refactor(api): resolve sudo/systemctl/reboot/poweroff paths at startup

Use shutil.which() with safe fallbacks for the four privileged binaries
instead of relying on bare names being resolved by the subprocess shell
search. Resolves paths once at module load rather than per-call.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

scripts/download_pixlet.sh

@@ -118,7 +118,7 @@ total_count=${#ARCHITECTURES[@]}
 
 for arch in "${!ARCHITECTURES[@]}"; do
     if download_binary "$arch" "${ARCHITECTURES[$arch]}"; then
-        success_count=$((success_count + 1))
+        ((success_count++))
     fi
 done
 

src/display_manager.py

@@ -3,7 +3,6 @@ if os.getenv("EMULATOR", "false") == "true":
     from RGBMatrixEmulator import RGBMatrix, RGBMatrixOptions
 else:
     from rgbmatrix import RGBMatrix, RGBMatrixOptions
-from contextlib import contextmanager
 from PIL import Image, ImageDraw, ImageFont
 import time
 from typing import Dict, Any, List, Tuple
@@ -29,8 +28,6 @@ class DisplayManager:
         self.config = config or {}
         self._force_fallback = force_fallback
         self._suppress_test_pattern = suppress_test_pattern
-        # When True, update_display() and clear() skip hardware writes (used during off-screen content capture)
-        self._capture_mode_active = False
         # Snapshot settings for web preview integration (service writes, web reads)
         self._snapshot_path = "/tmp/led_matrix_preview.png"
         self._snapshot_min_interval_sec = 0.2  # max ~5 fps
@@ -258,22 +255,6 @@ class DisplayManager:
         except Exception as e:
             logger.error(f"Error drawing test pattern: {e}", exc_info=True)
 
-    @contextmanager
-    def capture_mode(self):
-        """Suppress hardware output during off-screen content capture.
-
-        Plugins call update_display() as part of their normal display() flow.
-        When fetching content for Vegas mode the render loop is still running,
-        so any incidental hardware write causes a visible flash on the matrix.
-        Entering this context prevents those writes without affecting the PIL
-        image buffer, which the adapter reads to extract content.
-        """
-        self._capture_mode_active = True
-        try:
-            yield
-        finally:
-            self._capture_mode_active = False
-
     def update_display(self):
         """Update the display using double buffering with proper sync."""
         try:
@@ -284,9 +265,6 @@ class DisplayManager:
                 self._write_snapshot_if_due()
                 return
                 
-            if self._capture_mode_active:
-                return  # Skip hardware write — content is being captured off-screen
-
             # Copy the current image to the offscreen canvas   
             self.offscreen_canvas.SetImage(self.image)
             
@@ -327,22 +305,20 @@ class DisplayManager:
             self.image = Image.new('RGB', (self.matrix.width, self.matrix.height))
             self.draw = ImageDraw.Draw(self.image)
             
-            if not self._capture_mode_active:
+            # Clear both canvases and the underlying matrix to ensure no artifacts
-                # Clear both canvases and the underlying matrix to ensure no artifacts.
-                # Failures are non-fatal — the image buffer is already black above, so
-                # the next update_display() call will push clean content regardless.
             try:
                 self.offscreen_canvas.Clear()
-                except (RuntimeError, OSError) as e:
+            except Exception:
-                    logger.error("Failed to clear offscreen canvas: %s", e)
+                pass
             try:
                 self.current_canvas.Clear()
-                except (RuntimeError, OSError) as e:
+            except Exception:
-                    logger.error("Failed to clear current canvas: %s", e)
+                pass
             try:
+                # Extra safety: clear the matrix front buffer as well
                 self.matrix.Clear()
-                except (RuntimeError, OSError) as e:
+            except Exception:
-                    logger.error("Failed to clear matrix front buffer: %s", e)
+                pass
             
             # Note: We do NOT call update_display() here to avoid black flashes.
             # The caller should call update_display() after drawing new content.

