lsup_rdf/cpython/graph_obj.h

#ifndef _PY_GRAPH_MOD_H
#define _PY_GRAPH_MOD_H

#define PY_SSIZE_T_CLEAN

#include <Python.h>
#include <structmember.h>

#include "graph.h"
#include "triple_obj.h"


typedef struct {
    PyObject_HEAD
    LSUP_Graph *ob_struct;
} GraphObject;


static int
Graph_init (GraphObject *self, PyObject *args, PyObject *kwargs)
{
    unsigned char store_type;

    if (!PyArg_ParseTuple (args, "b", &store_type))
        return -1;

    self->ob_struct = LSUP_graph_new ((LSUP_store_type)store_type);
    if (!self->ob_struct) {
        PyErr_SetString (PyExc_ValueError, "Could not create graph.");
        return -1;
    }

    return 0;
}

static void
Graph_dealloc (GraphObject *self)
{
    LSUP_graph_free (self->ob_struct);
    Py_TYPE (self)->tp_free ((PyObject *) self);
}


static PyObject *
Graph_get_size (GraphObject *self, void *closure)
{
    size_t gr_size = LSUP_graph_size (self->ob_struct);
    PyObject *size = PyLong_FromSize_t (gr_size);

    Py_INCREF (size);
    return size;
}

/*
 * FIXME This should be deleted and the setter set to NULL or omitted, but
 * in doing so Python 3.8 raises a SystemError: bad call flags. See
 * https://bugs.python.org/issue39884 No resolution is clear yet.
 */
static int
Graph_set_size (GraphObject *self, PyObject value, void *closure)
{ return -1; }


static PyObject *
Graph_get_uri (GraphObject *self, void *closure)
{
    PyObject *uri = PyUnicode_FromString (
            LSUP_graph_uri (self->ob_struct)->data);

    Py_INCREF (uri);
    return uri;
}


static int
Graph_set_uri (GraphObject *self, PyObject *uri, void *closure)
{
    if (PyUnicode_READY (uri) != 0) return -1; // TODO redundant?
    if (PyUnicode_KIND (uri) != PyUnicode_1BYTE_KIND) return -1;

    LSUP_rc rc = LSUP_graph_set_uri (self->ob_struct, PyUnicode_DATA (uri));

    return rc == LSUP_OK ? 0 : -1;
}


static PyGetSetDef Graph_getsetters[] = {
    {
        .name = "__len__",
        .get = (getter) Graph_get_size,
        .set = (setter) Graph_set_size,
        .doc = "Number of triples in the graph.",
        //.closure = NULL,
    },
    {
        "uri", (getter) Graph_get_uri, (setter) Graph_set_uri,
        "Graph URI.", NULL
    },
    {NULL}
};


static PyObject *
Graph_copy (PyTypeObject *cls, PyObject *src)
{
    if (! PyObject_TypeCheck (src, cls)) return NULL;

    GraphObject *res = (GraphObject *) cls->tp_alloc(cls, 0);
    if (!res) return NULL;

    res->ob_struct = LSUP_graph_copy (((GraphObject *) src)->ob_struct);

    Py_INCREF(res);
    return (PyObject *) res;
}


/* TODO implement LSUP_graph_equals
static PyObject *
Graph_richcmp (PyObject *gr1, PyObject *gr2, int op)
{
    if (op != Py_EQ && op != Py_NE) Py_RETURN_NOTIMPLEMENTED;

    PyObject *res = NULL;

    LSUP_Graph *t1 = ((GraphObject *) gr1)->ob_struct;
    LSUP_Graph *t2 = ((GraphObject *) gr2)->ob_struct;

    if (LSUP_graph_equals (t1, t2) && op == Py_EQ) Py_RETURN_TRUE;
    Py_RETURN_FALSE;
 }
*/


/* TODO Implement mdbstore bool ops
static inline PyObject *
Graph_bool_op (
        PyTypeObject *cls, LSUP_bool_op op, PyObject *gr1, PyObject *gr2)
{
    if (! PyObject_TypeCheck (gr1, cls) || ! PyObject_TypeCheck (gr2, cls))
        return NULL;

