def answer_query(self, query):
"""Selects the top N geographically closest SliverTools to the client.
Finds the top N closest SliverTools to the client and returns them.
Note that N is currently hardcoded to 4.
Args:
query: A LookupQuery instance.
Returns:
A list of SliverTool entities on success, or None if there is no
SliverTool available that matches the query.
"""
# Return no more than MAX_RESULTS SliverTools in the result.
MAX_RESULTS = 4
candidates = self.get_candidates(query)
if len(candidates) == 0:
logging.error('No results found for %s.', query.tool_id)
return None
if (query.latitude is None) or (query.longitude is None):
logging.warning('No latide/longitude, return a random sliver tool.')
return [random.choice(candidates)]
min_distance = float('+inf')
sliver_tool_bins = {}
sliver_tools = []
distances = {}
# Combine the candidates into bins by site.
for sliver_tool in candidates:
if not sliver_tool_bins.has_key(sliver_tool.site_id):
sliver_tool_bins[sliver_tool.site_id] = [sliver_tool]
else:
sliver_tool_bins[sliver_tool.site_id].append(sliver_tool)
for site_id in sliver_tool_bins:
# Take a random sliver from the list.
sliver_tool = random.choice(sliver_tool_bins[site_id])
# Check if we already computed the distance of this site.
if distances.has_key(sliver_tool.site_id):
current_distance = distances[sliver_tool.site_id]
else:
current_distance = distance.distance(
query.latitude,
query.longitude,
sliver_tool.latitude,
sliver_tool.longitude)
distances[sliver_tool.site_id] = current_distance
sliver_tools.append(\
sliver_tool_distance.SliverToolDistance(sliver_tool, \
current_distance))
sliver_tools_sorted = sorted(sliver_tools, key=attrgetter('distance'))
final_results = []
for std in sliver_tools_sorted:
final_results.append(std.sliver_tool)
return final_results[:MAX_RESULTS]
def _add_candidate(self, query, candidate, site_distances, tool_distances):
if candidate.site_id not in site_distances:
site_distances[candidate.site_id] = distance.distance(
query.latitude, query.longitude, candidate.latitude,
candidate.longitude)
tool_distances.append({
'distance': site_distances[candidate.site_id],
'tool': candidate
})
def _add_candidate(self, query, candidate, site_distances, tool_distances):
if candidate.site_id not in site_distances:
site_distances[candidate.site_id] = distance.distance(
query.latitude, query.longitude, candidate.latitude,
candidate.longitude)
tool_distances.append({
'distance': site_distances[candidate.site_id],
'tool': candidate
})
def testInvalidInputs(self):
import math
from numbers import Number
dist = 0
try:
dist = distance.distance(-700, 1000, 999, -5454)
except Exception:
self.fail("distance threw an exception on invalid entry")
self.assertTrue(isinstance(dist, Number))
self.assertFalse(math.isnan(dist))
def testInvalidInputs(self):
import math
from numbers import Number
dist = 0
try:
dist = distance.distance(-700, 1000, 999, -5454)
except Exception:
self.fail("distance threw an exception on invalid entry")
self.assertTrue(isinstance(dist, Number))
self.assertFalse(math.isnan(dist))
def answer_query(self, query):
"""Selects the geographically closest SliverTool.
Args:
query: A LookupQuery instance.
Returns:
A SliverTool entity in case of success, or None if there is no
SliverTool available that matches the query.
"""
candidates = self.get_candidates(query)
if len(candidates) == 0:
logging.error('No results found for %s.', query.tool_id)
return None
if (query.latitude is None) or (query.longitude is None):
logging.warning('No latide/longitude, return a random sliver tool.')
return [random.choice(candidates)]
min_distance = float('+inf')
closest_sliver_tools = []
distances = {}
# Compute for each SliverTool the distance and add keep in the
# 'closest_sliver_tools' list only the SliverTools whose distance is
# less or equal than the current minimum.
for sliver_tool in candidates:
# Check if we already computed the distance of this site.
if distances.has_key(sliver_tool.site_id):
current_distance = distances[sliver_tool.site_id]
else:
current_distance = distance.distance(
query.latitude,
query.longitude,
sliver_tool.latitude,
sliver_tool.longitude)
distances[sliver_tool.site_id] = current_distance
# Update the min distance and add the SliverTool to the list.
if current_distance < min_distance:
min_distance = current_distance
closest_sliver_tools = [sliver_tool]
elif current_distance == min_distance:
closest_sliver_tools.append(sliver_tool)
# Add the min_distance to the query so it can be logged later. Round to
# the next highest kilometre radius to remove precision.
query.distance = math.ceil(min_distance)
# Choose randomly among candidates with the same, minimum distance.
return [random.choice(closest_sliver_tools)]
def log_location(self, query, sliver_tools):
"""Logs the client Country and compares Maxmind to AppEngine distance"""
if query.tool_id != 'ndt_ssl':
# We only want to look at ndt_ssl clients for now.
return
if type(sliver_tools) != list or not sliver_tools:
logging.info('unexpected sliver_tools type: %s', len(sliver_tools))
return
if query._geolocation_type != constants.GEOLOCATION_APP_ENGINE:
# We cannot compare AppEngine location to Maxmind in this case.
return
t0 = datetime.datetime.now()
# Log client country to display geomap summaries of client origins.
logging.info('[client.country],%s', query.country)
