Ejemplo n.º 1
0
 def setUp(self):
     self.do_infra = InMemoryInfrastructure()
     self.do_infra.set_random_seed(12345)
     self.logger = logging.getLogger(__name__)
     self.random = Random(43210)
     self.created_pids = []
     self.prefix = TESTING_CONFIG_DEFAULTS["handle-prefix"] + "/"
Ejemplo n.º 2
0
 def setUp(self):
     self.do_infra = InMemoryInfrastructure()
     self.do_infra.set_random_seed(12345)
     self.logger = logging.getLogger(__name__)
     self.random = Random(43210)
     self.created_pids = []
     self.prefix = TESTING_CONFIG_DEFAULTS["handle-prefix"]+"/"
Ejemplo n.º 3
0
class TestDOInfrastructure(unittest.TestCase):
    
    def setUp(self):
        self.do_infra = InMemoryInfrastructure()
        self.do_infra.set_random_seed(12345)
        self.logger = logging.getLogger(__name__)
        self.random = Random(43210)
        self.created_pids = []
        self.prefix = TESTING_CONFIG_DEFAULTS["handle-prefix"]+"/"
        
    def tearDown(self):
        pass
    
    def __check_dobj3_references(self, dobj3, dobj1, dobj2):
        i = 0
        iter3 = dobj3.iter_reference_keys()
        for k in iter3:
            assert k == "successor"
            i += 1
        assert i == 1
        assert dobj3.get_references("notexisting") == []
        succ = dobj3.get_references("successor")
        assert len(succ) == 2
        assert succ[0].identifier == dobj1.identifier
        assert succ[1].identifier == dobj2.identifier

    
    def test_do_values(self):
        # values
        pid = self.prefix+"test_do_values"
        resloc = "http://www.example.com/1"
        restype = "MY_TEST_TYPE"
        pid2 = self.prefix+"test_do_values_2"
        pid3 = self.prefix+"test_do_values_3"
        # create DO
        dobj = self.do_infra.create_do(pid)
        self.created_pids.append(pid)
        assert dobj != None
        dobj.resource_location = resloc
        assert dobj.resource_location == resloc
        dobj._resource_type = restype
        assert dobj._resource_type == restype
        # look up and assert
        dobj2 = self.do_infra.lookup_pid(pid)
        assert dobj2 != None
        assert dobj2.resource_location == resloc
        assert dobj2._resource_type == restype
        # create a second DO
        dobj2 = self.do_infra.create_do(pid2)
        self.created_pids.append(pid2)
        assert dobj2 != None
        # create a third DO
        dobj3 = self.do_infra.create_do(pid3)
        self.created_pids.append(pid3)
        assert dobj3 != None
        dobj3.add_do_reference("successor", dobj)
        dobj3.add_do_reference("successor", dobj2)
        dobj2.add_do_reference("predecessor", dobj3)
        dobj.add_do_reference("predecessor", dobj3)
        dobj.set_property_value(20, "myproperty20", 1)
        dobj.set_property_value(21, "myproperty21", "abc")
        # check references
        self.__check_dobj3_references(dobj3, dobj, dobj2)
        # retrieve dobj3 from infra and check references
        dobj3 = self.do_infra.lookup_pid(pid3)
        self.__check_dobj3_references(dobj3, dobj, dobj2)
        # check properties
        dobj = self.do_infra.lookup_pid(pid)
        assert dobj.is_property_assigned(20) == True
        assert dobj.is_property_assigned(21) == True
        assert dobj.is_property_assigned(22) == False
        assert dobj.get_property_value(20) == ("myproperty20", "1")
        assert dobj.get_property_value(21) == ("myproperty21", "abc")
        dobj.set_property_value(20, "myproperty20", "2")
        assert dobj.get_property_value(20) == ("myproperty20", "2")
        dobj = self.do_infra.lookup_pid(pid)
        assert dobj.get_property_value(20) == ("myproperty20", "2")
        # test prevention of property overwrite
        try:
            dobj.set_property_value(20, "this_should_not_work", "value")
            self.fail("Successful overwrite of existing property with different name!")
        except PropertyNameMismatchError:
            pass
        else:
            raise
        # delete and check for removal
        self.do_infra.delete_do(pid)
        dobj = self.do_infra.lookup_pid(pid)
        assert dobj == None
        
