Enum Compression 

pub enum Compression {
    None,
    Gzip(u8),
}

How an HDF5 event dataset is stored on disk.

Events are the one thing eventcv writes in bulk, and they compress far better than their raw width suggests: t is monotonically increasing and p is one bit wearing a whole byte, so a byte shuffle followed by deflate typically more than halves a recording. Uncompressed is still offered because a live capture would rather spend the bytes than the CPU.

Variants

None

Chunked but unfiltered — the fastest to write.

Gzip(u8)

Byte-shuffled, then deflated at this level (1..=9).

Implementations

impl Compression

pub fn level(self) -> Option<u8>

The deflate level, or None when the data is stored unfiltered. Level 0 is treated as off: HDF5 accepts it, but it pays the filter’s framing cost to compress nothing.

Trait Implementations

impl Clone for Compression

fn clone(&self) -> Compression

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for Compression

impl Debug for Compression

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Compression

Gzip level 1, because on event columns almost all of the win comes from the byte shuffle rather than from how hard deflate then looks. Measured on a 167 M-event simulation: unfiltered 2.18 GB / 22 s, level 1 429 MB / 35 s, level 4 408 MB / 42 s. Level 4 spends a fifth more time to save a twentieth more space, which is the wrong side of the trade for a default.

fn default() -> Self

Returns the “default value” for a type.

impl Eq for Compression

impl PartialEq for Compression

fn eq(&self, other: &Compression) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for Compression