⚡ Bolt: Optimize Hashtag stream allocations

.jules/bolt.md

@@ -49,3 +49,7 @@
 ## 2025-02-13 - Cached compiled regular expressions in filtering logic
 **Learning:** `HtmlParser.applyFilterHighlights` was compiling a regular expression (`Pattern.compile(...)`) for each keyword matched against the text inside a `while` and `for` loop, leading to repeated pattern compilation overhead in a rendering hot path. Using `LruCache<String, Pattern>` avoids unbounded growth while significantly reducing allocations and compilation time.
 **Action:** Always precompile or cache expensive `Pattern.compile` calls, especially inside nested loops or frequently invoked methods like `onBindViewHolder` equivalents or text formatters.
+
+## 2025-05-28 - [Stream Allocation in HashtagTimelineFragment]
+**Learning:** `HashtagTimelineFragment.updateHeader` was using `hashtag.history.stream().mapToInt(h->h.uses).sum()` and similar stream operations to compute post/account counts. Since this executes during UI updates, the repeated stream allocation contributes to GC churn in the hot path.
+**Action:** Replaced stream usages with explicit loop methods (`getWeekPosts()`, `getWeekAccounts()`) directly in the `Hashtag` model, minimizing allocation overhead and improving rendering performance.

mastodon/src/main/java/de/icod/techidon/fragments/HashtagTimelineFragment.java

@@ -362,9 +362,9 @@ private void updateHeader(){
 			return;
 
 		if(hashtag.history!=null && !hashtag.history.isEmpty()){
-			int weekPosts=hashtag.history.stream().mapToInt(h->h.uses).sum();
+			int weekPosts=hashtag.getWeekPosts();
 			int todayPosts=hashtag.history.get(0).uses;
-			int numAccounts=hashtag.history.stream().mapToInt(h->h.accounts).sum();
+			int numAccounts=hashtag.getWeekAccounts();
 			int hSpace=V.dp(8);
 			SpannableStringBuilder ssb=new SpannableStringBuilder();
 			ssb.append(getResources().getQuantityString(R.plurals.x_posts, weekPosts, weekPosts));

mastodon/src/main/java/de/icod/techidon/model/Hashtag.java

@@ -56,4 +56,14 @@ public int getWeekPosts(){
 		}
 		return sum;
 	}
+
+	public int getWeekAccounts(){
+		// Optimization: Use loop instead of Stream to avoid allocation overhead in hot paths.
+		if(history==null) return 0;
+		int sum=0;
+		for(History h:history){
+			sum+=h.accounts;
+		}
+		return sum;
+	}
 }

mastodon/src/test/java/de/icod/techidon/model/HashtagTest.java

@@ -40,4 +40,39 @@ public void testGetWeekPosts_NullHistoryReturnsZero() {
         hashtag.history = null;
         assertEquals(0, hashtag.getWeekPosts());
     }
+
+
+    @Test
+    public void testGetWeekAccounts_CalculatesCorrectSum() {
+        Hashtag hashtag = new Hashtag();
+        hashtag.history = new ArrayList<>();
+
+        History h1 = new History();
+        h1.accounts = 5;
+        hashtag.history.add(h1);
+
+        History h2 = new History();
+        h2.accounts = 10;
+        hashtag.history.add(h2);
+
+        History h3 = new History();
+        h3.accounts = 3;
+        hashtag.history.add(h3);
+
+        assertEquals(18, hashtag.getWeekAccounts());
+    }
+
+    @Test
+    public void testGetWeekAccounts_EmptyHistoryReturnsZero() {
+        Hashtag hashtag = new Hashtag();
+        hashtag.history = Collections.emptyList();
+        assertEquals(0, hashtag.getWeekAccounts());
+    }
+
+    @Test
+    public void testGetWeekAccounts_NullHistoryReturnsZero() {
+        Hashtag hashtag = new Hashtag();
+        hashtag.history = null;
+        assertEquals(0, hashtag.getWeekAccounts());
+    }
 }