Further alert implementation #17

data/spot.py

@@ -1,3 +1,5 @@
+import copy
+import hashlib
 import json
 from dataclasses import dataclass
 from datetime import datetime
@@ -16,7 +18,7 @@ from core.utils import infer_mode_type_from_mode, infer_band_from_freq, infer_co
 @dataclass
 class Spot:
     # Unique identifier for the spot
-    id: int = None
+    id: str = None
     # Callsign of the operator that has been spotted
     dx_call: str = None
     # Callsign of the operator that has spotted them
@@ -207,8 +209,15 @@ class Spot:
         # is likely at home.
         self.location_good = self.location_source == "SPOT" or (self.location_source == "QRZ" and not "/" in self.dx_call)
 
-        # Always create an ID based on a hashcode
-        self.id = hash(str(self))
+        # Always create an ID based on a hash of every parameter *except* received_time. This is used as the index
+        # to a map, which as a byproduct avoids us having multiple duplicate copies of the object that are identical
+        # apart from that they were retrieved from the API at different times. Note that the simple Python hash()
+        # function includes a seed randomly generated at runtime; this is therefore not consistent between runs. But we
+        # use diskcache to store our data between runs, so we use SHA256 which does not include this random element.
+        self_copy = copy.deepcopy(self)
+        self_copy.received_time = 0
+        self_copy.received_time_iso = ""
+        self.id = hashlib.sha256(str(self_copy).encode("utf-8")).hexdigest()
 
     # JSON serialise
     def to_json(self):