zbar-windows/python/enum.c

/*------------------------------------------------------------------------
 *  Copyright 2009-2010 (c) Jeff Brown <spadix@users.sourceforge.net>
 *
 *  This file is part of the ZBar Bar Code Reader.
 *
 *  The ZBar Bar Code Reader is free software; you can redistribute it
 *  and/or modify it under the terms of the GNU Lesser Public License as
 *  published by the Free Software Foundation; either version 2.1 of
 *  the License, or (at your option) any later version.
 *
 *  The ZBar Bar Code Reader is distributed in the hope that it will be
 *  useful, but WITHOUT ANY WARRANTY; without even the implied warranty
 *  of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Lesser Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser Public License
 *  along with the ZBar Bar Code Reader; if not, write to the Free
 *  Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 *  Boston, MA  02110-1301  USA
 *
 *  http://sourceforge.net/projects/zbar
 *------------------------------------------------------------------------*/

#include "zbarmodule.h"

static char enumitem_doc[] = PyDoc_STR(
    "simple enumeration item.\n"
    "\n"
    "associates an int value with a name for printing.");

static zbarEnumItem*
enumitem_new (PyTypeObject *type,
              PyObject *args,
              PyObject *kwds)
{
    int val = 0;
    PyObject *name = NULL;
    static char *kwlist[] = { "value", "name", NULL };
    if(!PyArg_ParseTupleAndKeywords(args, kwds, "iS", kwlist, &val, &name))
        return(NULL);

    zbarEnumItem *self = (zbarEnumItem*)type->tp_alloc(type, 0);
    if(!self)
        return(NULL);

#if PY_MAJOR_VERSION >= 3
    PyLongObject *longval = (PyLongObject*)PyLong_FromLong(val);
    if (!longval) {
        Py_DECREF(self);
        return(NULL);
    }

    /* we assume the "fast path" for a single-digit ints (see longobject.c) */
    /* this also holds if we get a small_int preallocated long */
    Py_SIZE(&self->val) = Py_SIZE(longval);
    self->val.ob_digit[0] = longval->ob_digit[0];
    Py_DECREF(longval);
#else
    self->val.ob_ival = val;
#endif
    self->name = name;
    return(self);
}

static void
enumitem_dealloc (zbarEnumItem *self)
{
    Py_CLEAR(self->name);
    ((PyObject*)self)->ob_type->tp_free((PyObject*)self);
}

static PyObject*
enumitem_str (zbarEnumItem *self)
{
    Py_INCREF(self->name);
    return(self->name);
}

#if PY_MAJOR_VERSION < 3
/* tp_print was dropped on Python 3.9 */
static int
enumitem_print (zbarEnumItem *self,
                FILE *fp,
                int flags)
{
    return(self->name->ob_type->tp_print(self->name, fp, flags));
}
#endif

static PyObject*
enumitem_repr (zbarEnumItem *self)
{
    PyObject *name = PyObject_Repr(self->name);
    if(!name)
        return(NULL);
#if PY_MAJOR_VERSION >= 3
    PyObject *repr =
        PyUnicode_FromFormat("%s(%ld, %U)",
                             ((PyObject*)self)->ob_type->tp_name,
                             PyLong_AsLong((PyObject *)self), name);
#else
    char *namestr = PyString_AsString(name);
    PyObject *repr =
        PyString_FromFormat("%s(%ld, %s)",
                            ((PyObject*)self)->ob_type->tp_name,
                            self->val.ob_ival, namestr);
#endif
    Py_DECREF(name);
    return((PyObject*)repr);
}

PyTypeObject zbarEnumItem_Type = {
    PyVarObject_HEAD_INIT(NULL, 0)
    .tp_name        = "zbar.EnumItem",
    .tp_doc         = enumitem_doc,
    .tp_basicsize   = sizeof(zbarEnumItem),
    .tp_flags       = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,
    .tp_new         = (newfunc)enumitem_new,
    .tp_dealloc     = (destructor)enumitem_dealloc,
    .tp_str         = (reprfunc)enumitem_str,
#if PY_MAJOR_VERSION < 3
    .tp_print       = (printfunc)enumitem_print,
#endif
    .tp_repr        = (reprfunc)enumitem_repr,
};


zbarEnumItem*
zbarEnumItem_New (PyObject *byname,
                  PyObject *byvalue,
                  int val,
                  const char *name)
{
    zbarEnumItem *self = PyObject_New(zbarEnumItem, &zbarEnumItem_Type);
    if(!self)
        return(NULL);
#if PY_MAJOR_VERSION >= 3
    PyLongObject *longval = (PyLongObject*)PyLong_FromLong(val);
    if (!longval) {
        Py_DECREF(self);
        return(NULL);
    }