    def test_infra_operations(self):
        dobj = self.do_infra.lookup_pid(self.prefix+"does-not-exist")
        assert dobj == None
        # duplication attempts
        dobj = self.do_infra.create_do(self.prefix+"duplicate")
        self.created_pids.append(self.prefix+"duplicate")
        assert dobj != None
        try:
            dobj2 = self.do_infra.create_do(self.prefix+"duplicate")
            self.fail("Creation attempt of object with duplicate PID successful!")
        except PIDAlreadyExistsError:
            pass
        else:
            self.fail("Creation attempt of object with duplicate PID successful/compromised!")
            
    def test_random_pid_allocation(self):
        for x in range (0,10):
            dobj = self.do_infra.create_do()
            self.created_pids.append(dobj.identifier)
            assert dobj != None
            self.logger.info(dobj.identifier)
    
    def test_aliases(self):
        resloc = "http://www.example.com/alias_original"
        id_orig = self.prefix+"alias_original"
        id_alias1 = self.prefix+"alias1"
        id_alias2 = self.prefix+"alias2"
        dobj1 = self.do_infra.create_do(id_orig)
        id_orig = dobj1.identifier
        self.created_pids.append(id_orig)
        assert dobj1 != None
        dobj1.resource_location = resloc
        assert dobj1.resource_location == resloc
        assert dobj1.get_alias_identifiers() == []
        # alias 1 -> orig
        id_alias1 = self.do_infra.create_alias(dobj1, id_alias1)
        assert id_alias1 != None
        self.created_pids.append(id_alias1)
        assert self.do_infra.is_alias(id_alias1) == True
        # alias 2 -> alias 1 -> orig
        id_alias2 = self.do_infra.create_alias(id_alias1, id_alias2)
        assert id_alias2 != None
        self.created_pids.append(id_alias2)
        assert self.do_infra.is_alias(id_alias2) == True
        # check aliases
        assert self.do_infra.is_alias(id_orig) == False
        dobj = self.do_infra.lookup_pid(id_alias2)
        assert dobj != None
        assert dobj.identifier == id_orig
        assert dobj.resource_location == resloc
        assert dobj.get_alias_identifiers() == [id_alias2, id_alias1]
        dobj = self.do_infra.lookup_pid(id_alias1)
        assert dobj != None
        assert dobj.identifier == id_orig
        assert dobj.resource_location == resloc
        assert dobj.get_alias_identifiers() == [id_alias1]
        # look up directly, check if no aliases noted
        dobj = self.do_infra.lookup_pid(id_orig)
        assert dobj.get_alias_identifiers() == []
        
        # delete alias
        assert self.do_infra.delete_alias(id_alias1) == True
        assert self.do_infra.lookup_pid(id_alias1) == None
        
        # self.do_infra.lookup_pid(id_alias2) -> broken chain, check for exception
        try:
            self.do_infra.lookup_pid(id_alias2)
            self.fail("Could resolve broken alias chain without Exception being thrown!")
        except PIDAliasBrokenError:
            pass
        else:
            raise
        
