Struct DeltaEncoder 

pub struct DeltaEncoder {
    pub previous: Option<Vec<f32>>,
    pub stats: DeltaStats,
    /* private fields */
}

Stateful encoder that computes element-wise deltas between successive gradient rounds.

On the first call (or after DeltaEncoder::reset), the full gradient is returned. Subsequent calls return the element-wise difference from the previously stored gradient.

Fields

previous: Option<Vec<f32>>

The gradient that was sent in the previous round.

stats: DeltaStats

Cumulative statistics.

Implementations

impl DeltaEncoder

pub fn new() -> Self

Create a new delta encoder with no prior state.

pub fn encode_delta(&mut self, current: &[f32]) -> GradientDelta

Encode current as either a full gradient or a delta.

• If no previous gradient is stored, the full gradient is returned and is_full is set to true.
• Otherwise, the element-wise delta current[i] - previous[i] is returned.

The internal round counter is incremented on every call. If the length of current differs from the stored previous gradient, the previous state is discarded and a full send is performed.

pub fn decode_delta(&self, base: &[f32], delta: &GradientDelta) -> Vec<f32>

Reconstruct a full gradient from a base vector and a GradientDelta.

• If delta.is_full, returns a clone of delta.values.
• Otherwise, adds delta.values[i] to base[i] element-wise.

If the lengths of base and delta.values disagree, the shorter length is used (extra elements in the longer slice are silently ignored).

pub fn reset(&mut self)

Clear the stored previous gradient so that the next encode_delta call performs a full send.

Trait Implementations

impl Default for DeltaEncoder

fn default() -> Self

Returns the “default value” for a type.