src/vegas_mode/plugin_adapter.py

@@ -329,7 +329,6 @@ class PluginAdapter:
             # Save display state to restore after
             original_image = self.display_manager.image.copy()
 
-            with self.display_manager.capture_mode():
             # Method 1: Try _create_scrolling_display (stocks pattern)
             if hasattr(plugin, '_create_scrolling_display'):
                 logger.info(
@@ -409,7 +408,10 @@ class PluginAdapter:
             original_image = self.display_manager.image.copy()
             logger.info("[%s] Fallback: saved original display state", plugin_id)
 
-            # Ensure plugin has fresh data before capturing
+            # Lightweight in-memory data refresh before capturing.
+            # Full update() is intentionally skipped here — the background
+            # update tick in the Vegas coordinator handles periodic API
+            # refreshes so we don't block the content-fetch thread.
             has_update_data = hasattr(plugin, 'update_data')
             logger.info("[%s] Fallback: has update_data=%s", plugin_id, has_update_data)
             if has_update_data:
@@ -419,9 +421,7 @@ class PluginAdapter:
                 except (AttributeError, RuntimeError, OSError):
                     logger.exception("[%s] Fallback: update_data() failed", plugin_id)
 
-            # Clear and call plugin display — use capture_mode to suppress hardware writes
+            # Clear and call plugin display
-            # that plugins may trigger internally via update_display().
-            with self.display_manager.capture_mode():
             self.display_manager.clear()
             logger.info("[%s] Fallback: display cleared, calling display()", plugin_id)
 
@@ -436,7 +436,6 @@ class PluginAdapter:
 
             # Capture the result
             captured = self.display_manager.image.copy()
-
             logger.info(
                 "[%s] Fallback: captured frame %dx%d, mode=%s",
                 plugin_id, captured.width, captured.height, captured.mode
@@ -455,7 +454,6 @@ class PluginAdapter:
                     plugin_id
                 )
                 # Try once more with force_clear=True
-                with self.display_manager.capture_mode():
                 self.display_manager.clear()
                 plugin.display(force_clear=True)
                 captured = self.display_manager.image.copy()
@@ -587,6 +585,28 @@ class PluginAdapter:
             else:
                 self._content_cache.clear()
 
+    def invalidate_plugin_scroll_cache(self, plugin: 'BasePlugin', plugin_id: str) -> None:
+        """
+        Clear a plugin's scroll_helper cache so Vegas re-fetches fresh visuals.
+
+        Uses scroll_helper.clear_cache() to reset all cached state (cached_image,
+        cached_array, total_scroll_width, scroll_position, etc.) — not just the
+        image.  Without this, plugins that use scroll_helper (stocks, news,
+        odds-ticker, etc.) would keep serving stale scroll images even after
+        their data refreshes.
+
+        Args:
+            plugin: Plugin instance
+            plugin_id: Plugin identifier
+        """
+        scroll_helper = getattr(plugin, 'scroll_helper', None)
+        if scroll_helper is None:
+            return
+
+        if getattr(scroll_helper, 'cached_image', None) is not None:
+            scroll_helper.clear_cache()
+            logger.debug("[%s] Cleared scroll_helper cache", plugin_id)
+
     def get_content_type(self, plugin: 'BasePlugin', plugin_id: str) -> str:
         """
         Get the type of content a plugin provides.

src/vegas_mode/render_pipeline.py

@@ -202,25 +202,8 @@ class RenderPipeline:
             # Update scroll position
             self.scroll_helper.update_scroll_position()
 
