Adding a type of caching mechanism for the metadata/user information.

The current logic would work just fine if looking up for a singular user, however for the multiple posts via normal filtering would cause it to either:

1. Error out due to lack of service and/or creator id.

2. Produce no metadata

This builds a local cache during the process so it should only make a call for the user info once during the process.

gallery_dl/extractor/kemonoparty.py

@@ -55,28 +55,20 @@ def _init(self):
                 sort_keys=True, separators=(",", ":")).encode
 
     def items(self):
-        service = self.groups[2]
-        creator_id = self.groups[3]
+        _creator_info: dict = {}
 
         find_hash = re.compile(HASH_PATTERN).match
         generators = self._build_file_generators(self.config("files"))
         announcements = True if self.config("announcements") else None
         comments = True if self.config("comments") else False
         duplicates = True if self.config("duplicates") else False
         dms = True if self.config("dms") else None
-        profile = username = None
+        max_posts = self.config("max-posts")
 
         # prevent files from being sent with gzip compression
         headers = {"Accept-Encoding": "identity"}
 
-        if self.config("metadata") and service and creator_id:
-            #TODO - not sure if we should make this call for every post for a
-            # /posts all as it may be expensive
-            profile = self.api.creator_profile(service, creator_id)
-            username = profile["name"]
-
         posts = self.posts()
-        max_posts = self.config("max-posts")
         if max_posts:
             posts = itertools.islice(posts, max_posts)
         if self.revisions:
@@ -88,10 +80,19 @@ def items(self):
             post["_http_headers"] = headers
             post["date"] = self._parse_datetime(
                     post.get("published") or post.get("added") or "")
+            service = post["service"]
+            creator_id = post["user"]
+
+            if self.config("metadata"):
+                if _creator_info.get(f"{service}_{creator_id}") is None:
+                    _creator = self.api.creator_profile(service, creator_id)
+                    _creator_info[f"{service}_{creator_id}"] = _creator
+
+                post["user_profile"] = _creator_info[f"{service}_{creator_id}"]
+                post["username"] = _creator_info[f"{service}_{creator_id}"]['name']
+            else:
+                post["user_profile"] = post["username"] = post["user"]
 
-            if profile is not None:
-                post["username"] = username
-                post["user_profile"] = profile
             if comments:
                 try:
                     post["comments"] = self.api.creator_post_comments(