[2380] Merge branch 'trac2379' into trac2380

src/lib/dns/python/pydnspp.cc

@@ -777,6 +777,10 @@ PyInit_pydnspp(void) {
     po_IscException = PyErr_NewException("pydnspp.IscException", NULL, NULL);
     PyModule_AddObject(mod, "IscException", po_IscException);
 
+    po_InvalidOperation = PyErr_NewException("pydnspp.InvalidOperation",
+                                             NULL, NULL);
+    PyModule_AddObject(mod, "InvalidOperation", po_InvalidOperation);
+
     po_InvalidParameter = PyErr_NewException("pydnspp.InvalidParameter",
                                              NULL, NULL);
     PyModule_AddObject(mod, "InvalidParameter", po_InvalidParameter);

src/lib/dns/python/pydnspp_common.cc

@@ -47,6 +47,7 @@ namespace dns {
 namespace python {
 // For our 'general' isc::Exceptions
 PyObject* po_IscException;
+PyObject* po_InvalidOperation;
 PyObject* po_InvalidParameter;
 
 // For our own isc::dns::Exception

src/lib/dns/python/pydnspp_common.h

@@ -28,6 +28,7 @@ namespace dns {
 namespace python {
 // For our 'general' isc::Exceptions
 extern PyObject* po_IscException;
+extern PyObject* po_InvalidOperation;
 extern PyObject* po_InvalidParameter;
 
 // For our own isc::dns::Exception

src/lib/python/isc/datasrc/Makefile.am

@@ -20,6 +20,7 @@ datasrc_la_SOURCES += updater_python.cc updater_python.h
 datasrc_la_SOURCES += journal_reader_python.cc journal_reader_python.h
 datasrc_la_SOURCES += configurableclientlist_python.cc
 datasrc_la_SOURCES += configurableclientlist_python.h
+datasrc_la_SOURCES += zone_loader_python.cc zone_loader_python.h
 
 datasrc_la_CPPFLAGS = $(AM_CPPFLAGS) $(PYTHON_INCLUDES)
 datasrc_la_CXXFLAGS = $(AM_CXXFLAGS) $(PYTHON_CXXFLAGS)
@@ -35,6 +36,7 @@ EXTRA_DIST += finder_inc.cc
 EXTRA_DIST += iterator_inc.cc
 EXTRA_DIST += updater_inc.cc
 EXTRA_DIST += journal_reader_inc.cc
+EXTRA_DIST += zone_loader_inc.cc
 
 CLEANDIRS = __pycache__
 

src/lib/python/isc/datasrc/__init__.py

@@ -2,7 +2,7 @@ import sys
 import os
 
 # The datasource factory loader uses dlopen, as does python
-# for its modules. Some dynamic linkers do not play nice if 
+# for its modules. Some dynamic linkers do not play nice if
 # modules are not loaded with RTLD_GLOBAL, a symptom of which
 # is that exceptions are not recognized by type. So to make
 # sure this doesn't happen, we temporarily set RTLD_GLOBAL
@@ -31,5 +31,4 @@ else:
 sys.setdlopenflags(flags)
 
 from isc.datasrc.sqlite3_ds import *
-from isc.datasrc.master import *
 

src/lib/python/isc/datasrc/client_python.cc

@@ -374,6 +374,17 @@ wrapDataSourceClient(DataSourceClient* client,
     return (container.release());
 }
 
+DataSourceClient&
+PyDataSourceClient_ToDataSourceClient(PyObject* client_obj) {
+    if (client_obj == NULL) {
+        isc_throw(PyCPPWrapperException,
+                  "obj argument NULL in Name PyObject conversion");
+    }
+    const s_DataSourceClient* client =
+        static_cast<const s_DataSourceClient*>(client_obj);
+    return (*client->client);
+}
+
 } // namespace python
 } // namespace datasrc
 } // namespace isc

src/lib/python/isc/datasrc/client_python.h

@@ -44,6 +44,9 @@ wrapDataSourceClient(DataSourceClient* client,
                      LifeKeeper>& life_keeper = boost::shared_ptr<ClientList::
                      FindResult::LifeKeeper>());
 
+DataSourceClient&
+PyDataSourceClient_ToDataSourceClient(PyObject* client_obj);
+
 } // namespace python
 } // namespace datasrc
 } // namespace isc

src/lib/python/isc/datasrc/datasrc.cc

@@ -29,6 +29,7 @@
 #include "updater_python.h"
 #include "journal_reader_python.h"
 #include "configurableclientlist_python.h"
+#include "zone_loader_python.h"
 
