fiveq-website-2026/massiveedit/architecture.md

Architecture Blueprint

Layers

1. File Access Layer

• LargeFileBackend wraps buffered random reads.
• ChunkCache adds LRU chunk caching for streaming document access.

2. Text Model Layer

• PieceTable references original file ranges plus append-only add buffer.
• Original bytes are fetched on-demand via callback; no full-file load.

3. Index Layer

• LineIndexer incrementally scans bytes and lazily materializes line starts.

4. Search Layer

• SearchEngine provides basic plain/regex matches.
• SearchThreadPool executes chunked background searches.

5. Session Layer

• DocumentSession coordinates backend/model/index lifecycle.
• Exposes UI-friendly APIs (lines, lineAt, saveAs, undo/redo, startSearch).

6. UI Layer

• MainWindow wires menus and status.
• LargeFileView implements viewport-based rendering for visible lines only.

Milestones

M1 - Real Large File Open

• Done: replaced preview mode with chunked streaming reads + file-backed piece table.
• Done: added LRU cache for original file chunks.

M2 - Editing Correctness

• Done: transactional edit commands and undo/redo stacks.
• Next: persistent durable operation log across restarts.

M3 - Search/Replace at Scale

• Done: worker thread pool and chunked background search.
• Next: match navigation/highlighting and replace workflows.

M4 - Platform Hardening

• CRLF/LF normalization policy.
• File lock conflict handling.
• Recovery and crash-safe temp files.