Struct ChiselCounters 

#[non_exhaustive]
pub struct ChiselCounters {
    pub cache_hits: u64,
    pub cache_misses: u64,
    pub pages_allocated: u64,
    pub fsync_calls: u64,
}

Cumulative engine-activity counters since open().

Snapshot semantics: Chisel::counters() returns a value-type copy. The returned struct does NOT update as the engine continues to do work — read it again to observe new totals. Counters are cumulative from open; they reset implicitly on close() + reopen because the underlying PageCache and PageIo are reconstructed.

Intended use: the bench harness reads counters() before and after each measurement, reports the delta. General-purpose introspection (debugging, observability) is also supported — the counters are cheap (Cell<u64> increment in single-writer code paths).

Fields:

• cache_hits — PageCache::get returned a cached page without disk I/O.
• cache_misses — PageCache::get had to load from disk (and validate checksum). Hit rate is hits / (hits + misses).
• pages_allocated — page allocations, counting BOTH file extensions (PageCache::new_page, a new id past the high-water mark) AND freemap reuses (PageCache::claim_page, a page id freed by a prior committed transaction and handed back out). Reuse is the common case once the handle table / membership index allocate COW pages through the freemap-aware path, so a counter that ignored it would read ~0 for a steady-state mutating workload. The actual disk write happens on the next flush().
• fsync_calls — PageIo::fsync invocations that SUCCEEDED. Three per Chisel commit (pre-drain flush, data-page flush, then superblock fsync); zero between commits in a normal txn. A failed fsync poisons the engine (I1 / fsyncgate) and is not counted; cache_misses by contrast counts attempted misses even when the subsequent load fails. The asymmetry is intentional — see PageIo::fsync and I1 in ISSUES.md for the rationale.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

cache_hits: u64

cache_misses: u64

pages_allocated: u64

fsync_calls: u64

Trait Implementations

impl Clone for ChiselCounters

fn clone(&self) -> ChiselCounters

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ChiselCounters

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for ChiselCounters

fn default() -> ChiselCounters

Returns the “default value” for a type.

impl Eq for ChiselCounters

impl PartialEq for ChiselCounters

fn eq(&self, other: &ChiselCounters) -> bool

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for ChiselCounters