NEWS

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Rfmalloc 0.1.0

• Fixed native Ops edge semantics to match base R for logical &/| with NA and numeric / by zero (Inf/NaN instead of forcing NA), and corrected mixed-type native Ops regression tests.
• Optimized [[ on fmalloc ALTREP vectors to bypass subset-copy for scalar extraction, removing a major per-element regression hotspot observed in scalar read loops.
• Added version 2 C API exports for zero-copy native interoperability: Rfmalloc_is_fmalloc_vector, Rfmalloc_vector_type, Rfmalloc_vector_length, and Rfmalloc_vector_payload_ptr.
• Added ALTREP regression tests ensuring scalar [[ no longer returns wrapped fmalloc vectors and that out-of-bounds [[ signals the expected bounds error.
• Added ALTREP attribute regression coverage for matrix/array/data.frame attribute roundtripping and set minimum R dependency to R (>= 4.4.0).
• Added create_fmalloc_matrix() and create_fmalloc_array() constructors and create_fmalloc_data_frame() plus as_fmalloc_matrix(), as_fmalloc_array(), and as_fmalloc_data_frame() convenience converters for metadata-only reshaping.
• Switched create_fmalloc_vector() and matrix/array constructors to length/dimension validation that supports non-negative exact double lengths and long-vector-friendly R_xlen_t handling (up to 2^52) while keeping dimension elements within integer limits.
• Added copy = FALSE mode to as_fmalloc_matrix() and as_fmalloc_array() to install shape metadata in-place on fmalloc ALTREP vectors via C-level attribute assignment, with new tests proving this mode avoids additional payload allocations.
• Added S3 class tagging for fmalloc vectors/matrices/arrays and method dispatch for core Ops, Summary, and matrix reduction families (rowSums, colSums, rowMeans, colMeans) so key operators and reductions execute on fmalloc-backed inputs through package-backed handlers.
• Replaced matrix summary/reduction fallback paths with explicit in-package kernels for range, rowSums, colSums, rowMeans, and colMeans so results match base R edge-case semantics while avoiding unnecessary large intermediate allocations.
• Clarified explicit fallback behavior: rowSums(), colSums(), rowMeans(), and colMeans() now warn and delegate to base R when inputs are not exact 2D matrices or dims != 1L; Summary/Math/Math2 scalar or zero-length results remain ordinary R scalars by design.
• Added a runtime-sharing policy for opened runtimes in-process: opening the same backing file path now returns the existing shared runtime (with matching mode) and prevents accidental same-file multi-handle mode mismatches.
• Added diagnose_fmalloc_runtime() for runtime+catalog diagnostics, including record state counts, payload usage summaries, and an explicit compaction status note to explain why catalog compaction is not yet implemented.
• Implemented nested fmalloc list persistence by reference for persistent runtimes.
• Added recursive fmalloc list/container serialized-reference recovery in ALTREP serialization/unserialization.
• Added explicit vector destroy API destroy_fmalloc_vector() with mode-aware semantics and persistent unsafe reclaim mode.
• Added explicit reference-count failure behavior when destroying a vector that is still referenced by another fmalloc list.
• Fixed list child validation to require the same runtime pointer (not only matching UUID) when storing fmalloc elements in fmalloc list containers.
• Hardened ALTREP subset behavior by only taking the fast native path for strictly positive integer indexes; all other index types/values (including 0, negative, fractional REALSXP, and mixed modes) now fall back to base R semantics.
• Switched serialized persistent metadata fields (offset, nbytes, catalog_offset, generation) to fixed-width hex string encoding for exact 64-bit persistence; restoration now accepts both new hex and legacy numeric encodings.
• Clarified that full view-based subset support remains experimental (current behavior is subset-copy with copy-on-write duplication controls).
• Documented Simon Urbanek custom allocator PoC separately from Rfmalloc's prior allocator implementation in README references.