-            # Determine if the cycle is done.
+            # Check if cycle is complete
-            #
+            if self.scroll_helper.is_scroll_complete():
-            # scroll_helper considers a cycle complete only after
-            # total_distance_scrolled >= total_scroll_width + display_width.
-            # That extra display_width of travel causes a "wrap-around" phase
-            # where scroll_position resets to ~0 and the first plugin's content
-            # re-enters from the right — the user sees this 2-3 s window as
-            # "a plugin partially displaying before the next one starts."
-            #
-            # We end the cycle as soon as total_distance_scrolled reaches
-            # total_scroll_width (the wrap-around point), before any second-pass
-            # content becomes visible.  scroll_helper.is_scroll_complete() is
-            # kept as a fallback for edge-cases where that threshold is skipped.
-            at_wrap_point = (
-                not self._cycle_complete and
-                self.scroll_helper.total_distance_scrolled >= self.scroll_helper.total_scroll_width
-            )
-
-            if at_wrap_point or self.scroll_helper.is_scroll_complete():
                 if not self._cycle_complete:
                     self._cycle_complete = True
                     self.stats['scroll_cycles'] += 1
@@ -228,20 +211,6 @@ class RenderPipeline:
                         "Scroll cycle complete after %.1fs",
                         time.time() - self._cycle_start_time
                     )
-                    # Push blank immediately so the hardware never shows
-                    # post-wrap content while the coordinator recomposes.
-                    try:
-                        from PIL import Image as _Image
-                        blank = _Image.new('RGB', (self.display_width, self.display_height))
-                        self.display_manager.image = blank
-                        self.display_manager.update_display()
-                    except (ImportError, OSError, RuntimeError, ValueError, TypeError, MemoryError) as exc:
-                        logger.error(
-                            "Failed to push blank frame at cycle end "
-                            "(display=%dx%d): %s",
-                            self.display_width, self.display_height, exc
-                        )
-                return True  # Cycle done; coordinator starts new cycle next frame
 
             # Get visible portion
             visible_frame = self.scroll_helper.get_visible_portion()

web_interface/app.py

@@ -226,24 +226,13 @@ def serve_plugin_asset(plugin_id, filename):
                 'message': 'Internal server error'
             }), 500
 
-# Prime psutil CPU measurement once at startup so interval=None returns a real value
-try:
-    import psutil as _psutil_prime
-    _psutil_prime.cpu_percent(interval=None)
-except ImportError:
-    pass
-
 # Cached AP mode check — avoids creating a WiFiManager per request
 _ap_mode_cache = {'value': False, 'timestamp': 0}
-_AP_MODE_CACHE_TTL = 30  # seconds — AP mode is user-initiated; 30s is fine
+_AP_MODE_CACHE_TTL = 5  # seconds
-
-# Cached ledmatrix service status for SSE stats stream
-_ledmatrix_service_cache = {'active': False, 'timestamp': 0}
-_LEDMATRIX_SERVICE_CACHE_TTL = 15  # seconds
 
 def is_ap_mode_active():
     """
-    Check if access point mode is currently active (cached, 30s TTL).
+    Check if access point mode is currently active (cached, 5s TTL).
     Uses a direct systemctl check instead of instantiating WiFiManager.
     """
     now = time.time()
@@ -455,8 +444,7 @@ def system_status_generator():
             # Try to import psutil for system stats
             try:
                 import psutil
-                # interval=None is non-blocking; primed at module startup above
+                cpu_percent = round(psutil.cpu_percent(interval=1), 1)
-                cpu_percent = round(psutil.cpu_percent(interval=None), 1)
                 memory = psutil.virtual_memory()
                 memory_used_percent = round(memory.percent, 1)
                 
@@ -473,17 +461,14 @@ def system_status_generator():
                 memory_used_percent = 0
                 cpu_temp = 0
             
-            # Check if display service is running (cached to avoid per-client subprocess forks)
+            # Check if display service is running
-            now = time.time()
+            service_active = False
-            if (now - _ledmatrix_service_cache['timestamp']) >= _LEDMATRIX_SERVICE_CACHE_TTL:
             try:
                 result = subprocess.run(['systemctl', 'is-active', 'ledmatrix'], 
                                       capture_output=True, text=True, timeout=2)
-                    _ledmatrix_service_cache['active'] = result.stdout.strip() == 'active'
+                service_active = result.stdout.strip() == 'active'
             except (subprocess.SubprocessError, OSError):
                 pass
-                _ledmatrix_service_cache['timestamp'] = now
-            service_active = _ledmatrix_service_cache['active']
             
             status = {
                 'timestamp': time.time(),
@@ -561,7 +546,7 @@ def display_preview_generator():
         except Exception as e:
             yield {'error': str(e)}
         
