Struct IdfStats 

pub struct IdfStats {
    pub doc_count: u64,
    pub total_tokens: u64,
    pub term_df: HashMap<String, u64>,
}

Corpus-level IDF statistics accumulated from all ingested documents.

Serialized via bincode + zstd and stored as a file alongside the Iceberg metadata.

Fields

doc_count: u64

Number of documents (rows) seen.

total_tokens: u64

Sum of all document token lengths (used for avg_doc_len).

term_df: HashMap<String, u64>

Document frequency: number of documents containing each term.

Implementations

impl IdfStats

pub fn avg_doc_len(&self) -> f32

pub fn idf(&self, term: &str) -> f32

BM25+ IDF: always positive, avoids negative values for terms appearing in >50% of docs.

pub fn merge_batch(&mut self, texts: &[&str])

Merge DF counts from a new batch of text documents into this stats object.

Each &str is one document. Prunes to MAX_VOCAB by dropping lowest-DF terms after merge (keeps highest-DF terms which are most useful for BM25 normalization).

pub fn to_bytes(&self) -> AilakeResult<Vec<u8>>

Serialize to zstd-compressed bincode bytes.

pub fn from_bytes(bytes: &[u8]) -> AilakeResult<Self>

Deserialize from zstd-compressed bincode bytes.

Trait Implementations

impl Clone for IdfStats

fn clone(&self) -> IdfStats

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for IdfStats

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

Formats the value using the given formatter.

impl Default for IdfStats

fn default() -> IdfStats

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for IdfStats

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for IdfStats

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.