
  119. if ( dbm_delete(dp->di_dbm, krec) < 0 ) {
  120. dbm_clearerr(dp->di_dbm);
  121. PyErr_SetString(PyExc_KeyError,
  122. PyString_AS_STRING((PyStringObject *)v));
  123. return -1;
  124. }
  125. } else {
  126. if ( !PyArg_Parse(w, "s#", &drec.dptr, &tmp_size) ) {
  127. PyErr_SetString(PyExc_TypeError,
  128. "dbm mappings have string elements only");
  129. return -1;
  130. }
  131. drec.dsize = tmp_size;
  132. if ( dbm_store(dp->di_dbm, krec, drec, DBM_REPLACE) < 0 ) {
  133. dbm_clearerr(dp->di_dbm);
  134. PyErr_SetString(DbmError,
  135. "cannot add item to database");
  136. return -1;
  137. }
  138. }
  139. if ( dbm_error(dp->di_dbm) ) {
  140. dbm_clearerr(dp->di_dbm);
  141. PyErr_SetString(DbmError, "");
  142. return -1;
  143. }
  144. return 0;
  145. }
  146. static int
  147. dbm_contains(register dbmobject *dp, PyObject *v)
  148. {
  149. datum key, val;
  150. if (PyString_AsStringAndSize(v, (char **)&key.dptr,
  151. (Py_ssize_t *)&key.dsize)) {
  152. return -1;
  153. }
  154. /* Expand check_dbmobject_open to return -1 */
  155. if (dp->di_dbm == NULL) {
  156. PyErr_SetString(DbmError, "DBM object has already been closed");
  157. return -1;
  158. }
  159. val = dbm_fetch(dp->di_dbm, key);
  160. return val.dptr != NULL;
  161. }
  162. static PySequenceMethods dbm_as_sequence = {
  163. (lenfunc)dbm_length, /*_length*/
  164. 0, /*sq_concat*/
  165. 0, /*sq_repeat*/
  166. 0, /*sq_item*/
  167. 0, /*sq_slice*/
  168. 0, /*sq_ass_item*/
  169. 0, /*sq_ass_slice*/
  170. (objobjproc)dbm_contains, /*sq_contains*/
  171. 0, /*sq_inplace_concat*/
  172. 0 /*sq_inplace_repeat*/
  173. };
  174. static PyMappingMethods dbm_as_mapping = {
  175. (lenfunc)dbm_length, /*mp_length*/
  176. (binaryfunc)dbm_subscript, /*mp_subscript*/
  177. (objobjargproc)dbm_ass_sub, /*mp_ass_subscript*/
  178. };
  179. static PyObject *
  180. dbm__close(register dbmobject *dp, PyObject *unused)
  181. {
  182. if (dp->di_dbm)
  183. dbm_close(dp->di_dbm);
  184. dp->di_dbm = NULL;
  185. Py_INCREF(Py_None);
  186. return Py_None;
  187. }
  188. static PyObject *
  189. dbm_keys(register dbmobject *dp, PyObject *unused)
  190. {
  191. register PyObject *v, *item;
  192. datum key;
  193. int err;
  194. check_dbmobject_open(dp);
  195. v = PyList_New(0);
  196. if (v == NULL)
  197. return NULL;
  198. for (key = dbm_firstkey(dp->di_dbm); key.dptr;
  199. key = dbm_nextkey(dp->di_dbm)) {
  200. item = PyString_FromStringAndSize(key.dptr, key.dsize);
  201. if (item == NULL) {
  202. Py_DECREF(v);
  203. return NULL;
  204. }
  205. err = PyList_Append(v, item);
  206. Py_DECREF(item);
  207. if (err != 0) {
  208. Py_DECREF(v);
  209. return NULL;
  210. }
  211. }
  212. return v;
  213. }
  214. static PyObject *
  215. dbm_has_key(register dbmobject *dp, PyObject *args)
  216. {
  217. char *tmp_ptr;
  218. datum key, val;
  219. int tmp_size;
  220. if (!PyArg_ParseTuple(args, "s#:has_key", &tmp_ptr, &tmp_size))
  221. return NULL;
  222. key.dptr = tmp_ptr;
  223. key.dsize = tmp_size;
  224. check_dbmobject_open(dp);
  225. val = dbm_fetch(dp->di_dbm, key);
  226. return PyInt_FromLong(val.dptr != NULL);
  227. }
  228. static PyObject *
  229. dbm_get(register dbmobject *dp, PyObject *args)
  230. {
  231. datum key, val;
  232. PyObject *defvalue = Py_None;
  233. char *tmp_ptr;
  234. int tmp_size;
  235. if (!PyArg_ParseTuple(args, "s#|O:get",
  236. &tmp_ptr, &tmp_size, &defvalue))
  237. return NULL;
  238. key.dptr = tmp_ptr;
  239. key.dsize = tmp_size;
  240. check_dbmobject_open(dp);
  241. val = dbm_fetch(dp->di_dbm, key);
  242. if (val.dptr != NULL)
  243. return PyString_FromStringAndSize(val.dptr, val.dsize);
  244. else {
  245. Py_INCREF(defvalue);
  246. return defvalue;
  247. }
  248. }
  249. static PyObject *
  250. dbm_setdefault(register dbmobject *dp, PyObject *args)
  251. {
  252. datum key, val;
  253. PyObject *defvalue = NULL;
  254. char *tmp_ptr;
  255. int tmp_size;
  256. if (!PyArg_ParseTuple(args, "s#|S:setdefault",
  257. &tmp_ptr, &tmp_size, &defvalue))
