httpd: cache gc.get_objects and get_db_health calls

httpd.py

@@ -53,6 +53,13 @@ _memory_sample_max = 60  # Keep last 60 samples (5 min at 5s intervals)
 _peak_rss = 0
 _start_rss = 0
 
+# Cache for expensive operations
+_gc_objects_cache = {'value': 0, 'time': 0}
+_gc_objects_ttl = 30  # seconds
+
+_db_health_cache = {'value': {}, 'time': 0}
+_db_health_ttl = 10  # seconds
+
 
 def get_system_stats():
     """Collect system resource statistics."""
@@ -139,7 +146,13 @@ def get_system_stats():
         stats['gc_count_gen0'] = gc_counts[0]
         stats['gc_count_gen1'] = gc_counts[1]
         stats['gc_count_gen2'] = gc_counts[2]
-        stats['gc_objects'] = len(gc.get_objects())
+        # Cache gc.get_objects() - expensive call (~23ms)
+        global _gc_objects_cache
+        now = time.time()
+        if now - _gc_objects_cache['time'] > _gc_objects_ttl:
+            _gc_objects_cache['value'] = len(gc.get_objects())
+            _gc_objects_cache['time'] = now
+        stats['gc_objects'] = _gc_objects_cache['value']
     except Exception:
         stats['gc_count_gen0'] = stats['gc_count_gen1'] = stats['gc_count_gen2'] = 0
         stats['gc_objects'] = 0
@@ -148,7 +161,12 @@ def get_system_stats():
 
 
 def get_db_health(db):
-    """Get database health and statistics."""
+    """Get database health and statistics (cached)."""
+    global _db_health_cache
+    now = time.time()
+    if now - _db_health_cache['time'] < _db_health_ttl:
+        return _db_health_cache['value']
+
     stats = {}
     try:
         # Database file size
@@ -211,6 +229,9 @@ def get_db_health(db):
     except Exception:
         pass
 
+    # Update cache
+    _db_health_cache['value'] = stats
+    _db_health_cache['time'] = time.time()
     return stats
 
 # Detect if gevent has monkey-patched the environment