 #include <util/python/pycppwrapper_util.h>
 #include <dns/python/pydnspp_common.h>
@@ -180,6 +181,23 @@ initModulePart_ZoneIterator(PyObject* mod) {
     return (true);
 }
 
+bool
+initModulePart_ZoneLoader(PyObject* mod) {
+    // We initialize the static description object with PyType_Ready(),
+    // then add it to the module. This is not just a check! (leaving
+    // this out results in segmentation faults)
+    if (PyType_Ready(&zone_loader_type) < 0) {
+        return (false);
+    }
+    void* p = &zone_loader_type;
+    if (PyModule_AddObject(mod, "ZoneLoader", static_cast<PyObject*>(p)) < 0) {
+        return (false);
+    }
+    Py_INCREF(&zone_loader_type);
+
+    return (true);
+}
+
 bool
 initModulePart_ZoneUpdater(PyObject* mod) {
     // We initialize the static description object with PyType_Ready(),
@@ -234,8 +252,9 @@ initModulePart_ZoneJournalReader(PyObject* mod) {
 }
 
 PyObject* po_DataSourceError;
-PyObject* po_OutOfZone;
+PyObject* po_MasterFileError;
 PyObject* po_NotImplemented;
+PyObject* po_OutOfZone;
 
 PyModuleDef iscDataSrc = {
     { PyObject_HEAD_INIT(NULL) NULL, 0, NULL},
@@ -260,6 +279,26 @@ PyInit_datasrc(void) {
         return (NULL);
     }
 
+    try {
+        po_DataSourceError = PyErr_NewException("isc.datasrc.Error", NULL,
+                                                NULL);
+        PyObjectContainer(po_DataSourceError).installToModule(mod, "Error");
+        po_MasterFileError = PyErr_NewException("isc.datasrc.MasterFileError",
+                                                po_DataSourceError, NULL);
+        PyObjectContainer(po_MasterFileError).
+            installToModule(mod, "MasterFileError");
+        po_OutOfZone = PyErr_NewException("isc.datasrc.OutOfZone", NULL, NULL);
+        PyObjectContainer(po_OutOfZone).installToModule(mod, "OutOfZone");
+        po_NotImplemented = PyErr_NewException("isc.datasrc.NotImplemented",
+                                               NULL, NULL);
+        PyObjectContainer(po_NotImplemented).installToModule(mod,
+                                                             "NotImplemented");
+
+    } catch (...) {
+        Py_DECREF(mod);
+        return (NULL);
+    }
+
     if (!initModulePart_DataSourceClient(mod)) {
         Py_DECREF(mod);
         return (NULL);
@@ -290,17 +329,7 @@ PyInit_datasrc(void) {
         return (NULL);
     }
 
-    try {
-        po_DataSourceError = PyErr_NewException("isc.datasrc.Error", NULL,
-                                                NULL);
-        PyObjectContainer(po_DataSourceError).installToModule(mod, "Error");
-        po_OutOfZone = PyErr_NewException("isc.datasrc.OutOfZone", NULL, NULL);
-        PyObjectContainer(po_OutOfZone).installToModule(mod, "OutOfZone");
-        po_NotImplemented = PyErr_NewException("isc.datasrc.NotImplemented",
-                                               NULL, NULL);
-        PyObjectContainer(po_NotImplemented).installToModule(mod,
-                                                             "NotImplemented");
-    } catch (...) {
+    if (!initModulePart_ZoneLoader(mod)) {
         Py_DECREF(mod);
         return (NULL);
     }

src/lib/python/isc/datasrc/master.py

@@ -182,7 +182,7 @@ def records(input):
 
         if paren == 1 or not record:
             continue
-        
+
         ret = ' '.join(record)
         record = []
         oldsize = size

src/lib/python/isc/datasrc/tests/Makefile.am

 PYCOVERAGE_RUN = @PYCOVERAGE_RUN@
 # old tests, TODO remove or change to use new API?
 #PYTESTS = master_test.py
-PYTESTS =  datasrc_test.py sqlite3_ds_test.py clientlist_test.py
+PYTESTS =  datasrc_test.py sqlite3_ds_test.py
+PYTESTS += clientlist_test.py zone_loader_test.py
 EXTRA_DIST = $(PYTESTS)
 
