Method #updateMultiplicity

packages/db-ivm/src/operators/topKState.ts:67–84

(
    key: K,
    multiplicity: number,
  )

  }

  #updateMultiplicity(
    key: K,
    multiplicity: number,
  ): { oldMultiplicity: number; newMultiplicity: number } {
    if (multiplicity === 0) {
      const current = this.#multiplicities.get(key) ?? 0
      return { oldMultiplicity: current, newMultiplicity: current }
    }

    const oldMultiplicity = this.#multiplicities.get(key) ?? 0
    const newMultiplicity = oldMultiplicity + multiplicity
    if (newMultiplicity === 0) {
      this.#multiplicities.delete(key)
    } else {
      this.#multiplicities.set(key, newMultiplicity)
    }
    return { oldMultiplicity, newMultiplicity }
  }
}

/**