com.eignex.kumulant/schema/runtime/GroupedStat

GroupedStat

interface GroupedStat : Stat<GroupResult> (source)

Marker interface for stats whose result is a GroupResult. Implemented by StatGroup and its modality variants. Used in the group declarator below to enforce that nested-group entries actually produce GroupResult rather than some other Result shape.

Inheritors

AbstractStatGroup

Properties

concurrency

abstract val concurrency: Concurrency

Thread-safety mode fixed at construction. See Concurrency for the shared contract and the implementation's KDoc for its cell and lock strategy.

Functions

create

abstract fun create(concurrency: Concurrency? = null): Stat<GroupResult>

Create an independent accumulator at the configured baseline. A null concurrency preserves this accumulator's mode; a non-null value overrides it. Modality subtypes narrow the return type to preserve the input shape.

merge

abstract fun merge(values: GroupResult, timestampNanos: Long = currentTimeNanos())

Fold a compatible snapshot values into this accumulator at timestampNanos. Implementations document whether the combine is exact or approximate and which state the snapshot omits. The source accumulator is unaffected.

read

abstract fun read(timestampNanos: Long = currentTimeNanos()): GroupResult

Return the current result evaluated at timestampNanos. Time-independent statistics ignore the timestamp. Reading does not add an observation.

reset

abstract fun reset()

Restore the configured baseline, including any prior seed. Preserves the configuration and concurrency.

validateMerge

open fun validateMerge(values: GroupResult)

Validate values for merge without changing accumulator state. Containers validate every child before merging any of them. Successful validation checks compatibility; it does not make a concurrent merge transactional.