    def test_sets(self):
        # create a set
        id_ele = [self.prefix+"setele1", self.prefix+"setele2", self.prefix+"setele3"]
        id_set = self.prefix+"set"
        non_ele_id = self.prefix+"some-non-ele"
        ele = []
        for i in range(len(id_ele)):
            newele = self.do_infra.create_do(id_ele[i])
            ele.append(newele)
            id_ele[i] = newele.identifier
            self.created_pids.append(newele.identifier)
        ele_set = self.do_infra.create_do(id_set, DigitalObjectSet)
        assert ele_set != None
        self.created_pids.append(ele_set.identifier)
        id_set = ele_set.identifier
        for e in ele:
            ele_set.add_do(e)
        # check if this is a set
        ele_set = self.do_infra.lookup_pid(id_set)
        assert isinstance(ele_set, DigitalObjectSet)
        # check if all subelements are present
        num_subele = 0
        for sele in ele_set.iter_set_elements():
            id_ele.index(sele.identifier)
            num_subele += 1
        assert num_subele == 3
        assert ele_set.num_set_elements() == 3
        # now extend and check again
        ele_set = self.do_infra.lookup_pid(id_set)
        id_ele += [self.prefix+"setele4"]
        newele = self.do_infra.create_do(id_ele[3])
        id_ele[3] = newele.identifier
        self.created_pids.append(newele.identifier)
        ele_set.add_do(newele)
        # check if all subelements are present
        ele_set = self.do_infra.lookup_pid(id_set)
        num_subele = 0
        for sele in ele_set.iter_set_elements():
            id_ele.index(sele.identifier)
            num_subele += 1
            assert sele.get_parent_pids(ele_set.CHARACTERISTIC_SEGMENT_NUMBER) == set([id_set])
        assert num_subele == 4
        assert ele_set.num_set_elements() == 4        
        # containment checks
        non_ele = self.do_infra.create_do(non_ele_id)
        self.created_pids.append(non_ele.identifier)
        ele_set = self.do_infra.lookup_pid(id_set)
        for e in id_ele:
            assert ele_set.contains_do(self.do_infra.lookup_pid(e))
        assert ele_set.contains_do(self.do_infra.lookup_pid(non_ele_id)) == False
        # test 'delete from set'-operation
        ele_set.remove_do(self.do_infra.lookup_pid(id_ele[0]))
        num_subele = 0
        for sele in ele_set.iter_set_elements():
            id_ele.index(sele.identifier)
            num_subele += 1
        assert num_subele == 3
        assert len(self.do_infra.lookup_pid(id_ele[0]).get_parent_pids(ele_set.CHARACTERISTIC_SEGMENT_NUMBER)) == 0
        assert ele_set.num_set_elements() == 3
        # test prevention of property overwrite
        try:
            ele_set.set_property_value(BASE_INDEX_HASHMAP_SIZE + ele_set.CHARACTERISTIC_SEGMENT_NUMBER, "this_should_not_work", "value")
            self.fail("Successful overwrite of hashmap size through a property!")
        except PropertyNameMismatchError:
            pass
        else:
            raise
        
        
    def test_lists(self):
        id_listele = [self.prefix+"listele1", self.prefix+"listele2", self.prefix+"listele3"]
        listele = []
        # create elements
        for i in range(len(id_listele)):
            newele = self.do_infra.create_do(id_listele[i])
            listele.append(newele)
            id_listele[i] = newele.identifier
            self.created_pids.append(newele.identifier)
        # test array
        id_array = self.prefix+"array"
        do_array = self.do_infra.create_do(id_array, DigitalObjectArray)
        self.created_pids.append(do_array.identifier)
        self.list_basic(do_array, id_listele, listele)
        # test linked list
        id_llist = self.prefix+"linkedlist"
        do_llist = self.do_infra.create_do(id_llist, DigitalObjectLinkedList)
        self.created_pids.append(do_llist.identifier)
        self.list_basic(do_llist, id_listele, listele)
        self.list_linked(do_llist, id_listele, listele)
        
