Fix large file memory explosion (Issue #457)#498
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Lcstyle wants to merge 10 commits intopop-os:masterfrom
Closed
Fix large file memory explosion (Issue #457)#498Lcstyle wants to merge 10 commits intopop-os:masterfrom
Lcstyle wants to merge 10 commits intopop-os:masterfrom
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…backup capabilities
Root cause: cosmic-text's shape_until_scroll() uses INFINITY as scroll_end when buffer height is not set, causing ALL lines to be shaped on file load. Each character requires ~200 bytes of glyph/layout data, so a 60MB file was consuming 18.8GB RAM (313x multiplier). Fix: Set a minimal buffer height (100px) before loading files >1MB. This limits initial shaping to ~5 visible lines instead of all lines. The proper height is set during rendering, and additional lines are shaped on-demand as user scrolls. Results: - Before: 60MB file -> 18.8GB RAM (crashes on 8-16GB systems) - After: 60MB file -> 0.2GB RAM (94x memory reduction) Also includes PR pop-os#479 Save As fix: - Added resolve_path() helper for canonical path resolution - Added set_path() and save_as() methods to EditorTab - SaveAsResult now checks if file is already open in another tab Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
For files larger than the configurable threshold (default 5MB), skip the FNV-1a hash computation which iterates over every byte. This eliminates startup lag for large files. Features disabled for large files: - Undo-to-saved detection (check_and_reset_if_unchanged) - Backup content change detection New config option: max_hash_file_size_mb - Default: 5 MB - Set to 0 to always compute hash (not recommended for large files) - Configurable per-user in cosmic-edit settings Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
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Closing in favor of cleaner, separate PRs:
This addresses the review feedback about having too many unrelated commits in one PR. |
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@mmstick it might be a little messy but I am running the updated build locally, loads 200mb instantly, scroll bar works, no more OOM crashes.. I'm not a RUST developer so please have mercy on the code, claude did generate it but the design was mostly mine. BTW Cosmic Desktop is my new primary OS so i need to make this work and make it better everyday. I am running cosmic on Fedora43, thanks for all your hard work so far, it's beautiful and very very fast. |
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Summary
Root Cause Analysis
Found that
cosmic-text'sshape_until_scroll()usesf32::INFINITYasscroll_endwhen buffer height isn't set. This causes ALL lines to be shaped on file load, before the window even renders.Each character requires ~200 bytes of glyph/layout data:
ShapeGlyph: ~100 bytes (positions, font info, metrics, colors)LayoutGlyph: ~100 bytes (positions, font info, bidi level, etc.)Result: 60MB file × 313x multiplier = 18.8GB RAM → OOM crash on systems with <16GB RAM
Fix
Set a minimal buffer height (100px) before loading files >1MB. This limits initial shaping to ~5 visible lines. The proper height is set during rendering, and additional lines are shaped on-demand as user scrolls.
Results
Test Plan
🤖 Generated with Claude Code