Struct winter_prover::TraceTableFragment

pub struct TraceTableFragment<'a, B: StarkField> { /* private fields */ }

A set of consecutive rows of an execution trace.

An execution trace fragment is a “view” into the specific execution trace. Updating data in the fragment, directly updates the data in the underlying execution trace.

A fragment cannot be instantiated directly but is created by executing TraceTable::fragments() method.

A fragment always contains contiguous rows, and the number of rows is guaranteed to be a power of two.

Implementations

impl<'a, B: StarkField> TraceTableFragment<'a, B>

pub fn index(&self) -> usize

Returns the index of this fragment.

pub fn offset(&self) -> usize

Returns the step at which the fragment starts in the context of the original execution trace.

pub fn length(&self) -> usize

Returns the number of rows in this execution trace fragment.

pub fn width(&self) -> usize

Returns the width of the fragment (same as the width of the underlying execution trace).

pub fn fill<I, T>(&mut self, init_state: I, update_state: T)

where I: FnOnce(&mut [B]), T: FnMut(usize, &mut [B]),

Fills all rows in the fragment.

The rows are filled by executing the provided closures as follows:

• init closure is used to initialize the first row of the fragment; it receives a mutable reference to the first state initialized to all zeros. Contents of the state are copied into the first row of the fragment after the closure returns.
• update closure is used to populate all subsequent rows of the fragment; it receives two parameters:
  • index of the last updated row (starting with 0).
  • a mutable reference to the last updated state; the contents of the state are copied into the next row of the fragment after the closure returns.

pub fn update_row(&mut self, row_idx: usize, row_data: &[B])

Updates a single row in the fragment with provided data.