Struct winter_verifier::AirContext

pub struct AirContext<B>where
    B: StarkField,{ /* private fields */ }

STARK parameters and trace properties for a specific execution of a computation.

Implementations

impl<B> AirContext<B>where
    B: StarkField,

pub fn new(
    trace_info: TraceInfo,
    transition_constraint_degrees: Vec<TransitionConstraintDegree, Global>,
    num_assertions: usize,
    options: ProofOptions
) -> AirContext<B>

Returns a new instance of AirContext instantiated for computations which require a single execution trace segment.

The list of transition constraint degrees defines the total number of transition constraints and their expected degrees. Constraint evaluations computed by Air::evaluate_transition() function are expected to be in the order defined by this list.

Panics

Panics if

• transition_constraint_degrees is an empty vector.
• num_assertions is zero.
• Blowup factor specified by the provided options is too small to accommodate degrees of the specified transition constraints.
• trace_info describes a multi-segment execution trace.

pub fn new_multi_segment(
    trace_info: TraceInfo,
    main_transition_constraint_degrees: Vec<TransitionConstraintDegree, Global>,
    aux_transition_constraint_degrees: Vec<TransitionConstraintDegree, Global>,
    num_main_assertions: usize,
    num_aux_assertions: usize,
    options: ProofOptions
) -> AirContext<B>

Returns a new instance of AirContext instantiated for computations which require multiple execution trace segments.

The lists of transition constraint degrees defines the total number of transition constraints and their expected degrees. Constraint evaluations computed by Air::evaluate_transition() function are expected to be in the order defined by main_transition_constraint_degrees list. Constraint evaluations computed by Air::evaluate_aux_transition() function are expected to be in the order defined by aux_transition_constraint_degrees list.

Panics

Panics if

• main_transition_constraint_degrees is an empty vector.
• num_main_assertions is zero.
• trace_info.is_multi_segment() == true but:
  • aux_transition_constraint_degrees is an empty vector.
  • num_aux_assertions is zero.
• trace_info.is_multi_segment() == false but:
  • aux_transition_constraint_degrees is a non-empty vector.
  • num_aux_assertions is greater than zero.
• Blowup factor specified by the provided options is too small to accommodate degrees of the specified transition constraints.

pub fn trace_len(&self) -> usize

Returns length of the execution trace for an instance of a computation.

pub fn trace_poly_degree(&self) -> usize

Returns degree of trace polynomials for an instance of a computation.

The degree is always trace_length - 1.

pub fn ce_domain_size(&self) -> usize

Returns size of the constraint evaluation domain.

This is guaranteed to be a power of two, and is equal to trace_length * ce_blowup_factor.

pub fn composition_degree(&self) -> usize

Returns the degree to which all constraint polynomials are normalized before they are composed together.

This degree is always ce_domain_size - 1.

pub fn lde_domain_size(&self) -> usize

Returns the size of the low-degree extension domain.

This is guaranteed to be a power of two, and is equal to trace_length * lde_blowup_factor.

pub fn num_transition_constraints(&self) -> usize

Returns the number of transition constraints for a computation.

The number of transition constraints is defined by the total number of transition constraint degree descriptors (for both the main and the auxiliary trace constraints). This number is used to determine how many transition constraint coefficients need to be generated for merging transition constraints into a composition polynomial.

pub fn num_main_transition_constraints(&self) -> usize

Returns the number of transition constraints placed against the main trace segment.

pub fn num_aux_transition_constraints(&self) -> usize

Returns the number of transition constraints placed against all auxiliary trace segments.

pub fn num_assertions(&self) -> usize

Returns the total number of assertions defined for a computation.

The number of assertions consists of the assertions placed against the main segment of an execution trace as well as assertions placed against all auxiliary trace segments.

pub fn num_transition_exemptions(&self) -> usize

Returns the number of rows at the end of an execution trace to which transition constraints do not apply.

This is guaranteed to be at least 1 (which is the default value), but could be greater. The maximum number of exemptions is determined by a combination of transition constraint degrees and blowup factor specified for the computation.

pub fn set_num_transition_exemptions(self, n: usize) -> AirContext<B>

Sets the number of transition exemptions for this context.

Panics

Panics if:

• The number of exemptions is zero.
• The number of exemptions exceeds half of the trace length.
• Given the combination of transition constraints degrees and the blowup factor in this context, the number of exemptions is too larger for a valid computation of the constraint composition polynomial.

Trait Implementations

impl<B> Clone for AirContext<B>where
    B: Clone + StarkField,

fn clone(&self) -> AirContext<B>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<B> PartialEq<AirContext<B>> for AirContext<B>where
    B: PartialEq<B> + StarkField,

fn eq(&self, other: &AirContext<B>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<B> Eq for AirContext<B>where
    B: Eq + StarkField,

impl<B> StructuralEq for AirContext<B>where
    B: StarkField,

impl<B> StructuralPartialEq for AirContext<B>where
    B: StarkField,