Struct ColumnsCodec 

pub struct ColumnsCodec {
    columns: Vec<DictionaryCodec>,
}

Independently encodes each column.

Fields

columns: Vec<DictionaryCodec>

Implementations

impl ColumnsCodec

pub(crate) fn decode<'a>(&'a self, bytes: &'a [u8]) -> ColumnsIter<'a>

Decode a row-encoded byte slice into per-column byte slices.

pub(crate) fn encode<'a, I>(&mut self, iter: I, output: &mut Vec<u8>)

where I: IntoIterator<Item = &'a [u8]>,

Encode a sequence of column byte slices, updating per-column statistics.

pub(crate) fn new_from<'a>(stats: impl IntoIterator<Item = &'a Self>) -> Self

Construct a codec valid for the union of the supplied codecs’ data.

pub(crate) fn borrow_row(row: &RowRef) -> ColumnsIter<'_>

Reveal a row’s bytes for fast-path comparison, with no codec to consult.

impl ColumnsCodec

pub(crate) fn heap_size(&self, callback: &mut impl FnMut(usize, usize))

Visit contained allocations to determine their size and capacity.

impl ColumnsCodec

pub(crate) fn observe<'a, I>(&mut self, iter: I)

where I: IntoIterator<Item = &'a [u8]>,

Record a row’s column values in the statistics without encoding.

Used during the stats-gathering phase, where we want the heavy-hitter and tag-usage information but store the row raw, so encoding into a throwaway buffer would be pure waste.

impl ColumnsCodec

pub(crate) fn new_safe(self) -> Self

Construct a codec using only structurally safe tags.

Consumes self: this is only ever called on stats that have just been taken out of a container and are about to be discarded, so we move the per-column MisraGries summaries through rather than cloning them.

Trait Implementations

impl Debug for ColumnsCodec

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

Formats the value using the given formatter.

impl Default for ColumnsCodec

fn default() -> ColumnsCodec

Returns the “default value” for a type.