class Searcher(object):
def __init__(self, aerospike_connector):
self._search_index = SearchIndex(aerospike_connector)
def search(self, params):
if params.features == None or len(params.features) == 0:
signs = self._search_nearest(params)
else:
signs = self._search_by_fea(params)
return self._make_result(params, signs)
def _records_processor(self, params, heap):
def _impl(record):
entry = SearchEntry()
entry.sign_id = int(record['sign_id'])
entry.rank = record.get('rank')
# Min rank threshold
if entry.rank != None and entry.rank < params.min_rank:
return
# Legacy
if entry.rank == None:
entry.rank = 0
location = record['location'].unwrap().get('coordinates')
entry.distance = geo.distance(params.latitude, params.longitude, location[1], location[0])
heap.push(entry)
return _impl
def _search_nearest(self, params):
heap = SearchResultsHeap(params.max_n, lambda entry: -entry.distance)
# Retrieve records
self._search_index.search_nearest(params.user_id, \
params.latitude, \
params.longitude, \
params.radius, \
self._records_processor(params, heap))
# Resort
signs = heap.results.values()
signs.sort(key=lambda entry: entry.distance)
return signs
def _search_by_fea(self, params):
heap = SearchResultsHeap(params.max_n, lambda entry: entry.rank)
# Normailize features vector
qsum = 0
for fea in params.features:
qsum = qsum + fea * fea
qsum = math.sqrt(qsum)
for i in range(len(params.features)):
params.features[i] = params.features[i] / qsum
# Retrieve records
self._search_index.search_by_fea(params.user_id, \
params.latitude, \
params.longitude, \
params.radius, \
params.features, \
self._records_processor(params, heap))
# Resort
signs = heap.results.values()
if params.sort_by == SearchParams.SORT_BY_RANK or \
params.sort_by == SearchParams.SORT_BY_UNKNOWN:
signs.sort(key=lambda entry: entry.rank, reverse=True)
else:
signs.sort(key=lambda entry: entry.distance)
return signs
def _make_result(self, params, signs):
signs_list = list()
for sign in signs:
signs_list.append({
'sign_id': sign.sign_id,
'distance': sign.distance
})
debug = None
if params.debug:
weights = list()
for sign in signs:
weights.append({
'sign_id': sign.sign_id,
'weight': sign.rank
})
debug = {
'weights': weights
}
return signs_list, debug