    def list_basic(self, do_list, id_listele, listele):
        assert do_list != None
        # add array elements
        for e in listele:
            do_list.append_do(e)
        # re-load array
        do_list = self.do_infra.lookup_pid(do_list.identifier)
        assert do_list is not None
        assert do_list.num_elements() == len(listele)
        # verify array elements
        for i in range(len(listele)):
            assert do_list.contains(id_listele[i])
            dobj = do_list.get_do(i)
            assert dobj.identifier == id_listele[i]
        # check index function
        for i in range(len(id_listele)):
            dobj = self.do_infra.lookup_pid(id_listele[i])
            assert do_list.index_of(dobj) == i
        # remove middle element
        do_list.remove_do(1)
        assert do_list.num_elements() == 2
        assert do_list.get_do(0).identifier == id_listele[0]
        assert do_list.get_do(1).identifier == id_listele[2]
        assert do_list.contains(id_listele[1]) == False
        # re-insert at beginning
        do_list.insert_do(listele[1], 0)
        assert do_list.num_elements() == 3
        assert do_list.get_do(0).identifier == id_listele[1]
        assert do_list.get_do(1).identifier == id_listele[0]
        assert do_list.get_do(2).identifier == id_listele[2]
        # insert same element twice
        do_list.insert_do(listele[0], 0)
        do_list.insert_do(listele[0], 3)
        assert do_list.num_elements() == 5
        assert do_list.get_do(0).identifier == id_listele[0]
        assert do_list.get_do(1).identifier == id_listele[1]
        assert do_list.get_do(2).identifier == id_listele[0]
        assert do_list.get_do(3).identifier == id_listele[0]
        assert do_list.get_do(4).identifier == id_listele[2]
        # check parents
        for i in range(len(listele)):
            assert listele[i].get_parent_pids(do_list.CHARACTERISTIC_SEGMENT_NUMBER) == set([do_list.identifier]) 
        # remove all elements
        while do_list.num_elements() > 0:
            do_list.remove_do(0)
        assert do_list.num_elements() == 0
        try:
            do_list.get_do(0)
            assert False
        except IndexError:
            # all fine
            pass
        except:
            raise 
                            
    def list_linked(self, do_list, id_listele, listele):
        # do_list is empty
        assert do_list.first_element() == (None, None)
        assert do_list.last_element() == (None, None)
        # add all entries
        for ele in listele:
            do_list.append_do(ele)
        # add some duplicates
        do_list.append_do(listele[0])
        do_list.append_do(listele[2])
        do_list.append_do(listele[1])
        do_list.append_do(listele[1])
        do_list.append_do(listele[1])
        # re-load
        do_list = self.do_infra.lookup_pid(do_list.identifier)
        assert do_list is not None
        assert do_list.num_elements() == 8
        assert do_list.first_element()[0].identifier == id_listele[0]
        assert do_list.last_element()[0].identifier == id_listele[1]
        # test forward iteration
        e, occ = do_list.first_element()
        i = 0
        while e:
            assert e.identifier == do_list.get_do(i).identifier
            i += 1
            e, occ = do_list.next_element(e, occ)
        assert i == do_list.num_elements()
Ejemplo n.º 4
0
class TestDOInfrastructure(unittest.TestCase):
    def setUp(self):
        self.do_infra = InMemoryInfrastructure()
        self.do_infra.set_random_seed(12345)
        self.logger = logging.getLogger(__name__)
        self.random = Random(43210)
        self.created_pids = []
        self.prefix = TESTING_CONFIG_DEFAULTS["handle-prefix"] + "/"

    def tearDown(self):
        pass

    def __check_dobj3_references(self, dobj3, dobj1, dobj2):
        i = 0
        iter3 = dobj3.iter_reference_keys()
        for k in iter3:
            assert k == "successor"
            i += 1
        assert i == 1
        assert dobj3.get_references("notexisting") == []
        succ = dobj3.get_references("successor")
        assert len(succ) == 2
        assert succ[0].identifier == dobj1.identifier
        assert succ[1].identifier == dobj2.identifier

