Struct MemoryOpSolver

pub(crate) struct MemoryOpSolver<F> {
    pub(super) block_value: Vec<F>,
}

Maintains the state for solving MemoryInit and MemoryOp opcodes.

Fields

block_value: Vec<F>

Known values of the memory block, based on the index This vec starts as big as it needs to, when initialized, then evolves as we process the opcodes.

Implementations

impl<F: AcirField> MemoryOpSolver<F>

pub(crate) fn new( init: &[Witness], initial_witness: &WitnessMap<F>, ) -> Result<Self, OpcodeResolutionError<F>>

Creates a new MemoryOpSolver with the values given in init.

fn len(&self) -> u32

fn index_from_field(&self, index: F) -> Result<u32, OpcodeResolutionError<F>>

Convert a field element into a memory index Only 32 bits values are valid memory indices

fn write_memory_index( &mut self, index: u32, value: F, ) -> Result<(), OpcodeResolutionError<F>>

Update the ‘block_value’ map with the provided index/value Returns an ‘IndexOutOfBounds’ error if the index is outside the block range.

fn read_memory_index(&self, index: u32) -> Result<F, OpcodeResolutionError<F>>

Returns the value stored in the ‘block_value’ map for the provided index Returns an ‘IndexOutOfBounds’ error if the index is not in the map.

pub(crate) fn solve_memory_op( &mut self, op: &MemOp<F>, initial_witness: &mut WitnessMap<F>, pedantic_solving: bool, ) -> Result<(), OpcodeResolutionError<F>>

Update the ‘block_values’ by processing the provided Memory opcode The opcode ‘op’ contains the index and value of the operation and the type of the operation. They are all stored as an acir::native_types::Expression The type of ‘operation’ is ‘0’ for a read and ‘1’ for a write. It must be a constant expression. Index is not required to be constant but it must reduce to a known value for processing the opcode. This is done by doing the (partial) evaluation of its expression, using the provided witness map.

READ: read the block at index op.index and update op.value with the read value

• ‘op.value’ must reduce to a witness (after the evaluation of its expression)
• the value is updated in the provided witness map, for the ‘op.value’ witness

WRITE: update the block at index ‘op.index’ with ‘op.value’

• ‘op.value’ must reduce to a known value

If a requirement is not met, it returns an error.