python-libfdisk/context.c

/*
 * (C) 2022 Soleta Consulting S.L. <info@soleta.eu>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * Author: Jose M. Guisado <jguisado@soleta.eu>
 */


#include "fdisk.h"

static PyMemberDef Context_members[] = {
	{ NULL }
};


static void Context_dealloc(ContextObject *self)
{
	if (!self->cxt) /* if init fails */
		return;

	fdisk_unref_context(self->cxt);
	Py_TYPE(self)->tp_free((PyObject *) self);
}

static PyObject *Context_new(PyTypeObject *type,
			 PyObject *args __attribute__((unused)),
			 PyObject *kwds __attribute__((unused)))
{
	ContextObject *self = (ContextObject*) type->tp_alloc(type, 0);

	if (self) {
		self->cxt = NULL;
		self->lb = NULL;
		self->tb = NULL;
	}

	return (PyObject *)self;
}

#define Context_HELP "Context(device=None, details=None)"
static int Context_init(ContextObject *self, PyObject *args, PyObject *kwds)
{
	char *device = NULL;
	int details, rc = 0;
	char *kwlist[] = {
		"device", "details",
		NULL
	};

	if (!PyArg_ParseTupleAndKeywords(args,
					kwds, "|sp", kwlist,
					&device, &details)) {
		PyErr_SetString(PyExc_TypeError, ARG_ERR);
		return -1;
	}

	if (self->cxt)
		fdisk_unref_context(self->cxt);

	self->cxt = fdisk_new_context();
	if (!self->cxt) {
		PyErr_SetString(PyExc_MemoryError, "Couldn't allocate context");
		return -1;
	}

	/* XXX: always readonly */
	if (device && (rc = fdisk_assign_device(self->cxt, device, 1)))
		return -1;
	if (details && (rc = fdisk_enable_details(self->cxt, details)))
		return -1;

	fdisk_get_partitions(self->cxt, &self->tb);

	return 0;
}


#define Context_assign_device_HELP "assign_device(device)\n\n" \
	"Open the device, discovery topology, geometry, detect disklabel " \
	"and switch the current label driver to reflect the probing result. "
static PyObject *Context_assign_device(ContextObject *self, PyObject *args, PyObject *kwds)
{
	char *fname;

	if (!PyArg_ParseTuple(args, "s", &fname)) {
		PyErr_SetString(PyExc_TypeError, ARG_ERR);
		return NULL;
	}

	/* Assert self->cxt */

	/* XXX: readonly */
	fdisk_assign_device(self->cxt, fname, 1);

	self->lb = fdisk_get_label(self->cxt, NULL);
	fdisk_get_partitions(self->cxt, &self->tb);

	/* XXX: check rc*/
	Py_INCREF(Py_None);
	return Py_None;
}
#define Context_partition_to_string_HELP "partition_to_string(pa, field)\n\n" \
	"Retrieve partition field using fdisk_partition_to_string." \
	"Field constants are available as FDISK_LABEL_*"
static PyObject *Context_partition_to_string(ContextObject *self, PyObject *args, PyObject *kwds)
{
	struct fdisk_partition *pa;
	enum fdisk_fieldtype field;
	PartitionObject *part;
	PyObject *ret;
	char *data;

	if (!PyArg_ParseTuple(args, "O!i", &PartitionType, &part, &field)) {
		PyErr_SetString(PyExc_TypeError, ARG_ERR);
		return NULL;
	}

	pa = part->pa;

	fdisk_partition_to_string(pa, self->cxt, field, &data);
	ret = Py_BuildValue("s", data);
	free(data);

	return ret;
}
static PyMethodDef Context_methods[] = {
	{"assign_device",	(PyCFunction)Context_assign_device, METH_VARARGS, Context_assign_device_HELP},
	{"partition_to_string",	(PyCFunction)Context_partition_to_string, METH_VARARGS, Context_partition_to_string_HELP},
	{NULL}
};


