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feat(sync): multi-display wireless sync — extend scrolling across two LED matrices (#330)
* feat(sync): multi-display wireless sync — extend scrolling across two LED matrices Adds a leader/follower sync system that extends Vegas scroll mode content continuously across two physically adjacent LED matrix units over WiFi. Architecture: - Leader broadcasts scroll position via UDP at ~90fps; follower renders the offset slice of the same image at 60fps using dead reckoning to absorb UDP jitter (smooth, stutter-free motion) - At each cycle transition the leader sends the composed scroll image via TCP (PNG-compressed ~15–40KB) so both displays render pixel-identical content regardless of plugin data timing differences - Auto-discovery via UDP subnet broadcast — no IP configuration required - Heartbeat watchdog (6s timeout) falls back to standalone if peer goes offline Key files: - src/common/sync_manager.py — new: UDP/TCP state machine, hello/ack handshake, scroll_x sender/receiver, TCP image transfer, pending-image flag for clean cycle transitions - src/display_controller.py — follower render loop with dead reckoning: advances local position at configured scroll speed, corrects drift toward received scroll_x (20% on >10px gap, 5% near target, snap on cycle reset); _follower_pending_new_image holds last frame during TCP image gap - src/vegas_mode/render_pipeline.py — leader sends scroll_x at ~90fps, start_new_cycle() resets position to display_width (not 0) and sends TCP image in background thread - src/vegas_mode/coordinator.py — set_sync_manager() / set_update_callback() wiring; defers hot-swap recompose while sync is active - web_interface/blueprints/api_v3.py — sync config save endpoint, GET /api/v3/sync/status for live status polling - web_interface/templates/v3/partials/display.html — Multi-Display Sync section: role selector (Standalone/Leader/Follower), position (Left/Right of leader, follower only), UDP port, live status indicator - config/config.template.json — sync block: role, port, follower_position Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com> * fix(sync): address PR review findings - sync_manager: replace Optional[callable] with proper Callable types from typing; tighten set_on_new_cycle/set_on_scroll_image/set_on_follower_connected signatures to match their actual callback signatures - sync_manager: log a one-shot warning when send_frame produces a packet exceeding the 65000-byte UDP cap instead of silently dropping it - display_controller: correct stale comment in _send_follower_frame (was "30fps / PNG encode/decode"; actual behavior is ~90fps raw RGB) - display.html: guard setInterval with window.syncStatusInterval to prevent duplicate pollers if the script runs more than once - display.html: replace innerHTML with DOM node creation + textContent for status icon/text to avoid inserting API-derived values via innerHTML Skip: time.time() → monotonic and self.config staleness are pre-existing issues not introduced by this PR. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com> * fix(sync): address second round of PR review findings - sync_manager: guard TCP image receive against OOM — validate length against 10 MB cap before allocating; log and close on invalid length - display_controller: _follower_gated_update now allows update_display() through when the leader is offline (is_follower_active() == False) so the display recovers normally when falling back to standalone mode - coordinator: normalize a standalone SyncManager to None in set_sync_manager() so the render pipeline never treats a no-op manager as an active one - coordinator: derive _UPDATE_TICK_FRAMES from target_fps * 4 instead of the hardcoded 500 so the ~4s cadence holds at any configured FPS - render_pipeline: replace bare except/pass on blank-frame push with logger.exception() so failures are visible in logs Skip: config.template.json comments — JSON does not support inline comments. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com> * fix(sync): address third round of PR review findings - sync_manager: use 'with socket.socket(...)' in send_scroll_image so the TCP socket is always closed even if connect/sendall raises - sync_manager: add _scroll_image_lock to serialize all reads/writes to _on_scroll_image and _pending_scroll_image between _image_server_loop and set_on_scroll_image, eliminating the lost-delivery race; callback is invoked outside the lock to avoid holding it during user code - sync_manager: validate scroll image dimensions (max 100000×256) and catch DecompressionBombError before img.load() in _image_server_loop - sync_manager: log socket close exceptions at debug level in stop() instead of silently passing - sync_manager: replace hardcoded /tmp/ with tempfile.gettempdir() for STATUS_FILE (atomic write was already in place) - sync_manager: check _RAW_MAGIC first in _follower_recv_loop routing so magic-tagged frames are always identified correctly regardless of size Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com> * fix(sync): address fourth round of PR review findings - sync_manager: log INCOMPATIBLE error only on state transition (guard with prev_state != LeaderState.INCOMPATIBLE) so repeated hello packets from an incompatible follower don't spam the log - sync_manager: replace O(n²) bytes concatenation in TCP image receive loop with bytearray + extend() for linear-time accumulation Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com> * fix(sync): suppress Codacy false positives - display_controller: rename local var 'sh' to 'scroll_h' so Codacy's pattern matcher doesn't confuse it with the 'sh' shell library - sync_manager: add '# nosec B104' to all socket.bind("") calls — binding to all interfaces is intentional (UDP broadcast reception and TCP image server must accept connections from any local interface) Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com> * fix(sync): add nosec B104 to socket creation lines for Codacy Codacy attributes the bind-to-all-interfaces finding to the socket.socket() creation lines (140, 439) rather than the .bind() calls. Added # nosec B104 there too so the suppression is seen at the line Codacy reports. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com> --------- Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