    /* we assume the "fast path" for a single-digit ints (see longobject.c) */
    /* this also holds if we get a small_int preallocated long */
    Py_SIZE(&self->val) = Py_SIZE(longval);
    self->val.ob_digit[0] = longval->ob_digit[0];
    Py_DECREF(longval);

    self->name = PyUnicode_FromString(name);
#else
    self->val.ob_ival = val;
    self->name = PyString_FromString(name);
#endif
    if(!self->name ||
       (byname && PyDict_SetItem(byname, self->name, (PyObject*)self)) ||
       (byvalue && PyDict_SetItem(byvalue, (PyObject*)self, (PyObject*)self))) {
        Py_DECREF((PyObject*)self);
        return(NULL);
    }
    return(self);
}


static char enum_doc[] = PyDoc_STR(
    "enumeration container for EnumItems.\n"
    "\n"
    "exposes items as read-only attributes");

/* FIXME add iteration */

static int
enum_traverse (zbarEnum *self,
               visitproc visit,
               void *arg)
{
    Py_VISIT(self->byname);
    Py_VISIT(self->byvalue);
    return(0);
}

static int
enum_clear (zbarEnum *self)
{
    Py_CLEAR(self->byname);
    Py_CLEAR(self->byvalue);
    return(0);
}

static void
enum_dealloc (zbarEnum *self)
{
    enum_clear(self);
    ((PyObject*)self)->ob_type->tp_free((PyObject*)self);
}

PyTypeObject zbarEnum_Type = {
    PyVarObject_HEAD_INIT(NULL, 0)
    .tp_name        = "zbar.Enum",
    .tp_doc         = enum_doc,
    .tp_basicsize   = sizeof(zbarEnum),
    .tp_flags       = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE |
                      Py_TPFLAGS_HAVE_GC,
    .tp_dictoffset  = offsetof(zbarEnum, byname),
    .tp_traverse    = (traverseproc)enum_traverse,
    .tp_clear       = (inquiry)enum_clear,
    .tp_dealloc     = (destructor)enum_dealloc,
};


zbarEnum*
zbarEnum_New ()
{
    zbarEnum *self = PyObject_GC_New(zbarEnum, &zbarEnum_Type);
    if(!self)
        return(NULL);
    self->byname = PyDict_New();
    self->byvalue = PyDict_New();
    if(!self->byname || !self->byvalue) {
        Py_DECREF(self);
        return(NULL);
    }
    return(self);
}

int
zbarEnum_Add (zbarEnum *self,
              int val,
              const char *name)
{
    zbarEnumItem *item;
    item = zbarEnumItem_New(self->byname, self->byvalue, val, name);
    if(!item)
        return(-1);
    return(0);
}

zbarEnumItem*
zbarEnum_LookupValue (zbarEnum *self,
                      int val)
{
#if PY_MAJOR_VERSION >= 3
    PyObject *key = PyLong_FromLong(val);
#else
    PyObject *key = PyInt_FromLong(val);
#endif
    zbarEnumItem *e = (zbarEnumItem*)PyDict_GetItem(self->byvalue, key);
    if(!e)
        return((zbarEnumItem*)key);
    Py_INCREF((PyObject*)e);
    Py_DECREF(key);
    return(e);
}

PyObject*
zbarEnum_SetFromMask (zbarEnum *self,
                      unsigned int mask)
{
    PyObject *result = PySet_New(NULL);
    PyObject *key, *item;
    Py_ssize_t i = 0;
    while(PyDict_Next(self->byvalue, &i, &key, &item)) {
#if PY_MAJOR_VERSION >= 3
        unsigned long val = (unsigned long)PyLong_AsLong(item);
#else
        int val = PyInt_AsLong(item);
#endif
        if(val < sizeof(mask) * 8 && ((mask >> val) & 1))
            PySet_Add(result, item);
    }
    return(result);
}