def test_get_needed_absolute_time_range(m_dt):
m_dt.now.return_value = datetime.datetime.fromtimestamp(1455390419)
# Magic: http://www.voidspace.org.uk/python/mock/examples.html#partial-mocking
m_dt.side_effect = lambda *args, **kw: datetime.datetime(*args, **kw)
example = {'start_absolute': 1234567890000}
s, e = get_needed_absolute_time_range(example)
assert e is None
assert s == datetime.datetime.fromtimestamp(1234567890)
example = {'start_absolute': 1234567890000, 'end_absolute': 1234657890000}
s, e = get_needed_absolute_time_range(example)
assert s == datetime.datetime.fromtimestamp(1234567890)
assert e == datetime.datetime.fromtimestamp(1234657890)
example = {
'start_relative': {
'value': '1',
'unit': 'hours'
},
'end_relative': {
'value': '1',
'unit': 'minutes'
}
}
s, e = get_needed_absolute_time_range(example)
assert s == datetime.datetime.now() - datetime.timedelta(hours=1)
assert e == datetime.datetime.now() - datetime.timedelta(minutes=1)
def test_get_needed_absolute_time_range(m_dt):
m_dt.now.return_value = datetime.datetime.fromtimestamp(1455390419)
# Magic: http://www.voidspace.org.uk/python/mock/examples.html#partial-mocking
m_dt.side_effect = lambda *args, **kw: datetime.datetime(*args, **kw)
example = {'start_absolute': 1234567890000}
s, e = get_needed_absolute_time_range(example)
assert e is None
assert s == datetime.datetime.fromtimestamp(1234567890)
example = {'start_absolute': 1234567890000, 'end_absolute': 1234657890000}
s, e = get_needed_absolute_time_range(example)
assert s == datetime.datetime.fromtimestamp(1234567890)
assert e == datetime.datetime.fromtimestamp(1234657890)
example = {
'start_relative': {'value': '1', 'unit': 'hours'},
'end_relative': {'value': '1', 'unit': 'minutes'}
}
s, e = get_needed_absolute_time_range(example)
assert s == datetime.datetime.now() - datetime.timedelta(hours=1)
assert e == datetime.datetime.now() - datetime.timedelta(minutes=1)
def process_cache_hit(config, redis_client, kquery, kairos_time_range):
""" KQuery found in cache. Decide whether to return solely cached data or to update cached data.
If cached data should be updated, figure out how to do it.
:param config: 'tscached' level from config file.
:param redis_client: redis.StrictRedis
:param kquery: kquery.KQuery object
:param kairos_time_range: dict, time range straight from the HTTP request payload
:return: 2-tuple: (dict: kquery resp to be added to HTTP resp, str: type of cache operation)
:raise: utils.BackendQueryFailure, if a Kairos lookup failed.
"""
# this relies on KQuery.get_cached() having a side effect. it must be called before this function.
kq_result = kquery.cached_data
try:
start_cache = datetime.datetime.fromtimestamp(
float(kq_result['earliest_data']))
end_cache = datetime.datetime.fromtimestamp(
float(kq_result['last_add_data']))
except: # some sort of cache malformation or error, doesn't matter what.
start_cache = None
end_cache = None
start_request, end_request = get_needed_absolute_time_range(
kairos_time_range)
staleness_threshold = config['data']['staleness_threshold']
range_needed = get_range_needed(start_request, end_request, start_cache,
end_cache, staleness_threshold,
kquery.window_size)
if not range_needed: # hot cache
return hot(redis_client, kquery, kairos_time_range), 'hot'
else:
merge_method = range_needed[2]
if merge_method == FETCH_ALL: # warm, but data doesn't support merging.
logging.info('Odd COLD scenario: data exists.')
return cold(config, redis_client, kquery,
kairos_time_range), 'cold_overwrite'
elif merge_method in [FETCH_BEFORE,
FETCH_AFTER]: # warm, merging supported.
mode = 'warm_' + merge_method
return warm(config, redis_client, kquery, kairos_time_range,
range_needed), mode
else:
raise BackendQueryFailure(
"Received unsupported range_needed value: %s" %
range_needed[2])
def process_cache_hit(config, redis_client, kquery, kairos_time_range):
""" KQuery found in cache. Decide whether to return solely cached data or to update cached data.
If cached data should be updated, figure out how to do it.
:param config: 'tscached' level from config file.
:param redis_client: redis.StrictRedis
:param kquery: kquery.KQuery object
:param kairos_time_range: dict, time range straight from the HTTP request payload
:return: 2-tuple: (dict: kquery resp to be added to HTTP resp, str: type of cache operation)
:raise: utils.BackendQueryFailure, if a Kairos lookup failed.
"""
# this relies on KQuery.get_cached() having a side effect. it must be called before this function.
kq_result = kquery.cached_data
try:
start_cache = datetime.datetime.fromtimestamp(float(kq_result['earliest_data']))
end_cache = datetime.datetime.fromtimestamp(float(kq_result['last_add_data']))
except: # some sort of cache malformation or error, doesn't matter what.
start_cache = None
end_cache = None
start_request, end_request = get_needed_absolute_time_range(kairos_time_range)
staleness_threshold = config['data']['staleness_threshold']
range_needed = get_range_needed(start_request, end_request, start_cache,
end_cache, staleness_threshold, kquery.window_size)
if not range_needed: # hot cache
return hot(redis_client, kquery, kairos_time_range), 'hot'
else:
merge_method = range_needed[2]
if merge_method == FETCH_ALL: # warm, but data doesn't support merging.
logging.info('Odd COLD scenario: data exists.')
return cold(config, redis_client, kquery, kairos_time_range), 'cold_overwrite'
elif merge_method in [FETCH_BEFORE, FETCH_AFTER]: # warm, merging supported.
mode = 'warm_' + merge_method
return warm(config, redis_client, kquery, kairos_time_range, range_needed), mode
else:
raise BackendQueryFailure("Received unsupported range_needed value: %s" % range_needed[2])