    def test_do_values(self):
        # values
        pid = self.prefix + "test_do_values"
        resloc = "http://www.example.com/1"
        restype = "MY_TEST_TYPE"
        pid2 = self.prefix + "test_do_values_2"
        pid3 = self.prefix + "test_do_values_3"
        # create DO
        dobj = self.do_infra.create_do(pid)
        self.created_pids.append(pid)
        assert dobj != None
        dobj.resource_location = resloc
        assert dobj.resource_location == resloc
        dobj._resource_type = restype
        assert dobj._resource_type == restype
        # look up and assert
        dobj2 = self.do_infra.lookup_pid(pid)
        assert dobj2 != None
        assert dobj2.resource_location == resloc
        assert dobj2._resource_type == restype
        # create a second DO
        dobj2 = self.do_infra.create_do(pid2)
        self.created_pids.append(pid2)
        assert dobj2 != None
        # create a third DO
        dobj3 = self.do_infra.create_do(pid3)
        self.created_pids.append(pid3)
        assert dobj3 != None
        dobj3.add_do_reference("successor", dobj)
        dobj3.add_do_reference("successor", dobj2)
        dobj2.add_do_reference("predecessor", dobj3)
        dobj.add_do_reference("predecessor", dobj3)
        dobj.set_property_value(20, "myproperty20", 1)
        dobj.set_property_value(21, "myproperty21", "abc")
        # check references
        self.__check_dobj3_references(dobj3, dobj, dobj2)
        # retrieve dobj3 from infra and check references
        dobj3 = self.do_infra.lookup_pid(pid3)
        self.__check_dobj3_references(dobj3, dobj, dobj2)
        # check properties
        dobj = self.do_infra.lookup_pid(pid)
        assert dobj.is_property_assigned(20) == True
        assert dobj.is_property_assigned(21) == True
        assert dobj.is_property_assigned(22) == False
        assert dobj.get_property_value(20) == ("myproperty20", "1")
        assert dobj.get_property_value(21) == ("myproperty21", "abc")
        dobj.set_property_value(20, "myproperty20", "2")
        assert dobj.get_property_value(20) == ("myproperty20", "2")
        dobj = self.do_infra.lookup_pid(pid)
        assert dobj.get_property_value(20) == ("myproperty20", "2")
        # test prevention of property overwrite
        try:
            dobj.set_property_value(20, "this_should_not_work", "value")
            self.fail(
                "Successful overwrite of existing property with different name!"
            )
        except PropertyNameMismatchError:
            pass
        else:
            raise
        # delete and check for removal
        self.do_infra.delete_do(pid)
        dobj = self.do_infra.lookup_pid(pid)
        assert dobj == None

    def test_infra_operations(self):
        dobj = self.do_infra.lookup_pid(self.prefix + "does-not-exist")
        assert dobj == None
        # duplication attempts
        dobj = self.do_infra.create_do(self.prefix + "duplicate")
        self.created_pids.append(self.prefix + "duplicate")
        assert dobj != None
        try:
            dobj2 = self.do_infra.create_do(self.prefix + "duplicate")
            self.fail(
                "Creation attempt of object with duplicate PID successful!")
        except PIDAlreadyExistsError:
            pass
        else:
            self.fail(
                "Creation attempt of object with duplicate PID successful/compromised!"
            )

    def test_random_pid_allocation(self):
        for x in range(0, 10):
            dobj = self.do_infra.create_do()
            self.created_pids.append(dobj.identifier)
            assert dobj != None
            self.logger.info(dobj.identifier)

    def test_aliases(self):
        resloc = "http://www.example.com/alias_original"
        id_orig = self.prefix + "alias_original"
        id_alias1 = self.prefix + "alias1"
        id_alias2 = self.prefix + "alias2"
        dobj1 = self.do_infra.create_do(id_orig)
        id_orig = dobj1.identifier
        self.created_pids.append(id_orig)
        assert dobj1 != None
        dobj1.resource_location = resloc
        assert dobj1.resource_location == resloc
        assert dobj1.get_alias_identifiers() == []
        # alias 1 -> orig
        id_alias1 = self.do_infra.create_alias(dobj1, id_alias1)
        assert id_alias1 != None
        self.created_pids.append(id_alias1)
        assert self.do_infra.is_alias(id_alias1) == True
        # alias 2 -> alias 1 -> orig
        id_alias2 = self.do_infra.create_alias(id_alias1, id_alias2)
        assert id_alias2 != None
        self.created_pids.append(id_alias2)
        assert self.do_infra.is_alias(id_alias2) == True
        # check aliases
        assert self.do_infra.is_alias(id_orig) == False
        dobj = self.do_infra.lookup_pid(id_alias2)
        assert dobj != None
        assert dobj.identifier == id_orig
        assert dobj.resource_location == resloc
        assert dobj.get_alias_identifiers() == [id_alias2, id_alias1]
        dobj = self.do_infra.lookup_pid(id_alias1)
        assert dobj != None
        assert dobj.identifier == id_orig
        assert dobj.resource_location == resloc
        assert dobj.get_alias_identifiers() == [id_alias1]
        # look up directly, check if no aliases noted
        dobj = self.do_infra.lookup_pid(id_orig)
        assert dobj.get_alias_identifiers() == []

