class JournalNavigator(object):
"""Iterates over journal JSON."""
def __init__(self):
"""Constructor"""
self.__input_stream = None
self.__decoder = json.JSONDecoder()
def __iter__(self):
"""Iterate over the contents of the journal."""
self.__check_open()
return self
def open(self, path):
"""Open the journal to be able to iterate over its contents.
Args:
path: [string] The path to load the journal from.
"""
if self.__input_stream != None:
raise ValueError('Navigator is already open.')
self.__input_stream = RecordInputStream(open(path, 'r'))
def close(self):
"""Close the journal."""
self.__check_open()
self.__input_stream.close()
self.__input_stream = None
def next(self):
"""Return the next item in the journal.
Raises:
StopIteration when there are no more elements.
"""
self.__check_open()
json_str = self.__input_stream.next()
try:
return self.__decoder.decode(json_str)
except ValueError:
print 'Invalid json record:\n{0}'.format(json_str)
raise
def __check_open(self):
"""Verify that the navigator is open (and thus valid to iterate)."""
if self.__input_stream is None:
raise ValueError('Navigator is not open.')
def test_write_message_with_metadata(self):
"""Verify the journal messages contain the metadata we add."""
output = StringIO()
journal = TestJournal(output)
offset = len(output.getvalue())
journal.write_message('My message.', str='ABC', num=123)
metadata = {'str': 'ABC', 'num': 123}
message_json_text = self.expect_message_text(journal.clock,
'My message.', metadata)
input_stream = RecordInputStream(StringIO(output.getvalue()[offset:]))
decoder = json.JSONDecoder(encoding='ASCII')
expect_obj = decoder.decode(message_json_text)
got_obj = decoder.decode(input_stream.next())
self.assertItemsEqual(expect_obj, got_obj)
def test_write_message_with_metadata(self):
"""Verify the journal messages contain the metadata we add."""
output = StringIO()
journal = TestJournal(output)
offset = len(output.getvalue())
journal.write_message('My message.', str='ABC', num=123)
metadata = {'str': 'ABC', 'num': 123}
message_json_text = self.expect_message_text(
journal.clock, 'My message.', metadata)
input_stream = RecordInputStream(StringIO(output.getvalue()[offset:]))
decoder = json.JSONDecoder(encoding='ASCII')
expect_obj = decoder.decode(message_json_text)
got_obj = decoder.decode(input_stream.next())
self.assertItemsEqual(expect_obj, got_obj)
def test_context_logging(self):
offset = len(_journal_file.getvalue())
logger = JournalLogger('test_journal_logger')
logger.addHandler(JournalLogHandler(path=None))
citest_extra = {'foo':'bar'}
start_time = _journal_clock.last_time
JournalLogger.execute_in_context(
'The Test Context',
lambda: {logger.debug('Test Log Message')},
**citest_extra)
expect_sequence = [
{
'_title': 'The Test Context',
'_type': 'JournalContextControl',
'_timestamp': start_time + 1,
'_thread': thread.get_ident(),
'control': 'BEGIN',
'foo': 'bar',
},
{
'_value': 'Test Log Message',
'_type': 'JournalMessage',
'_level': logging.DEBUG,
'_timestamp': start_time + 2,
'_thread': thread.get_ident(),
'format': 'pre'
},
{
'_type': 'JournalContextControl',
'_timestamp': start_time + 3,
'_thread': thread.get_ident(),
'control': 'END'
}
]
entry_str = _journal_file.getvalue()[offset:]
input_stream = RecordInputStream(StringIO(entry_str))
for expect in expect_sequence:
json_str = input_stream.next()
json_dict = json_module.JSONDecoder(encoding='utf-8').decode(json_str)
self.assertEqual(expect, json_dict)
def test_store(self):
"""Verify we store objects as JSON snapshots."""
data = TestData('NAME', 1234, TestDetails())
decoder = json.JSONDecoder(encoding='ASCII')
snapshot = JsonSnapshot()
snapshot.add_object(data)
time_function = lambda: 1.23
journal = Journal(time_function)
output = StringIO()
journal.open_with_file(output)
offset = len(output.getvalue())
journal.store(data)
contents = output.getvalue()
got_stream = RecordInputStream(StringIO(contents[offset:]))
got_json_str = got_stream.next()
got = decoder.decode(got_json_str)
json_object = snapshot.to_json_object()
json_object['_timestamp'] = time_function()
json_object['_thread'] = threading.current_thread().ident
self.assertItemsEqual(json_object, got)
def test_context_logging(self):
offset = len(_journal_file.getvalue())
logger = JournalLogger('test_journal_logger')
logger.addHandler(JournalLogHandler(path=None))
citest_extra = {'foo': 'bar'}
start_time = _journal_clock.last_time
JournalLogger.execute_in_context(
'The Test Context', lambda: {logger.debug('Test Log Message')},
**citest_extra)
expect_sequence = [{
'_title': 'The Test Context',
'_type': 'JournalContextControl',
'_timestamp': start_time + 1,
'_thread': thread.get_ident(),
'control': 'BEGIN',
'foo': 'bar',
}, {
'_value': 'Test Log Message',
'_type': 'JournalMessage',
'_level': logging.DEBUG,
'_timestamp': start_time + 2,
'_thread': thread.get_ident(),
'format': 'pre'
}, {
'_type': 'JournalContextControl',
'_timestamp': start_time + 3,
'_thread': thread.get_ident(),
'control': 'END'
}]
entry_str = _journal_file.getvalue()[offset:]
input_stream = RecordInputStream(StringIO(entry_str))
for expect in expect_sequence:
json_str = input_stream.next()
json_dict = json_module.JSONDecoder(
encoding='utf-8').decode(json_str)
self.assertEqual(expect, json_dict)
def test_store(self):
"""Verify we store objects as JSON snapshots."""
data = TestData('NAME', 1234, TestDetails())
decoder = json.JSONDecoder(encoding='ASCII')
snapshot = JsonSnapshot()
snapshot.add_object(data)
time_function = lambda: 1.23
journal = Journal(time_function)
output = StringIO()
journal.open_with_file(output)
offset = len(output.getvalue())
journal.store(data)
contents = output.getvalue()
got_stream = RecordInputStream(StringIO(contents[offset:]))
got_json_str = got_stream.next()
got = decoder.decode(got_json_str)
json_object = snapshot.to_json_object()
json_object['_timestamp'] = time_function()
json_object['_thread'] = threading.current_thread().ident
self.assertItemsEqual(json_object, got)
