Stick to actual timestamps and no timeout eviction

Author: weebl2000

src/helpers/SimpleMeshTables.h

@@ -8,11 +8,10 @@
 
 #define MAX_PACKET_HASHES  128
 #define MAX_PACKET_ACKS     64
-#define HASH_TTL_MS        60000  // 60 seconds - entries older than this are considered expired
 
 class SimpleMeshTables : public mesh::MeshTables {
   uint8_t _hashes[MAX_PACKET_HASHES*MAX_HASH_SIZE];
-  uint16_t _last_seen[MAX_PACKET_HASHES];  // timestamp for LRU + TTL, wraps every 65s
+  uint32_t _last_seen[MAX_PACKET_HASHES];  // timestamp for LRU eviction
   uint32_t _acks[MAX_PACKET_ACKS];
   int _next_ack_idx;
   uint32_t _direct_dups, _flood_dups;
@@ -34,7 +33,7 @@ class SimpleMeshTables : public mesh::MeshTables {
     f.read((uint8_t *) &_acks[0], sizeof(_acks));
     f.read((uint8_t *) &_next_ack_idx, sizeof(_next_ack_idx));
     // Treat restored hashes as just seen - give them fresh timestamps
-    uint16_t now = millis();
+    uint32_t now = millis();
     const uint8_t* sp = _hashes;
     for (int i = 0; i < MAX_PACKET_HASHES; i++, sp += MAX_HASH_SIZE) {
       // Check if slot has data (not all zeros)
@@ -74,49 +73,37 @@ class SimpleMeshTables : public mesh::MeshTables {
       return false;
     }
 
-    uint16_t now = millis();
+    uint32_t now = millis();
     uint8_t hash[MAX_HASH_SIZE];
     packet->calculatePacketHash(hash);
 
     int oldest_idx = 0;
-    uint16_t oldest_age = 0;
-    int expired_idx = -1;
+    uint32_t oldest_age = 0;
 
     const uint8_t* sp = _hashes;
     for (int i = 0; i < MAX_PACKET_HASHES; i++, sp += MAX_HASH_SIZE) {
-      uint16_t age = (uint16_t)(now - _last_seen[i]);
-
-      if (memcmp(hash, sp, MAX_HASH_SIZE) == 0) {
-        // Check if expired (last_seen == 0 means never set)
-        if (_last_seen[i] != 0 && age <= HASH_TTL_MS) {
-          // Valid match - refresh timestamp (LRU touch) and return true
-          _last_seen[i] = now;
-          if (packet->isRouteDirect()) {
-            _direct_dups++;   // keep some stats
-          } else {
-            _flood_dups++;
-          }
-          return true;
+      uint32_t age = now - _last_seen[i];
+
+      if (memcmp(hash, sp, MAX_HASH_SIZE) == 0 && _last_seen[i] != 0) {
+        // Match found - refresh timestamp (LRU touch) and return true
+        _last_seen[i] = now;
+        if (packet->isRouteDirect()) {
+          _direct_dups++;   // keep some stats
+        } else {
+          _flood_dups++;
         }
-        // Expired match - treat as not seen, reuse this slot
-        expired_idx = i;
-        break;
+        return true;
       }
 
       // Track oldest entry for LRU eviction
       if (age > oldest_age) {
         oldest_age = age;
         oldest_idx = i;
       }
-
-      // Track first expired slot (including never-used slots where last_seen == 0)
-      if (expired_idx < 0 && (_last_seen[i] == 0 || age > HASH_TTL_MS)) {
-        expired_idx = i;
-      }
     }
 
-    // Not found - insert into expired slot or evict oldest (LRU)
-    int insert_idx = (expired_idx >= 0) ? expired_idx : oldest_idx;
+    // Not found - evict oldest (LRU)
+    int insert_idx = oldest_idx;
     memcpy(&_hashes[insert_idx*MAX_HASH_SIZE], hash, MAX_HASH_SIZE);
     _last_seen[insert_idx] = now;
     return false;