Struct ValueDictionary 

pub struct ValueDictionary { /* private fields */ }

Per-collection value dictionary.

Implementations

impl ValueDictionary

pub fn new(config: ValueDictionaryConfig) -> Self

Create a dictionary with custom configuration.

pub fn encode( &mut self, field_id: FieldId, value: &[u8], ) -> Result<StoredValue, DictionaryError>

Encode a value for a field.

Values are dictionary-encoded only when:

• observed field cardinality is below low_cardinality_threshold, and
• value length is at least min_len_for_dictionary.

pub fn decode(&self, stored: &StoredValue) -> Result<Vec<u8>, DictionaryError>

Decode a stored value back to owned bytes.

pub fn cardinality_estimate(&self, field_id: FieldId) -> usize

Return the configured cardinality estimate for a field.

pub fn len(&self) -> usize

Number of unique values stored in the dictionary.

pub fn is_empty(&self) -> bool

Returns true when the dictionary has no values.

Trait Implementations

impl Debug for ValueDictionary

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

Formats the value using the given formatter.

impl Default for ValueDictionary

fn default() -> ValueDictionary

Returns the “default value” for a type.