sip4-tqt/siplib/voidptr.c

/*
 * SIP-TQt library code.
 *
 * Copyright (c) 2010 Riverbank Computing Limited <info@riverbankcomputing.com>
 *
 * This file is part of SIP-TQt.
 *
 * This copy of SIP-TQt is licensed for use under the terms of the SIP License
 * Agreement.  See the file LICENSE for more details.
 *
 * This copy of SIP-TQt may also used under the terms of the GNU General Public
 * License v2 or v3 as published by the Free Software Foundation which can be
 * found in the files LICENSE-GPL2 and LICENSE-GPL3 included in this package.
 *
 * SIP-TQt is supplied WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 */


#include <Python.h>

#include <stddef.h>

#include "sip-tqt.h"
#include "sipint.h"


/* The object data structure. */
typedef struct {
    PyObject_HEAD
    void *voidptr;
    SIP_SSIZE_T size;
    int rw;
} sipVoidPtrObject;


/* The structure used to hold the results of a voidptr conversion. */
struct vp_values {
    void *voidptr;
    SIP_SSIZE_T size;
    int rw;
};


static PyObject *make_voidptr(void *voidptr, SIP_SSIZE_T size, int rw);
static int vp_convertor(PyObject *arg, struct vp_values *vp);


/*
 * Implement __new__ for the type.
 */
static PyObject *sipVoidPtr_new(PyTypeObject *subtype, PyObject *args,
        PyObject *kw)
{
    static char *kwlist[] = {"address", "size", "writeable", NULL};

    struct vp_values vp_conversion;
    SIP_SSIZE_T size = -1;
    int rw = -1;
    PyObject *obj;

    if (!PyArg_ParseTupleAndKeywords(args, kw,
            "O&|ni:voidptr",
            kwlist, vp_convertor, &vp_conversion, &size, &rw))
        return NULL;

    /* Use the explicit size if one was given. */
    if (size >= 0)
        vp_conversion.size = size;

    /* Use the explicit writeable flag if one was given. */
    if (rw >= 0)
        vp_conversion.rw = rw;

    /* Create the instance. */
    if ((obj = subtype->tp_alloc(subtype, 0)) == NULL)
        return NULL;

    /* Save the values. */
    ((sipVoidPtrObject *)obj)->voidptr = vp_conversion.voidptr;
    ((sipVoidPtrObject *)obj)->size = vp_conversion.size;
    ((sipVoidPtrObject *)obj)->rw = vp_conversion.rw;

    return obj;
}


/*
 * The read buffer implementation for Python v3.
 */
static int sipVoidPtr_getbuffer(PyObject *self, Py_buffer *buf, int flags)
{
    sipVoidPtrObject *v = (sipVoidPtrObject *)self;

    return PyBuffer_FillInfo(buf, self, v->voidptr, v->size, !v->rw, flags);
}


/*
 * Implement int() for the type.
 */
static PyObject *sipVoidPtr_int(sipVoidPtrObject *v)
{
    return PyLong_FromVoidPtr(v->voidptr);
}


/*
 * Implement ascapsule() for the type.
 */
static PyObject *sipVoidPtr_ascapsule(sipVoidPtrObject *v, PyObject *arg)
{
    return PyCapsule_New(v->voidptr, NULL, NULL);
}


/*
 * Implement asstring() for the type.
 */
static PyObject *sipVoidPtr_asstring(sipVoidPtrObject *v, PyObject *args,
        PyObject *kw)
{
    static char *kwlist[] = {"size", NULL};

    SIP_SSIZE_T size = -1;

    if (!PyArg_ParseTupleAndKeywords(args, kw,
            "|n:asstring",
            kwlist, &size))
        return NULL;

    /* Use the current size if one wasn't explicitly given. */
    if (size < 0)
        size = v->size;

    if (size < 0)
    {
        PyErr_SetString(PyExc_ValueError,
                "a size must be given or the sip_tqt.voidptr must have a size");
        return NULL;
    }

    return PyBytes_FromStringAndSize(v->voidptr, size);
}


/*
 * Implement getsize() for the type.
 */
static PyObject *sipVoidPtr_getsize(sipVoidPtrObject *v, PyObject *arg)
{
    return PyLong_FromSsize_t(v->size);
}


