pgmodule.c

关系型数据库 Postgresql 6.5.2

static PyObject *
pg_getattr(pgobject * self, char *name)
{

	/*
	 * Although we could check individually, there are only a few
	 * attributes that don't require a live connection and unless someone
	 * has an urgent need, this will have to do
	 */
	if (!self->cnx)
	{
		PyErr_SetString(PyExc_TypeError, "Connection is not valid");
		return NULL;
	}

	/* list postgreSQL connection fields */

	/* postmaster host */
	if (!strcmp(name, "host"))
	{
		char	   *r = PQhost(self->cnx);

		return r ? PyString_FromString(r) : PyString_FromString("localhost");
	}

	/* postmaster port */
	if (!strcmp(name, "port"))
		return PyInt_FromLong(atol(PQport(self->cnx)));

	/* selected database */
	if (!strcmp(name, "db"))
		return PyString_FromString(PQdb(self->cnx));

	/* selected options */
	if (!strcmp(name, "options"))
		return PyString_FromString(PQoptions(self->cnx));

	/* selected postgres tty */
	if (!strcmp(name, "tty"))
		return PyString_FromString(PQtty(self->cnx));

	/* error (status) message */
	if (!strcmp(name, "error"))
		return PyString_FromString(PQerrorMessage(self->cnx));

	/* connection status : 1 - OK, 0 - BAD */
	if (!strcmp(name, "status"))
		return PyInt_FromLong(PQstatus(self->cnx) == CONNECTION_OK ? 1 : 0);

	/* provided user name */
	if (!strcmp(name, "user"))
		return PyString_FromString("Deprecated facility");
	/* return PyString_FromString(fe_getauthname("<unknown user>")); */

	/* attributes list */
	if (!strcmp(name, "__members__"))
	{
		PyObject   *list = PyList_New(8);

		if (list)
		{
			PyList_SetItem(list, 0, PyString_FromString("host"));
			PyList_SetItem(list, 1, PyString_FromString("port"));
			PyList_SetItem(list, 2, PyString_FromString("db"));
			PyList_SetItem(list, 3, PyString_FromString("options"));
			PyList_SetItem(list, 4, PyString_FromString("tty"));
			PyList_SetItem(list, 5, PyString_FromString("error"));
			PyList_SetItem(list, 6, PyString_FromString("status"));
			PyList_SetItem(list, 7, PyString_FromString("user"));
		}

		return list;
	}

	return Py_FindMethod(pgobj_methods, (PyObject *) self, name);
}

/* object type definition */
staticforward PyTypeObject PgType = {
	PyObject_HEAD_INIT(NULL)
	0,							/* ob_size */
	"pgobject",					/* tp_name */
	sizeof(pgobject),			/* tp_basicsize */
	0,							/* tp_itemsize */
	/* methods */
	(destructor) pg_dealloc,	/* tp_dealloc */
	0,							/* tp_print */
	(getattrfunc) pg_getattr,	/* tp_getattr */
	0,							/* tp_setattr */
	0,							/* tp_compare */
	0,							/* tp_repr */
	0,							/* tp_as_number */
	0,							/* tp_as_sequence */
	0,							/* tp_as_mapping */
	0,							/* tp_hash */
};


/* query object methods */
static struct PyMethodDef pgquery_methods[] = {
	{"getresult", (PyCFunction) pgquery_getresult, 1, pgquery_getresult__doc__},
	{"dictresult", (PyCFunction) pgquery_dictresult, 1, pgquery_dictresult__doc__},
	{"fieldname", (PyCFunction) pgquery_fieldname, 1, pgquery_fieldname__doc__},
	{"fieldnum", (PyCFunction) pgquery_fieldnum, 1, pgquery_fieldnum__doc__},
	{"listfields", (PyCFunction) pgquery_listfields, 1, pgquery_listfields__doc__},
	{"ntuples", (PyCFunction) pgquery_ntuples, 1, pgquery_ntuples__doc__},
	{NULL, NULL}
};

/* gets query object attributes */
static PyObject *
pgquery_getattr(pgqueryobject * self, char *name)
{
	/* list postgreSQL connection fields */
	return Py_FindMethod(pgquery_methods, (PyObject *) self, name);
}

