/Modules/dbmmodule.c
http://unladen-swallow.googlecode.com/ · C · 417 lines · 367 code · 43 blank · 7 comment · 77 complexity · fdee1b50c0b8aa72143799ad9ac8443f MD5 · raw file
- /* 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_GDBM_DASH_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) (Py_TYPE(v) == &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 int
- dbm_contains(register dbmobject *dp, PyObject *v)
- {
- datum key, val;
- if (PyString_AsStringAndSize(v, (char **)&key.dptr,
- (Py_ssize_t *)&key.dsize)) {
- return -1;
- }
- /* Expand check_dbmobject_open to return -1 */
- if (dp->di_dbm == NULL) {
- PyErr_SetString(DbmError, "DBM object has already been closed");
- return -1;
- }
- val = dbm_fetch(dp->di_dbm, key);
- return val.dptr != NULL;
- }
- static PySequenceMethods dbm_as_sequence = {
- (lenfunc)dbm_length, /*_length*/
- 0, /*sq_concat*/
- 0, /*sq_repeat*/
- 0, /*sq_item*/
- 0, /*sq_slice*/
- 0, /*sq_ass_item*/
- 0, /*sq_ass_slice*/
- (objobjproc)dbm_contains, /*sq_contains*/
- 0, /*sq_inplace_concat*/
- 0 /*sq_inplace_repeat*/
- };
- 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 PyObject *
- dbm_has_key(register dbmobject *dp, PyObject *args)
- {
- char *tmp_ptr;
- datum key, val;
- int tmp_size;
-
- if (!PyArg_ParseTuple(args, "s#:has_key", &tmp_ptr, &tmp_size))
- return NULL;
- key.dptr = tmp_ptr;
- key.dsize = tmp_size;
- check_dbmobject_open(dp);
- val = dbm_fetch(dp->di_dbm, key);
- return PyInt_FromLong(val.dptr != NULL);
- }
- static PyObject *
- dbm_get(register dbmobject *dp, PyObject *args)
- {
- datum key, val;
- PyObject *defvalue = Py_None;
- char *tmp_ptr;
- int tmp_size;
- if (!PyArg_ParseTuple(args, "s#|O:get",
- &tmp_ptr, &tmp_size, &defvalue))
- return NULL;
- key.dptr = tmp_ptr;
- 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;
- char *tmp_ptr;
- int tmp_size;
- if (!PyArg_ParseTuple(args, "s#|S:setdefault",
- &tmp_ptr, &tmp_size, &defvalue))
- return NULL;
- key.dptr = tmp_ptr;
- 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."},
- {"has_key", (PyCFunction)dbm_has_key, METH_VARARGS,
- "has_key(key} -> boolean\nReturn true iff key is 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 = {
- PyVarObject_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*/
- 0, /*tp_hash*/
- 0, /*tp_call*/
- 0, /*tp_str*/
- 0, /*tp_getattro*/
- 0, /*tp_setattro*/
- 0, /*tp_as_buffer*/
- Py_TPFLAGS_DEFAULT, /*tp_xxx4*/
- };
- /* ----------------------------------------------------------------- */
- 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;
- Dbmtype.ob_type = &PyType_Type;
- 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);
- }