Issue #25: Add geo.get_place_ids_in_radius.

app/constants.py

@@ -18,6 +18,7 @@ def _findTablePrefix():
 _venues = "venues"
 _events = "events"
 _searches = "searches"
+_locations = "locations"
 
 # number of seconds after a search in a given area that it should be cached.
 searchCacheExpiry = 60 * 60 * 20 # s
@@ -32,6 +33,7 @@ def _findTablePrefix():
 venuesTable = _tablePrefix + _venues
 eventsTable = _tablePrefix + _events
 searchesTable = _tablePrefix + _searches
+locationsTable = _tablePrefix + _venues + '/' + _locations
 
 statusTable = "api_availability"
 

app/geo.py

@@ -0,0 +1,39 @@
+"""Geo-related utility functions.
+
+TODO:
+- Should this be in a util folder?
+- Inefficient to have a firebase instance for every file?
+
+"""
+from app.constants import locationsTable
+from config import FIREBASE_CONFIG
+
+import app.geofire as geofire
+import pyrebase
+
+_firebase = pyrebase.initialize_app(FIREBASE_CONFIG)
+
+
+def get_place_ids_in_radius(center, radius_km, cached_locations_table=None):
+    """Returns all place_ids in the DB within a radius from the given center.
+    :param center: is (lat, lng)
+    :param cached_locations_table: a direct pull of the geofire `.../location/` table; use this to avoid downloading the table again.
+    :return: A set of place ids within the given radius.
+    """
+    if cached_locations_table is None:
+        location_table = _get_locations_table()
+    else:
+        location_table = cached_locations_table
+
+    out = set()
+    for place_id, vals in location_table.iteritems():
+        lat, lng = vals['l']
+        coord = (lat, lng)
+        if geofire.distance(center, coord) > radius_km:
+            continue
+        out.add(place_id)
+    return out
+
+
+def _get_locations_table():
+    return _firebase.database().child(locationsTable).get().val()