[trac915] added a utility python loadable module for testing,

"pyunittests_util".  It currently has one method named fix_current_time()
to tweak the current time value for time dependent python libraries
using C++ backend.

configure.ac

@@ -776,6 +776,7 @@ AC_CONFIG_FILES([Makefile
                  src/lib/util/io/Makefile
                  src/lib/util/io/tests/Makefile
                  src/lib/util/unittests/Makefile
+                 src/lib/util/pyunittests/Makefile
                  src/lib/util/tests/Makefile
                  tests/Makefile
                  tests/system/Makefile

src/lib/util/Makefile.am

@@ -1,4 +1,4 @@
-SUBDIRS = . tests unittests io
+SUBDIRS = . tests unittests io pyunittests
 # The io/tests is hack, because otherwise we can not order these directories
 # properly. Unittests use io and io/tests use unittest.
 

src/lib/util/pyunittests/Makefile.am

@@ -0,0 +1,14 @@
+AM_CPPFLAGS = -I$(top_srcdir)/src/lib -I$(top_builddir)/src/lib
+AM_CPPFLAGS += $(BOOST_INCLUDES)
+AM_CXXFLAGS = $(B10_CXXFLAGS)
+
+pyexec_LTLIBRARIES = pyunittests_util.la
+pyunittests_util_la_SOURCES = pyunittests_util.cc
+pyunittests_util_la_CPPFLAGS = $(AM_CPPFLAGS) $(PYTHON_INCLUDES)
+pyunittests_util_la_LDFLAGS = $(PYTHON_LDFLAGS)
+
+# Python prefers .so, while some OSes (specifically MacOS) use a different
+# suffix for dynamic objects.  -module is necessary to work this around.
+pyunittests_util_la_LDFLAGS += -module
+pyunittests_util_la_LIBADD = $(top_builddir)/src/lib/util/libutil.la
+pyunittests_util_la_LIBADD += $(PYTHON_LIB)

src/lib/util/pyunittests/pyunittests_util.cc

@@ -0,0 +1,84 @@
+// Copyright (C) 2011  Internet Systems Consortium, Inc. ("ISC")
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+#include <Python.h>
+
+#include <stdint.h>
+
+// see util/time_utilities.h
+namespace isc {
+namespace util {
+namespace detail {
+extern int64_t (*gettimeFunction)();
+}
+}
+}
+
+namespace {
+int64_t fake_current_time;
+
+int64_t
+getFakeTime() {
+    return (fake_current_time);
+}
+
+PyObject*
+fixCurrentTime(PyObject*, PyObject* args) {
+    PyObject* maybe_none;
+    if (PyArg_ParseTuple(args, "L", &fake_current_time)) {
+        isc::util::detail::gettimeFunction = getFakeTime;
+    } else if (PyArg_ParseTuple(args, "O", &maybe_none) &&
+               maybe_none == Py_None) {
+        isc::util::detail::gettimeFunction = NULL;
+    } else {
+         PyErr_SetString(PyExc_TypeError, "Invalid arguments to "
+                         "pyunittests_util.fix_current_time");
+         return (NULL);
+    }
+
+    PyErr_Clear();
+    Py_RETURN_NONE;
+}
+
+PyMethodDef PyUnittestsUtilMethods[] = {
+    { "fix_current_time", fixCurrentTime, METH_VARARGS,
+      "Fix the current system time at the specified (fake) value.\n\n"
+      "This is useful for testing modules that depend on the current time.\n"
+      "Note that it only affects C++ modules that use gettimeWrapper() "
+      "defined in libutil, which allows a hook for testing.\n"
+      "If an integer (signed 64bit) is given, the current time will be fixed "
+      "to that value; if None is specified (which is the default) the use of "
+      "faked time will be canceled."
+    },
+    { NULL, NULL, 0, NULL}
+};
+
+PyModuleDef pyunittests_util = {
+    { PyObject_HEAD_INIT(NULL) NULL, 0, NULL},
+    "pyunittests_util",
+    "This module is a collection of utilities useful for testing "
+    "the BIND 10 C++ binding modules.",
+    -1,
+    PyUnittestsUtilMethods,
+    NULL,
+    NULL,
+    NULL,
+    NULL
+};
+} // end of unnamed namespace
+
+PyMODINIT_FUNC
+PyInit_pyunittests_util(void) {
+    return (PyModule_Create(&pyunittests_util));
+}