Method to_bytes

nodedb-fts/src/block.rs:115–149

Serialize the block to bytes. Layout: ```text [doc_count: u16 LE] [packed_doc_id_deltas: len u32 LE + bytes] [packed_term_freqs: len u32 LE + bytes] [fieldnorms: doc_count bytes] [position_data: for each doc, count u16 LE + packed positions] ```

(&self)

    /// [position_data: for each doc, count u16 LE + packed positions]
    /// ```
    pub fn to_bytes(&self) -> Vec<u8> {
        let mut buf = Vec::new();

        // Doc count.
        buf.extend_from_slice(&(self.doc_ids.len() as u16).to_le_bytes());

        // Delta-encoded, bitpacked surrogate IDs (raw u32 on disk).
        let raw_ids: Vec<u32> = self.doc_ids.iter().map(|s| s.0).collect();
        let deltas = delta::encode(&raw_ids);
        let packed_ids = bitpack::pack(&deltas);
        buf.extend_from_slice(&(packed_ids.len() as u32).to_le_bytes());
        buf.extend_from_slice(&packed_ids);

        // Bitpacked term frequencies.
        let packed_freqs = bitpack::pack(&self.term_freqs);
        buf.extend_from_slice(&(packed_freqs.len() as u32).to_le_bytes());
        buf.extend_from_slice(&packed_freqs);

        // Fieldnorms (raw bytes, 1 per doc).
        buf.extend_from_slice(&self.fieldnorms);

        // Position data: for each doc, [count: u16 LE][packed positions].
        for positions in &self.positions {
            buf.extend_from_slice(&(positions.len() as u16).to_le_bytes());
            if !positions.is_empty() {
                let packed_pos = bitpack::pack(positions);
                buf.extend_from_slice(&(packed_pos.len() as u16).to_le_bytes());
                buf.extend_from_slice(&packed_pos);
            } else {
                buf.extend_from_slice(&0u16.to_le_bytes());
            }
        }

        buf
    }

    /// Deserialize a block from bytes. Returns `None` if malformed.
    pub fn from_bytes(buf: &[u8]) -> Option<Self> {