v1.0.0

The first stable release. Both packages leave preview: [Experimental] is removed from every public type, so the ONECOMPRESS001-ONECOMPRESS010 and ONEARCHIVE001 diagnostics no longer exist and the NoWarn entries that opted in can be deleted. From 1.0 the API follows semantic versioning and compressed bytes per codec and level are stable within 1.x (README, Stability). The README speed tables are remeasured against the fastest managed .NET libraries on an AMD Ryzen 9 7950X3D and an Apple M2; the two rows still below the 0.87 bar are marked there.

Added

• Zip recovery mode (ZipReaderOptions.Recovery, MaxRecoveryBytes, ZipReader.Damage, ZipDamage, ZipDamageKind): resynchronises on the next local header after garbage or a damaged header, falls back to the local headers when the end record or central directory is missing or inconsistent, and reports skipped ranges and damaged or truncated entries. Off by default; reading is unchanged without it. The zip-recover fuzz target covers it.
• Documentation: a README on the family shape with compiled snippets, a docs index with one page per codec family and container, package readmes, THIRD-PARTY-NOTICES.md, and XML documentation on every public member. Package validation against 0.7.0-preview.1 runs on every pack.
• bench/Managed: size-matched comparison rows (a row is met when some level of ours is within +1% of the library's size at no less than 0.87 of its speed), small-payload dictionary rows and checksum rows.

Fixed

• LZMA2: Lzma2Encoder.Flush with a binary-tree match finder could write a stream that decoded to different bytes; fixed.

Changed

These speed-ups change compressed bytes at the levels listed (sizes stay within the bar's +1% of the managed libraries; bytes remain identical on every platform and thread count). Other levels write the same bytes as 0.7.0-preview.1.

• Zstandard: faster levels 1-4 (leaner match loops, one-read code tables, search state computed once per block); levels 3-9 (shallower search at 7 and 9, faster greedy level 5, one cut per block with long-distance matching, cheaper block cuts); levels 13-18 (insert-only tree walk, thinner insertions, prefetching in the optimal parser, shallower dense tail at 13, wider at 18); and levels 1-4 with a dictionary, which probe the dictionary at every second or fourth position since the last match and extend matches backward. Compression with a dictionary on small payloads (game snapshot data) is considerably faster. The decoder loops are compiled fully optimized on first use.
• LZMA and xz: faster hash-chain encoder with identical bytes for the same search (batched position insertion, bucket prefetch, branch-free bit coding, wider match compares). Preset 0 uses the 4-byte hash chain, presets 0 and 1 skip the look-ahead for matches of 3 and 4 bytes or more, and preset 2 searches 12 candidates, so bytes at presets 0-2 differ (preset 1 was later retuned again, see below).
• Brotli: faster decode (UTF-8 context table, wider root table, fewer refills). Quality 3 is a four-way greedy parse, quality 4 a single-block-type lazy parse, qualities 1 and 2 are retuned, and qualities 10 and 11 price literals in UTF-8 context, skip the dictionary search under a long tree match, and use finer block splitting (four refinement passes at 11), so bytes at q1-q4, q10 and q11 differ.
• xz/LZMA preset 1 searches less and takes 3-byte matches at once: faster, output differs at preset 1 only.
• LZ4: decoding with a dictionary reads the dictionary in place, keeps its history between blocks and copies short pieces exactly, which makes dictionary decode of small blocks about as fast as the fastest managed library. Compressed bytes are unchanged.
• Timestamps in ar, cpio and ISO 9660 headers that cannot be represented are reported as unknown (null) instead of throwing, found by fuzzing.
• Benchmarks time every candidate in fully optimized code from the first call.