Alex Blank
c754984df8
Complete rewrite of the terminal pipeline for VS Code Server-level responsiveness. Key improvements: Backend: - Replace blocking select.select(0.1) with asyncio.add_reader() for event-driven PTY reading (eliminates ~110ms polling latency) - Add output batching (2ms window) to reduce WebSocket frame overhead - Add flow control: client acks processed bytes, server pauses PTY reads at 64KB threshold, resumes at 32KB - Add 5s ack timeout fallback to prevent stuck sessions Frontend: - Switch WebSocket to binary mode (binaryType = 'arraybuffer') - Eliminate Blob -> arrayBuffer async conversion overhead - Add flow control ack messages (every 4096 bytes or 100ms) - Add xterm-addon-webgl with graceful DOM fallback - Add performance tuning (scrollback=10000, fastScrollSensitivity) SDD artifacts: - openspec/explorations/terminal-responsiveness.md - openspec/proposals/terminal-responsiveness.md - openspec/specs/terminal-responsiveness.md - openspec/designs/terminal-responsiveness.md - openspec/tasks/terminal-responsiveness.md Quality gates: pytest (19 passed, 1 skipped), tsc --noEmit clean
61 lines
2.0 KiB
Markdown
61 lines
2.0 KiB
Markdown
# Tasks: High-Performance Web Terminal
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## Task 1: Rewrite TerminalSession with asyncio-native I/O
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**Status:** pending
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**Files:** `apps/api/src/services/terminal_session.py` (full rewrite)
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**Description:**
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- Replace `select.select()` with `asyncio.add_reader()` for event-driven PTY reading
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- Add output batching (2ms window)
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- Add flow control (pause/resume based on client ack)
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- Keep docker exec subprocess (optimized)
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- Remove circular buffer (not needed with event-driven architecture)
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## Task 2: Update TerminalManager for new session class
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**Status:** pending
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**Files:** `apps/api/src/services/terminal_manager.py`
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**Description:**
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- Update imports to use rewritten TerminalSession
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- Verify session lifecycle methods still work
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- Update DB persistence calls
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## Task 3: Update WebSocket endpoint for binary frames + flow control
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**Status:** pending
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**Files:** `apps/api/src/api/terminal.py`
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**Description:**
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- Accept binary output frames from TerminalSession
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- Handle `ack` flow control messages from client
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- Send `ping` heartbeat
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- Maintain existing auth and session management
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## Task 4: Update frontend for binary WebSocket + WebGL
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**Status:** pending
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**Files:** `apps/web/src/components/terminal.tsx`, `apps/web/package.json`
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**Description:**
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- Set `ws.binaryType = "arraybuffer"`
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- Send flow control `ack` messages
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- Add xterm-addon-webgl with DOM fallback
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- Optimize resize handling
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## Task 5: Add performance benchmarks
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**Status:** pending
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**Files:** `apps/api/tests/benchmark_terminal.py`
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**Description:**
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- Input latency benchmark
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- Output throughput benchmark
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- Resize latency benchmark
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- Reconnection time benchmark
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## Task 6: Update/fix unit tests
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**Status:** pending
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**Files:** `apps/api/tests/unit/test_tool_instances_legacy.py`, new tests
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**Description:**
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- Fix any tests broken by terminal changes
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- Add tests for new TerminalSession features
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## Task 7: Run full test suite
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**Status:** pending
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**Description:**
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- Run all API tests
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- Verify no regressions
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- Report quality gate results
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