 EXTRA_DIST += testdata/brokendb.sqlite3
@@ -9,7 +10,10 @@ EXTRA_DIST += testdata/example.com.sqlite3
 EXTRA_DIST += testdata/newschema.sqlite3
 EXTRA_DIST += testdata/oldschema.sqlite3
 EXTRA_DIST += testdata/new_minor_schema.sqlite3
+EXTRA_DIST += testdata/example.com
+EXTRA_DIST += testdata/example.com.ch
 CLEANFILES = $(abs_builddir)/rwtest.sqlite3.copied
+CLEANFILES += $(abs_builddir)/zoneloadertest.sqlite3
 
 # If necessary (rare cases), explicitly specify paths to dynamic libraries
 # required by loadable python modules.

src/lib/python/isc/datasrc/tests/testdata/example.com

+example.com.         1000  IN  SOA a.dns.example.com. mail.example.com. 1 1 1 1 1
+example.com.         1000  IN  NS  a.dns.example.com.
+example.com.         1000  IN  NS  b.dns.example.com.
+example.com.         1000  IN  NS  c.dns.example.com.
+a.dns.example.com.   1000  IN  A    1.1.1.1
+b.dns.example.com.   1000  IN  A    3.3.3.3
+b.dns.example.com.   1000  IN  AAAA 4:4::4:4
+b.dns.example.com.   1000  IN  AAAA 5:5::5:5

src/lib/python/isc/datasrc/tests/testdata/example.com.ch

+example.com.         1000  CH  SOA a.dns.example.com. mail.example.com. 1 1 1 1 1
+example.com.         1000  CH  NS  a.dns.example.com.
+example.com.         1000  CH  NS  b.dns.example.com.
+example.com.         1000  CH  NS  c.dns.example.com.
+a.dns.example.com.   1000  CH  A    1.1.1.1
+b.dns.example.com.   1000  CH  A    3.3.3.3
+b.dns.example.com.   1000  CH  AAAA 4:4::4:4
+b.dns.example.com.   1000  CH  AAAA 5:5::5:5