/* query type definition */
staticforward PyTypeObject PgQueryType = {
	PyObject_HEAD_INIT(NULL)
	0,							/* ob_size */
	"pgqueryobject",			/* tp_name */
	sizeof(pgqueryobject),		/* tp_basicsize */
	0,							/* tp_itemsize */
	/* methods */
	(destructor) pgquery_dealloc,		/* tp_dealloc */
	(printfunc) pgquery_print,	/* tp_print */
	(getattrfunc) pgquery_getattr,		/* tp_getattr */
	0,							/* tp_setattr */
	0,							/* tp_compare */
	0,							/* tp_repr */
	0,							/* tp_as_number */
	0,							/* tp_as_sequence */
	0,							/* tp_as_mapping */
	0,							/* tp_hash */
};



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

/* MODULE FUNCTIONS */

#ifdef DEFAULT_VARS

/* gets default host */
static char getdefhost__doc__[] =
"get_defhost() -- return default database host.";

static PyObject *
pggetdefhost(PyObject * self, PyObject * args)
{
	/* checks args */
	if (!PyArg_ParseTuple(args, ""))
	{
		PyErr_SetString(PyExc_SyntaxError,
						"method get_defhost() takes no parameter.");
		return NULL;
	}

	Py_XINCREF(pg_default_host);
	return pg_default_host;
}

/* sets default host */
static char setdefhost__doc__[] =
"set_defhost(string) -- set default database host. Return previous value.";

static PyObject *
pgsetdefhost(PyObject * self, PyObject * args)
{
	char	   *temp = NULL;
	PyObject   *old;

	/* gets arguments */
	if (!PyArg_ParseTuple(args, "z", &temp))
	{
		PyErr_SetString(PyExc_TypeError,
						"set_defhost(name), with name (string/None).");
		return NULL;
	}

	/* adjusts value */
	old = pg_default_host;

	if (temp)
		pg_default_host = PyString_FromString(temp);
	else
	{
		Py_INCREF(Py_None);
		pg_default_host = Py_None;
	}

	return old;
}

/* gets default base */
static char getdefbase__doc__[] =
"get_defbase() -- return default database name.";

static PyObject *
pggetdefbase(PyObject * self, PyObject * args)
{
	/* checks args */
	if (!PyArg_ParseTuple(args, ""))
	{
		PyErr_SetString(PyExc_SyntaxError,
						"method get_defbase() takes no parameter.");
		return NULL;
	}

	Py_XINCREF(pg_default_base);
	return pg_default_base;
}

/* sets default base */
static char setdefbase__doc__[] =
"set_defbase(string) -- set default database name. Return previous value";

static PyObject *
pgsetdefbase(PyObject * self, PyObject * args)
{
	char	   *temp = NULL;
	PyObject   *old;

	/* gets arguments */
	if (!PyArg_ParseTuple(args, "z", &temp))
	{
		PyErr_SetString(PyExc_TypeError,
						"set_defbase(name), with name (string/None).");
		return NULL;
	}

	/* adjusts value */
	old = pg_default_base;

	if (temp)
		pg_default_base = PyString_FromString(temp);
	else
	{
		Py_INCREF(Py_None);
		pg_default_base = Py_None;
	}

	return old;
}

/* gets default options */
static char getdefopt__doc__[] =
"get_defopt() -- return default database options.";

static PyObject *
pggetdefopt(PyObject * self, PyObject * args)
{
	/* checks args */
	if (!PyArg_ParseTuple(args, ""))
	{
		PyErr_SetString(PyExc_SyntaxError,
						"method get_defopt() takes no parameter.");
		return NULL;
	}

	Py_XINCREF(pg_default_opt);
	return pg_default_opt;
}

/* sets default opt */
static char setdefopt__doc__[] =
"set_defopt(string) -- set default database options. Return previous value.";

static PyObject *
pgsetdefopt(PyObject * self, PyObject * args)
{
	char	   *temp = NULL;
	PyObject   *old;

	/* gets arguments */
	if (!PyArg_ParseTuple(args, "z", &temp))
	{
		PyErr_SetString(PyExc_TypeError,
						"set_defopt(name), with name (string/None).");
		return NULL;
	}

