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)

    17 static char *which_dbm = "ndbm";

    18 #else

    19 static char *which_dbm = "GNU gdbm";  /* EMX port of GDBM */

    20 #endif

    21 #elif defined(HAVE_GDBM_NDBM_H)

    22 #include <gdbm/ndbm.h>

    23 static char *which_dbm = "GNU gdbm";

    24 #elif defined(HAVE_BERKDB_H)

    25 #include <db.h>

    26 static char *which_dbm = "Berkeley DB";

    27 #else

    28 #error "No ndbm.h available!"

    29 #endif

    30 

    31 typedef struct {

    32 	PyObject_HEAD

    33 	int di_size;	/* -1 means recompute */

    34 	DBM *di_dbm;

    35 } dbmobject;

    36 

    37 static PyTypeObject Dbmtype;

    38 

    39 #define is_dbmobject(v) (Py_TYPE(v) == &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 

    44 static PyObject *DbmError;

    45 

    46 static PyObject *

    47 newdbmobject(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 

    65 static void

    66 dbm_dealloc(register dbmobject *dp)

    67 {

    68         if ( dp->di_dbm )

    69 		dbm_close(dp->di_dbm);

    70 	PyObject_Del(dp);

    71 }

    72 

    73 static Py_ssize_t

    74 dbm_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 

    93 static PyObject *

    94 dbm_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 

   118 static int

   119 dbm_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 

   164 static int

   165 dbm_contains(register dbmobject *dp, PyObject *v)

   166 {

   167 	datum key, val;

   168 

   169 	if (PyString_AsStringAndSize(v, (char **)&key.dptr,

   170 	                             (Py_ssize_t *)&key.dsize)) {

   171 		return -1;

   172 	}

   173 

   174 	/* Expand check_dbmobject_open to return -1 */

   175 	if (dp->di_dbm == NULL) {

   176 		PyErr_SetString(DbmError, "DBM object has already been closed");

   177 		return -1;

   178 	}

   179 	val = dbm_fetch(dp->di_dbm, key);

   180 	return val.dptr != NULL;

   181 }

   182 

   183 static PySequenceMethods dbm_as_sequence = {

   184     (lenfunc)dbm_length,        /*_length*/

   185     0,                          /*sq_concat*/

   186     0,                          /*sq_repeat*/

   187     0,                          /*sq_item*/

   188     0,                          /*sq_slice*/

   189     0,                          /*sq_ass_item*/

   190     0,                          /*sq_ass_slice*/

   191     (objobjproc)dbm_contains,   /*sq_contains*/

   192     0,                          /*sq_inplace_concat*/

   193     0                           /*sq_inplace_repeat*/

   194 };

   195 

   196 static PyMappingMethods dbm_as_mapping = {

   197 	(lenfunc)dbm_length,		/*mp_length*/

   198 	(binaryfunc)dbm_subscript,	/*mp_subscript*/

   199 	(objobjargproc)dbm_ass_sub,	/*mp_ass_subscript*/

   200 };

   201 

   202 static PyObject *

   203 dbm__close(register dbmobject *dp, PyObject *unused)

   204 {

   205         if (dp->di_dbm)

   206 		dbm_close(dp->di_dbm);

   207 	dp->di_dbm = NULL;

   208 	Py_INCREF(Py_None);

   209 	return Py_None;

   210 }

   211 

   212 static PyObject *

   213 dbm_keys(register dbmobject *dp, PyObject *unused)

   214 {

   215 	register PyObject *v, *item;

   216 	datum key;

   217 	int err;

   218 

   219         check_dbmobject_open(dp);

   220 	v = PyList_New(0);

   221 	if (v == NULL)

   222 		return NULL;

   223 	for (key = dbm_firstkey(dp->di_dbm); key.dptr;

   224 	     key = dbm_nextkey(dp->di_dbm)) {

   225 		item = PyString_FromStringAndSize(key.dptr, key.dsize);

   226 		if (item == NULL) {

   227 			Py_DECREF(v);

   228 			return NULL;