    GraphObject *res = (GraphObject *) cls->tp_alloc (cls, 0);
    if (!res) return NULL;

    res->ob_struct = LSUP_graph_bool_op (
            op, ((GraphObject *) gr1)->ob_struct,
            ((GraphObject *) gr2)->ob_struct);

    Py_INCREF(res);
    return (PyObject *) res;
}
*/


static int Graph_add (PyObject *self, PyObject *triples)
{
    // Triple may be any iterable.
    if (! PyIter_Check (triples)) return -1;

    PyObject *trp_obj = NULL;
    int rc = 0;
    size_t i;
    LSUP_SerTriple *sspo = STRP_DUMMY;
    LSUP_GraphIterator *it = LSUP_graph_add_stream_init (
            ((GraphObject *)self)->ob_struct);

    for (i = 0; (trp_obj = PyIter_Next (triples)); i++) {
        if (!PyObject_TypeCheck (trp_obj, &TripleType)) {
            rc = -1;
            goto finalize;
        }

        TRACE ("Inserting triple #%lu\n", i);

        LSUP_triple_serialize (((TripleObject *)trp_obj)->ob_struct, sspo);
        LSUP_rc db_rc = LSUP_graph_add_stream_iter (it, sspo);

        if (db_rc == LSUP_OK) rc = LSUP_OK;
        if (UNLIKELY (db_rc < 0)) {
            rc = -1;
            goto finalize;
        }
    }
    LSUP_striple_free (sspo);

finalize:
    LSUP_graph_add_stream_done (it);
    LSUP_striple_free (sspo);

    return rc;
}


static int Graph_remove (PyObject *self, PyObject *s, PyObject *p, PyObject *o)
{
    return 0;
}

static PyObject *Graph_lookup (
        PyObject *self, PyObject *s, PyObject *p, PyObject *o)
{
    return NULL;
}


static PyMethodDef Graph_methods[] = {
    {"copy", (PyCFunction) Graph_copy, METH_CLASS, "Copy a graph."},
    {"add", (PyCFunction) Graph_add, METH_O, "Add triples to a graph."},
    {
        "remove", (PyCFunction) Graph_remove, METH_VARARGS,
        "Remove triples from a graph by matching a pattern."
    },
    {
        "lookup", (PyCFunction) Graph_lookup, METH_VARARGS,
        "Look triples in a graph by matching a pattern."
    },
};


/* TODO Implement mdbstore bool ops
static inline PyObject *Graph_bool_and (
        PyTypeObject *cls, PyObject *gr1, PyObject *gr2)
{ return Graph_bool_op (cls, LSUP_BOOL_INTERSECTION, gr1, gr2); }

static inline PyObject *Graph_bool_or (
        PyTypeObject *cls, PyObject *gr1, PyObject *gr2)
{ return Graph_bool_op (cls, LSUP_BOOL_UNION, gr1, gr2); }

static inline PyObject *Graph_bool_subtract (
        PyTypeObject *cls, PyObject *gr1, PyObject *gr2)
{ return Graph_bool_op (cls, LSUP_BOOL_SUBTRACTION, gr1, gr2); }

static inline PyObject *Graph_bool_xor (
        PyTypeObject *cls, PyObject *gr1, PyObject *gr2)
{ return Graph_bool_op (cls, LSUP_BOOL_XOR, gr1, gr2); }

static PyNumberMethods Graph_number_methods = {
    .nb_and = (binaryfunc) Graph_bool_and,
    .nb_or = (binaryfunc) Graph_bool_or,
    .nb_subtract = (binaryfunc) Graph_bool_subtract,
    .nb_xor = (binaryfunc) Graph_bool_xor,
};
*/

PyTypeObject GraphType = {
    PyVarObject_HEAD_INIT(NULL, 0)
    .tp_name = "graph.Graph",
    .tp_doc = "RDF graph",
    .tp_basicsize = sizeof(GraphObject),
    .tp_itemsize = 0,
    .tp_flags = Py_TPFLAGS_DEFAULT,
    .tp_new = PyType_GenericNew,
    .tp_init = (initproc) Graph_init,
    .tp_dealloc = (destructor) Graph_dealloc,
    .tp_methods = Graph_methods,
    .tp_getset = Graph_getsetters,
    //.tp_richcompare = Graph_richcmp, TODO implement LSUP_graph_equals
    //.tp_as_number = &Graph_number_methods,
};

#endif