svb

svb is a pure-Rust StreamVByte library covering all major codec variants for u16, u32, and u64 integers. Delta and zigzag encoding are composable layers on top. SIMD back-ends are available for x86-64 (SSSE3, AVX2) and AArch64 (NEON).

What is StreamVByte?

StreamVByte is a family of integer compression schemes that store values in a variable number of bytes. Rather than interleaving the control information with the data, StreamVByte places all control bytes in a separate stream. This layout makes SIMD-accelerated decode practical: a batch of control bytes can be loaded and shuffled in a single instruction, determining widths for an entire group of values without branching.

encoded buffer layout
┌────────────────────┬─────────────────────────────────────┐
│   control stream   │            data stream               │
│  ceil(n/4) bytes   │         variable length              │
└────────────────────┴─────────────────────────────────────┘

Each 2-bit tag in the control stream describes the byte width of the corresponding value. Four values share one control byte. The byte widths available depend on the codec variant.

Codec variants at a glance

Variant	Element	Tag width	Byte widths	Best for
`Svb16`	`u16`	1 bit	1/2	ONT VBZ signal data
`U32Classic`	`u32`	2 bits	1/2/3/4	General u32, C-library compatible
`U32Variant0124`	`u32`	2 bits	0/1/2/4	Sparse u32 (many zeros)
`U64Coder1234`	`u64`	2 bits	1/2/3/4	u64 values that fit in u32
`U64Coder1248`	`u64`	2 bits	1/2/4/8	Full u64 range

API docs

Rustdoc API reference is published at docs.rs/svb.