@cloud-carbon-footprint/core/src/storage/StorageEstimator.ts

The core logic to get cloud usage data and estimate energy and carbon emissions.

/*
 * © 2021 Thoughtworks, Inc.
 */

import {
  CloudConstantsEmissionsFactors,
  CloudConstants,
  estimateCo2,
  FootprintEstimate,
  IFootprintEstimator,
} from '../.'
import { StorageUsage } from '.'

export class StorageEstimator implements IFootprintEstimator {
  coefficient: number

  constructor(coefficient: number) {
    this.coefficient = coefficient
  }

  estimate(
    data: StorageUsage[],
    region: string,
    emissionsFactors: CloudConstantsEmissionsFactors,
    constants: CloudConstants,
  ): FootprintEstimate[] {
    return data.map((d: StorageUsage) => {
      const estimatedKilowattHours = this.estimateKilowattHours(
        d.terabyteHours,
        constants.powerUsageEffectiveness,
        constants.replicationFactor,
      )

      return {
        timestamp: d.timestamp,
        kilowattHours: estimatedKilowattHours,
        co2e: estimateCo2(estimatedKilowattHours, region, emissionsFactors),
      }
    })
  }

  private estimateKilowattHours(
    terabyteHours: number,
    powerUsageEffectiveness: number,
    replicationFactor = 1,
  ) {
    // This function multiplies the usage in terabyte hours this by the SSD or HDD co-efficient and the storage's replication factor,
    // then by PUE to account for extra power used by data center (lights, infrastructure, etc.), then converts to kilowatt-hours
    return (
      (terabyteHours *
        this.coefficient *
        powerUsageEffectiveness *
        replicationFactor) /
      1000
    )
  }
}