Chrome does not cache 206 Partial Content responses for <video> elements
without an explicit Cache-Control header. When VirtualScroller recycles
cards and creates new <video> elements with the same URL, Chrome
re-downloads the full video (several MB each) instead of using the cache.
Verified via Chrome DevTools: same .mp4 URL appears 2-3 times in network
trace as separate requests with no cache hit, each returning 206. With
Cache-Control: max-age=86400, the browser will reuse the cached response
for 24 hours across scroll cycles.
Video preview files are ~3.5MB while image previews are ~50-100KB (due
to WebP optimization), making caching especially impactful for videos.
The previous commit (a19ddc14) restored Linux sendfile but kept the
manual streaming path for Windows via sys.platform guard. A Windows
user reports performance is still worse than v1.0.5.
Switch back to web.FileResponse for all files on all platforms as the
default. The IOCP crash is an edge case (fast scrolling through many
video previews) that affects few users, while the Python chunked I/O
performance penalty affects everyone.
_stream_file() is kept as an unused fallback for a future compat
setting toggle.
- Restrict manual video streaming to Windows only (sys.platform == 'win32');
Linux/macOS now uses kernel sendfile (zero-copy DMA) via aiohttp FileResponse
- Add Cache-Control: public, max-age=86400 to streaming responses so browsers
cache video previews across scroll cycles
- Increase chunk size from 256KB to 1MB to reduce async iteration overhead on
Windows where streaming is still required
aiohttp's FileResponse uses _sendfile_native on Windows (IOCP-based), which crashes with ov.getresult() when the client disconnects mid-transfer. This happens constantly when users scroll through a gallery of animated previews (video files like .mp4/.webm).
Detect video extensions and stream manually via StreamResponse + chunked reads instead, gracefully handling ConnectionResetError. Images continue using FileResponse (small files, sendfile works fine).
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
- Add `_entry_is_symlink` method to detect symlinks and Windows junctions
- Include first-level symlinks in fingerprint for better cache invalidation
- Re-enable preview path validation for security
- Update tests to verify retargeted symlinks trigger rescan
Temporary workaround for issues #772 and #774 where valid previews
are rejected. Path validation is disabled until proper fix for
preview root path handling is implemented.
