Files
Mainline/engine/app.py
David Gwilliam 4c97cfe6aa fix: Implement ViewportFilterStage to prevent FontStage performance regression with large datasets
## Summary

Fixed critical performance issue where demo/poetry presets would hang for 10+ seconds due to FontStage rendering all 1438+ headline items instead of just the visible ~5 items.

## Changes

### Core Fix: ViewportFilterStage
- New pipeline stage that filters items to only those fitting in the viewport
- Reduces 1438 items → ~5 items (288x reduction) before FontStage
- Prevents expensive PIL font rendering operations on items that won't be displayed
- Located: engine/pipeline/adapters.py:348-403

### Pipeline Integration
- Updated app.py to add ViewportFilterStage before FontStage for headlines/poetry sources
- Ensures correct data flow: source → viewport_filter → font → camera → effects → display
- ViewportFilterStage depends on 'source' capability, providing pass-through filtering

### Display Protocol Enhancement
- Added is_quit_requested() and clear_quit_request() method signatures to Display protocol
- Documented as optional methods for backends supporting keyboard input
- Already implemented by pygame backend, now formally part of protocol

### Debug Infrastructure
- Added MAINLINE_DEBUG_DATAFLOW environment variable logging throughout pipeline
- Logs stage input/output types and data sizes to stderr (when flag enabled)
- Verified working: 1438 → 5 item reduction shown in debug output

### Performance Testing
- Added pytest-benchmark (v5.2.3) as dev dependency for statistical benchmarking
- Created comprehensive performance regression tests (tests/test_performance_regression.py)
- Tests verify:
  - ViewportFilterStage filters 2000 items efficiently (<1ms)
  - FontStage processes filtered items quickly (<50ms)
  - 288x performance improvement ratio maintained
  - Pipeline doesn't hang with large datasets
- All 523 tests passing, including 7 new performance tests

## Performance Impact

**Before:** FontStage renders all 1438 items per frame → 10+ second hang
**After:** FontStage renders ~5 items per frame → sub-second execution

Real-world impact: Demo preset now responsive and usable with news sources.

## Testing

- Unit tests: 523 passed, 16 skipped
- Regression tests: Catch performance degradation with large datasets
- E2E verification: Debug logging confirms correct pipeline flow
- Benchmark suite: Statistical performance tracking enabled
2026-03-16 22:43:53 -07:00

