Struct ColumnarBuffer 

pub struct ColumnarBuffer { /* private fields */ }

Columnar buffer with lazy field extraction.

This buffer stores events in both row and columnar format:

• events: Original events preserved for predicates/emit operations
• timestamps: Eagerly extracted timestamps for temporal operations
• columns: Lazily populated cache of extracted field columns

When an aggregation needs a field, the column is extracted once and cached for subsequent aggregations on the same field.

Implementations

impl ColumnarBuffer

pub fn new() -> Self

Create a new empty columnar buffer.

pub fn with_capacity(capacity: usize) -> Self

Create a new columnar buffer with the specified capacity.

pub fn push(&mut self, event: SharedEvent)

Push an event into the buffer.

This eagerly extracts the timestamp and clears any cached columns to maintain consistency.

pub fn drain_front(&mut self, count: usize) -> Vec<SharedEvent>

Drain the first count events from the buffer.

Returns the drained events as a Vec<SharedEvent>. Clears all cached columns since indices shift.

pub fn take_all(&mut self) -> Vec<SharedEvent>

Take all events from the buffer, leaving it empty.

Returns the events as a Vec<SharedEvent>.

pub fn clear(&mut self)

Clear all events from the buffer.

pub fn events(&self) -> &[SharedEvent]

Get the events as a slice.

pub fn timestamps(&self) -> &[i64]

Get the timestamps as a slice (milliseconds since epoch).

pub const fn len(&self) -> usize

Get the number of events in the buffer.

pub const fn is_empty(&self) -> bool

Check if the buffer is empty.

pub fn ensure_float_column(&mut self, field: &str) -> &[f64]

Ensure a Float64 column exists for the given field.

If the column is already cached, returns the cached slice. Otherwise, extracts the field from all events and caches it.

Missing values are stored as f64::NAN.

pub fn ensure_int_column(&mut self, field: &str) -> &[i64]

Ensure an Int64 column exists for the given field.

If the column is already cached, returns the cached slice. Otherwise, extracts the field from all events and caches it.

Missing values are stored as i64::MIN.

pub fn ensure_string_column(&mut self, field: &str) -> &[Option<Arc<str>>]

Ensure a String column exists for the given field.

If the column is already cached, returns the cached slice. Otherwise, extracts the field from all events and caches it.

pub fn has_column(&self, field: &str) -> bool

Check if a column is already cached.

pub fn get_column(&self, field: &str) -> Option<&Column>

Get the cached column if it exists.

pub fn checkpoint(&self) -> ColumnarCheckpoint

Create a checkpoint of the buffer for persistence.

Note: Columns are NOT checkpointed - they are lazily re-extracted on restore.

pub fn restore(&mut self, cp: &ColumnarCheckpoint)

Restore buffer state from a checkpoint.

pub fn from_events(events: Vec<SharedEvent>) -> Self

Create from a Vec of SharedEvents.

Trait Implementations

impl Debug for ColumnarBuffer

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

Formats the value using the given formatter.

impl Default for ColumnarBuffer

fn default() -> Self

Returns the “default value” for a type.