/*
 * Implement setsize() for the type.
 */
static PyObject *sipVoidPtr_setsize(sipVoidPtrObject *v, PyObject *arg)
{
    SIP_SSIZE_T size;

    size = PyLong_AsSsize_t(arg);

    if (PyErr_Occurred())
        return NULL;

    v->size = size;

    Py_INCREF(Py_None);
    return Py_None;
}


/*
 * Implement getwriteable() for the type.
 */
static PyObject *sipVoidPtr_getwriteable(sipVoidPtrObject *v, PyObject *arg)
{
    return PyBool_FromLong(v->rw);
}


/*
 * Implement setwriteable() for the type.
 */
static PyObject *sipVoidPtr_setwriteable(sipVoidPtrObject *v, PyObject *arg)
{
    int rw;

    rw = (int)PyLong_AsLong(arg);

    if (PyErr_Occurred())
        return NULL;

    v->rw = rw;

    Py_INCREF(Py_None);
    return Py_None;
}


/* The methods data structure. */
static PyMethodDef sipVoidPtr_Methods[] = {
    {"ascapsule", (PyCFunction)sipVoidPtr_ascapsule, METH_NOARGS, NULL},
    {"asstring", (PyCFunction)sipVoidPtr_asstring, METH_VARARGS|METH_KEYWORDS, NULL},
    {"getsize", (PyCFunction)sipVoidPtr_getsize, METH_NOARGS, NULL},
    {"setsize", (PyCFunction)sipVoidPtr_setsize, METH_O, NULL},
    {"getwriteable", (PyCFunction)sipVoidPtr_getwriteable, METH_NOARGS, NULL},
    {"setwriteable", (PyCFunction)sipVoidPtr_setwriteable, METH_O, NULL},
    {NULL}
};


/* The number methods data structure. */
static PyNumberMethods sipVoidPtr_NumberMethods = {
    0,                      /* nb_add */
    0,                      /* nb_subtract */
    0,                      /* nb_multiply */
    0,                      /* nb_remainder */
    0,                      /* nb_divmod */
    0,                      /* nb_power */
    0,                      /* nb_negative */
    0,                      /* nb_positive */
    0,                      /* nb_absolute */
    0,                      /* nb_bool (Python v3), nb_nonzero (Python v2) */
    0,                      /* nb_invert */
    0,                      /* nb_lshift */
    0,                      /* nb_rshift */
    0,                      /* nb_and */
    0,                      /* nb_xor */
    0,                      /* nb_or */
    (unaryfunc)sipVoidPtr_int,  /* nb_int */
    0,                      /* nb_reserved */
    0,                      /* nb_float */
    0,                      /* nb_inplace_add */
    0,                      /* nb_inplace_subtract */
    0,                      /* nb_inplace_multiply */
    0,                      /* nb_inplace_remainder */
    0,                      /* nb_inplace_power */
    0,                      /* nb_inplace_lshift */
    0,                      /* nb_inplace_rshift */
    0,                      /* nb_inplace_and */
    0,                      /* nb_inplace_xor */
    0,                      /* nb_inplace_or */
    0,                      /* nb_floor_divide */
    0,                      /* nb_true_divide */
    0,                      /* nb_inplace_floor_divide */
    0,                      /* nb_inplace_true_divide */
    0                       /* nb_index */
};


/* The buffer methods data structure. */
static PyBufferProcs sipVoidPtr_BufferProcs = {
    sipVoidPtr_getbuffer,
    NULL,
};