263 lines
8.2 KiB
Python

"""
Application orchestrator — pipeline mode entry point.
"""
import sys
import time
import effects_plugins
from engine import config
from engine.display import DisplayRegistry
from engine.effects import PerformanceMonitor, get_registry, set_monitor
from engine.fetch import fetch_all, fetch_poetry, load_cache
from engine.pipeline import (
Pipeline,
PipelineConfig,
get_preset,
list_presets,
)
from engine.pipeline.adapters import (
SourceItemsToBufferStage,
create_stage_from_display,
create_stage_from_effect,
)
def main():
"""Main entry point - all modes now use presets."""
if config.PIPELINE_DIAGRAM:
try:
from engine.pipeline import generate_pipeline_diagram
except ImportError:
print("Error: pipeline diagram not available")
return
print(generate_pipeline_diagram())
return
preset_name = None
if config.PRESET:
preset_name = config.PRESET
elif config.PIPELINE_MODE:
preset_name = config.PIPELINE_PRESET
else:
preset_name = "demo"
available = list_presets()
if preset_name not in available:
print(f"Error: Unknown preset '{preset_name}'")
print(f"Available presets: {', '.join(available)}")
sys.exit(1)
run_pipeline_mode(preset_name)
def run_pipeline_mode(preset_name: str = "demo"):
"""Run using the new unified pipeline architecture."""
print(" \033[1;38;5;46mPIPELINE MODE\033[0m")
print(" \033[38;5;245mUsing unified pipeline architecture\033[0m")
effects_plugins.discover_plugins()
monitor = PerformanceMonitor()
set_monitor(monitor)
preset = get_preset(preset_name)
if not preset:
print(f" \033[38;5;196mUnknown preset: {preset_name}\033[0m")
sys.exit(1)
print(f" \033[38;5;245mPreset: {preset.name} - {preset.description}\033[0m")
params = preset.to_params()
params.viewport_width = 80
params.viewport_height = 24
pipeline = Pipeline(
config=PipelineConfig(
source=preset.source,
display=preset.display,
camera=preset.camera,
effects=preset.effects,
)
)
print(" \033[38;5;245mFetching content...\033[0m")
# Handle special sources that don't need traditional fetching
introspection_source = None
if preset.source == "pipeline-inspect":
items = []
print(" \033[38;5;245mUsing pipeline introspection source\033[0m")
elif preset.source == "empty":
items = []
print(" \033[38;5;245mUsing empty source (no content)\033[0m")
else:
cached = load_cache()
if cached:
items = cached
elif preset.source == "poetry":
items, _, _ = fetch_poetry()
else:
items, _, _ = fetch_all()
if not items:
print(" \033[38;5;196mNo content available\033[0m")
sys.exit(1)
print(f" \033[38;5;82mLoaded {len(items)} items\033[0m")
# CLI --display flag takes priority over preset
# Check if --display was explicitly provided
display_name = preset.display
if "--display" in sys.argv:
idx = sys.argv.index("--display")
if idx + 1 < len(sys.argv):
display_name = sys.argv[idx + 1]
display = DisplayRegistry.create(display_name)
if not display:
print(f" \033[38;5;196mFailed to create display: {display_name}\033[0m")
sys.exit(1)
display.init(80, 24)
effect_registry = get_registry()
# Create source stage based on preset source type
if preset.source == "pipeline-inspect":
from engine.data_sources.pipeline_introspection import (
PipelineIntrospectionSource,
)
from engine.pipeline.adapters import DataSourceStage
introspection_source = PipelineIntrospectionSource(
pipeline=None, # Will be set after pipeline.build()
viewport_width=80,
viewport_height=24,
)
pipeline.add_stage(
"source", DataSourceStage(introspection_source, name="pipeline-inspect")
)
elif preset.source == "empty":
from engine.data_sources.sources import EmptyDataSource
from engine.pipeline.adapters import DataSourceStage
empty_source = EmptyDataSource(width=80, height=24)
pipeline.add_stage("source", DataSourceStage(empty_source, name="empty"))
else:
from engine.data_sources.sources import ListDataSource
from engine.pipeline.adapters import DataSourceStage
list_source = ListDataSource(items, name=preset.source)
pipeline.add_stage("source", DataSourceStage(list_source, name=preset.source))
# Add FontStage for headlines/poetry (default for demo)
if preset.source in ["headlines", "poetry"]:
from engine.pipeline.adapters import FontStage, ViewportFilterStage
# Add viewport filter to prevent rendering all items
pipeline.add_stage(
"viewport_filter", ViewportFilterStage(name="viewport-filter")
)
pipeline.add_stage("font", FontStage(name="font"))
else:
# Fallback to simple conversion for other sources
pipeline.add_stage("render", SourceItemsToBufferStage(name="items-to-buffer"))
# Add camera stage if specified in preset
if preset.camera:
from engine.camera import Camera
from engine.pipeline.adapters import CameraStage
camera = None
if preset.camera == "vertical":
camera = Camera.vertical()
elif preset.camera == "horizontal":
camera = Camera.horizontal()
elif preset.camera == "omni":
camera = Camera.omni()
elif preset.camera == "floating":
camera = Camera.floating()
elif preset.camera == "bounce":
camera = Camera.bounce()
if camera:
pipeline.add_stage("camera", CameraStage(camera, name=preset.camera))
for effect_name in preset.effects:
effect = effect_registry.get(effect_name)
if effect:
pipeline.add_stage(
f"effect_{effect_name}", create_stage_from_effect(effect, effect_name)
)
pipeline.add_stage("display", create_stage_from_display(display, display_name))
pipeline.build()
# For pipeline-inspect, set the pipeline after build to avoid circular dependency
if introspection_source is not None:
introspection_source.set_pipeline(pipeline)
if not pipeline.initialize():
print(" \033[38;5;196mFailed to initialize pipeline\033[0m")
sys.exit(1)
print(" \033[38;5;82mStarting pipeline...\033[0m")
print(" \033[38;5;245mPress Ctrl+C to exit\033[0m\n")
ctx = pipeline.context
ctx.params = params
ctx.set("display", display)
ctx.set("items", items)
ctx.set("pipeline", pipeline)
ctx.set("pipeline_order", pipeline.execution_order)
current_width = 80
current_height = 24
if hasattr(display, "get_dimensions"):
current_width, current_height = display.get_dimensions()
params.viewport_width = current_width
params.viewport_height = current_height
try:
frame = 0
while True:
params.frame_number = frame
ctx.params = params
result = pipeline.execute(items)
if result.success:
display.show(result.data, border=params.border)
if hasattr(display, "is_quit_requested") and display.is_quit_requested():
if hasattr(display, "clear_quit_request"):
display.clear_quit_request()
raise KeyboardInterrupt()
if hasattr(display, "get_dimensions"):
new_w, new_h = display.get_dimensions()
if new_w != current_width or new_h != current_height:
current_width, current_height = new_w, new_h
params.viewport_width = current_width
params.viewport_height = current_height
time.sleep(1 / 60)
frame += 1
except KeyboardInterrupt:
pipeline.cleanup()
display.cleanup()
print("\n \033[38;5;245mPipeline stopped\033[0m")
return
pipeline.cleanup()
display.cleanup()
print("\n \033[38;5;245mPipeline stopped\033[0m")
if __name__ == "__main__":
main()