-        time.sleep(1.0)  # Check once per second — halves PIL encode overhead vs 0.5s
+        time.sleep(0.5)  # Check 2 times per second (reduced frequency for better performance)
 
 # Logs generator for SSE
 def logs_generator():

web_interface/blueprints/api_v3.py

@@ -4277,13 +4277,8 @@ def _set_missing_booleans_to_false(config, schema_props, form_keys, prefix='', c
         elif prop_type == 'object' and 'properties' in prop_schema:
             # Recurse into nested objects
             if config_node is not None:
-                # Inside an array item — only recurse if the sub-object already exists.
+                # Inside an array item — ensure nested dict exists in item
-                # Never create optional sub-objects that weren't submitted; doing so
+                if prop_name not in node or not isinstance(node[prop_name], dict):
-                # produces e.g. logo:{} on feed items with no logo, which then fails
-                # schema validation when the object has required fields (id, path).
-                if prop_name not in node:
-                    continue
-                if not isinstance(node[prop_name], dict):
                     node[prop_name] = {}
                 _set_missing_booleans_to_false(
                     config, prop_schema['properties'], form_keys, full_path,
@@ -4423,22 +4418,10 @@ def _filter_config_by_schema(config, schema, prefix=''):
         prop_schema = schema_props[key]
 
         # Handle nested objects recursively
-        item_prefix = f"{prefix}.{key}" if prefix else key
         if isinstance(value, dict) and prop_schema.get('type') == 'object' and 'properties' in prop_schema:
-            filtered[key] = _filter_config_by_schema(value, prop_schema, item_prefix)
+            filtered[key] = _filter_config_by_schema(value, prop_schema, f"{prefix}.{key}" if prefix else key)
-        elif isinstance(value, list) and prop_schema.get('type') == 'array':
-            items_schema = prop_schema.get('items', {})
-            if isinstance(items_schema, dict) and items_schema.get('type') == 'object' and 'properties' in items_schema:
-                # Filter each item in the array so extra fields are stripped before
-                # schema validation (important when items has additionalProperties: false)
-                filtered[key] = [
-                    _filter_config_by_schema(item, items_schema, item_prefix) if isinstance(item, dict) else item
-                    for item in value
-                ]
         else:
-                filtered[key] = value
+            # Keep the value as-is for non-object types
-        else:
-            # Keep the value as-is for non-object/non-array types
             filtered[key] = value
 
     return filtered
@@ -7594,126 +7577,6 @@ _STARLARK_APPS_DIR = PROJECT_ROOT / 'starlark-apps'
 _STARLARK_MANIFEST_FILE = _STARLARK_APPS_DIR / 'manifest.json'
 
