From 71a429ebca6e2ab09b4806b7a4b5ec78fc86a5e2 Mon Sep 17 00:00:00 2001
From: Lloyd <lloyd@rightup.co.uk>
Date: Mon, 27 Oct 2025 12:45:30 +0000
Subject: [PATCH] Refactor packet handling: replace custom hash function with
 built-in packet hash method and clean up unused code

---
 repeater/engine.py | 49 +++++-----------------------------------------
 1 file changed, 5 insertions(+), 44 deletions(-)

diff --git a/repeater/engine.py b/repeater/engine.py
index dd7b4d6..bdbeeb0 100644
--- a/repeater/engine.py
+++ b/repeater/engine.py
@@ -2,7 +2,7 @@ import asyncio
 import logging
 import time
 from collections import OrderedDict
-from typing import Any, Dict, Optional, Tuple
+from typing import Optional, Tuple
 
 from pymc_core.node.handlers.base import BaseHandler
 from pymc_core.protocol import Packet
@@ -13,48 +13,13 @@ from pymc_core.protocol.constants import (
     ROUTE_TYPE_DIRECT,
     ROUTE_TYPE_FLOOD,
 )
-from pymc_core.protocol.packet_utils import PacketHeaderUtils
+from pymc_core.protocol.packet_utils import PacketHeaderUtils, PacketTimingUtils
 
 from repeater.airtime import AirtimeManager
 
 logger = logging.getLogger("RepeaterHandler")
 
 
-class PacketTimingUtils:
-
-    @staticmethod
-    def estimate_airtime_ms(
-        packet_length_bytes: int, radio_config: Optional[Dict[str, Any]] = None
-    ) -> float:
-
-        if radio_config is None:
-            radio_config = {
-                "spreading_factor": 10,
-                "bandwidth": 250000,
-                "coding_rate": 5,
-                "preamble_length": 8,
-            }
-
-        sf = radio_config.get("spreading_factor", 10)
-        bw = radio_config.get("bandwidth", 250000)  # Hz
-        cr = radio_config.get("coding_rate", 5)
-        preamble = radio_config.get("preamble_length", 8)
-
-        # LoRa symbol duration: Ts = 2^SF / BW
-        symbol_duration_ms = (2**sf) / (bw / 1000)
-
-        # Number of payload symbols
-        payload_symbols = max(
-            8, int((8 * packet_length_bytes - 4 * sf + 28 + 16) / (4 * (sf - 2))) * (cr + 4)
-        )
-
-        # Total time = preamble + payload
-        preamble_ms = (preamble + 4.25) * symbol_duration_ms
-        payload_ms = payload_symbols * symbol_duration_ms
-
-        return preamble_ms + payload_ms
-
-
 class RepeaterHandler(BaseHandler):
 
     @staticmethod
@@ -191,7 +156,7 @@ class RepeaterHandler(BaseHandler):
             )
 
         # Check if this is a duplicate
-        pkt_hash = self._packet_hash(packet)
+        pkt_hash = packet.calculate_packet_hash().hex()
         is_dupe = pkt_hash in self.seen_packets and not transmitted
 
         # Set drop reason for duplicates
@@ -281,11 +246,7 @@ class RepeaterHandler(BaseHandler):
         for k in expired:
             del self.seen_packets[k]
 
-    def _packet_hash(self, packet: Packet) -> str:
 
-        if len(packet.payload or b"") >= 8:
-            return packet.payload[:8].hex()
-        return (packet.payload or b"").hex()
 
     def _get_drop_reason(self, packet: Packet) -> str:
 
@@ -389,7 +350,7 @@ class RepeaterHandler(BaseHandler):
 
     def is_duplicate(self, packet: Packet) -> bool:
 
-        pkt_hash = self._packet_hash(packet)
+        pkt_hash = packet.calculate_packet_hash().hex()
         if pkt_hash in self.seen_packets:
             logger.debug(f"Duplicate suppressed: {pkt_hash[:16]}")
             return True
@@ -397,7 +358,7 @@ class RepeaterHandler(BaseHandler):
 
     def mark_seen(self, packet: Packet):
 
-        pkt_hash = self._packet_hash(packet)
+        pkt_hash = packet.calculate_packet_hash().hex()
         self.seen_packets[pkt_hash] = time.time()
 
         if len(self.seen_packets) > self.max_cache_size: