import { IThrottlerResponse , IThrottlerHelper , IThrottlingMetrics , } from "@fluidframework/server-services-core" ; /**
 * Super simple Token Bucket IThrottlerHelper implementation for use in tests.
 */ export class TestThrottlerHelper implements IThrottlerHelper { private readonly throttleStorage : { [ key ] : IThrottlingMetrics ; } ; constructor ( /**
     * Number of operations allowed per ms.
     */ private readonly opsPerMs ) { this . throttleStorage = { } ; } public async updateCount ( id , count ) { const now = Date . now ( ) ; const throttlingMetrics = this . throttleStorage [ id ] || { count : this . opsPerMs , lastCoolDownAt : now , throttleStatus : false , throttleReason : undefined , retryAfterInMs : 0 } ; const timeSinceLastCooldown = now - throttlingMetrics . lastCoolDownAt ; throttlingMetrics . count += Math . floor ( timeSinceLastCooldown * this . opsPerMs ) ; throttlingMetrics . lastCoolDownAt = now ; throttlingMetrics . count -= count ; if ( throttlingMetrics . count < 0 ) { const exceededByCount = Math . abs ( throttlingMetrics . count ) ; throttlingMetrics . throttleStatus = true ; throttlingMetrics . retryAfterInMs = exceededByCount / this . opsPerMs ; throttlingMetrics . throttleReason = `Count exceeded by ${ exceededByCount } at ${ now }` ; } else { throttlingMetrics . throttleStatus = false ; throttlingMetrics . retryAfterInMs = 0 ; throttlingMetrics . throttleReason = undefined ; } this . throttleStorage [ id ] = throttlingMetrics ; return this . getThrottlerResponseFromThrottlingMetrics ( throttlingMetrics ) ; } public async getThrottleStatus ( id ) { const throttlingMetrics = this . throttleStorage [ id ] ; if ( ! throttlingMetrics ) { return undefined ; } return this . getThrottlerResponseFromThrottlingMetrics ( throttlingMetrics ) ; } private getThrottlerResponseFromThrottlingMetrics ( throttlingMetrics ) { return { throttleStatus : throttlingMetrics . throttleStatus , throttleReason : throttlingMetrics . throttleReason , retryAfterInMs : throttlingMetrics . retryAfterInMs } ; } }