1 /* microprotocols.c - minimalist and non-validating protocols implementation
2 *
3 * Copyright (C) 2003-2004 Federico Di Gregorio <[email protected]>
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
28 #include "cursor.h"
29 #include "microprotocols.h"
30 #include "prepare_protocol.h"
31
32
33 /* pysqlite_microprotocols_init - initialize the adapters dictionary */
34
35 int
pysqlite_microprotocols_init(PyObject * module)36 pysqlite_microprotocols_init(PyObject *module)
37 {
38 /* create adapters dictionary and put it in module namespace */
39 pysqlite_state *state = pysqlite_get_state(module);
40 state->psyco_adapters = PyDict_New();
41 if (state->psyco_adapters == NULL) {
42 return -1;
43 }
44
45 return PyModule_AddObjectRef(module, "adapters", state->psyco_adapters);
46 }
47
48
49 /* pysqlite_microprotocols_add - add a reverse type-caster to the dictionary */
50
51 int
pysqlite_microprotocols_add(pysqlite_state * state,PyTypeObject * type,PyObject * proto,PyObject * cast)52 pysqlite_microprotocols_add(pysqlite_state *state, PyTypeObject *type,
53 PyObject *proto, PyObject *cast)
54 {
55 PyObject* key;
56 int rc;
57
58 assert(type != NULL);
59 assert(proto != NULL);
60 key = Py_BuildValue("(OO)", (PyObject*)type, proto);
61 if (!key) {
62 return -1;
63 }
64
65 rc = PyDict_SetItem(state->psyco_adapters, key, cast);
66 Py_DECREF(key);
67
68 return rc;
69 }
70
71 /* pysqlite_microprotocols_adapt - adapt an object to the built-in protocol */
72
73 PyObject *
pysqlite_microprotocols_adapt(pysqlite_state * state,PyObject * obj,PyObject * proto,PyObject * alt)74 pysqlite_microprotocols_adapt(pysqlite_state *state, PyObject *obj,
75 PyObject *proto, PyObject *alt)
76 {
77 PyObject *adapter, *key, *adapted;
78
79 /* we don't check for exact type conformance as specified in PEP 246
80 because the PrepareProtocolType type is abstract and there is no
81 way to get a quotable object to be its instance */
82
83 /* look for an adapter in the registry */
84 key = Py_BuildValue("(OO)", (PyObject*)Py_TYPE(obj), proto);
85 if (!key) {
86 return NULL;
87 }
88 adapter = PyDict_GetItemWithError(state->psyco_adapters, key);
89 Py_DECREF(key);
90 if (adapter) {
91 Py_INCREF(adapter);
92 adapted = PyObject_CallOneArg(adapter, obj);
93 Py_DECREF(adapter);
94 return adapted;
95 }
96 if (PyErr_Occurred()) {
97 return NULL;
98 }
99
100 /* try to have the protocol adapt this object */
101 if (_PyObject_LookupAttr(proto, state->str___adapt__, &adapter) < 0) {
102 return NULL;
103 }
104 if (adapter) {
105 adapted = PyObject_CallOneArg(adapter, obj);
106 Py_DECREF(adapter);
107
108 if (adapted == Py_None) {
109 Py_DECREF(adapted);
110 }
111 else if (adapted || !PyErr_ExceptionMatches(PyExc_TypeError)) {
112 return adapted;
113 }
114 else {
115 PyErr_Clear();
116 }
117 }
118
119 /* and finally try to have the object adapt itself */
120 if (_PyObject_LookupAttr(obj, state->str___conform__, &adapter) < 0) {
121 return NULL;
122 }
123 if (adapter) {
124 adapted = PyObject_CallOneArg(adapter, proto);
125 Py_DECREF(adapter);
126
127 if (adapted == Py_None) {
128 Py_DECREF(adapted);
129 }
130 else if (adapted || !PyErr_ExceptionMatches(PyExc_TypeError)) {
131 return adapted;
132 }
133 else {
134 PyErr_Clear();
135 }
136 }
137
138 if (alt) {
139 return Py_NewRef(alt);
140 }
141 /* else set the right exception and return NULL */
142 PyErr_SetString(state->ProgrammingError, "can't adapt");
143 return NULL;
144 }
145