   229 		}

   230 		err = PyList_Append(v, item);

   231 		Py_DECREF(item);

   232 		if (err != 0) {

   233 			Py_DECREF(v);

   234 			return NULL;

   235 		}

   236 	}

   237 	return v;

   238 }

   239 

   240 static PyObject *

   241 dbm_has_key(register dbmobject *dp, PyObject *args)

   242 {

   243 	char *tmp_ptr;

   244 	datum key, val;

   245 	int tmp_size;

   246 	

   247 	if (!PyArg_ParseTuple(args, "s#:has_key", &tmp_ptr, &tmp_size))

   248 		return NULL;

   249 	key.dptr = tmp_ptr;

   250 	key.dsize = tmp_size;

   251         check_dbmobject_open(dp);

   252 	val = dbm_fetch(dp->di_dbm, key);

   253 	return PyInt_FromLong(val.dptr != NULL);

   254 }

   255 

   256 static PyObject *

   257 dbm_get(register dbmobject *dp, PyObject *args)

   258 {

   259 	datum key, val;

   260 	PyObject *defvalue = Py_None;

   261 	char *tmp_ptr;

   262 	int tmp_size;

   263 

   264 	if (!PyArg_ParseTuple(args, "s#|O:get",

   265                               &tmp_ptr, &tmp_size, &defvalue))

   266 		return NULL;

   267 	key.dptr = tmp_ptr;

   268 	key.dsize = tmp_size;

   269         check_dbmobject_open(dp);

   270 	val = dbm_fetch(dp->di_dbm, key);

   271 	if (val.dptr != NULL)

   272 		return PyString_FromStringAndSize(val.dptr, val.dsize);

   273 	else {

   274 		Py_INCREF(defvalue);

   275 		return defvalue;

   276 	}

   277 }

   278 

   279 static PyObject *

   280 dbm_setdefault(register dbmobject *dp, PyObject *args)

   281 {

   282 	datum key, val;

   283 	PyObject *defvalue = NULL;

   284 	char *tmp_ptr;

   285 	int tmp_size;

   286 

   287 	if (!PyArg_ParseTuple(args, "s#|S:setdefault",

   288                               &tmp_ptr, &tmp_size, &defvalue))

   289 		return NULL;

   290 	key.dptr = tmp_ptr;

   291 	key.dsize = tmp_size;

   292         check_dbmobject_open(dp);

   293 	val = dbm_fetch(dp->di_dbm, key);

   294 	if (val.dptr != NULL)

   295 		return PyString_FromStringAndSize(val.dptr, val.dsize);

   296 	if (defvalue == NULL) {

   297 		defvalue = PyString_FromStringAndSize(NULL, 0);

   298 		if (defvalue == NULL)

   299 			return NULL;

   300 	}

   301 	else

   302 		Py_INCREF(defvalue);

   303 	val.dptr = PyString_AS_STRING(defvalue);

   304 	val.dsize = PyString_GET_SIZE(defvalue);

   305 	if (dbm_store(dp->di_dbm, key, val, DBM_INSERT) < 0) {

   306 		dbm_clearerr(dp->di_dbm);

   307 		PyErr_SetString(DbmError, "cannot add item to database");

   308 		return NULL;

   309 	}

   310 	return defvalue;

   311 }

   312 

   313 static PyMethodDef dbm_methods[] = {

   314 	{"close",	(PyCFunction)dbm__close,	METH_NOARGS,

   315 	 "close()\nClose the database."},

   316 	{"keys",	(PyCFunction)dbm_keys,		METH_NOARGS,

   317 	 "keys() -> list\nReturn a list of all keys in the database."},

   318 	{"has_key",	(PyCFunction)dbm_has_key,	METH_VARARGS,

   319 	 "has_key(key} -> boolean\nReturn true iff key is in the database."},

   320 	{"get",		(PyCFunction)dbm_get,		METH_VARARGS,

   321 	 "get(key[, default]) -> value\n"

   322 	 "Return the value for key if present, otherwise default."},

   323 	{"setdefault",	(PyCFunction)dbm_setdefault,	METH_VARARGS,

   324 	 "setdefault(key[, default]) -> value\n"