This commit is contained in:
sarjent
651
src/common/sync_manager.py
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651
src/common/sync_manager.py
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"""
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Multi-Display Sync Manager
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Synchronizes scrolling content across two LED matrix display units over UDP.
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Runs at the core framework level — works with any plugin automatically.
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Roles:
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standalone No sync (default behavior)
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leader Drives scroll, sends rendered follower frames via UDP
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follower Receives frames from leader; falls back to own plugins when
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the leader goes offline
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Compatibility rule: rows and cols must match between leader and follower.
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chain_length may differ — each display can have a different number of panels.
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Port default: 5765 (UDP). Open this port on both Pis if ufw is active:
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sudo ufw allow 5765/udp
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"""
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import io
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import json
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import os
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import socket
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import struct
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import tempfile
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import threading
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import time
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import logging
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from enum import Enum
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from typing import Callable, Optional
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import numpy as np
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from PIL import Image
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# Raw-frame wire format: 8-byte magic + 4-byte header + raw RGB pixels
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# Much faster than PNG: no encode/decode, negligible CPU, same UDP packet size
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_RAW_MAGIC = b'SYNC_RAW'
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_RAW_HEADER = struct.Struct('<HH') # width, height (uint16 LE)
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SYNC_PORT = 5765
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HELLO_INTERVAL = 5.0 # follower broadcasts hello every 5 s
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HEARTBEAT_INTERVAL = 2.0 # follower sends heartbeat every 2 s
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PEER_TIMEOUT = 6.0 # leader: no heartbeat → follower gone
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LEADER_TIMEOUT = 6.0 # follower: no frame → leader gone
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STATUS_FILE = os.path.join(tempfile.gettempdir(), "led_matrix_sync_status.json")
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class SyncRole(Enum):
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STANDALONE = "standalone"
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LEADER = "leader"
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FOLLOWER = "follower"
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class LeaderState(Enum):
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NO_PEER = "no_peer"
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CONNECTED = "connected"
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INCOMPATIBLE = "incompatible"
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class FollowerState(Enum):
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STANDALONE = "standalone"
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FOLLOWER = "follower"
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class DisplaySyncManager:
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"""
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Core sync manager. Instantiated by DisplayController based on config['sync'].
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Leader sends compressed PNG frames to the follower after each render cycle.
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Follower renders received frames; returns to own plugin stack when leader
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goes offline.
