Struct VirtualDataSlice 

pub struct VirtualDataSlice { /* private fields */ }

A columnar data slice returned from a virtual server view query.

This struct represents a rectangular slice of data from a view, stored internally as Arrow builders during population and frozen into a RecordBatch on first consumption.

Implementations

impl VirtualDataSlice

pub fn new(config: ViewConfig) -> Self

pub fn from_arrow_ipc(&mut self, ipc: &[u8]) -> Result<(), Box<dyn Error>>

Loads data from Arrow IPC file format bytes, with automatic post-processing based on the view configuration.

When group_by is active, extracts __GROUPING_ID__ and __ROW_PATH_N__ columns to build self.row_path, then removes __GROUPING_ID__ from the output RecordBatch. The __ROW_PATH_N__ columns are kept in the frozen batch so downstream Arrow IPC consumers (with_typed_arrays, used by viewer-charts to drive its categorical/numeric axis resolvers and tree-hierarchy walkers) see them inline — matching the native perspective-server’s to_arrow output when machine_column_names: true.

pub fn render_to_columns_json( &mut self, style: RowPathStyle, id: bool, ) -> Result<String, Box<dyn Error>>

Serializes the data to a column-oriented JSON string.

style selects between the legacy __ROW_PATH__ sidecar (Sidecar, used by to_columns) and the native per-level __ROW_PATH_N__ columns (PerLevel, currently unused — reserved for the future deprecation of __ROW_PATH__). See RowPathStyle for context.

id emits an __ID__ column of per-row identities, matching the native engine’s to_columns(id = true) shape for grouped views (each row’s identity is its __ROW_PATH__ prefix). Ungrouped views have no row_path and emit no __ID__ — consumers fall back to positional identity, as before.

pub fn set_col<T: SetVirtualDataColumn>( &mut self, name: &str, grouping_id: Option<usize>, index: usize, value: T, ) -> Result<(), Box<dyn Error>>

Sets a value in a column at the specified row index.

A __ROW_PATH_N__ value is added to the row’s __ROW_PATH__ sidecar path when grouping_id marks level N as un-rolled-up, and is always written to the __ROW_PATH_N__ column itself, which is kept in the frozen batch as in Self::from_arrow_ipc - see the comment there. Otherwise, the value is inserted into the named column.

Creates the column if it does not already exist.

Trait Implementations

impl Debug for VirtualDataSlice

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

Formats the value using the given formatter.