src/lib/python/isc/datasrc/tests/zone_loader_test.py

+# Copyright (C) 2012  Internet Systems Consortium.
+#
+# Permission to use, copy, modify, and 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 INTERNET SYSTEMS CONSORTIUM
+# DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
+# INTERNET SYSTEMS CONSORTIUM 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.
+
+import isc.datasrc
+import isc.dns
+
+import os
+import unittest
+import shutil
+
+# Constants and common data used in tests
+
+TESTDATA_PATH = os.environ['TESTDATA_PATH']
+TESTDATA_WRITE_PATH = os.environ['TESTDATA_WRITE_PATH']
+
+ZONE_FILE = TESTDATA_PATH + '/example.com'
+STATIC_ZONE_FILE = '../../../../datasrc/static.zone'
+SOURCE_DB_FILE = TESTDATA_PATH + '/example.com.source.sqlite3'
+ORIG_DB_FILE = TESTDATA_PATH + '/example.com.sqlite3'
+DB_FILE = TESTDATA_WRITE_PATH + '/zoneloadertest.sqlite3'
+DB_CLIENT_CONFIG = '{ "database_file": "' + DB_FILE + '" }'
+DB_SOURCE_CLIENT_CONFIG = '{ "database_file": "' + SOURCE_DB_FILE + '" }'
+
+ORIG_SOA_TXT = 'example.com. 3600 IN SOA master.example.com. ' +\
+               'admin.example.com. 1234 3600 1800 2419200 7200\n'
+NEW_SOA_TXT = 'example.com. 1000 IN SOA a.dns.example.com. ' +\
+              'mail.example.com. 1 1 1 1 1\n'
+
+
+class ZoneLoaderTests(unittest.TestCase):
+    def setUp(self):
+        self.test_name = isc.dns.Name("example.com")
+        self.test_file = ZONE_FILE
+        self.client = isc.datasrc.DataSourceClient("sqlite3", DB_CLIENT_CONFIG)
+        # Make a fresh copy of the database
+        shutil.copy(ORIG_DB_FILE, DB_FILE)
+
+    def test_bad_constructor(self):
+        self.assertRaises(TypeError, isc.datasrc.ZoneLoader)
+        self.assertRaises(TypeError, isc.datasrc.ZoneLoader, 1)
+        self.assertRaises(TypeError, isc.datasrc.ZoneLoader,
+                          None, self.test_name, self.test_file)
+        self.assertRaises(TypeError, isc.datasrc.ZoneLoader,
+                          self.client, None, self.test_file)
+        self.assertRaises(TypeError, isc.datasrc.ZoneLoader,
+                          self.client, self.test_name, None)
+        self.assertRaises(TypeError, isc.datasrc.ZoneLoader,
+                          self.client, self.test_name, self.test_file, 1)
+
+    def check_zone_soa(self, soa_txt):
+        """
+        Check that the given SOA RR exists and matches the expected string
+        """
+        result, finder = self.client.find_zone(self.test_name)
+        self.assertEqual(self.client.SUCCESS, result)
+        result, rrset, _ = finder.find(self.test_name, isc.dns.RRType.SOA())
+        self.assertEqual(finder.SUCCESS, result)
+        self.assertEqual(soa_txt, rrset.to_text())
+
+    def check_load(self, loader):
+        self.check_zone_soa(ORIG_SOA_TXT)
+        loader.load()
+        self.check_zone_soa(NEW_SOA_TXT)
+
+        # And after that, it should throw
+        self.assertRaises(isc.dns.InvalidOperation, loader.load)
+
+    def test_load_from_file(self):
+        loader = isc.datasrc.ZoneLoader(self.client, self.test_name,
+                                        self.test_file)
+        self.check_load(loader)
+
+    def test_load_from_client(self):
+        source_client = isc.datasrc.DataSourceClient('sqlite3',
+                                                     DB_SOURCE_CLIENT_CONFIG)
+        loader = isc.datasrc.ZoneLoader(self.client, self.test_name,
+                                        source_client)
+        self.check_load(loader)
+
+    def check_load_incremental(self, loader):
+        # New zone has 8 RRs
+        # After 5, it should return False
+        self.assertFalse(loader.load_incremental(5))
+        # New zone should not have been loaded yet
+        self.check_zone_soa(ORIG_SOA_TXT)
+
+        # After 5 more, it should return True (only having read 3)
+        self.assertTrue(loader.load_incremental(5))
+        # New zone should now be loaded
+        self.check_zone_soa(NEW_SOA_TXT)
+
+        # And after that, it should throw
+        self.assertRaises(isc.dns.InvalidOperation, loader.load_incremental, 5)
+
+    def test_load_from_file_incremental(self):
+        # Create loader and load the zone
+        loader = isc.datasrc.ZoneLoader(self.client, self.test_name,
+                                        self.test_file)
+        self.check_load_incremental(loader)
+
+    def test_load_from_client_incremental(self):
+        source_client = isc.datasrc.DataSourceClient('sqlite3',
+                                                     DB_SOURCE_CLIENT_CONFIG)
+        loader = isc.datasrc.ZoneLoader(self.client, self.test_name,
+                                        source_client)
+        self.check_load_incremental(loader)
+
+    def test_bad_file(self):
+        self.check_zone_soa(ORIG_SOA_TXT)
+        loader = isc.datasrc.ZoneLoader(self.client, self.test_name,
+                                        'no such file')
+        self.assertRaises(isc.datasrc.MasterFileError, loader.load)
+        self.check_zone_soa(ORIG_SOA_TXT)
+
+    def test_bad_file_incremental(self):
+        self.check_zone_soa(ORIG_SOA_TXT)
+        loader = isc.datasrc.ZoneLoader(self.client, self.test_name,
+                                        'no such file')
+        self.assertRaises(isc.datasrc.MasterFileError,
+                          loader.load_incremental, 1)
+        self.check_zone_soa(ORIG_SOA_TXT)
+
+    def test_no_such_zone_in_target(self):
+        self.assertRaises(isc.datasrc.Error, isc.datasrc.ZoneLoader,
+                          self.client, isc.dns.Name("unknownzone"),
+                          self.test_file)
+
+    def test_no_such_zone_in_source(self):
+        source_client = isc.datasrc.DataSourceClient('sqlite3',
+                                                     DB_SOURCE_CLIENT_CONFIG)
+        self.assertRaises(isc.datasrc.Error, isc.datasrc.ZoneLoader,
+                          self.client, isc.dns.Name("unknownzone"),
+                          source_client)
+
+    def test_no_ds_load_support(self):
+        # This may change in the future, but atm, the in-mem ds does
+        # not support the API the zone loader uses (it has direct load calls)
+        inmem_client = isc.datasrc.DataSourceClient('memory',
+                                                    '{ "type": "memory" }');
+        self.assertRaises(isc.datasrc.NotImplemented,
+                          isc.datasrc.ZoneLoader,
+                          inmem_client, self.test_name, self.test_file)
+
+    def test_wrong_class_from_file(self):
+        # If the file has wrong class, it is not detected until load time
+        loader = isc.datasrc.ZoneLoader(self.client, self.test_name,
+                                        self.test_file + '.ch')
+        self.assertRaises(isc.datasrc.MasterFileError, loader.load)
+
+    def test_wrong_class_from_client(self):
+        # For ds->ds loading, wrong class is detected upon construction
+        # Need a bit of the extended setup for CH source client
+        clientlist = isc.datasrc.ConfigurableClientList(isc.dns.RRClass.CH())
+        clientlist.configure('[ { "type": "static", "params": "' +
+                             STATIC_ZONE_FILE +'" } ]', False)
+        source_client, _, _ = clientlist.find(isc.dns.Name("bind."),
+                                              False, False)
+        self.assertRaises(isc.dns.InvalidParameter, isc.datasrc.ZoneLoader,
+                          self.client, isc.dns.Name("bind."), source_client)
+
+    def test_exception(self):
+        # Just check if masterfileerror is subclass of datasrc.Error
+        self.assertTrue(issubclass(isc.datasrc.MasterFileError,
+                                   isc.datasrc.Error))
+
+if __name__ == "__main__":
+    isc.log.init("bind10")
+    isc.log.resetUnitTestRootLogger()
+    unittest.main()