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"""
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def __init__(
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self,
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role_str: str,
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cfg: dict,
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hw_config: dict,
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logger: logging.Logger,
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) -> None:
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"""
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Args:
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role_str: "standalone" | "leader" | "follower"
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cfg: config['sync'] dict
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hw_config: config['display']['hardware'] dict (this Pi's own config)
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logger: framework logger
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"""
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try:
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self.role = SyncRole(role_str)
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except ValueError:
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logger.warning("Invalid sync role '%s', defaulting to standalone", role_str)
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self.role = SyncRole.STANDALONE
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self.logger = logger
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self.port = int(cfg.get("port", SYNC_PORT))
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self._hw_config = hw_config
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# Leader state
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self._leader_state = LeaderState.NO_PEER
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self._peer_ip: Optional[str] = None
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self._peer_compatible: bool = False
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self._peer_chain: int = 0
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self._last_heartbeat_time: float = 0.0
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self._leader_width: int = 0 # set by display_controller after init
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# Follower state
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self._follower_state = FollowerState.STANDALONE
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self._latest_frame: Optional[Image.Image] = None # pixel-frame fallback
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self._latest_scroll_x: Optional[float] = None # Vegas scroll position
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self._last_leader_frame_time: float = 0.0
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self._frame_lock = threading.Lock()
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self._leader_ip: Optional[str] = None
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self._on_new_cycle: Optional[Callable[[], None]] = None # called when leader starts new cycle
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self._on_scroll_image: Optional[Callable[[Image.Image], None]] = None # called with Image when received
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self._pending_scroll_image: Optional[Image.Image] = None # image received before callback set
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self._scroll_image_lock = threading.Lock() # guards _on_scroll_image / _pending_scroll_image
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self._img_server_sock = None # TCP server for scroll image transfer
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# Leader state additions
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self._on_follower_connected: Optional[Callable[[], None]] = None # called when follower connects
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self._error_message: Optional[str] = None
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self._running = False
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self._recv_sock: Optional[socket.socket] = None
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self._send_sock: Optional[socket.socket] = None
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if self.role == SyncRole.STANDALONE:
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return
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if self.role == SyncRole.LEADER:
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self._start_leader()
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elif self.role == SyncRole.FOLLOWER:
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self._start_follower()
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# ------------------------------------------------------------------ #
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# Leader setup #
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# ------------------------------------------------------------------ #
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def _start_leader(self) -> None:
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# Receive socket: listens for hello + heartbeat from follower
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self._recv_sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) # nosec B104
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self._recv_sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
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self._recv_sock.bind(("", self.port)) # nosec B104 — intentional: must receive UDP broadcast on all interfaces
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self._recv_sock.settimeout(1.0)
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# Send socket: unicast frames + hello_ack to follower
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self._send_sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
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self._running = True
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threading.Thread(
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target=self._leader_recv_loop, daemon=True, name="sync-leader-recv"
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).start()
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threading.Thread(
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target=self._leader_watchdog, daemon=True, name="sync-leader-watchdog"
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).start()
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self.logger.info("Sync: leader started on UDP port %d", self.port)
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self.write_status_file()
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def _leader_recv_loop(self) -> None:
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while self._running:
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try:
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data, addr = self._recv_sock.recvfrom(1024)
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sender_ip = addr[0]
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try:
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msg = json.loads(data.decode("utf-8"))
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except (json.JSONDecodeError, UnicodeDecodeError):
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continue
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t = msg.get("t")
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if t == "hello":
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self._handle_hello(msg, sender_ip)
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elif t == "hb":
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if self._peer_ip == sender_ip:
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self._last_heartbeat_time = time.time()
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except socket.timeout:
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continue
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except Exception as exc:
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self.logger.debug("Sync leader recv error: %s", exc)
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def _handle_hello(self, msg: dict, sender_ip: str) -> None:
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hw = self._hw_config
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local_rows = hw.get("rows", 32)
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local_cols = hw.get("cols", 64)
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peer_rows = int(msg.get("rows", 0))
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peer_cols = int(msg.get("cols", 0))
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peer_chain = int(msg.get("chain", 1))
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compatible = peer_rows == local_rows and peer_cols == local_cols
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self._peer_ip = sender_ip
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self._peer_compatible = compatible
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self._peer_chain = peer_chain
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self._last_heartbeat_time = time.time()
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prev_state = self._leader_state
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if compatible:
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if prev_state != LeaderState.CONNECTED:
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self.logger.info(
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"Sync: follower connected at %s (chain=%d)", sender_ip, peer_chain
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)
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self._leader_state = LeaderState.CONNECTED
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self._error_message = None
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# Send scroll image immediately on new connection so follower has identical content
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if prev_state != LeaderState.CONNECTED and self._on_follower_connected:
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threading.Thread(
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target=self._on_follower_connected,
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daemon=True, name="sync-leader-img-push"
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).start()
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else:
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self._leader_state = LeaderState.INCOMPATIBLE
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self._error_message = (
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f"Incompatible panels: follower is {peer_cols}x{peer_rows}, "
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f"leader is {local_cols}x{local_rows}. "
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f"rows and cols must match between displays."
