Struct CostModel 

pub struct CostModel {
    pub split_cost: i64,
    pub compression_percent: i64,
    pub min_split_items: i64,
    pub runt_patience: u32,
}

The two constants the SectionPolicy::Cost model is built from, exposed so they can be swept rather than argued about.

Fields

split_cost: i64

Bytes a split costs. 64 by default: a fresh section header, a fresh R-tree leaf and the framing of a fresh zlib stream.

compression_percent: i64

Percentage of a widening that survives deflate. 25 by default: the columns a wider encoding adds are near-constant-stride coordinates, of which deflate keeps very little.

min_split_items: i64

Fewest items a section must hold to count as worth writing. Below this SectionPolicy::Runt will not close a section, and SectionPolicy::Adaptive counts one against its patience.

runt_patience: u32

How many too-short sections in a row SectionPolicy::Adaptive writes before it concludes that splitting is not working here.

Trait Implementations

impl Clone for CostModel

fn clone(&self) -> CostModel

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for CostModel

impl Debug for CostModel

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

Formats the value using the given formatter.

impl Default for CostModel

fn default() -> Self

Returns the “default value” for a type.

impl Eq for CostModel

impl PartialEq for CostModel

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for CostModel