Method drain

nodedb-columnar/src/memtable/mod.rs:157–169

Drain the memtable: return all column data and reset to empty.

(&mut self)

    /// Drain the memtable: return all column data and reset to empty.
    pub fn drain(&mut self) -> (ColumnarSchema, Vec<ColumnData>, usize) {
        let columns = std::mem::replace(
            &mut self.columns,
            self.schema
                .columns
                .iter()
                .map(|col| ColumnData::new(&col.column_type, col.nullable))
                .collect(),
        );
        let row_count = self.row_count;
        self.row_count = 0;
        (self.schema.clone(), columns, row_count)
    }

    /// Drain with automatic dictionary encoding for low-cardinality String columns.
    pub fn drain_optimized(&mut self) -> (ColumnarSchema, Vec<ColumnData>, usize) {