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)
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if prev_state != LeaderState.INCOMPATIBLE:
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self.logger.error("Sync: %s", self._error_message)
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if self._leader_state != prev_state:
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self.write_status_file()
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ack = json.dumps({
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"t": "hello_ack",
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"compatible": compatible,
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"leader_width": self._leader_width,
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"error": self._error_message,
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}).encode("utf-8")
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try:
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self._send_sock.sendto(ack, (sender_ip, self.port))
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except Exception as exc:
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self.logger.debug("Sync: hello_ack send failed: %s", exc)
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def _leader_watchdog(self) -> None:
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while self._running:
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time.sleep(1.0)
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if self._leader_state == LeaderState.CONNECTED:
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if time.time() - self._last_heartbeat_time > PEER_TIMEOUT:
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self.logger.info(
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"Sync: follower heartbeat timeout — peer disconnected"
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)
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self._leader_state = LeaderState.NO_PEER
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self._peer_ip = None
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self._peer_compatible = False
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self.write_status_file()
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def _image_server_loop(self) -> None:
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"""Follower: TCP server that receives the leader's scroll image at each new cycle."""
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while self._running:
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try:
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conn, addr = self._img_server_sock.accept()
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conn.settimeout(10.0)
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try:
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# 4-byte big-endian length prefix
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hdr = b""
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while len(hdr) < 4:
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chunk = conn.recv(4 - len(hdr))
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if not chunk:
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break
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hdr += chunk
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if len(hdr) < 4:
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continue
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length = int.from_bytes(hdr, "big")
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_MAX_IMAGE_BYTES = 10 * 1024 * 1024 # 10 MB — well above any real scroll image
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if length <= 0 or length > _MAX_IMAGE_BYTES:
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self.logger.warning(
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"Sync: rejected TCP image with invalid length %d (max %d) from %s",
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length, _MAX_IMAGE_BYTES, addr,
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)
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conn.close()
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continue
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data = bytearray()
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while len(data) < length:
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chunk = conn.recv(min(65536, length - len(data)))
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if not chunk:
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break
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data.extend(chunk)
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img = Image.open(io.BytesIO(data))
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_MAX_W, _MAX_H = 100_000, 256 # generous for any real scroll image
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if img.width > _MAX_W or img.height > _MAX_H:
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self.logger.warning(
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"Sync: rejected oversized scroll image %dx%d (max %dx%d) from %s",
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img.width, img.height, _MAX_W, _MAX_H, addr,
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)
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continue
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try:
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img.load()
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except (Image.DecompressionBombError, ValueError) as exc:
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self.logger.warning("Sync: rejected decompression bomb from %s: %s", addr, exc)
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continue
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self.logger.info(
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"Sync: received scroll image %dx%d (%d bytes compressed)",
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img.width, img.height, length,
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)
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with self._scroll_image_lock:
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if self._on_scroll_image:
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cb = self._on_scroll_image
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else:
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# Callback not registered yet (startup race) — cache it
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self._pending_scroll_image = img
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cb = None
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if cb:
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cb(img)
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finally:
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conn.close()
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except socket.timeout:
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continue
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except Exception as exc:
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self.logger.debug("Sync: image server error: %s", exc)
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def send_scroll_image(self, image: Image.Image) -> None:
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"""Leader: send the full scroll image to the follower via TCP.
