Struct ExtraColumns 

pub struct ExtraColumns { /* private fields */ }

Storage for user-defined extra columns on a replay buffer.

Each column is a flat Vec<f32> with a fixed dimensionality, stored contiguously for cache-friendly sampling. When no columns are registered, this struct has zero overhead — no allocations occur.

Implementations

impl ExtraColumns

pub fn new() -> Self

Create empty extra-column storage. No allocations until register().

pub fn register(&mut self, name: &str, dim: usize) -> ColumnHandle

Register a new column. Returns a handle for O(1) access.

Must be called before any data is pushed. If storage has already been allocated (via allocate()), the new column is pre-allocated too.

pub fn num_columns(&self) -> usize

Number of registered columns.

pub fn column_info(&self, handle: ColumnHandle) -> (&str, usize)

Get column name and dim by handle.

pub fn allocate(&mut self, capacity: usize)

Pre-allocate storage for a given capacity.

pub fn push( &mut self, handle: ColumnHandle, pos: usize, values: &[f32], ) -> Result<(), RloxError>

Write values for one column at a given buffer position.

The values slice must have length equal to the column’s dimensionality.

pub fn sample(&self, handle: ColumnHandle, indices: &[usize]) -> Vec<f32>

Gather values for one column at the given sampled indices.

Returns a flat Vec<f32> of length indices.len() * dim.

pub fn sample_all(&self, indices: &[usize]) -> Vec<(String, Vec<f32>)>

Gather all columns at the given sampled indices.

Returns (column_name, flat_data) pairs. Only called when num_columns() > 0.

pub fn clear(&mut self)

Clear all data (keep column registrations and capacity).

Trait Implementations

impl Debug for ExtraColumns

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

Formats the value using the given formatter.

impl Default for ExtraColumns

fn default() -> Self

Returns the “default value” for a type.