src/lib/python/isc/datasrc/zone_loader_inc.cc

+namespace {
+const char* const ZoneLoader_doc = "\
+\n\
+Class to load data into a data source client.\n\
+\n\
+This is a small wrapper class that is able to load data into a data source.\n\
+It can load either from another data source or from a master file. The\n\
+purpose of the class is only to hold the state for incremental loading.\n\
+\n\
+The old content of zone is discarded and no journal is stored.\n\
+\n\
+The constructor takes three arguments:\n\
+- The datasource (isc.datasrc.DataSourceClient) to load the zone into\n\
+- The name (isc.dns.Name) to load\n\
+- either a string (for a file) or another DataSourceClient to load from\n\
+\n\
+Upon construction, no loading is done yet.\n\
+\n\
+It can throw:\n\
+DataSourceError, in case the zone does not exist in destination.\n\
+    This class does not support creating brand new zones, only loading\n\
+    data into them. In case a new zone is needed, it must be created\n\
+    beforehand (with create_zone()).\n\
+    DataSourceError is also thrown in case the zone is not present in the\n\
+    source DataSourceClient, and in case of other possibly low-level\n\
+    errors.\n\
+InvalidParameter, in case the class of destination and source\n\
+    differs.\n\
+NotImplemented in case target data source client doesn't provide an updater\n\
+    or the source data source client doesn't provide an iterator.\n\
+\n\
+";
+
+const char* const ZoneLoader_loadIncremental_doc = "\
+\n\
+Load up to limit RRs.\n\
+\n\
+This performs a part of the loading. In case there's enough data in the\n\
+source, it copies limit RRs. It can copy less RRs during the final call\n\
+(when there's less than limit left).\n\
+\n\
+This can be called repeatedly until the whole zone is loaded, having\n\
+pauses in the loading for some purposes (for example reporting\n\
+progress).\n\
+\n\
+It has one parameter: limit (integer), The maximum allowed number of RRs\n\
+to be loaded during this call.\n\
+\n\
+Returns True in case the loading is completed, and False if there's more\n\
+to load.\n\
+\n\
+It can throw:\n\
+InvalidOperation, in case the loading was already completed before this\n\
+    call (by load() or by a loadIncremental that returned true).\n\
+DataSourceError, in case some error (possibly low-level) happens.\n\
+MasterFileError when the master_file is badly formatted or some similar\n\
+    problem is found when loading the master file.\n\
+\n\
+Note: If the limit is exactly the number of RRs available to be loaded,\n\
+      the method still returns false and true'll be returned on the next\n\
+      call (which will load 0 RRs). This is because the end of iterator or\n\
+      master file is detected when reading past the end, not when the last\n\
+      one is read.\n\
+\n\
+";
+
+const char* const ZoneLoader_load_doc = "\
+\n\
+Performs the entire load operation.\n\
+\n\
+Depending on zone size, this could take a long time.\n\
+\n\
+This method has no parameters and does not return anything.\n\
+\n\
+It can throw:\n\
+InvalidOperation, in case the loading was already completed before this call.\n\
+MasterFileError, when the master_file is badly formatted or some\n\
+                 similar problem is found when loading the master file.\n\
+DataSourceError, in case some error (possibly low-level) happens.\n\
+\n\
+";
+
+} // unnamed namespace