  258. return NULL;
  259. key.dptr = tmp_ptr;
  260. key.dsize = tmp_size;
  261. check_dbmobject_open(dp);
  262. val = dbm_fetch(dp->di_dbm, key);
  263. if (val.dptr != NULL)
  264. return PyString_FromStringAndSize(val.dptr, val.dsize);
  265. if (defvalue == NULL) {
  266. defvalue = PyString_FromStringAndSize(NULL, 0);
  267. if (defvalue == NULL)
  268. return NULL;
  269. }
  270. else
  271. Py_INCREF(defvalue);
  272. val.dptr = PyString_AS_STRING(defvalue);
  273. val.dsize = PyString_GET_SIZE(defvalue);
  274. if (dbm_store(dp->di_dbm, key, val, DBM_INSERT) < 0) {
  275. dbm_clearerr(dp->di_dbm);
  276. PyErr_SetString(DbmError, "cannot add item to database");
  277. return NULL;
  278. }
  279. return defvalue;
  280. }
  281. static PyMethodDef dbm_methods[] = {
  282. {"close", (PyCFunction)dbm__close, METH_NOARGS,
  283. "close()\nClose the database."},
  284. {"keys", (PyCFunction)dbm_keys, METH_NOARGS,
  285. "keys() -> list\nReturn a list of all keys in the database."},
  286. {"has_key", (PyCFunction)dbm_has_key, METH_VARARGS,
  287. "has_key(key} -> boolean\nReturn true iff key is in the database."},
  288. {"get", (PyCFunction)dbm_get, METH_VARARGS,
  289. "get(key[, default]) -> value\n"
  290. "Return the value for key if present, otherwise default."},
  291. {"setdefault", (PyCFunction)dbm_setdefault, METH_VARARGS,
  292. "setdefault(key[, default]) -> value\n"
  293. "Return the value for key if present, otherwise default. If key\n"
  294. "is not in the database, it is inserted with default as the value."},
  295. {NULL, NULL} /* sentinel */
  296. };
  297. static PyObject *
  298. dbm_getattr(dbmobject *dp, char *name)
  299. {
  300. return Py_FindMethod(dbm_methods, (PyObject *)dp, name);
  301. }
  302. static PyTypeObject Dbmtype = {
  303. PyVarObject_HEAD_INIT(NULL, 0)
  304. "dbm.dbm",
  305. sizeof(dbmobject),
  306. 0,
  307. (destructor)dbm_dealloc, /*tp_dealloc*/
  308. 0, /*tp_print*/
  309. (getattrfunc)dbm_getattr, /*tp_getattr*/
  310. 0, /*tp_setattr*/
  311. 0, /*tp_compare*/
  312. 0, /*tp_repr*/
  313. 0, /*tp_as_number*/
  314. &dbm_as_sequence, /*tp_as_sequence*/
  315. &dbm_as_mapping, /*tp_as_mapping*/
  316. 0, /*tp_hash*/
  317. 0, /*tp_call*/
  318. 0, /*tp_str*/
  319. 0, /*tp_getattro*/
  320. 0, /*tp_setattro*/
  321. 0, /*tp_as_buffer*/
  322. Py_TPFLAGS_DEFAULT, /*tp_xxx4*/
  323. };
  324. /* ----------------------------------------------------------------- */
  325. static PyObject *
  326. dbmopen(PyObject *self, PyObject *args)
  327. {
  328. char *name;
  329. char *flags = "r";
  330. int iflags;
  331. int mode = 0666;
  332. if ( !PyArg_ParseTuple(args, "s|si:open", &name, &flags, &mode) )
  333. return NULL;
  334. if ( strcmp(flags, "r") == 0 )
  335. iflags = O_RDONLY;
  336. else if ( strcmp(flags, "w") == 0 )
  337. iflags = O_RDWR;
  338. else if ( strcmp(flags, "rw") == 0 ) /* B/W compat */
  339. iflags = O_RDWR|O_CREAT;
  340. else if ( strcmp(flags, "c") == 0 )
  341. iflags = O_RDWR|O_CREAT;
  342. else if ( strcmp(flags, "n") == 0 )
  343. iflags = O_RDWR|O_CREAT|O_TRUNC;
  344. else {
  345. PyErr_SetString(DbmError,
  346. "arg 2 to open should be 'r', 'w', 'c', or 'n'");
  347. return NULL;
  348. }
  349. return newdbmobject(name, iflags, mode);
  350. }
  351. static PyMethodDef dbmmodule_methods[] = {
  352. { "open", (PyCFunction)dbmopen, METH_VARARGS,
  353. "open(path[, flag[, mode]]) -> mapping\n"
  354. "Return a database object."},
  355. { 0, 0 },
  356. };
  357. PyMODINIT_FUNC
  358. initdbm(void) {
  359. PyObject *m, *d, *s;
  360. Dbmtype.ob_type = &PyType_Type;
  361. m = Py_InitModule("dbm", dbmmodule_methods);
  362. if (m == NULL)
  363. return;
  364. d = PyModule_GetDict(m);
  365. if (DbmError == NULL)
  366. DbmError = PyErr_NewException("dbm.error", NULL, NULL);
  367. s = PyString_FromString(which_dbm);
  368. if (s != NULL) {
  369. PyDict_SetItemString(d, "library", s);
  370. Py_DECREF(s);
  371. }
  372. if (DbmError != NULL)
  373. PyDict_SetItemString(d, "error", DbmError);
  374. }