Snappier

What's Changed

• Fix nullable attributes leaking as public by @brantburnett in https://github.com/brantburnett/Snappier/pull/94

Full Changelog: https://github.com/brantburnett/Snappier/compare/release/1.1.5...release/1.1.6

What's Changed

• Update README.md - Correcting wrong descriptions by @mjebrahimi in https://github.com/brantburnett/Snappier/pull/91
• Switch NuGet to use a license expression to assist with SBOM analysis by @brantburnett in https://github.com/brantburnett/Snappier/pull/93

New Contributors

• @mjebrahimi made their first contribution in https://github.com/brantburnett/Snappier/pull/91

Full Changelog: https://github.com/brantburnett/Snappier/compare/release/1.1.4...release/1.1.5

This release primarily includes performance improvements around stream decompression in .NET 8, but does show some minor decompression improvements on other runtimes (except .NET 4.8 which is not a priority). Also includes a bug fix for a stream decompression corner case.

What's Changed

• Eliminate most CharTable range checks by @brantburnett in https://github.com/brantburnett/Snappier/pull/81
• Apply various code analysis improvements by @brantburnett in https://github.com/brantburnett/Snappier/pull/82
• Handle null chunk type using enum value by @brantburnett in https://github.com/brantburnett/Snappier/pull/83
• Improve .NET 8 stream decompression perf by @brantburnett in https://github.com/brantburnett/Snappier/pull/84
• Refactor DecompressAllTags to reduce duplicate code by @brantburnett in https://github.com/brantburnett/Snappier/pull/85
• Use an inline array for decompression scratch by @brantburnett in https://github.com/brantburnett/Snappier/pull/86
• Fix stream decompression corner case failure by @brantburnett in https://github.com/brantburnett/Snappier/pull/89
• Don't pass around references to the scrach buffer by @brantburnett in https://github.com/brantburnett/Snappier/pull/90

Decompression Benchmarks

BenchmarkDotNet v0.13.10, Windows 11 (10.0.22621.3007/22H2/2022Update/SunValley2)
12th Gen Intel Core i7-1270P, 1 CPU, 16 logical and 12 physical cores
.NET SDK 8.0.101

Full Changelog: https://github.com/brantburnett/Snappier/compare/release/1.1.3...release/1.1.4

What's Changed

• Update to target .NET 8 by @brantburnett in https://github.com/brantburnett/Snappier/pull/80

Full Changelog: https://github.com/brantburnett/Snappier/compare/release/1.1.2...release/1.1.3

What's Changed

• Update COPYING.txt by @brantburnett in https://github.com/brantburnett/Snappier/pull/74
• Rework test reporter for public PRs by @brantburnett in https://github.com/brantburnett/Snappier/pull/78
• Fix test reporter typo by @brantburnett in https://github.com/brantburnett/Snappier/pull/79
• check table size greater than by @ak88 in https://github.com/brantburnett/Snappier/pull/77

New Contributors

• @ak88 made their first contribution in https://github.com/brantburnett/Snappier/pull/77

Full Changelog: https://github.com/brantburnett/Snappier/compare/release/1.1.1...release/1.1.2

This release includes some fixes to logic that could have caused unsafe memory access in cases where GC rearranges memory if they occurred at the precise moment when an out-of-range reference was on the stack. These moments are very short-lived and should be impossible to create intentionally, but they still represent a security risk.

What's Changed

• Allow ref byte to point just past the end of spans by @brantburnett in https://github.com/brantburnett/Snappier/pull/73

Full Changelog: https://github.com/brantburnett/Snappier/compare/release/1.1.0...release/1.1.1

Breaking Changes

This release no longer includes explicit support for the unsupported runtimes .NET Core 3.0/3.1 or .NET 5.0. These runtimes are now supported via the .NET Standard 2.0 target. While they should still function, it is untested and the lack of hardware intrinsic support will most likely result in degraded performance compared to 1.0.

What's Changed

• All use of GC pinning and fixed buffers has been replaced with byte references and System.Runtime.CompilerServices.Unsafe. This should have less impact on garbage collection performance, especially on systems with continuous Snappy load.
• Reduced heap allocations
• Ported some performance improvements from the reference implementation that were added since the original port
• Lots more performance tweaks

Performance

This release sees a consistent improvement in both compression and decompression performance across all supported frameworks on my Core i7-10850H CPU, especially on decompression. On .NET 6, the time was reduced by 18% when compressing 64KB of HTML and 52% when decompressing. In some cases, the decompression time is reduced by as much as 66%.