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PNG compression typically reduces a 5000×32 image to ~20–50KB,
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transferring in <20ms on local WiFi. Called at new_cycle and on
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first connection so both Pis always have identical cached_arrays.
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"""
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if self.role != SyncRole.LEADER:
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return
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if self._leader_state != LeaderState.CONNECTED or not self._peer_ip:
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return
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try:
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buf = io.BytesIO()
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image.save(buf, format="PNG", optimize=True)
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data = buf.getvalue()
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with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as sock:
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sock.settimeout(5.0)
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sock.connect((self._peer_ip, self.port + 1))
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sock.sendall(len(data).to_bytes(4, "big") + data)
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self.logger.info(
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"Sync: sent scroll image %dx%d (%d bytes compressed)",
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image.width, image.height, len(data),
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)
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except Exception as exc:
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self.logger.debug("Sync: image send error: %s", exc)
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def set_on_follower_connected(self, callback: Callable[[], None]) -> None:
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"""Leader: callback fired (in a thread) when a compatible follower first connects.
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Use this to push the current scroll image immediately.
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If a follower is already connected when this is called, fires right away
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(handles the race where follower connects during leader startup).
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"""
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self._on_follower_connected = callback
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if self._leader_state == LeaderState.CONNECTED:
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threading.Thread(
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target=callback, daemon=True, name="sync-leader-img-push-late"
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).start()
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def set_on_scroll_image(self, callback: Callable[[Image.Image], None]) -> None:
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"""Follower: callback fired with the received Image when leader sends scroll image.
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If an image was received before this callback was registered (startup race),
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fires immediately with that cached image.
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"""
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with self._scroll_image_lock:
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self._on_scroll_image = callback
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pending = self._pending_scroll_image
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self._pending_scroll_image = None
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if pending is not None:
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callback(pending)
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def send_scroll_x(self, scroll_x: float) -> None:
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"""Leader (Vegas mode): broadcast scroll position instead of a pixel frame.
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The follower renders from its own local pipeline at scroll_x - display_width.
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~20 bytes vs ~18KB for raw frames — eliminates all content-change artifacts.
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"""
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if self.role != SyncRole.LEADER:
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return
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if self._leader_state != LeaderState.CONNECTED or not self._peer_ip:
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return
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try:
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msg = json.dumps({"t": "sx", "x": round(scroll_x, 2)}).encode("utf-8")
|
||||
self._send_sock.sendto(msg, (self._peer_ip, self.port))
|
||||
except Exception as exc:
|
||||
self.logger.debug("Sync: scroll_x send error: %s", exc)
|
||||
|
||||
def send_new_cycle(self) -> None:
|
||||
"""Leader: signal that a new scroll cycle has started so follower rebuilds its image."""
|
||||
if self.role != SyncRole.LEADER:
|
||||
return
|
||||
if self._leader_state != LeaderState.CONNECTED or not self._peer_ip:
|
||||
return
|
||||
try:
|
||||
self._send_sock.sendto(b'{"t":"nc"}', (self._peer_ip, self.port))
|
||||
except Exception as exc:
|
||||
self.logger.debug("Sync: new_cycle send error: %s", exc)
|
||||
|
||||
def send_frame(self, image: Image.Image) -> None:
|
||||
"""Leader: send a rendered frame to the follower as raw RGB bytes.
|
||||
Raw format is orders of magnitude faster than PNG on Pi hardware —
|
||||
no encode on sender, no decode on receiver.
|
||||
Packet: 8-byte magic + 4-byte (width, height) header + raw RGB bytes.
