v0.3.0

What's Changed

No breaking changes. All existing APIs remain fully backward compatible. Code written for v0.2.0 works without modification.

New Features

• Add batch write APIs: setCellValues(), setRowValues(), setSheetData() for efficient bulk cell writes with a single FFI call
• Add binary buffer protocol for bulk cell data transfer: getRowsBuffer(), setSheetDataBuffer(), and SheetData class for O(1) random access
• Add CompactCellRef.from_coordinates() for zero-allocation cell reference construction
• Export new types: SheetData, CellValue, CellTypeName, JsCellEntry

Performance

• 96% memory reduction for large sheet reads (100k rows: 361MB -> 13.5MB) via buffer-based FFI transfer
• 48% faster StreamWriter by eliminating XML serialize-then-deserialize round-trip (direct struct construction)
• Optimize XML Cell memory layout: CellTypeTag enum (1 byte) replaces Option<String>, CompactCellRef ([u8;10] inline) replaces heap-allocated String
• Internal get_rows() returns u32 column numbers instead of String, eliminating ~1M String allocations per large sheet
• O(log n) binary search for row/cell lookup replaces O(n) linear scan; HashMap-based O(1) sheet name index
• SST optimization: pre-sized containers, owned String transfer, reduced allocations on load
• Save path: fast compression (deflate level 1), pre-allocated serialize buffers
• Read path: pre-allocated buffers using ZIP entry size hints

Bug Fixes

• Fix cell.col not populated after applyStreamWriter(), causing binary search lookups to fail
• Fix Biome formatting and folder ignore pattern issues

Build & Infra

• Convert Node.js package from JavaScript to TypeScript (SWC, then migrated to tsdown)
• Replace SWC + tsc pipeline with tsdown for single-step transpilation and .d.ts generation
• Hide NativeWorkbook from public API; re-export SheetData types from package entry
• Add release automation skill

Benchmarks

• Add Rust native benchmark with multi-run statistics (median/min/max/p95/RSS)
• Add Node.js comparison benchmark (SheetKit vs ExcelJS vs SheetJS)
• Fix memory measurement to use RSS instead of heapUsed for accurate native memory tracking

Documentation

• Add buffer transfer architecture docs (binary format spec, dense/sparse auto-switch, FFI strategy)
• Update API reference with bulk data transfer methods and memory comparison tables
• Update charts, images, conditional formatting, and encryption docs for accuracy

Full Changelog: v0.2.0...v0.3.0