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 | /** the adapters registry **/ |
33 | |
34 | static PyObject *psyco_adapters = NULL; |
35 | |
36 | /* pysqlite_microprotocols_init - initialize the adapters dictionary */ |
37 | |
38 | int |
39 | pysqlite_microprotocols_init(PyObject *module) |
40 | { |
41 | /* create adapters dictionary and put it in module namespace */ |
42 | if ((psyco_adapters = PyDict_New()) == NULL) { |
43 | return -1; |
44 | } |
45 | |
46 | int res = PyModule_AddObjectRef(module, "adapters" , psyco_adapters); |
47 | Py_DECREF(psyco_adapters); |
48 | |
49 | return res; |
50 | } |
51 | |
52 | |
53 | /* pysqlite_microprotocols_add - add a reverse type-caster to the dictionary */ |
54 | |
55 | int |
56 | pysqlite_microprotocols_add(PyTypeObject *type, PyObject *proto, PyObject *cast) |
57 | { |
58 | PyObject* key; |
59 | int rc; |
60 | |
61 | if (proto == NULL) proto = (PyObject*)pysqlite_PrepareProtocolType; |
62 | |
63 | key = Py_BuildValue("(OO)" , (PyObject*)type, proto); |
64 | if (!key) { |
65 | return -1; |
66 | } |
67 | |
68 | rc = PyDict_SetItem(psyco_adapters, key, cast); |
69 | Py_DECREF(key); |
70 | |
71 | return rc; |
72 | } |
73 | |
74 | /* pysqlite_microprotocols_adapt - adapt an object to the built-in protocol */ |
75 | |
76 | PyObject * |
77 | pysqlite_microprotocols_adapt(PyObject *obj, PyObject *proto, PyObject *alt) |
78 | { |
79 | _Py_IDENTIFIER(__adapt__); |
80 | _Py_IDENTIFIER(__conform__); |
81 | PyObject *adapter, *key, *adapted; |
82 | |
83 | /* we don't check for exact type conformance as specified in PEP 246 |
84 | because the pysqlite_PrepareProtocolType type is abstract and there is no |
85 | way to get a quotable object to be its instance */ |
86 | |
87 | /* look for an adapter in the registry */ |
88 | key = Py_BuildValue("(OO)" , (PyObject*)Py_TYPE(obj), proto); |
89 | if (!key) { |
90 | return NULL; |
91 | } |
92 | adapter = PyDict_GetItemWithError(psyco_adapters, key); |
93 | Py_DECREF(key); |
94 | if (adapter) { |
95 | Py_INCREF(adapter); |
96 | adapted = PyObject_CallOneArg(adapter, obj); |
97 | Py_DECREF(adapter); |
98 | return adapted; |
99 | } |
100 | if (PyErr_Occurred()) { |
101 | return NULL; |
102 | } |
103 | |
104 | /* try to have the protocol adapt this object */ |
105 | if (_PyObject_LookupAttrId(proto, &PyId___adapt__, &adapter) < 0) { |
106 | return NULL; |
107 | } |
108 | if (adapter) { |
109 | adapted = PyObject_CallOneArg(adapter, obj); |
110 | Py_DECREF(adapter); |
111 | |
112 | if (adapted == Py_None) { |
113 | Py_DECREF(adapted); |
114 | } |
115 | else if (adapted || !PyErr_ExceptionMatches(PyExc_TypeError)) { |
116 | return adapted; |
117 | } |
118 | else { |
119 | PyErr_Clear(); |
120 | } |
121 | } |
122 | |
123 | /* and finally try to have the object adapt itself */ |
124 | if (_PyObject_LookupAttrId(obj, &PyId___conform__, &adapter) < 0) { |
125 | return NULL; |
126 | } |
127 | if (adapter) { |
128 | adapted = PyObject_CallOneArg(adapter, proto); |
129 | Py_DECREF(adapter); |
130 | |
131 | if (adapted == Py_None) { |
132 | Py_DECREF(adapted); |
133 | } |
134 | else if (adapted || !PyErr_ExceptionMatches(PyExc_TypeError)) { |
135 | return adapted; |
136 | } |
137 | else { |
138 | PyErr_Clear(); |
139 | } |
140 | } |
141 | |
142 | if (alt) { |
143 | return Py_NewRef(alt); |
144 | } |
145 | /* else set the right exception and return NULL */ |
146 | PyErr_SetString(pysqlite_ProgrammingError, "can't adapt" ); |
147 | return NULL; |
148 | } |
149 | |