 
-def _find_pixlet_binary(explicit_path: Optional[str] = None) -> Optional[str]:
-    """Find pixlet binary: explicit path → bundled binary → system PATH."""
-    import platform
-    if explicit_path and os.path.isfile(explicit_path) and os.access(explicit_path, os.X_OK):
-        return explicit_path
-    bin_dir = PROJECT_ROOT / "bin" / "pixlet"
-    system = platform.system().lower()
-    machine = platform.machine().lower()
-    if system == "linux":
-        if "aarch64" in machine or "arm64" in machine:
-            name = "pixlet-linux-arm64"
-        elif "x86_64" in machine or "amd64" in machine:
-            name = "pixlet-linux-amd64"
-        else:
-            name = None
-    elif system == "darwin":
-        name = "pixlet-darwin-arm64" if "arm64" in machine else "pixlet-darwin-amd64"
-    else:
-        name = None
-    if name:
-        bundled = bin_dir / name
-        if bundled.is_file():
-            if os.access(str(bundled), os.X_OK):
-                return str(bundled)
-            try:
-                bundled.chmod(0o755)
-            except OSError:
-                logger.warning("Could not make pixlet bundled binary executable (%s); falling back to PATH", bundled)
-            else:
-                if os.access(str(bundled), os.X_OK):
-                    return str(bundled)
-                logger.warning("Pixlet bundled binary still not executable after chmod (%s); falling back to PATH", bundled)
-    return shutil.which("pixlet")
-
-
-def _standalone_render_starlark_app(app_id: str) -> Tuple[bool, int, Optional[str]]:
-    """Render a Starlark app via pixlet directly (no plugin required).
-
-    Reads the .star file and config from starlark-apps/{app_id}/, runs pixlet,
-    and saves the output to cached_render.webp in the same directory.
-    This is the web-service fallback when starlark-apps plugin is not loaded.
-
-    Returns (success, http_status_code, error_message).
-    """
-    manifest = _read_starlark_manifest()
-    if not isinstance(manifest, dict):
-        return False, 400, "Invalid manifest shape: expected object with 'apps' mapping"
-    apps = manifest.get('apps', {})
-    if not isinstance(apps, dict):
-        return False, 400, "Invalid manifest shape: expected object with 'apps' mapping"
-    app_data = apps.get(app_id)
-    if not app_data:
-        return False, 404, f"App not found: {app_id}"
-
-    app_dir = _STARLARK_APPS_DIR / app_id
-    star_file = app_dir / app_data.get('star_file', f'{app_id}.star')
-    if not star_file.exists():
-        return False, 404, f"Star file not found: {star_file}"
-
-    full_config = api_v3.config_manager.load_config() if api_v3.config_manager else {}
-    plugin_config = full_config.get('starlark-apps', {})
-
-    pixlet_path = _find_pixlet_binary(plugin_config.get('pixlet_path'))
-    if not pixlet_path:
-        return False, 503, "Pixlet binary not found — install pixlet first"
-
-    magnify = plugin_config.get('magnify')
-    if magnify is None:
-        hw = full_config.get('display', {}).get('hardware', {})
-        cols = hw.get('cols', 64)
-        chain = hw.get('chain_length', 1)
-        rows = hw.get('rows', 32)
-        magnify = max(1, min(8, int(min((cols * chain) / 64, rows / 32))))
-    else:
-        try:
-            magnify = max(1, min(8, int(magnify)))
-        except (ValueError, TypeError):
-            magnify = 1
-
-    config_file = app_dir / 'config.json'
-    app_config: Dict[str, Any] = {}
-    if config_file.exists():
-        try:
-            with open(config_file) as f:
-                app_config = json.load(f)
-        except json.JSONDecodeError as e:
-            return False, 400, f"Invalid config.json for {app_id} ({config_file}): {e}"
-        except OSError as e:
-            return False, 400, f"Cannot read config.json for {app_id} ({config_file}): {e}"
-        if not isinstance(app_config, dict):
-            return False, 400, (
-                f"config.json for {app_id} must be a JSON object, "
-                f"got {type(app_config).__name__}"
-            )
-
-    INTERNAL_KEYS = {'render_interval', 'display_duration'}
-    pixlet_config = {k: v for k, v in app_config.items() if k not in INTERNAL_KEYS}
-
-    output_path = str(app_dir / 'cached_render.webp')
-    cmd = [pixlet_path, 'render', str(star_file)]
-    for key, value in pixlet_config.items():
-        if not re.match(r'^[a-zA-Z_][a-zA-Z0-9_]*$', key):
-            continue
-        value_str = 'true' if value is True else 'false' if value is False else str(value)
-        if re.search(r'[`$|<>&;\x00]|\$\(', value_str):
-            continue
-        cmd.append(f'{key}={value_str}')
-    cmd.extend(['-o', output_path, '-m', str(magnify)])
-
-    try:
-        result = subprocess.run(cmd, capture_output=True, text=True, timeout=30, cwd=str(app_dir))
-        if result.returncode == 0 and os.path.isfile(output_path):
-            return True, 200, None
-        return False, 502, f"Pixlet failed (exit {result.returncode}): {result.stderr.strip()}"
-    except subprocess.TimeoutExpired:
-        return False, 504, "Render timed out after 30s"
-    except Exception as e:
-        return False, 500, f"Render error: {e}"
-
-
 def _read_starlark_manifest() -> Dict[str, Any]:
     """Read the starlark-apps manifest.json directly from disk."""
     try:
@@ -7833,11 +7696,24 @@ def get_starlark_status():
                 'display_info': magnify_info
             })
 
