PNG screenshots are now the default for dashboard previews,
with SVG available by setting WEBTERM_SCREENSHOT_MODE=svg.
Documentation and tests updated accordingly.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
The dashboard now always downloads SVG on right-click even when
PNG thumbnails are enabled, while keeping SVG as the default mode
in the docs and tests.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
PNG screenshots are now gated by WEBTERM_SCREENSHOT_MODE.
The dashboard selects SVG by default and switches to PNG when enabled,
with ETag caching and eviction for both formats.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
When no WebSocket client is connected, the session's readLoop still
processes every byte of terminal output through the go-te VT parser
(tracker.Feed), Screen.Draw grapheme segmentation, and string
allocations — even though nobody is consuming the screen state.
For programs like btop inside tmux that produce continuous full-screen
redraws, this causes sustained CPU usage and GC pressure over hours.
Fix: after a 10-second idle threshold (no client connected), skip
tracker.Feed() and only maintain the replay buffer. When a client
reconnects (UpdateConnector) or a screenshot is requested
(GetScreenSnapshot), rebuild the tracker by replaying the buffer
through a fresh VT parser instance.
Changes:
- Add idleSince atomic timestamp + MarkIdle() to Session interface
- handleOutput() skips tracker.Feed when idle > threshold
- UpdateConnector() clears idle flag and rebuilds tracker from replay
- GetScreenSnapshot() rebuilds stale tracker on-demand for screenshots
- Wire MarkIdle() call into handleWebSocket cleanup (client disconnect)
- Add TestIdleTrackerPauseAndRebuild covering the full lifecycle
Close retired websocket connections in stopWSClient so clients reconnect promptly instead of remaining in a stdin-only state with no returning output. Add regression coverage to verify stopWSClient actively disconnects the websocket.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Replace silent output frame dropping with fail-fast slow-client disconnects when websocket send queues saturate, and replace unbounded stdin write goroutine spawning with a bounded queue + worker and timeout-driven disconnect under input backlog. Also add targeted regression tests for queue saturation and stdin backlog disconnect behavior.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Guard route client cleanup against stale websocket/session close paths so newer connections keep receiving output after focus/reconnect transitions. Also refresh websocket read deadlines on every inbound message and add regression tests covering both reconnect and stale-session-close race scenarios.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Introduce a dashboard workflow to export screenshot SVGs without external font URL references.
Server changes:
- Added screenshot query flags: sanitize_font_urls=1 and download=1.
- Added SVG sanitization that strips @font-face src:url(...) for the vendored font path.
- Added safe filename normalization for download responses.
- Added Content-Disposition attachment support for downloadable screenshot exports.
- Preserved existing cache behavior while computing ETags from the actual response variant.
Dashboard changes:
- Added tile contextmenu handler (right-click) to trigger sanitized SVG download per tile.
- Download URL includes cache-busting timestamp to avoid stale browser downloads.
Tests:
- Added coverage for sanitized download response (attachment header + font URL removal).
- Added coverage asserting dashboard HTML includes right-click sanitized download wiring.
- Validated with make format && make check.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Address intermittent stalls seen after many hours by improving liveness detection and failure handling for both streaming channels.
WebSocket changes:
- Added periodic server ping frames and a read deadline refreshed by pong replies.
- On sender write/ping failure, explicitly close the underlying connection so clients promptly observe disconnect and reconnect instead of remaining half-open.
SSE changes:
- Excluded /events from gzip middleware and added X-Accel-Buffering: no to reduce proxy buffering risk.
- Stop the SSE loop on write errors for activity/keepalive frames so dead subscribers are cleaned up immediately.
Tests:
- Added regression coverage for gzip bypass on /events.
- Added regression coverage ensuring SSE handler exits and unsubscribes on write failure.
- Verified with make format && make check.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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