view Modules/_sqlite/row.c @ 87690:66c1c9f32567 default tip

Add use_weakref option to functools.lru_cache The use_weakref option makes lru_cache create weak references to the function arguments when creating the cache key, which prevents them from staying in the memory forever even after all other references to them are gone. This is a proof of concept for http://bugs.python.org/issue19859
author Radomir Dopieralski <devel@sheep.art.pl>
date Tue, 03 Dec 2013 16:02:48 +0100
parents 855e172bcac4
children
line wrap: on
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/* row.c - an enhanced tuple for database rows
 *
 * Copyright (C) 2005-2010 Gerhard Häring <gh@ghaering.de>
 *
 * This file is part of pysqlite.
 *
 * This software is provided 'as-is', without any express or implied
 * warranty.  In no event will the authors be held liable for any damages
 * arising from the use of this software.
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you must not
 *    claim that you wrote the original software. If you use this software
 *    in a product, an acknowledgment in the product documentation would be
 *    appreciated but is not required.
 * 2. Altered source versions must be plainly marked as such, and must not be
 *    misrepresented as being the original software.
 * 3. This notice may not be removed or altered from any source distribution.
 */

#include "row.h"
#include "cursor.h"

void pysqlite_row_dealloc(pysqlite_Row* self)
{
    Py_XDECREF(self->data);
    Py_XDECREF(self->description);

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

int pysqlite_row_init(pysqlite_Row* self, PyObject* args, PyObject* kwargs)
{
    PyObject* data;
    pysqlite_Cursor* cursor;

    self->data = 0;
    self->description = 0;

    if (!PyArg_ParseTuple(args, "OO", &cursor, &data)) {
        return -1;
    }

    if (!PyObject_IsInstance((PyObject*)cursor, (PyObject*)&pysqlite_CursorType)) {
        PyErr_SetString(PyExc_TypeError, "instance of cursor required for first argument");
        return -1;
    }

    if (!PyTuple_Check(data)) {
        PyErr_SetString(PyExc_TypeError, "tuple required for second argument");
        return -1;
    }

    Py_INCREF(data);
    self->data = data;

    Py_INCREF(cursor->description);
    self->description = cursor->description;

    return 0;
}

PyObject* pysqlite_row_subscript(pysqlite_Row* self, PyObject* idx)
{
    long _idx;
    char* key;
    Py_ssize_t nitems, i;
    char* compare_key;

    char* p1;
    char* p2;

    PyObject* item;

    if (PyLong_Check(idx)) {
        _idx = PyLong_AsLong(idx);
        item = PyTuple_GetItem(self->data, _idx);
        Py_XINCREF(item);
        return item;
    } else if (PyUnicode_Check(idx)) {
        key = _PyUnicode_AsString(idx);
        if (key == NULL)
            return NULL;

        nitems = PyTuple_Size(self->description);

        for (i = 0; i < nitems; i++) {
            PyObject *obj;
            obj = PyTuple_GET_ITEM(self->description, i);
            obj = PyTuple_GET_ITEM(obj, 0);
            compare_key = _PyUnicode_AsString(obj);
            if (!compare_key) {
                return NULL;
            }

            p1 = key;
            p2 = compare_key;

            while (1) {
                if ((*p1 == (char)0) || (*p2 == (char)0)) {
                    break;
                }

                if ((*p1 | 0x20) != (*p2 | 0x20)) {
                    break;
                }

                p1++;
                p2++;
            }

            if ((*p1 == (char)0) && (*p2 == (char)0)) {
                /* found item */
                item = PyTuple_GetItem(self->data, i);
                Py_INCREF(item);
                return item;
            }

        }

        PyErr_SetString(PyExc_IndexError, "No item with that key");
        return NULL;
    }
    else if (PySlice_Check(idx)) {
        PyErr_SetString(PyExc_ValueError, "slices not implemented, yet");
        return NULL;
    }
    else {
        PyErr_SetString(PyExc_IndexError, "Index must be int or string");
        return NULL;
    }
}

Py_ssize_t pysqlite_row_length(pysqlite_Row* self, PyObject* args, PyObject* kwargs)
{
    return PyTuple_GET_SIZE(self->data);
}