-        # Plugin not loaded - check Pixlet availability via shared resolver
+        # Plugin not loaded - check Pixlet availability directly
-        # (respects user-configured pixlet_path, bundled binary, and system PATH)
+        import shutil
-        full_config = api_v3.config_manager.load_config() if api_v3.config_manager else {}
+        import platform
-        pixlet_path = _find_pixlet_binary(full_config.get('starlark-apps', {}).get('pixlet_path'))
+
-        pixlet_available = pixlet_path is not None
+        system = platform.system().lower()
+        machine = platform.machine().lower()
+        bin_dir = PROJECT_ROOT / 'bin' / 'pixlet'
+
+        pixlet_binary = None
+        if system == "linux":
+            if "aarch64" in machine or "arm64" in machine:
+                pixlet_binary = bin_dir / "pixlet-linux-arm64"
+            elif "x86_64" in machine or "amd64" in machine:
+                pixlet_binary = bin_dir / "pixlet-linux-amd64"
+        elif system == "darwin":
+            pixlet_binary = bin_dir / ("pixlet-darwin-arm64" if "arm64" in machine else "pixlet-darwin-amd64")
+
+        pixlet_available = (pixlet_binary and pixlet_binary.exists()) or shutil.which('pixlet') is not None
 
         # Read app counts from manifest
         manifest = _read_starlark_manifest()
@@ -8290,27 +8166,20 @@ def toggle_starlark_app(app_id):
 def render_starlark_app(app_id):
     """Force render a Starlark app."""
     try:
-        is_valid, err = _validate_starlark_app_path(app_id)
-        if not is_valid:
-            return jsonify({'status': 'error', 'message': err}), 400
-
         starlark_plugin = _get_starlark_plugin()
-        if starlark_plugin:
+        if not starlark_plugin:
+            return jsonify({'status': 'error', 'message': 'Rendering requires the main LEDMatrix service (plugin not loaded in web service)'}), 503
+
         app = starlark_plugin.apps.get(app_id)
         if not app:
             return jsonify({'status': 'error', 'message': f'App not found: {app_id}'}), 404
+
         success = starlark_plugin._render_app(app, force=True)
         if success:
-                return jsonify({'status': 'success', 'message': 'App rendered',
+            return jsonify({'status': 'success', 'message': 'App rendered', 'frame_count': len(app.frames) if app.frames else 0})
-                                'frame_count': len(app.frames) if app.frames else 0})
+        else:
             return jsonify({'status': 'error', 'message': 'Failed to render app'}), 500
 
-        # Web-service context: plugin not loaded, call pixlet directly
-        success, status_code, error = _standalone_render_starlark_app(app_id)
-        if success:
-            return jsonify({'status': 'success', 'message': 'App rendered successfully', 'frame_count': 0}), status_code
-        return jsonify({'status': 'error', 'message': error or 'Render failed', 'frame_count': 0}), status_code
-
     except Exception as e:
         logger.exception("[Starlark] render_starlark_app failed")
         return jsonify({'status': 'error', 'message': 'Failed to render Starlark app'}), 500