static PyObject *Context_get_nsectors(ContextObject *self)
{
	return PyLong_FromUnsignedLong(fdisk_get_nsectors(self->cxt));
}
static PyObject *Context_get_sector_size(ContextObject *self)
{
	return PyLong_FromUnsignedLong(fdisk_get_sector_size(self->cxt));
}
static PyObject *Context_get_devname(ContextObject *self)
{
	return PyObjectResultStr(fdisk_get_devname(self->cxt));
}
static PyObject *Context_get_label(ContextObject *self)
{
	struct fdisk_context *cxt = self->cxt;

	if (fdisk_has_label(cxt)) {
		return PyObjectResultLabel(fdisk_get_label(cxt, NULL));
	} else {
		Py_RETURN_NONE;
	}
}
static PyObject *Context_get_nparts(ContextObject *self)
{
	return PyLong_FromLong(fdisk_table_get_nents(self->tb));
}
static PyObject *Context_get_partitions(ContextObject *self)
{
	PyObject *p, *list = PyList_New(0); /* XXX: null if failed*/
	struct fdisk_partition *pa;
	struct fdisk_iter *itr;
	struct fdisk_table *tb;
	/* char *data; */
	
	tb = self->tb;
	itr = fdisk_new_iter(FDISK_ITER_FORWARD);

	while(fdisk_table_next_partition(tb, itr, &pa) == 0) {
		/* const char *name = fdisk_partition_get_name(pa);*/
		p = PyObjectResultPartition(pa);
		PyList_Append(list, p);
		/*free(data);*/
	}	

	fdisk_free_iter(itr);

	return list;
}
static PyGetSetDef Context_getseters[] = {
	{"nsectors",	(getter)Context_get_nsectors, NULL, "context number of sectors", NULL},
	{"sector_size",	(getter)Context_get_sector_size, NULL, "context sector size", NULL},
	{"devname",	(getter)Context_get_devname, NULL, "context devname", NULL},
	{"label",	(getter)Context_get_label, NULL, "context label type", NULL},
	{"nparts",	(getter)Context_get_nparts, NULL, "context label number of existing partitions", NULL},
	{"partitions",	(getter)Context_get_partitions, NULL, "context partitions", NULL},
	{NULL}
};

static PyObject *Context_repr(ContextObject *self)
{
	return PyUnicode_FromFormat("<libfdisk.Context object at %p, details=%s>",
			self, fdisk_is_details(self->cxt) ? "True" : "False");
}

PyTypeObject ContextType = {
	PyVarObject_HEAD_INIT(NULL, 0)
	"libfdisk.Context", /*tp_name*/
	sizeof(ContextObject), /*tp_basicsize*/
	0, /*tp_itemsize*/
	(destructor)Context_dealloc, /*tp_dealloc*/
	0, /*tp_print*/
	NULL, /*tp_getattr*/
	NULL, /*tp_setattr*/
	NULL, /*tp_compare*/
	(reprfunc) Context_repr,
	NULL, /*tp_as_number*/
	NULL, /*tp_as_sequence*/
	NULL, /*tp_as_mapping*/
	NULL, /*tp_hash */
	NULL, /*tp_call*/
	NULL, /*tp_str*/
	NULL, /*tp_getattro*/
	NULL, /*tp_setattro*/
	NULL, /*tp_as_buffer*/
	Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/
	Context_HELP, /* tp_doc */
	NULL, /* tp_traverse */
	NULL, /* tp_clear */
	NULL, /* tp_richcompare */
	0, /* tp_weaklistoffset */
	NULL, /* tp_iter */
	NULL, /* tp_iternext */
	Context_methods, /* tp_methods */
	Context_members, /* tp_members */
	Context_getseters, /* tp_getset */
	NULL, /* tp_base */
	NULL, /* tp_dict */
	NULL, /* tp_descr_get */
	NULL, /* tp_descr_set */
	0, /* tp_dictoffset */
	(initproc)Context_init, /* tp_init */
	NULL, /* tp_alloc */
	Context_new, /* tp_new */
};

void Context_AddModuleObject(PyObject *mod)
{
	if (PyType_Ready(&ContextType) < 0)
		return;

	Py_INCREF(&ContextType);
	PyModule_AddObject(mod, "Context", (PyObject *)&ContextType);
}