perf(map): eliminate redundant PNG serialization in Q10 rendering pipeline

Author: allenporter

roborock/map/b01_q10_map_parser.py

@@ -801,8 +801,8 @@ def parse_packet(self, packet: Q10MapPacket) -> ParsedMapData:
         """
         return self.parsed_from_packet(packet)
 
-    def parsed_from_packet(self, packet: Q10MapPacket) -> ParsedMapData:
-        """Render a (possibly erase-modified) packet into a PNG + ``MapData``."""
+    def map_data_from_packet(self, packet: Q10MapPacket) -> MapData:
+        """Build MapData with a rendered base image, without PNG serialization."""
         image = self._render(packet)
 
         map_data = MapData()
@@ -830,8 +830,14 @@ def parsed_from_packet(self, packet: Q10MapPacket) -> ParsedMapData:
         if packet.carpet_mask is not None:
             map_data.carpet_map = {i for i, value in enumerate(packet.carpet_mask) if value}
 
+        return map_data
+
+    def parsed_from_packet(self, packet: Q10MapPacket) -> ParsedMapData:
+        """Render a (possibly erase-modified) packet into a PNG + ``MapData``."""
+        map_data = self.map_data_from_packet(packet)
         image_bytes = io.BytesIO()
-        image.save(image_bytes, format=_MAP_FILE_FORMAT)
+        if map_data.image is not None:
+            map_data.image.data.save(image_bytes, format=_MAP_FILE_FORMAT)
         return ParsedMapData(image_content=image_bytes.getvalue(), map_data=map_data)
 
     def _render(self, packet: Q10MapPacket) -> Image.Image:

roborock/map/b01_q10_render.py

@@ -109,10 +109,9 @@ def render_q10_map(
             # areas disappear (as the app shows).
             render_packet = erased_packet(packet, cells)
 
-    parsed = parser.parsed_from_packet(render_packet)
-    if parsed.image_content is None or parsed.map_data is None:
+    map_data = parser.map_data_from_packet(render_packet)
+    if map_data.image is None:
         raise RoborockException("Failed to render Q10 map image")
-    map_data = parsed.map_data
 
     has_drawables = False
     if trace_calibration is not None and trace is not None:
@@ -128,7 +127,9 @@ def render_q10_map(
     if has_drawables:
         return _draw_map_content(map_data, config=config)
 
-    return parsed.image_content
+    buffer = io.BytesIO()
+    map_data.image.data.save(buffer, format="PNG")
+    return buffer.getvalue()
 
 
 def solve_q10_calibration(