src/lib/python/isc/datasrc/zone_loader_python.cc

+// Copyright (C) 2012  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.
+
+// Enable this if you use s# variants with PyArg_ParseTuple(), see
+// http://docs.python.org/py3k/c-api/arg.html#strings-and-buffers
+//#define PY_SSIZE_T_CLEAN
+
+// Python.h needs to be placed at the head of the program file, see:
+// http://docs.python.org/py3k/extending/extending.html#a-simple-example
+#include <Python.h>
+
+#include <util/python/pycppwrapper_util.h>
+
+#include <datasrc/zone_loader.h>
+#include <dns/python/name_python.h>
+#include <dns/python/pydnspp_common.h>
+#include <exceptions/exceptions.h>
+
+#include "client_python.h"
+#include "datasrc.h"
+#include "zone_loader_inc.cc"
+
+using namespace std;
+using namespace isc::dns::python;
+using namespace isc::datasrc;
+using namespace isc::datasrc::python;
+
+namespace {
+// The s_* Class simply covers one instantiation of the object
+class s_ZoneLoader : public PyObject {
+public:
+    s_ZoneLoader() : cppobj(NULL), client(NULL) {};
+    ZoneLoader* cppobj;
+    // a zoneloader should not survive its associated client,
+    // so add a ref to it at init
+    PyObject* client;
+};
+
+// General creation and destruction
+int
+ZoneLoader_init(PyObject* po_self, PyObject* args, PyObject*) {
+    s_ZoneLoader* self = static_cast<s_ZoneLoader*>(po_self);
+    PyObject *po_target_client = NULL;
+    PyObject *po_source_client = NULL;
+    PyObject *po_name = NULL;
+    char* master_file;
+    if (!PyArg_ParseTuple(args, "O!O!s", &datasourceclient_type,
+                          &po_target_client, &name_type, &po_name,
+                          &master_file) &&
+        !PyArg_ParseTuple(args, "O!O!O!", &datasourceclient_type,
+                          &po_target_client, &name_type, &po_name,
+                          &datasourceclient_type, &po_source_client)
+       ) {
+        return (-1);
+    }
+    PyErr_Clear();
+    try {
+        Py_INCREF(po_target_client);
+        self->client = po_target_client;
+        if (po_source_client != NULL) {
+            self->cppobj = new ZoneLoader(
+                PyDataSourceClient_ToDataSourceClient(po_target_client),
+                PyName_ToName(po_name),
+                PyDataSourceClient_ToDataSourceClient(po_source_client));
+        } else {
+            self->cppobj = new ZoneLoader(
+                PyDataSourceClient_ToDataSourceClient(po_target_client),
+                PyName_ToName(po_name),
+                master_file);
+        }
+        return (0);
+    } catch (const isc::InvalidParameter& ivp) {
+        PyErr_SetString(po_InvalidParameter, ivp.what());
+    } catch (const isc::datasrc::DataSourceError& dse) {
+        PyErr_SetString(getDataSourceException("Error"), dse.what());
+    } catch (const isc::NotImplemented& ni) {
+        PyErr_SetString(getDataSourceException("NotImplemented"), ni.what());
+    } catch (const std::exception& stde) {
+        PyErr_SetString(getDataSourceException("Error"), stde.what());
+    } catch (...) {
+        PyErr_SetString(getDataSourceException("Error"),
+                        "Unexpected exception");
+    }
+    return (-1);
+}
+
+void
+ZoneLoader_destroy(PyObject* po_self) {
+    s_ZoneLoader* self = static_cast<s_ZoneLoader*>(po_self