brk/crates/byteview

brk_byteview

BRK-maintained fork of byteview, published separately for use by the Bitcoin Research Kit. Its Rust library name remains byteview.

An immutable byte slice that may be inlined, and can be partially cloned without heap allocation.

Think of it as a specialized Arc<[u8]> that can be inlined (skip allocation for small values) and no weak count.

byteview was originally designed to speed up deserialization in lsm-tree, allow inlining of small values and reduce memory usage compared to Arc'd slices. Values with a known length can be constructed 2-2.5x faster than using Arc<[u8]>:

Sponsors

Memory usage

Allocating 200M "" (len=0) strings:

Struct	Memory Usage
Arc<[u8]>	9.6 GB
tokio::Bytes	6.4 GB
ByteView	4.8 GB

Allocating 200M "helloworld" (len=10) strings:

Struct	Memory Usage
Arc<[u8]>	12.8 GB
tokio::Bytes	12.8 GB
ByteView	4.8 GB

Allocating 100M "helloworldhelloworld" (len=20) strings:

Struct	Memory Usage
Arc<[u8]>	6.4 GB
tokio::Bytes	6.4 GB
ByteView	2.4 GB

Allocating 50M "helloworldhelloworldhelloworldhelloworld" (len=30) strings:

Struct	Memory Usage
Arc<[u8]>	4.0 GB
tokio::Bytes	4.0 GB
ByteView	3.6 GB

Allocating 500k "helloworld".repeat(1000) (len=10'000) strings:

Struct	Memory Usage
Arc<[u8]>	5 GB
tokio::Bytes	5 GB
ByteView	5 GB

Run fuzz tests

cargo +nightly fuzz run fuzz_target_1