PyObject* pysqlite_row_keys(pysqlite_Row* self, PyObject* args, PyObject* kwargs)
{
    PyObject* list;
    int nitems, i;

    list = PyList_New(0);
    if (!list) {
        return NULL;
    }
    nitems = PyTuple_Size(self->description);

    for (i = 0; i < nitems; i++) {
        if (PyList_Append(list, PyTuple_GET_ITEM(PyTuple_GET_ITEM(self->description, i), 0)) != 0) {
            Py_DECREF(list);
            return NULL;
        }
    }

    return list;
}

static int pysqlite_row_print(pysqlite_Row* self, FILE *fp, int flags)
{
    return (&PyTuple_Type)->tp_print(self->data, fp, flags);
}

static PyObject* pysqlite_iter(pysqlite_Row* self)
{
    return PyObject_GetIter(self->data);
}

static Py_hash_t pysqlite_row_hash(pysqlite_Row *self)
{
    return PyObject_Hash(self->description) ^ PyObject_Hash(self->data);
}

static PyObject* pysqlite_row_richcompare(pysqlite_Row *self, PyObject *_other, int opid)
{
    if (opid != Py_EQ && opid != Py_NE)
        Py_RETURN_NOTIMPLEMENTED;

    if (PyType_IsSubtype(Py_TYPE(_other), &pysqlite_RowType)) {
        pysqlite_Row *other = (pysqlite_Row *)_other;
        PyObject *res = PyObject_RichCompare(self->description, other->description, opid);
        if ((opid == Py_EQ && res == Py_True)
            || (opid == Py_NE && res == Py_False)) {
            Py_DECREF(res);
            return PyObject_RichCompare(self->data, other->data, opid);
        }
    }
    Py_RETURN_NOTIMPLEMENTED;
}

PyMappingMethods pysqlite_row_as_mapping = {
    /* mp_length        */ (lenfunc)pysqlite_row_length,
    /* mp_subscript     */ (binaryfunc)pysqlite_row_subscript,
    /* mp_ass_subscript */ (objobjargproc)0,
};

static PyMethodDef pysqlite_row_methods[] = {
    {"keys", (PyCFunction)pysqlite_row_keys, METH_NOARGS,
        PyDoc_STR("Returns the keys of the row.")},
    {NULL, NULL}
};


PyTypeObject pysqlite_RowType = {
        PyVarObject_HEAD_INIT(NULL, 0)
        MODULE_NAME ".Row",                             /* tp_name */
        sizeof(pysqlite_Row),                           /* tp_basicsize */
        0,                                              /* tp_itemsize */
        (destructor)pysqlite_row_dealloc,               /* tp_dealloc */
        (printfunc)pysqlite_row_print,                  /* tp_print */
        0,                                              /* tp_getattr */
        0,                                              /* tp_setattr */
        0,                                              /* tp_reserved */
        0,                                              /* tp_repr */
        0,                                              /* tp_as_number */
        0,                                              /* tp_as_sequence */
        0,                                              /* tp_as_mapping */
        (hashfunc)pysqlite_row_hash,                    /* tp_hash */
        0,                                              /* tp_call */
        0,                                              /* tp_str */
        0,                                              /* tp_getattro */
        0,                                              /* tp_setattro */
        0,                                              /* tp_as_buffer */
        Py_TPFLAGS_DEFAULT|Py_TPFLAGS_BASETYPE,         /* tp_flags */
        0,                                              /* tp_doc */
        (traverseproc)0,                                /* tp_traverse */
        0,                                              /* tp_clear */
        (richcmpfunc)pysqlite_row_richcompare,          /* tp_richcompare */
        0,                                              /* tp_weaklistoffset */
        (getiterfunc)pysqlite_iter,                     /* tp_iter */
        0,                                              /* tp_iternext */
        pysqlite_row_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 */
        (initproc)pysqlite_row_init,                    /* tp_init */
        0,                                              /* tp_alloc */
        0,                                              /* tp_new */
        0                                               /* tp_free */
};

extern int pysqlite_row_setup_types(void)
{
    pysqlite_RowType.tp_new = PyType_GenericNew;
    pysqlite_RowType.tp_as_mapping = &pysqlite_row_as_mapping;
    return PyType_Ready(&pysqlite_RowType);
}