1 /* microprotocols.c - minimalist and non-validating protocols implementation 2 * 3 * Copyright (C) 2003-2004 Federico Di Gregorio <fog (at) debian.org> 4 * 5 * This file is part of psycopg and was adapted for pysqlite. Federico Di 6 * Gregorio gave the permission to use it within pysqlite under the following 7 * license: 8 * 9 * This software is provided 'as-is', without any express or implied 10 * warranty. In no event will the authors be held liable for any damages 11 * arising from the use of this software. 12 * 13 * Permission is granted to anyone to use this software for any purpose, 14 * including commercial applications, and to alter it and redistribute it 15 * freely, subject to the following restrictions: 16 * 17 * 1. The origin of this software must not be misrepresented; you must not 18 * claim that you wrote the original software. If you use this software 19 * in a product, an acknowledgment in the product documentation would be 20 * appreciated but is not required. 21 * 2. Altered source versions must be plainly marked as such, and must not be 22 * misrepresented as being the original software. 23 * 3. This notice may not be removed or altered from any source distribution. 24 */ 25 26 #include <Python.h> 27 #include <structmember.h> 28 29 #include "cursor.h" 30 #include "microprotocols.h" 31 #include "prepare_protocol.h" 32 33 34 /** the adapters registry **/ 35 36 PyObject *psyco_adapters; 37 38 /* pysqlite_microprotocols_init - initialize the adapters dictionary */ 39 40 int 41 pysqlite_microprotocols_init(PyObject *dict) 42 { 43 /* create adapters dictionary and put it in module namespace */ 44 if ((psyco_adapters = PyDict_New()) == NULL) { 45 return -1; 46 } 47 48 return PyDict_SetItemString(dict, "adapters", psyco_adapters); 49 } 50 51 52 /* pysqlite_microprotocols_add - add a reverse type-caster to the dictionary */ 53 54 int 55 pysqlite_microprotocols_add(PyTypeObject *type, PyObject *proto, PyObject *cast) 56 { 57 PyObject* key; 58 int rc; 59 60 if (proto == NULL) proto = (PyObject*)&pysqlite_PrepareProtocolType; 61 62 key = Py_BuildValue("(OO)", (PyObject*)type, proto); 63 if (!key) { 64 return -1; 65 } 66 67 rc = PyDict_SetItem(psyco_adapters, key, cast); 68 Py_DECREF(key); 69 70 return rc; 71 } 72 73 /* pysqlite_microprotocols_adapt - adapt an object to the built-in protocol */ 74 75 PyObject * 76 pysqlite_microprotocols_adapt(PyObject *obj, PyObject *proto, PyObject *alt) 77 { 78 PyObject *adapter, *key; 79 80 /* we don't check for exact type conformance as specified in PEP 246 81 because the pysqlite_PrepareProtocolType type is abstract and there is no 82 way to get a quotable object to be its instance */ 83 84 /* look for an adapter in the registry */ 85 key = Py_BuildValue("(OO)", (PyObject*)obj->ob_type, proto); 86 if (!key) { 87 return NULL; 88 } 89 adapter = PyDict_GetItem(psyco_adapters, key); 90 Py_DECREF(key); 91 if (adapter) { 92 PyObject *adapted = PyObject_CallFunctionObjArgs(adapter, obj, NULL); 93 return adapted; 94 } 95 96 /* try to have the protocol adapt this object*/ 97 if (PyObject_HasAttrString(proto, "__adapt__")) { 98 PyObject *adapted = PyObject_CallMethod(proto, "__adapt__", "O", obj); 99 if (adapted) { 100 if (adapted != Py_None) { 101 return adapted; 102 } else { 103 Py_DECREF(adapted); 104 } 105 } 106 107 if (PyErr_Occurred() && !PyErr_ExceptionMatches(PyExc_TypeError)) 108 return NULL; 109 } 110 111 /* and finally try to have the object adapt itself */ 112 if (PyObject_HasAttrString(obj, "__conform__")) { 113 PyObject *adapted = PyObject_CallMethod(obj, "__conform__","O", proto); 114 if (adapted) { 115 if (adapted != Py_None) { 116 return adapted; 117 } else { 118 Py_DECREF(adapted); 119 } 120 } 121 122 if (PyErr_Occurred() && !PyErr_ExceptionMatches(PyExc_TypeError)) { 123 return NULL; 124 } 125 } 126 127 /* else set the right exception and return NULL */ 128 PyErr_SetString(pysqlite_ProgrammingError, "can't adapt"); 129 return NULL; 130 } 131 132 /** module-level functions **/ 133 134 PyObject * 135 pysqlite_adapt(pysqlite_Cursor *self, PyObject *args) 136 { 137 PyObject *obj, *alt = NULL; 138 PyObject *proto = (PyObject*)&pysqlite_PrepareProtocolType; 139 140 if (!PyArg_ParseTuple(args, "O|OO", &obj, &proto, &alt)) return NULL; 141 return pysqlite_microprotocols_adapt(obj, proto, alt); 142 } 143