Changelog

• Add .NET 6.0 target by @brantburnett in https://github.com/brantburnett/Snappier/pull/40
• Update CodeQL to use .NET 6 by @brantburnett in https://github.com/brantburnett/Snappier/pull/41
• Remove support for unsupported runtimes by @brantburnett in https://github.com/brantburnett/Snappier/pull/42
• Rename GitHub actions and run on release branches by @brantburnett in https://github.com/brantburnett/Snappier/pull/43
• Preload Pshufb fill pattern Vector128 by @brantburnett in https://github.com/brantburnett/Snappier/pull/44
• Make unit tests .NET 4.8 compatible by @brantburnett in https://github.com/brantburnett/Snappier/pull/45
• Switch CopyHelpers to use ref byte instead of byte* by @brantburnett in https://github.com/brantburnett/Snappier/pull/46
• Improve perf of UnalignedCopy64/128 by @brantburnett in https://github.com/brantburnett/Snappier/pull/47
• Rewrite decompressor AppendXXX methods to use refs by @brantburnett in https://github.com/brantburnett/Snappier/pull/48
• Rewrite decompressor RefillTagFromScatch method to use refs by @brantburnett in https://github.com/brantburnett/Snappier/pull/49
• Switch decompression input and scratch to use ref byte by @brantburnett in https://github.com/brantburnett/Snappier/pull/50
• Switch decompression buffer and op to use ref byte by @brantburnett in https://github.com/brantburnett/Snappier/pull/51
• Move steps to decompress from scratch to a separate method by @brantburnett in https://github.com/brantburnett/Snappier/pull/52
• Switch compression hash table from pinned ptr to ref by @brantburnett in https://github.com/brantburnett/Snappier/pull/53
• Reduce compression heap and buffer overhead by @brantburnett in https://github.com/brantburnett/Snappier/pull/54
• Use ref byte for compression output pointer by @brantburnett in https://github.com/brantburnett/Snappier/pull/55
• Use ref byte for compression input pointers by @brantburnett in https://github.com/brantburnett/Snappier/pull/56
• Switch stream decompression from pointers to spans by @brantburnett in https://github.com/brantburnett/Snappier/pull/57
• Use ThrowHelper for all exceptions by @brantburnett in https://github.com/brantburnett/Snappier/pull/58
• Cleanup benchmarks by @brantburnett in https://github.com/brantburnett/Snappier/pull/59
• Allow shorter compression output buffer lengths by @brantburnett in https://github.com/brantburnett/Snappier/pull/60
• Improve benchmark summaries by @brantburnett in https://github.com/brantburnett/Snappier/pull/61
• Fix compression stream benchmarks by @brantburnett in https://github.com/brantburnett/Snappier/pull/62
• Improve block benchmarks by @brantburnett in https://github.com/brantburnett/Snappier/pull/63
• Improve speed of hash table clear by @brantburnett in https://github.com/brantburnett/Snappier/pull/64
• Simplify PSHUFB copy logic for .NET 6/7 by @brantburnett in https://github.com/brantburnett/Snappier/pull/65
• Use CRC32 hash when available during compression by @brantburnett in https://github.com/brantburnett/Snappier/pull/66
• Remove some unnecessary unsafe blocks by @brantburnett in https://github.com/brantburnett/Snappier/pull/67
• Use ArrayPool instead of MemoryPool for the lookback buffer by @brantburnett in https://github.com/brantburnett/Snappier/pull/68
• Improve Log2Floor for legacy runtimes by @brantburnett in https://github.com/brantburnett/Snappier/pull/69
• Optimize FindMatchLength for x64 by @brantburnett in https://github.com/brantburnett/Snappier/pull/70
• Simplify stream decompress logic by @brantburnett in https://github.com/brantburnett/Snappier/pull/71
• Switch several arrays to static data references by @brantburnett in https://github.com/brantburnett/Snappier/pull/72

Full Changelog: https://github.com/brantburnett/Snappier/compare/release/1.0.0...release/1.1.0

Note that this release is focused on performance on Intel/AMD x64 processes on .NET Core 3.1 or .NET 5. It uses Intel intrinsics extensively, so performance will be slower on other CPU architectures or runtimes.

Various bug fixes found during beta