Merge from trunk

[plcapi.git] / trunk / psycopg2 / psycopg / microprotocols.c

diff --git a/trunk/psycopg2/psycopg/microprotocols.c b/trunk/psycopg2/psycopg/microprotocols.c
new file mode 100644 (file)
index 0000000..73abbfc
--- /dev/null
+++ b/trunk/psycopg2/psycopg/microprotocols.c
@@ -0,0 +1,161 @@
+/* microprotocols.c - minimalist and non-validating protocols implementation
+ *
+ * Copyright (C) 2003-2004 Federico Di Gregorio <fog@debian.org>
+ *
+ * This file is part of psycopg.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2,
+ * or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <Python.h>
+#include <structmember.h>
+
+#define PSYCOPG_MODULE
+#include "psycopg/config.h"
+#include "psycopg/python.h"
+#include "psycopg/psycopg.h"
+#include "psycopg/cursor.h"
+#include "psycopg/connection.h"
+#include "psycopg/microprotocols.h"
+#include "psycopg/microprotocols_proto.h"
+
+
+/** the adapters registry **/
+
+PyObject *psyco_adapters;
+
+/* microprotocols_init - initialize the adapters dictionary */
+
+int
+microprotocols_init(PyObject *dict)
+{
+    /* create adapters dictionary and put it in module namespace */
+    if ((psyco_adapters = PyDict_New()) == NULL) {
+        return -1;
+    }                         
+
+    PyDict_SetItemString(dict, "adapters", psyco_adapters);
+    
+    return 0;
+}
+
+
+/* microprotocols_add - add a reverse type-caster to the dictionary */
+
+int
+microprotocols_add(PyTypeObject *type, PyObject *proto, PyObject *cast)
+{
+    if (proto == NULL) proto = (PyObject*)&isqlquoteType;
+
+    Dprintf("microprotocols_add: cast %p for (%s, ?)", cast, type->tp_name);
+
+    PyDict_SetItem(psyco_adapters,
+                   Py_BuildValue("(OO)", (PyObject*)type, proto),
+                   cast);
+    return 0;
+}
+
+/* microprotocols_adapt - adapt an object to the built-in protocol */
+
+PyObject *
+microprotocols_adapt(PyObject *obj, PyObject *proto, PyObject *alt)
+{
+    PyObject *adapter, *key;
+
+    /* we don't check for exact type conformance as specified in PEP 246
+       because the ISQLQuote type is abstract and there is no way to get a
+       quotable object to be its instance */
+
+    Dprintf("microprotocols_adapt: trying to adapt %s", obj->ob_type->tp_name);
+    
+    /* look for an adapter in the registry */
+    key = Py_BuildValue("(OO)", (PyObject*)obj->ob_type, proto);
+    adapter = PyDict_GetItem(psyco_adapters, key);
+    Py_DECREF(key);
+    if (adapter) {
+        PyObject *adapted = PyObject_CallFunctionObjArgs(adapter, obj, NULL);
+        return adapted;
+    }
+
+    /* try to have the protocol adapt this object*/
+    if (PyObject_HasAttrString(proto, "__adapt__")) {
+        PyObject *adapted = PyObject_CallMethod(proto, "__adapt__", "O", obj);
+        if (adapted && adapted != Py_None) return adapted;
+        Py_XDECREF(adapted);
+        if (PyErr_Occurred() && !PyErr_ExceptionMatches(PyExc_TypeError))
+            return NULL;
+    }
+
+    /* and finally try to have the object adapt itself */   
+    if (PyObject_HasAttrString(obj, "__conform__")) {
+        PyObject *adapted = PyObject_CallMethod(obj, "__conform__","O", proto);
+        if (adapted && adapted != Py_None) return adapted;
+        Py_XDECREF(adapted);
+        if (PyErr_Occurred() && !PyErr_ExceptionMatches(PyExc_TypeError))
+            return NULL;
+    }
+    
+    /* else set the right exception and return NULL */
+    psyco_set_error(ProgrammingError, NULL, "can't adapt", NULL, NULL);
+    return NULL;
+}
+
+/* microprotocol_getquoted - utility function that adapt and call getquoted */
+
+PyObject *
+microprotocol_getquoted(PyObject *obj, connectionObject *conn)
+{
+    PyObject *res = NULL;
+    PyObject *tmp = microprotocols_adapt(
+        obj, (PyObject*)&isqlquoteType, NULL);
+    
+    if (tmp != NULL) {
+        Dprintf("microprotocol_getquoted: adapted to %s",
+                tmp->ob_type->tp_name);
+
+        /* if requested prepare the object passing it the connection */
+        if (PyObject_HasAttrString(tmp, "prepare") && conn) {
+            res = PyObject_CallMethod(tmp, "prepare", "O", (PyObject*)conn);
+            if (res == NULL) {
+                Py_DECREF(tmp);
+                return NULL;
+            }
+            else {
+                Py_DECREF(res);
+            }
+        }
+
+        /* call the getquoted method on tmp (that should exist because we
+           adapted to the right protocol) */
+        res = PyObject_CallMethod(tmp, "getquoted", NULL);
+        Py_DECREF(tmp);
+    }
+
+    /* we return res with one extra reference, the caller shall free it */
+    return res;
+}
+
+
+/** module-level functions **/
+
+PyObject *
+psyco_microprotocols_adapt(cursorObject *self, PyObject *args)
+{
+    PyObject *obj, *alt = NULL;
+    PyObject *proto = (PyObject*)&isqlquoteType;
+
+    if (!PyArg_ParseTuple(args, "O|OO", &obj, &proto, &alt)) return NULL;
+    return microprotocols_adapt(obj, proto, alt);
+}