|
||||
"""
|
||||
if self.role != SyncRole.LEADER:
|
||||
return
|
||||
if self._leader_state != LeaderState.CONNECTED or not self._peer_ip:
|
||||
return
|
||||
try:
|
||||
arr = np.asarray(image.convert("RGB"), dtype=np.uint8)
|
||||
header = _RAW_MAGIC + _RAW_HEADER.pack(image.width, image.height)
|
||||
data = header + arr.tobytes()
|
||||
if len(data) <= 65000:
|
||||
self._send_sock.sendto(data, (self._peer_ip, self.port))
|
||||
elif not getattr(self, '_oversized_frame_warned', False):
|
||||
self._oversized_frame_warned = True
|
||||
self.logger.warning(
|
||||
"Sync: frame too large for UDP (%d bytes, max 65000) — "
|
||||
"image %dx%d will not be sent; use TCP image sync instead",
|
||||
len(data), image.width, image.height,
|
||||
)
|
||||
except Exception as exc:
|
||||
self.logger.debug("Sync: frame send error: %s", exc)
|
||||
|
||||
def set_leader_width(self, width: int) -> None:
|
||||
"""Called by DisplayController once display_manager.width is known."""
|
||||
self._leader_width = width
|
||||
|
||||
# ------------------------------------------------------------------ #
|
||||
# Follower setup #
|
||||
# ------------------------------------------------------------------ #
|
||||
|
||||
def _start_follower(self) -> None:
|
||||
# Receive socket: listens for frames + hello_ack from leader
|
||||
self._recv_sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
|
||||
self._recv_sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
|
||||
self._recv_sock.bind(("", self.port)) # nosec B104 — intentional: must receive UDP broadcast on all interfaces
|
||||
self._recv_sock.settimeout(0.1)
|
||||
|
||||
# Send socket: broadcasts hello + heartbeat
|
||||
self._send_sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
|
||||
self._send_sock.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
|
||||
|
||||
self._running = True
|
||||
threading.Thread(
|
||||
target=self._follower_recv_loop, daemon=True, name="sync-follower-recv"
|
||||
).start()
|
||||
threading.Thread(
|
||||
target=self._follower_announce_loop, daemon=True, name="sync-follower-announce"
|
||||
).start()
|
||||
threading.Thread(
|
||||
target=self._follower_watchdog, daemon=True, name="sync-follower-watchdog"
|
||||
).start()
|
||||
# TCP server: receives scroll images from leader (port + 1)
|
||||
self._img_server_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) # nosec B104
|
||||
self._img_server_sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
|
||||
self._img_server_sock.bind(("", self.port + 1)) # nosec B104 — intentional: TCP server must accept connections on all interfaces
|
||||
self._img_server_sock.listen(1)
|
||||
self._img_server_sock.settimeout(1.0)
|
||||
threading.Thread(
|
||||
target=self._image_server_loop, daemon=True, name="sync-image-server"
|
||||
).start()
|
||||
|
||||
self.logger.info(
|
||||
"Sync: follower started on UDP port %d, image server on TCP %d",
|
||||
self.port, self.port + 1,
|
||||
)
|
||||
self.write_status_file()
|
||||
|
||||
def _follower_recv_loop(self) -> None:
|
||||
while self._running:
|
||||
try:
|
||||
data, addr = self._recv_sock.recvfrom(65535)
|
||||
sender_ip = addr[0]
|
||||
|
||||
if data[:8] == _RAW_MAGIC or len(data) > 512:
|
||||
# Frame data: prefer magic-tagged raw RGB; fall back to legacy PNG
|
||||
try:
|
||||
if data[:8] == _RAW_MAGIC:
|
||||
w, h = _RAW_HEADER.unpack(data[8:12])
|
||||
raw = data[12:]
|
||||
img = Image.frombuffer(
|
||||
"RGB", (w, h), raw, "raw", "RGB", 0, 1
|
||||
)
|
||||
else:
|
||||
# Fallback: try legacy PNG
|
||||
img = Image.open(io.BytesIO(data))
|
||||
img.load()
|
||||
with self._frame_lock:
|
||||
