Added thread filtering according to ChoD

src/rss_thread_watch/feed_generator.clj

@@ -0,0 +1,80 @@
+;; Copyright (C) 2023  Felisp
+;;
+;; This program is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU Affero General Public License as published by
+;; the Free Software Foundation, version 3 of the License.
+;;
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU Affero General Public License for more details.
+;;
+;; You should have received a copy of the GNU Affero General Public License
+;; along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+(ns rss-thread-watch.feed-generator
+  "Generates feed for requests"
+  (:require [ring.middleware.params :as rp]
+            [clj-rss.core :as rss]
+            [clojure.string :as s]
+            [rss-thread-watch.watcher :as cache])
+  (:gen-class))
+
+
+(defn indices
+  ;; https://stackoverflow.com/questions/8641305/find-index-of-an-element-matching-a-predicate-in-clojure
+  "Returns indexes of elements passing predicate"
+  [pred coll]
+   (keep-indexed #(when (pred %2) %1) coll))
+
+(defn new-guid-always
+  "Generates always unique GUID for Feed item.
+   This is used when user wants notification on every server update,
+   no matter whether thread actually changed it's position.
+
+   This is done by always making new GUID - (concat thread-number UNIX-time-of-data-update)"
+  [thread time]
+  (assoc thread guid (str (:no thread)
+                          "-"
+                          time)))
+
+(defn update-only-guid
+  "Generates new GUID for feed item ONLY if the threads ChoD increased
+
+   This is done by concating thread-number and it's rounded chod"
+  [thread]
+  (assoc thread :guid (format "%d-%.2f"
+                              (:no thread)
+                              :chod thread)))
+
+(defn filter-chod-posts
+  "Return list of all threads with equal or higher ChoD than requested"
+  [query-vec chod-treshold repeat?]
+  (let [time-of-generation (System/currentTimeMillis)
+        guid-fn (if repeat? (fn [x] (new-guid-always x time-of-generation))
+                    update-only-guid)
+        cache-start-index (first (indices (fn [x] (>= x chod-treshold))
+                                          @cache/chod-threads-cache))
+        ;; So we don't have to search thru everything we have cached
+        needed-cache-part (subvec @cache/chod-threads-cache cache-start-index)
+        actuall-matches (keep (fn [t]
+                                (let [title (:title t)]
+                                  (when (some (fn [querry]
+                                                (s/includes? title querry))
+                                              query-vec)
+                                    t)))
+                              needed-cache-part)]
+    ;; Finally generate and append GUIDs
+    (map guid-fn actuall-matches)))
+
+(defn http-handler
+  "Handles HTTP requests, returns generated feed
+
+   READS FROM GLOBALS:
+     rss-thread-watch.watcher.chod-threads-cache
+     rss-thread-watch.core.CONFIG"
+  [rqst]
+  {:status 200
+   :header {"Content-Type" "text/html"}
+   :body "All pony here ^:)"})
+

src/rss_thread_watch/watcher.clj

@@ -35,7 +35,7 @@
               (inc index)
               (conj! ret {:title (or (:sub thread) ;We use thread title if thread has it
                                      (:com thread) ;we use body if thread has it
-                                     "")           ;Thread has nothing, this prevents null pointer
+                                     "")           ;Thread has neither, this prevents null pointer
                           :no (:no thread)
                           :chod (* 100 (float (/ index threads-total)))}))))))
 
@@ -49,8 +49,6 @@
                          (process-page (:threads single-page) threads-total (inc (* page-number threads-per-page)))))
                      pages-to-index))))
 
-
-
 (defn update-thread-cache!
   "Updates cache of near-death threads. Writes to chod-threads-cache as side effect.
    [url] - Url to download data from