# Log only the first (closest) site.
sliver_tool = sliver_tools[0]
# Lookup the maxmind information, if it doesn't exist, then just
# return.
if not query._set_maxmind_geolocation(query.ip_address, None, None):
return
# Calculate the difference between the two systems.
difference = distance.distance(query._gae_latitude,
query._gae_longitude,
query._maxmind_latitude,
query._maxmind_longitude)
logging.info(
('[server.distance],{scheme},{tool_id},{site_id},{country},'
'{city},{same_country},{difference}').format(
scheme=self.request.scheme,
tool_id=query.tool_id,
site_id=sliver_tool.site_id,
country=sliver_tool.country,
city=sliver_tool.city,
same_country=(query._gae_country == query._maxmind_country),
difference=difference))
t1 = datetime.datetime.now()
logging.info('[log_location.delay],{delay}'.format(
delay=str((t1 - t0).total_seconds())))
def log_location(self, query, sliver_tools):
"""Logs the client Country and compares Maxmind to AppEngine distance"""
if query.tool_id != 'ndt_ssl':
# We only want to look at ndt_ssl clients for now.
return
if type(sliver_tools) != list or not sliver_tools:
logging.info('unexpected sliver_tools type: %s', len(sliver_tools))
return
if query._geolocation_type != constants.GEOLOCATION_APP_ENGINE:
# We cannot compare AppEngine location to Maxmind in this case.
return
t0 = datetime.datetime.now()
# Log client country to display geomap summaries of client origins.
logging.info('[client.country],%s', query.country)
# Log only the first (closest) site.
sliver_tool = sliver_tools[0]
# Lookup the maxmind information.
query._set_maxmind_geolocation(query.ip_address, None, None)
# Calculate the difference between the two systems.
difference = distance.distance(
query._gae_latitude, query._gae_longitude, query._maxmind_latitude,
query._maxmind_longitude)
logging.info((
'[server.distance],{scheme},{tool_id},{site_id},{country},'
'{city},{same_country},{difference}').format(
scheme=self.request.scheme,
tool_id=query.tool_id,
site_id=sliver_tool.site_id,
country=sliver_tool.country,
city=sliver_tool.city,
same_country=(query._gae_country == query._maxmind_country),
difference=difference))
t1 = datetime.datetime.now()
logging.info('[log_location.delay],{delay}'.format(delay=str((
t1 - t0).total_seconds())))
def _get_closest_n_candidates(self, query, max_results):
"""Selects the top N geographically closest SliverTools to the client.
Args:
query: A LookupQuery instance.
max_results: The maximum number of candidates to return.
Returns:
A list of SliverTool entities on success, or None if there is no
SliverTool available that matches the query.
"""
candidates = self._get_matching_candidates(query)
if not candidates:
return None
if (query.latitude is None) or (query.longitude is None):
logging.warning(
'No latitude/longitude, return random sliver tool(s).')
return random.sample(candidates, min(len(candidates), max_results))
# Pre-shuffle the candidates to randomize the order of equidistant
# results.
random.shuffle(candidates)
site_distances = {}
tool_distances = []
for candidate in candidates:
if candidate.site_id not in site_distances:
site_distances[candidate.site_id] = distance.distance(
query.latitude, query.longitude, candidate.latitude,
candidate.longitude)
tool_distances.append({
'distance': site_distances[candidate.site_id],
'tool': candidate
})
# Sort the tools by distance
tool_distances.sort(key=lambda t: t['distance'])
# Create a new list of just the sorted SliverTool objects.
sorted_tools = [t['tool'] for t in tool_distances]
return sorted_tools[:max_results]
def _get_closest_n_candidates(self, query, max_results):
"""Selects the top N geographically closest SliverTools to the client.
Args:
query: A LookupQuery instance.
max_results: The maximum number of candidates to return.
Returns:
A list of SliverTool entities on success, or None if there is no
SliverTool available that matches the query.
"""
candidates = self._get_matching_candidates(query)
if not candidates:
return None
if (query.latitude is None) or (query.longitude is None):
logging.warning(
'No latitude/longitude, return random sliver tool(s).')
return random.sample(candidates, min(len(candidates), max_results))
# Pre-shuffle the candidates to randomize the order of equidistant
# results.
random.shuffle(candidates)
site_distances = {}
tool_distances = []
for candidate in candidates:
if candidate.site_id not in site_distances:
site_distances[candidate.site_id] = distance.distance(
query.latitude, query.longitude, candidate.latitude,
candidate.longitude)
tool_distances.append({
'distance': site_distances[candidate.site_id],
'tool': candidate
})
# Sort the tools by distance
tool_distances.sort(key=lambda t: t['distance'])
# Create a new list of just the sorted SliverTool objects.
sorted_tools = [t['tool'] for t in tool_distances]
return sorted_tools[:max_results]
def testValidSmallDistance(self):
dist = distance.distance(0, 0, 10, 10)
self.assertEqual(1568.5205567985761, dist)
def testValidLargeDistance(self):
dist = distance.distance(20, 20, 100, 100)
self.assertEqual(8009.5721050828461, dist)
def testValidSmallDistance(self):
dist = distance.distance(0, 0, 10, 10)
self.assertEqual(1568.5205567985761, dist)
def testValidLargeDistance(self):
dist = distance.distance(20, 20, 100, 100)
self.assertEqual(8009.5721050828461, dist)
