perf(viewer): reuse click handlers instead of rebuilding them per render

Six factories built a fresh closure for every dropdown option on every
render and registered it in globals(). Mesop memoizes handler ids on the
function object itself (compute_fn_id is an unbounded lru_cache), so a new
closure per render meant a permanent entry per render: 300 renders of a
40-option dropdown added 12,000 entries instead of 40.

Hoist the factories to module level and memoize them by value, so the same
option yields the same function object and mesop's table stays flat. The
globals() writes go with them; nothing ever read those names.

Handler __name__ is load-bearing and stays: mesop derives identity from
name plus source, and all handlers from one factory share source, so
without it every option in a dropdown would dispatch to the same value.
Names now carry a short digest of the raw value, since the old sanitizer
mapped "a.b" and "a-b" to one name and silently merged them.

Author: omkargaikwad23

viewer/main.py

@@ -1,10 +1,13 @@
 import os
+import re
+import hashlib
 import mesop as me
 import pandas as pd
 import yaml
 import logging
 import json
 import subprocess
+from functools import lru_cache
 import precompute_trends
 import dataset_quality
 from summarizer import summarize_eval_scoring
@@ -310,6 +313,39 @@ def on_load(e: me.LoadEvent):
         state.ai_comparison = compare_evals(eval1, eval2)
 
 
+def _handler_name(prefix, *parts):
+    # Mesop identifies a handler by __name__ plus source, and every handler built by
+    # one factory shares its source, so the name has to carry the values. The digest
+    # keeps values that sanitize alike ("a.b" and "a-b") from sharing an identity.
+    raw = "\x00".join(str(p) for p in parts)
+    slug = re.sub(r"\W+", "_", raw.replace("\x00", "_"))
+    return f"{prefix}_{slug}_{hashlib.sha1(raw.encode()).hexdigest()[:8]}"
+
+
+# Mesop memoizes on the handler object itself, so a fresh closure per render grows
+# its table forever. Returning the same object per value keeps that table bounded.
+@lru_cache(maxsize=4096)
+def _set_filter_handler(field, value):
+    def handler(e: me.ClickEvent):
+        st = me.state(State)
+        setattr(st, field, value)
+        st.open_dropdown = ""
+
+    handler.__name__ = _handler_name("set", field, value)
+    return handler
+
+
+@lru_cache(maxsize=4096)
+def _status_row_handler(product, dataset):
+    def handler(e: me.ClickEvent):
+        st = me.state(State)
+        st.selected_main_tab = "List"
+        st.product_filter = product
+        st.dataset_filter = dataset
+        st.list_agent_tab = st.status_agent_tab
+
+    handler.__name__ = _handler_name("click_status_row", product, dataset)
+    return handler
 
 
 
@@ -526,22 +562,7 @@ def render_cell(text, color="#334155", cell_bg=None, on_click=None):
                             product_val = str(row['Product'])
                             dataset_val = str(row['Dataset'])
 
-                            def make_click_handler(p_val, d_val, g_val):
-                                def handler(e: me.ClickEvent):
-                                    st = me.state(State)
-                                    st.selected_main_tab = "List"
-                                    st.product_filter = p_val
-                                    st.dataset_filter = d_val
-                                    st.list_agent_tab = st.status_agent_tab
-                                
-                                safe_p = str(p_val).replace(" ", "_").replace(".", "_").replace("-", "_")
-                                safe_d = str(d_val).replace(" ", "_").replace(".", "_").replace("-", "_")
-                                handler_name = f"click_status_row_{safe_p}_{safe_d}"
-                                handler.__name__ = handler_name
-                                globals()[handler_name] = handler
-                                return handler
-                                
-                            click_handler = make_click_handler(product_val, dataset_val, row.get('model_config.generator'))
+                            click_handler = _status_row_handler(product_val, dataset_val)
                             render_cell(product_val, color="#2563eb", on_click=click_handler)
                             render_cell("N/A" if is_na else dataset_val, color="#2563eb", on_click=None if is_na else click_handler)
 
@@ -904,15 +925,7 @@ def toggle_eval_id_dropdown(e: me.ClickEvent):
                         st.open_dropdown = "eval_id"
 
                 def make_eval_id_handler(val):
-                    def handler(e: me.ClickEvent):
-                        st = me.state(State)
-                        st.eval_id_filter = val
-                        st.open_dropdown = ""
-    
-                    handler_name = f"click_eval_id_{val}"
-                    handler.__name__ = handler_name
-                    globals()[handler_name] = handler
-                    return handler
+                    return _set_filter_handler("eval_id_filter", val)
 
                 with me.box(
                     style=me.Style(
@@ -1005,17 +1018,7 @@ def toggle_product_dropdown(e: me.ClickEvent):
                         st.open_dropdown = "product"
 
                 def make_prod_dropdown_handler(val):
-                    def handler(e: me.ClickEvent):
-                        st = me.state(State)
-                        st.product_filter = val
-                        st.open_dropdown = ""
-    
-                    # Sanitize name for Mesop event routing
-                    safe_val = str(val).replace(" ", "_").replace(".", "_").replace("-", "_")
-                    handler_name = f"click_prod_dd_{safe_val}"
-                    handler.__name__ = handler_name
-                    globals()[handler_name] = handler
-                    return handler
+                    return _set_filter_handler("product_filter", val)
 
                 mk_prod_dd = make_prod_dropdown_handler
 
@@ -1110,17 +1113,7 @@ def toggle_requester_dropdown(e: me.ClickEvent):
                         st.open_dropdown = "requester"
 
                 def make_req_dropdown_handler(val):
-                    def handler(e: me.ClickEvent):
-                        st = me.state(State)
-                        st.requester_filter = val
-                        st.open_dropdown = ""
-    
-                    # Sanitize name for Mesop event routing
-                    safe_val = str(val).replace(" ", "_").replace(".", "_").replace("-", "_")
-                    handler_name = f"click_req_dd_{safe_val}"
-                    handler.__name__ = handler_name
-                    globals()[handler_name] = handler
-                    return handler
+                    return _set_filter_handler("requester_filter", val)
 
                 mk_req_dd = make_req_dropdown_handler
 
@@ -1215,17 +1208,7 @@ def toggle_dataset_dropdown(e: me.ClickEvent):
                         st.open_dropdown = "dataset"
 
                 def make_dataset_dropdown_handler(val):
-                    def handler(e: me.ClickEvent):
-                        st = me.state(State)
-                        st.dataset_filter = val
-                        st.open_dropdown = ""
-    
-                    # Sanitize name for Mesop event routing
-                    safe_val = str(val).replace(" ", "_").replace(".", "_").replace("-", "_")
-                    handler_name = f"click_dataset_dd_{safe_val}"
-                    handler.__name__ = handler_name
-                    globals()[handler_name] = handler
-                    return handler
+                    return _set_filter_handler("dataset_filter", val)
 
                 mk_dataset_dd = make_dataset_dropdown_handler
 
@@ -1320,15 +1303,7 @@ def toggle_rows_dropdown(e: me.ClickEvent):
                         st.open_dropdown = "rows_to_show"
 
                 def make_rows_handler(val):
-                    def handler(e: me.ClickEvent):
-                        st = me.state(State)
-                        st.rows_to_show = val
-                        st.open_dropdown = ""
-    
-                    handler_name = f"click_rows_{val}"
-                    handler.__name__ = handler_name
-                    globals()[handler_name] = handler
-                    return handler
+                    return _set_filter_handler("rows_to_show", val)
 
                 with me.box(
                     style=me.Style(