/* The type data structure. */
PyTypeObject sipVoidPtr_Type = {
    PyVarObject_HEAD_INIT(NULL, 0)
    "sip_tqt.voidptr",          /* tp_name */
    sizeof (sipVoidPtrObject),  /* tp_basicsize */
    0,                      /* tp_itemsize */
    0,                      /* tp_dealloc */
    0,                      /* tp_print */
    0,                      /* tp_getattr */
    0,                      /* tp_setattr */
    0,                      /* tp_reserved (Python v3), tp_compare (Python v2) */
    0,                      /* tp_repr */
    &sipVoidPtr_NumberMethods,  /* tp_as_number */
    0,                      /* tp_as_sequence */
    0,                      /* tp_as_mapping */
    0,                      /* tp_hash */
    0,                      /* tp_call */
    0,                      /* tp_str */
    0,                      /* tp_getattro */
    0,                      /* tp_setattro */
    &sipVoidPtr_BufferProcs,    /* tp_as_buffer */
    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,   /* tp_flags */
    0,                      /* tp_doc */
    0,                      /* tp_traverse */
    0,                      /* tp_clear */
    0,                      /* tp_richcompare */
    0,                      /* tp_weaklistoffset */
    0,                      /* tp_iter */
    0,                      /* tp_iternext */
    sipVoidPtr_Methods,     /* tp_methods */
    0,                      /* tp_members */
    0,                      /* tp_getset */
    0,                      /* tp_base */
    0,                      /* tp_dict */
    0,                      /* tp_descr_get */
    0,                      /* tp_descr_set */
    0,                      /* tp_dictoffset */
    0,                      /* tp_init */
    0,                      /* tp_alloc */
    sipVoidPtr_new,         /* tp_new */
};


/*
 * A convenience function to convert a C/C++ void pointer from a Python object.
 */
void *sip_api_convert_to_void_ptr(PyObject *obj)
{
    if (obj == NULL)
    {
        PyErr_SetString(PyExc_TypeError, "sip_tqt.voidptr is NULL");
        return NULL;
    }

    if (obj == Py_None)
        return NULL;

    if (PyObject_TypeCheck(obj, &sipVoidPtr_Type))
        return ((sipVoidPtrObject *)obj)->voidptr;

    if (PyCapsule_CheckExact(obj))
        return PyCapsule_GetPointer(obj, NULL);

    return PyLong_AsVoidPtr(obj);
}


/*
 * Convert a C/C++ void pointer to a sip_tqt.voidptr object.
 */
PyObject *sip_api_convert_from_void_ptr(void *val)
{
    return make_voidptr(val, -1, TRUE);
}


/*
 * Convert a C/C++ void pointer to a sip_tqt.voidptr object.
 */
PyObject *sip_api_convert_from_const_void_ptr(const void *val)
{
    return make_voidptr((void *)val, -1, FALSE);
}


/*
 * Convert a sized C/C++ void pointer to a sip_tqt.voidptr object.
 */
PyObject *sip_api_convert_from_void_ptr_and_size(void *val, SIP_SSIZE_T size)
{
    return make_voidptr(val, size, TRUE);
}


/*
 * Convert a sized C/C++ const void pointer to a sip_tqt.voidptr object.
 */
PyObject *sip_api_convert_from_const_void_ptr_and_size(const void *val,
        SIP_SSIZE_T size)
{
    return make_voidptr((void *)val, size, FALSE);
}


/*
 * Do the work of converting a void pointer.
 */
static PyObject *make_voidptr(void *voidptr, SIP_SSIZE_T size, int rw)
{
    sipVoidPtrObject *self;

    if (voidptr == NULL)
    {
        Py_INCREF(Py_None);
        return Py_None;
    }

    if ((self = PyObject_NEW(sipVoidPtrObject, &sipVoidPtr_Type)) == NULL)
        return NULL;

    self->voidptr = voidptr;
    self->size = size;
    self->rw = rw;

    return (PyObject *)self;
}


/*
 * Convert a Python object to the values needed to create a voidptr.
 */
static int vp_convertor(PyObject *arg, struct vp_values *vp)
{
    void *ptr;
    SIP_SSIZE_T size = -1;
    int rw = TRUE;

    if (arg == Py_None)
        ptr = NULL;
    else if (PyCapsule_CheckExact(arg))
        ptr = PyCapsule_GetPointer(arg, NULL);
    else if (PyObject_TypeCheck(arg, &sipVoidPtr_Type))
    {
        ptr = ((sipVoidPtrObject *)arg)->voidptr;
        size = ((sipVoidPtrObject *)arg)->size;
        rw = ((sipVoidPtrObject *)arg)->rw;
    }
    else
    {
        ptr = PyLong_AsVoidPtr(arg);

        if (PyErr_Occurred())
        {
            PyErr_SetString(PyExc_TypeError, "a single integer, CObject, None or another voidptr is required");
            return 0;
        }
    }

    vp->voidptr = ptr;
    vp->size = size;
    vp->rw = rw;

    return 1;
}