self._latest_frame = img
|
||||
self._last_leader_frame_time = time.time()
|
||||
self._leader_ip = sender_ip
|
||||
|
||||
if self._follower_state == FollowerState.STANDALONE:
|
||||
self._follower_state = FollowerState.FOLLOWER
|
||||
self.logger.info(
|
||||
"Sync: leader active at %s — switching to follower mode",
|
||||
sender_ip,
|
||||
)
|
||||
self.write_status_file()
|
||||
except Exception as exc:
|
||||
self.logger.debug("Sync: frame decode error: %s", exc)
|
||||
else:
|
||||
# Control message
|
||||
try:
|
||||
msg = json.loads(data.decode("utf-8"))
|
||||
t = msg.get("t")
|
||||
if t == "hello_ack":
|
||||
self._leader_ip = sender_ip
|
||||
self._peer_compatible = msg.get("compatible", False)
|
||||
self._error_message = msg.get("error")
|
||||
if not self._peer_compatible and self._error_message:
|
||||
self.logger.error(
|
||||
"Sync: leader rejected handshake — %s",
|
||||
self._error_message,
|
||||
)
|
||||
self.write_status_file()
|
||||
elif t == "sx":
|
||||
# Vegas scroll-position sync — tiny message, renders locally
|
||||
self._latest_scroll_x = float(msg["x"])
|
||||
self._last_leader_frame_time = time.time()
|
||||
self._leader_ip = sender_ip
|
||||
if self._follower_state == FollowerState.STANDALONE:
|
||||
self._follower_state = FollowerState.FOLLOWER
|
||||
self.logger.info(
|
||||
"Sync: leader active at %s — switching to follower mode",
|
||||
sender_ip,
|
||||
)
|
||||
self.write_status_file()
|
||||
if self._on_new_cycle:
|
||||
self._on_new_cycle() # build initial scroll image
|
||||
elif t == "nc":
|
||||
# Leader started a new scroll cycle — rebuild local image
|
||||
if self._on_new_cycle:
|
||||
self._on_new_cycle()
|
||||
except (json.JSONDecodeError, UnicodeDecodeError, KeyError):
|
||||
pass
|
||||
|
||||
except socket.timeout:
|
||||
continue
|
||||
except Exception as exc:
|
||||
self.logger.debug("Sync follower recv error: %s", exc)
|
||||
|
||||
def _follower_announce_loop(self) -> None:
|
||||
hw = self._hw_config
|
||||
hello = json.dumps({
|
||||
"t": "hello",
|
||||
"rows": hw.get("rows", 32),
|
||||
"cols": hw.get("cols", 64),
|
||||
"chain": hw.get("chain_length", 1),
|
||||
}).encode("utf-8")
|
||||
heartbeat = json.dumps({"t": "hb"}).encode("utf-8")
|
||||
dest = ("<broadcast>", self.port)
|
||||
|
||||
last_hello = 0.0
|
||||
last_hb = 0.0
|
||||
|
||||
while self._running:
|
||||
now = time.time()
|
||||
if now - last_hello >= HELLO_INTERVAL:
|
||||
try:
|
||||
self._send_sock.sendto(hello, dest)
|
||||
last_hello = now
|
||||
except Exception as exc:
|
||||
self.logger.debug("Sync: hello broadcast error: %s", exc)
|
||||
if now - last_hb >= HEARTBEAT_INTERVAL:
|
||||
try:
|
||||
self._send_sock.sendto(heartbeat, dest)
|
||||
last_hb = now
|
||||
except Exception as exc:
|
||||
self.logger.debug("Sync: heartbeat error: %s", exc)
|
||||
time.sleep(0.5)
|
||||
|
||||
def _follower_watchdog(self) -> None:
|
||||
while self._running:
|
||||
time.sleep(1.0)
|
||||
if self._follower_state == FollowerState.FOLLOWER:
|
||||
if time.time() - self._last_leader_frame_time > LEADER_TIMEOUT:
|
||||
self.logger.info(
|
||||
"Sync: leader frame timeout — returning to standalone mode"
|
||||
)
|
||||
self._follower_state = FollowerState.STANDALONE
|
||||
with self._frame_lock:
|
||||
self._latest_frame = None
|
||||
self.write_status_file()
|
||||
|
||||
# ------------------------------------------------------------------ #
|
||||
# Public API #
|
||||
# ------------------------------------------------------------------ #
|
||||
|
||||
def is_follower_active(self) -> bool:
|
||||
"""True when this Pi is in active follower mode (receiving frames)."""
