Struct WitnessLog 

pub struct WitnessLog { /* private fields */ }

Append-only witness log with configurable capacity.

When the log reaches capacity, the oldest records are dropped to make room for new ones, giving ring-buffer semantics. This bounds memory usage while preserving the most recent history for audit trails and flip-rate calculations.

Implementations

impl WitnessLog

pub fn new(capacity: usize) -> Self

Create a new witness log with the given maximum capacity.

A capacity of zero is treated as one (at least one record can be stored).

pub fn record(&mut self, timestamp: u64, event: WitnessEvent)

Record a witness event at the given timestamp.

If the log is at capacity, the oldest record is removed first.

pub fn len(&self) -> usize

Number of recorded events currently in the log.

pub fn is_empty(&self) -> bool

Whether the log contains no records.

pub fn recent(&self, n: usize) -> &[WitnessRecord]

Get the most recent n records.

Returns fewer than n if the log does not contain that many records.

pub fn all(&self) -> &[WitnessRecord]

Get all records currently in the log.

pub fn clear(&mut self)

Clear all records from the log.

pub fn count_tier_changes(&self) -> usize

Count the number of WitnessEvent::TierChange records.

pub fn count_evictions(&self) -> usize

Count the number of WitnessEvent::Eviction records.

pub fn count_checksum_failures(&self) -> usize

Count the number of WitnessEvent::ChecksumFailure records.

pub fn tier_flip_rate(&self, window_ticks: u64, num_blocks: u64) -> f32

Compute tier flip rate: tier changes per block per minute.

window_ticks is the size of the time window to consider (only records whose timestamp is >= max_timestamp - window_ticks are counted). num_blocks is the current total block count (used as the denominator).

Returns 0.0 when num_blocks is zero or when no tier changes fall within the window.