        # delete alias
        assert self.do_infra.delete_alias(id_alias1) == True
        assert self.do_infra.lookup_pid(id_alias1) == None

        # self.do_infra.lookup_pid(id_alias2) -> broken chain, check for exception
        try:
            self.do_infra.lookup_pid(id_alias2)
            self.fail(
                "Could resolve broken alias chain without Exception being thrown!"
            )
        except PIDAliasBrokenError:
            pass
        else:
            raise

    def test_sets(self):
        # create a set
        id_ele = [
            self.prefix + "setele1", self.prefix + "setele2",
            self.prefix + "setele3"
        ]
        id_set = self.prefix + "set"
        non_ele_id = self.prefix + "some-non-ele"
        ele = []
        for i in range(len(id_ele)):
            newele = self.do_infra.create_do(id_ele[i])
            ele.append(newele)
            id_ele[i] = newele.identifier
            self.created_pids.append(newele.identifier)
        ele_set = self.do_infra.create_do(id_set, DigitalObjectSet)
        assert ele_set != None
        self.created_pids.append(ele_set.identifier)
        id_set = ele_set.identifier
        for e in ele:
            ele_set.add_do(e)
        # check if this is a set
        ele_set = self.do_infra.lookup_pid(id_set)
        assert isinstance(ele_set, DigitalObjectSet)
        # check if all subelements are present
        num_subele = 0
        for sele in ele_set.iter_set_elements():
            id_ele.index(sele.identifier)
            num_subele += 1
        assert num_subele == 3
        assert ele_set.num_set_elements() == 3
        # now extend and check again
        ele_set = self.do_infra.lookup_pid(id_set)
        id_ele += [self.prefix + "setele4"]
        newele = self.do_infra.create_do(id_ele[3])
        id_ele[3] = newele.identifier
        self.created_pids.append(newele.identifier)
        ele_set.add_do(newele)
        # check if all subelements are present
        ele_set = self.do_infra.lookup_pid(id_set)
        num_subele = 0
        for sele in ele_set.iter_set_elements():
            id_ele.index(sele.identifier)
            num_subele += 1
            assert sele.get_parent_pids(
                ele_set.CHARACTERISTIC_SEGMENT_NUMBER) == set([id_set])
        assert num_subele == 4
        assert ele_set.num_set_elements() == 4
        # containment checks
        non_ele = self.do_infra.create_do(non_ele_id)
        self.created_pids.append(non_ele.identifier)
        ele_set = self.do_infra.lookup_pid(id_set)
        for e in id_ele:
            assert ele_set.contains_do(self.do_infra.lookup_pid(e))
        assert ele_set.contains_do(
            self.do_infra.lookup_pid(non_ele_id)) == False
        # test 'delete from set'-operation
        ele_set.remove_do(self.do_infra.lookup_pid(id_ele[0]))
        num_subele = 0
        for sele in ele_set.iter_set_elements():
            id_ele.index(sele.identifier)
            num_subele += 1
        assert num_subele == 3
        assert len(
            self.do_infra.lookup_pid(id_ele[0]).get_parent_pids(
                ele_set.CHARACTERISTIC_SEGMENT_NUMBER)) == 0
        assert ele_set.num_set_elements() == 3
        # test prevention of property overwrite
        try:
            ele_set.set_property_value(
                BASE_INDEX_HASHMAP_SIZE +
                ele_set.CHARACTERISTIC_SEGMENT_NUMBER, "this_should_not_work",
                "value")
            self.fail(
                "Successful overwrite of hashmap size through a property!")
        except PropertyNameMismatchError:
            pass
        else:
            raise