   325 	 "Return the value for key if present, otherwise default.  If key\n"

   326 	 "is not in the database, it is inserted with default as the value."},

   327 	{NULL,		NULL}		/* sentinel */

   328 };

   329 

   330 static PyObject *

   331 dbm_getattr(dbmobject *dp, char *name)

   332 {

   333 	return Py_FindMethod(dbm_methods, (PyObject *)dp, name);

   334 }

   335 

   336 static PyTypeObject Dbmtype = {

   337 	PyVarObject_HEAD_INIT(NULL, 0)

   338 	"dbm.dbm",

   339 	sizeof(dbmobject),

   340 	0,

   341 	(destructor)dbm_dealloc,  /*tp_dealloc*/

   342 	0,			  /*tp_print*/

   343 	(getattrfunc)dbm_getattr, /*tp_getattr*/

   344 	0,			  /*tp_setattr*/

   345 	0,			  /*tp_compare*/

   346 	0,			  /*tp_repr*/

   347 	0,			  /*tp_as_number*/

   348     &dbm_as_sequence,     /*tp_as_sequence*/

   349 	&dbm_as_mapping,	  /*tp_as_mapping*/

   350     0,                    /*tp_hash*/

   351     0,                    /*tp_call*/

   352     0,                    /*tp_str*/

   353     0,                    /*tp_getattro*/

   354     0,                    /*tp_setattro*/

   355     0,                    /*tp_as_buffer*/

   356     Py_TPFLAGS_DEFAULT,   /*tp_xxx4*/

   357 };

   358 

   359 /* ----------------------------------------------------------------- */

   360 

   361 static PyObject *

   362 dbmopen(PyObject *self, PyObject *args)

   363 {

   364 	char *name;

   365 	char *flags = "r";

   366 	int iflags;

   367 	int mode = 0666;

   368 

   369         if ( !PyArg_ParseTuple(args, "s|si:open", &name, &flags, &mode) )

   370 		return NULL;

   371 	if ( strcmp(flags, "r") == 0 )

   372 		iflags = O_RDONLY;

   373 	else if ( strcmp(flags, "w") == 0 )

   374 		iflags = O_RDWR;

   375 	else if ( strcmp(flags, "rw") == 0 ) /* B/W compat */

   376 		iflags = O_RDWR|O_CREAT; 

   377 	else if ( strcmp(flags, "c") == 0 )

   378 		iflags = O_RDWR|O_CREAT;

   379 	else if ( strcmp(flags, "n") == 0 )

   380 		iflags = O_RDWR|O_CREAT|O_TRUNC;

   381 	else {

   382 		PyErr_SetString(DbmError,

   383 				"arg 2 to open should be 'r', 'w', 'c', or 'n'");

   384 		return NULL;

   385 	}

   386         return newdbmobject(name, iflags, mode);

   387 }

   388 

   389 static PyMethodDef dbmmodule_methods[] = {

   390 	{ "open", (PyCFunction)dbmopen, METH_VARARGS,

   391 	  "open(path[, flag[, mode]]) -> mapping\n"

   392 	  "Return a database object."},

   393 	{ 0, 0 },

   394 };

   395 

   396 PyMODINIT_FUNC

   397 initdbm(void) {

   398 	PyObject *m, *d, *s;

   399 

   400 	Dbmtype.ob_type = &PyType_Type;

   401 	m = Py_InitModule("dbm", dbmmodule_methods);

   402 	if (m == NULL)

   403 		return;

   404 	d = PyModule_GetDict(m);

   405 	if (DbmError == NULL)

   406 		DbmError = PyErr_NewException("dbm.error", NULL, NULL);

   407 	s = PyString_FromString(which_dbm);

   408 	if (s != NULL) {

   409 		PyDict_SetItemString(d, "library", s);

   410 		Py_DECREF(s);

   411 	}

   412 	if (DbmError != NULL)

   413 		PyDict_SetItemString(d, "error", DbmError);

   414 }