	/* adjusts value */
	old = pg_default_opt;

	if (temp)
		pg_default_opt = PyString_FromString(temp);
	else
	{
		Py_INCREF(Py_None);
		pg_default_opt = Py_None;
	}

	return old;
}

/* gets default tty */
static char getdeftty__doc__[] =
"get_deftty() -- return default database debug terminal.";

static PyObject *
pggetdeftty(PyObject * self, PyObject * args)
{
	/* checks args */
	if (!PyArg_ParseTuple(args, ""))
	{
		PyErr_SetString(PyExc_SyntaxError,
						"method get_deftty() takes no parameter.");
		return NULL;
	}

	Py_XINCREF(pg_default_tty);
	return pg_default_tty;
}

/* sets default tty */
static char setdeftty__doc__[] =
"set_deftty(string) -- set default database debug terminal. "
"Return previous value.";

static PyObject *
pgsetdeftty(PyObject * self, PyObject * args)
{
	char	   *temp = NULL;
	PyObject   *old;

	/* gets arguments */
	if (!PyArg_ParseTuple(args, "z", &temp))
	{
		PyErr_SetString(PyExc_TypeError,
						"set_deftty(name), with name (string/None).");
		return NULL;
	}

	/* adjusts value */
	old = pg_default_tty;

	if (temp)
		pg_default_tty = PyString_FromString(temp);
	else
	{
		Py_INCREF(Py_None);
		pg_default_tty = Py_None;
	}

	return old;
}

/* gets default username */
static char getdefuser__doc__[] =
"get_defuser() -- return default database username.";

static PyObject *
pggetdefuser(PyObject * self, PyObject * args)
{
	/* checks args */
	if (!PyArg_ParseTuple(args, ""))
	{
		PyErr_SetString(PyExc_SyntaxError,
						"method get_defuser() takes no parameter.");

		return NULL;
	}

	Py_XINCREF(pg_default_user);
	return pg_default_user;
}

/* sets default username */
static char setdefuser__doc__[] =
"set_defuser() -- set default database username. Return previous value.";

static PyObject *
pgsetdefuser(PyObject * self, PyObject * args)
{
	char	   *temp = NULL;
	PyObject   *old;

	/* gets arguments */
	if (!PyArg_ParseTuple(args, "z", &temp))
	{
		PyErr_SetString(PyExc_TypeError,
						"set_defuser(name), with name (string/None).");
		return NULL;
	}

	/* adjusts value */
	old = pg_default_user;

	if (temp)
		pg_default_user = PyString_FromString(temp);
	else
	{
		Py_INCREF(Py_None);
		pg_default_user = Py_None;
	}

	return old;
}

/* sets default password */
static char setdefpasswd__doc__[] =
"set_defpasswd() -- set default database password.";

static PyObject *
pgsetdefpasswd(PyObject * self, PyObject * args)
{
	char	   *temp = NULL;
	PyObject   *old;

	/* gets arguments */
	if (!PyArg_ParseTuple(args, "z", &temp))
	{
		PyErr_SetString(PyExc_TypeError,
				"set_defpasswd(password), with password (string/None).");
		return NULL;
	}

	/* adjusts value */
	old = pg_default_passwd;

	if (temp)
		pg_default_passwd = PyString_FromString(temp);
	else
	{
		Py_INCREF(Py_None);
		pg_default_passwd = Py_None;
	}

	Py_INCREF(Py_None);
	return Py_None;
}

/* gets default port */
static char getdefport__doc__[] =
"get_defport() -- return default database port.";

static PyObject *
pggetdefport(PyObject * self, PyObject * args)
{
	/* checks args */
	if (!PyArg_ParseTuple(args, ""))
	{
		PyErr_SetString(PyExc_SyntaxError,
						"method get_defport() takes no parameter.");
		return NULL;
	}

	Py_XINCREF(pg_default_port);
	return pg_default_port;
}

/* sets default port */
static char setdefport__doc__[] =
"set_defport(integer) -- set default database port. Return previous value.";

static PyObject *
pgsetdefport(PyObject * self, PyObject * args)
{
	long int	port = -2;
	PyObject   *old;

