Merge pull request #1021 from mwohlert/instantly-apply-update-on-api-request

Apply targetState immediately after update request

src/api-binder.ts

@@ -579,7 +579,7 @@ export class APIBinder {
 			if (isFromApi || !_.isEqual(targetState, this.lastTarget)) {
 				await this.deviceState.setTarget(targetState);
 				this.lastTarget = _.cloneDeep(targetState);
-				this.deviceState.triggerApplyTarget({ force });
+				this.deviceState.triggerApplyTarget({ force, isFromApi });
 			}
 		})
 			.tapCatch(err => {

src/device-state.coffee

@@ -129,6 +129,8 @@ module.exports = class DeviceState extends EventEmitter
 		@lastSuccessfulUpdate = null
 		@failedUpdates = 0
 		@applyInProgress = false
+		@applyCancelled = false
+		@cancelDelay = null
 		@lastApplyStart = process.hrtime()
 		@scheduledApply = null
 		@shuttingDown = false
@@ -676,19 +678,31 @@ module.exports = class DeviceState extends EventEmitter
 		@applyUnblocker?()
 		return
 
-	triggerApplyTarget: ({ force = false, delay = 0, initial = false } = {}) =>
+	triggerApplyTarget: ({ force = false, delay = 0, initial = false, isFromApi = false } = {}) =>
 		if @applyInProgress
-			if !@scheduledApply?
+			if !@scheduledApply? || (isFromApi && @cancelDelay)
 				@scheduledApply = { force, delay }
+				if isFromApi
+					# Cancel promise delay if call came from api to prevent waiting due to backoff
+					@cancelDelay()
 			else
 				# If a delay has been set it's because we need to hold off before applying again,
 				# so we need to respect the maximum delay that has been passed
 				@scheduledApply.delay = Math.max(delay, @scheduledApply.delay)
 				@scheduledApply.force or= force
 			return
+		@applyCancelled = false
 		@applyInProgress = true
-		Promise.delay(delay)
+		new Promise (resolve, reject) =>
+			setTimeout(resolve, delay)
+			@cancelDelay = reject
+		.catch =>
+			@applyCancelled = true
 		.then =>
+			@cancelDelay = null
+			if @applyCancelled
+				log.info('Skipping applyTarget because of a cancellation')
+				return
 			@lastApplyStart = process.hrtime()
 			log.info('Applying target state')
 			@applyTarget({ force, initial })

test/05-device-state.spec.coffee

@@ -290,6 +290,22 @@ describe 'deviceState', ->
 			done()
 		, 5
 
+	it 'cancels current promise applying the target state', (done) ->
+		@deviceState.scheduledApply = { force: false, delay: 100 }
+		@deviceState.applyInProgress = true
+		@deviceState.applyCancelled = false
+		new Promise (resolve, reject) =>
+			setTimeout(resolve, 100000)
+			@deviceState.cancelDelay = reject
+		.catch =>
+			@deviceState.applyCancelled = true
+		.finally =>
+			expect(@deviceState.scheduledApply).to.deep.equal({ force: true, delay: 0 })
+			expect(@deviceState.applyCancelled).to.be.true
+			done()
+		@deviceState.triggerApplyTarget({ force: true, isFromApi: true })
+
+
 	it 'applies the target state for device config'
 
 	it 'applies the target state for applications'