cpython/Modules/_sqlite/microprotocols.c

161 lines
4.6 KiB
C

/* microprotocols.c - minimalist and non-validating protocols implementation
*
* Copyright (C) 2003-2004 Federico Di Gregorio <fog@debian.org>
*
* This file is part of psycopg and was adapted for pysqlite. Federico Di
* Gregorio gave the permission to use it within pysqlite under the following
* license:
*
* 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 <Python.h>
#include <structmember.h>
#include "cursor.h"
#include "microprotocols.h"
#include "prepare_protocol.h"
/** the adapters registry **/
static PyObject *psyco_adapters = NULL;
/* pysqlite_microprotocols_init - initialize the adapters dictionary */
int
pysqlite_microprotocols_init(PyObject *dict)
{
/* create adapters dictionary and put it in module namespace */
if ((psyco_adapters = PyDict_New()) == NULL) {
return -1;
}
return PyDict_SetItemString(dict, "adapters", psyco_adapters);
}
/* pysqlite_microprotocols_add - add a reverse type-caster to the dictionary */
int
pysqlite_microprotocols_add(PyTypeObject *type, PyObject *proto, PyObject *cast)
{
PyObject* key;
int rc;
if (proto == NULL) proto = (PyObject*)&pysqlite_PrepareProtocolType;
key = Py_BuildValue("(OO)", (PyObject*)type, proto);
if (!key) {
return -1;
}
rc = PyDict_SetItem(psyco_adapters, key, cast);
Py_DECREF(key);
return rc;
}
/* pysqlite_microprotocols_adapt - adapt an object to the built-in protocol */
PyObject *
pysqlite_microprotocols_adapt(PyObject *obj, PyObject *proto, PyObject *alt)
{
_Py_IDENTIFIER(__adapt__);
_Py_IDENTIFIER(__conform__);
PyObject *adapter, *key, *adapted;
/* we don't check for exact type conformance as specified in PEP 246
because the pysqlite_PrepareProtocolType type is abstract and there is no
way to get a quotable object to be its instance */
/* look for an adapter in the registry */
key = Py_BuildValue("(OO)", (PyObject*)obj->ob_type, proto);
if (!key) {
return NULL;
}
adapter = PyDict_GetItemWithError(psyco_adapters, key);
Py_DECREF(key);
if (adapter) {
Py_INCREF(adapter);
adapted = _PyObject_CallOneArg(adapter, obj);
Py_DECREF(adapter);
return adapted;
}
if (PyErr_Occurred()) {
return NULL;
}
/* try to have the protocol adapt this object */
if (_PyObject_LookupAttrId(proto, &PyId___adapt__, &adapter) < 0) {
return NULL;
}
if (adapter) {
adapted = _PyObject_CallOneArg(adapter, obj);
Py_DECREF(adapter);
if (adapted == Py_None) {
Py_DECREF(adapted);
}
else if (adapted || !PyErr_ExceptionMatches(PyExc_TypeError)) {
return adapted;
}
else {
PyErr_Clear();
}
}
/* and finally try to have the object adapt itself */
if (_PyObject_LookupAttrId(obj, &PyId___conform__, &adapter) < 0) {
return NULL;
}
if (adapter) {
adapted = _PyObject_CallOneArg(adapter, proto);
Py_DECREF(adapter);
if (adapted == Py_None) {
Py_DECREF(adapted);
}
else if (adapted || !PyErr_ExceptionMatches(PyExc_TypeError)) {
return adapted;
}
else {
PyErr_Clear();
}
}
if (alt) {
Py_INCREF(alt);
return alt;
}
/* else set the right exception and return NULL */
PyErr_SetString(pysqlite_ProgrammingError, "can't adapt");
return NULL;
}
/** module-level functions **/
PyObject *
pysqlite_adapt(pysqlite_Cursor *self, PyObject *args)
{
PyObject *obj, *alt = NULL;
PyObject *proto = (PyObject*)&pysqlite_PrepareProtocolType;
if (!PyArg_ParseTuple(args, "O|OO", &obj, &proto, &alt)) return NULL;
return pysqlite_microprotocols_adapt(obj, proto, alt);
}