	/* gets arguments */
	if ((!PyArg_ParseTuple(args, "l", &port)) || (port < -1))
	{
		PyErr_SetString(PyExc_TypeError, "set_defport(port), with port "
						"(positive integer/-1).");
		return NULL;
	}

	/* adjusts value */
	old = pg_default_port;

	if (port != -1)
		pg_default_port = PyLong_FromLong(port);
	else
	{
		Py_INCREF(Py_None);
		pg_default_port = Py_None;
	}

	return old;
}

#endif	 /* DEFAULT_VARS */

/* List of functions defined in the module */

static struct PyMethodDef pg_methods[] = {
	{"connect", (PyCFunction) pgconnect, 3, connect__doc__},

#ifdef DEFAULT_VARS
	{"get_defhost", pggetdefhost, 1, getdefhost__doc__},
	{"set_defhost", pgsetdefhost, 1, setdefhost__doc__},
	{"get_defbase", pggetdefbase, 1, getdefbase__doc__},
	{"set_defbase", pgsetdefbase, 1, setdefbase__doc__},
	{"get_defopt", pggetdefopt, 1, getdefopt__doc__},
	{"set_defopt", pgsetdefopt, 1, setdefopt__doc__},
	{"get_deftty", pggetdeftty, 1, getdeftty__doc__},
	{"set_deftty", pgsetdeftty, 1, setdeftty__doc__},
	{"get_defport", pggetdefport, 1, getdefport__doc__},
	{"set_defport", pgsetdefport, 1, setdefport__doc__},
	{"get_defuser", pggetdefuser, 1, getdefuser__doc__},
	{"set_defuser", pgsetdefuser, 1, setdefuser__doc__},
	{"set_defpasswd", pgsetdefpasswd, 1, setdefpasswd__doc__},
#endif	 /* DEFAULT_VARS */
	{NULL, NULL}				/* sentinel */
};

static char pg__doc__[] = "Python interface to PostgreSQL DB";

/* Initialization function for the module */
void		init_pg(void);		/* Python doesn't prototype this */
void
init_pg(void)
{
	PyObject   *mod,
			   *dict,
			   *v;

	/* Initialize here because some WIN platforms get confused otherwise */
	PglargeType.ob_type = PgType.ob_type = PgQueryType.ob_type = &PyType_Type;

	/* Create the module and add the functions */
	mod = Py_InitModule4("_pg", pg_methods, pg__doc__, NULL, PYTHON_API_VERSION);
	dict = PyModule_GetDict(mod);

	/* Add some symbolic constants to the module */
	PGError = PyString_FromString("pg.error");
	PyDict_SetItemString(dict, "error", PGError);

	/* Make the version available */
	v = PyString_FromString(PyPgVersion);
	PyDict_SetItemString(dict, "version", v);
	PyDict_SetItemString(dict, "__version__", v);
	Py_DECREF(v);

#ifdef LARGE_OBJECTS
	/* create mode for large objects */
	PyDict_SetItemString(dict, "INV_READ", PyInt_FromLong(INV_READ));
	PyDict_SetItemString(dict, "INV_WRITE", PyInt_FromLong(INV_WRITE));

	/* position flags for lo_lseek */
	PyDict_SetItemString(dict, "SEEK_SET", PyInt_FromLong(SEEK_SET));
	PyDict_SetItemString(dict, "SEEK_CUR", PyInt_FromLong(SEEK_CUR));
	PyDict_SetItemString(dict, "SEEK_END", PyInt_FromLong(SEEK_END));
#endif	 /* LARGE_OBJECTS */

#ifdef DEFAULT_VARS
	/* prepares default values */
	Py_INCREF(Py_None);
	pg_default_host = Py_None;
	Py_INCREF(Py_None);
	pg_default_base = Py_None;
	Py_INCREF(Py_None);
	pg_default_opt = Py_None;
	Py_INCREF(Py_None);
	pg_default_port = Py_None;
	Py_INCREF(Py_None);
	pg_default_tty = Py_None;
	Py_INCREF(Py_None);
	pg_default_user = Py_None;
	Py_INCREF(Py_None);
	pg_default_passwd = Py_None;
#endif	 /* DEFAULT_VARS */

	/* Check for errors */
	if (PyErr_Occurred())
		Py_FatalError("can't initialize module _pg");
}