|
||||
return (
|
||||
self.role == SyncRole.FOLLOWER
|
||||
and self._follower_state == FollowerState.FOLLOWER
|
||||
)
|
||||
|
||||
def get_latest_scroll_x(self) -> Optional[float]:
|
||||
"""Follower: return the most recently received Vegas scroll position, or None."""
|
||||
return self._latest_scroll_x
|
||||
|
||||
def set_on_new_cycle(self, callback: Callable[[], None]) -> None:
|
||||
"""Follower: register a callback fired when the leader starts a new scroll cycle.
|
||||
Used to trigger a local start_new_cycle() so both Pis rebuild from same fresh data.
|
||||
"""
|
||||
self._on_new_cycle = callback
|
||||
|
||||
def get_latest_frame(self) -> Optional[Image.Image]:
|
||||
"""Follower: return the most recently received pixel frame (non-Vegas fallback)."""
|
||||
with self._frame_lock:
|
||||
return self._latest_frame
|
||||
|
||||
def get_status(self) -> dict:
|
||||
"""Return sync state dict for the web API status endpoint."""
|
||||
hw = self._hw_config
|
||||
base = {
|
||||
"role": self.role.value,
|
||||
"port": self.port,
|
||||
"local_rows": hw.get("rows", 32),
|
||||
"local_cols": hw.get("cols", 64),
|
||||
"local_chain": hw.get("chain_length", 1),
|
||||
}
|
||||
|
||||
if self.role == SyncRole.STANDALONE:
|
||||
return {**base, "state": "standalone"}
|
||||
|
||||
if self.role == SyncRole.LEADER:
|
||||
return {
|
||||
**base,
|
||||
"state": self._leader_state.value,
|
||||
"peer_ip": self._peer_ip,
|
||||
"peer_compatible": self._peer_compatible,
|
||||
"peer_chain": self._peer_chain,
|
||||
"leader_width": self._leader_width,
|
||||
"error": self._error_message,
|
||||
}
|
||||
|
||||
# Follower
|
||||
return {
|
||||
**base,
|
||||
"state": self._follower_state.value,
|
||||
"leader_ip": self._leader_ip,
|
||||
"peer_compatible": self._peer_compatible,
|
||||
"error": self._error_message,
|
||||
}
|
||||
|
||||
def write_status_file(self) -> None:
|
||||
"""Write current sync status to STATUS_FILE for the web UI to read."""
|
||||
try:
|
||||
status = self.get_status()
|
||||
status["ts"] = time.time()
|
||||
tmp = STATUS_FILE + ".tmp"
|
||||
with open(tmp, "w") as f:
|
||||
json.dump(status, f)
|
||||
os.replace(tmp, STATUS_FILE)
|
||||
except Exception as exc:
|
||||
self.logger.debug("Sync: status file write error: %s", exc)
|
||||
|
||||
def stop(self) -> None:
|
||||
"""Shut down threads and close sockets."""
|
||||
self._running = False
|
||||
for sock in (self._recv_sock, self._send_sock, self._img_server_sock):
|
||||
if sock:
|
||||
try:
|
||||
sock.close()
|
||||
except Exception as exc:
|
||||
self.logger.debug("Sync: error closing socket: %s", exc)
|
||||
Reference in New Issue
Block a user