    def test_lists(self):
        id_listele = [
            self.prefix + "listele1", self.prefix + "listele2",
            self.prefix + "listele3"
        ]
        listele = []
        # create elements
        for i in range(len(id_listele)):
            newele = self.do_infra.create_do(id_listele[i])
            listele.append(newele)
            id_listele[i] = newele.identifier
            self.created_pids.append(newele.identifier)
        # test array
        id_array = self.prefix + "array"
        do_array = self.do_infra.create_do(id_array, DigitalObjectArray)
        self.created_pids.append(do_array.identifier)
        self.list_basic(do_array, id_listele, listele)
        # test linked list
        id_llist = self.prefix + "linkedlist"
        do_llist = self.do_infra.create_do(id_llist, DigitalObjectLinkedList)
        self.created_pids.append(do_llist.identifier)
        self.list_basic(do_llist, id_listele, listele)
        self.list_linked(do_llist, id_listele, listele)

    def list_basic(self, do_list, id_listele, listele):
        assert do_list != None
        # add array elements
        for e in listele:
            do_list.append_do(e)
        # re-load array
        do_list = self.do_infra.lookup_pid(do_list.identifier)
        assert do_list is not None
        assert do_list.num_elements() == len(listele)
        # verify array elements
        for i in range(len(listele)):
            assert do_list.contains(id_listele[i])
            dobj = do_list.get_do(i)
            assert dobj.identifier == id_listele[i]
        # check index function
        for i in range(len(id_listele)):
            dobj = self.do_infra.lookup_pid(id_listele[i])
            assert do_list.index_of(dobj) == i
        # remove middle element
        do_list.remove_do(1)
        assert do_list.num_elements() == 2
        assert do_list.get_do(0).identifier == id_listele[0]
        assert do_list.get_do(1).identifier == id_listele[2]
        assert do_list.contains(id_listele[1]) == False
        # re-insert at beginning
        do_list.insert_do(listele[1], 0)
        assert do_list.num_elements() == 3
        assert do_list.get_do(0).identifier == id_listele[1]
        assert do_list.get_do(1).identifier == id_listele[0]
        assert do_list.get_do(2).identifier == id_listele[2]
        # insert same element twice
        do_list.insert_do(listele[0], 0)
        do_list.insert_do(listele[0], 3)
        assert do_list.num_elements() == 5
        assert do_list.get_do(0).identifier == id_listele[0]
        assert do_list.get_do(1).identifier == id_listele[1]
        assert do_list.get_do(2).identifier == id_listele[0]
        assert do_list.get_do(3).identifier == id_listele[0]
        assert do_list.get_do(4).identifier == id_listele[2]
        # check parents
        for i in range(len(listele)):
            assert listele[i].get_parent_pids(
                do_list.CHARACTERISTIC_SEGMENT_NUMBER) == set(
                    [do_list.identifier])
        # remove all elements
        while do_list.num_elements() > 0:
            do_list.remove_do(0)
        assert do_list.num_elements() == 0
        try:
            do_list.get_do(0)
            assert False
        except IndexError:
            # all fine
            pass
        except:
            raise

    def list_linked(self, do_list, id_listele, listele):
        # do_list is empty
        assert do_list.first_element() == (None, None)
        assert do_list.last_element() == (None, None)
        # add all entries
        for ele in listele:
            do_list.append_do(ele)
        # add some duplicates
        do_list.append_do(listele[0])
        do_list.append_do(listele[2])
        do_list.append_do(listele[1])
        do_list.append_do(listele[1])
        do_list.append_do(listele[1])
        # re-load
        do_list = self.do_infra.lookup_pid(do_list.identifier)
        assert do_list is not None
        assert do_list.num_elements() == 8
        assert do_list.first_element()[0].identifier == id_listele[0]
        assert do_list.last_element()[0].identifier == id_listele[1]
        # test forward iteration
        e, occ = do_list.first_element()
        i = 0
        while e:
            assert e.identifier == do_list.get_do(i).identifier
            i += 1
            e, occ = do_list.next_element(e, occ)
        assert i == do_list.num_elements()