Improve notification reliability with handler retries and post-success ID marking

searcher/id.py

@@ -26,11 +26,14 @@ class ID:
                     logger.exception("An error occurred while attempting to open the id.json file.")
         return ids
 
-    def add(self, id: str) -> bool:
-        if not id in self._ids:
-            self._ids.append(id)
+    def contains(self, id_: str) -> bool:
+        return id_ in self._ids
+
+    def add(self, id_: str) -> bool:
+        if not id_ in self._ids:
+            self._ids.append(id_)
             with open("id.json", "w") as f:
                 json.dump(self._ids[-MAX_ID:], f, indent=3)
             self._ids = self._ids[-MAX_ID:]
             return True
-        return False
+        return False

searcher/searcher.py

@@ -8,11 +8,34 @@ import threading
 from typing import List, Union
 
 class Searcher:
+    _HANDLER_MAX_ATTEMPTS: int = 3
+    _HANDLER_INITIAL_BACKOFF: float = 2.0
+
     def __init__(self, searches: Union[List[Search], Search], request_verify: bool = True):
         self._searches: List[Search] = searches if isinstance(searches, list) else [searches]
         self._request_verify = request_verify
         self._id = ID()
 
+    def _handle_with_retry(self, search: Search, ad) -> bool:
+        for attempt in range(1, self._HANDLER_MAX_ATTEMPTS + 1):
+            try:
+                search.handler(ad, search.name)
+                return True
+            except Exception:
+                if attempt == self._HANDLER_MAX_ATTEMPTS:
+                    logger.exception(
+                        f"[{search.name}] Handler failed for ad {ad.id} after {attempt} attempts."
+                    )
+                    return False
+
+                delay = self._HANDLER_INITIAL_BACKOFF * (2 ** (attempt - 1))
+                logger.warning(
+                    f"[{search.name}] Handler failed for ad {ad.id}. "
+                    f"Retrying in {delay:.0f}s ({attempt}/{self._HANDLER_MAX_ATTEMPTS})."
+                )
+                time.sleep(delay)
+        return False
+
     def _search(self, search: Search) -> None:
         client = Client(proxy=search.proxy, request_verify=self._request_verify)
         while True:
@@ -20,12 +43,20 @@ class Searcher:
             try:
                 response = client.search(**search.parameters._kwargs, sort=Sort.NEWEST)
                 logger.debug(f"Successfully found {response.total} ad{'s' if response.total > 1 else ''}.")
-                ads = [ad for ad in response.ads if self._id.add(ad.id)]
+                ads = [ad for ad in response.ads if not self._id.contains(ad.id)]
                 if len(ads):
                     logger.info(f"Successfully found {len(ads)} new ad{'s' if len(ads) > 1 else ''}!")
+
+                notified = 0
                 for ad in ads:
-                    search.handler(ad, search.name)
-            except:
+                    if self._handle_with_retry(search, ad) and self._id.add(ad.id):
+                        notified += 1
+
+                if len(ads) and notified != len(ads):
+                    logger.warning(
+                        f"[{search.name}] {len(ads) - notified} ad{'s were' if len(ads) - notified > 1 else ' was'} not marked as seen and will be retried."
+                    )
+            except Exception:
                 logger.exception(f"An error occured.")
             time.sleep(search.delay - (time.time() - before) if search.delay - (time.time() - before) > 0 else 0)
 
@@ -37,4 +68,4 @@ class Searcher:
         for search in self._searches:
             threading.Thread(target=self._search, args=(search,), name=search.name).start()
             time.sleep(5) # Add latency between each thread to prevent spam
-        return True
+        return True