Improve performance when streaming to Inital State and prevent buffer growing unbounded

smartapps/initialstate-events/initial-state-event-streamer.src/initial-state-event-streamer.groovy

@@ -11,9 +11,9 @@
  *  Unless required by applicable law or agreed to in writing, software distributed under the License is distributed
  *  on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License
  *  for the specific language governing permissions and limitations under the License.
- *  
+ *
  *  SmartThings data is sent from this SmartApp to Initial State. This is event data only for
- *  devices for which the user has authorized. Likewise, Initial State's services call this 
+ *  devices for which the user has authorized. Likewise, Initial State's services call this
  *  SmartApp on the user's behalf to configure Initial State specific parameters. The ToS and
  *  Privacy Policy for Initial State can be found here: https://www.initialstate.com/terms
  */
@@ -90,7 +90,7 @@ def subscribeToEvents() {
 	if (beacons != null) {
 		subscribe(beacons, "presence", genericHandler)
 	}
-	
+
 	if (cos != null) {
 		subscribe(cos, "carbonMonoxide", genericHandler)
 	}
@@ -218,7 +218,7 @@ def setAccessKey() {
 		atomicState.grokerSubdomain = "$newGrokerSubdomain"
 		atomicState.isBucketCreated = false
 	}
-    
+
 	if (newAccessKey && newAccessKey != atomicState.accessKey) {
 		atomicState.accessKey = "$newAccessKey"
 		atomicState.isBucketCreated = false
@@ -262,7 +262,7 @@ def uninstalled() {
 }
 
 def tryCreateBucket() {
-	
+
 	// can't ship events if there is no grokerSubdomain
 	if (atomicState.grokerSubdomain == null || atomicState.grokerSubdomain == "") {
 		log.error "streaming url is currently null"
@@ -330,57 +330,54 @@ def genericHandler(evt) {
 // This is a handler function for flushing the event buffer
 // after a specified amount of time to reduce the load on ST servers
 def flushBuffer() {
+	def eventBuffer = atomicState.eventBuffer
 	log.trace "About to flush the buffer on schedule"
-	if (atomicState.eventBuffer != null && atomicState.eventBuffer.size() > 0) {
-		tryShipEvents()
+	if (eventBuffer != null && eventBuffer.size() > 0) {
+		atomicState.eventBuffer = []
+		tryShipEvents(eventBuffer)
 	}
 }
 
 def eventHandler(name, value) {
-	log.debug atomicState.eventBuffer
-
-	def eventBuffer = atomicState.eventBuffer
 	def epoch = now() / 1000
-	
-	// if for some reason this code block is being run
-	// but the SmartApp wasn't propery setup during install
-	// we need to set initialize the eventBuffer.
-	if (!atomicState.eventBuffer) {
-		atomicState.eventBuffer = []
-	}
+	def eventBuffer = atomicState.eventBuffer ?: []
 	eventBuffer << [key: "$name", value: "$value", epoch: "$epoch"]
-	
-	log.debug eventBuffer
-
-	atomicState.eventBuffer = eventBuffer
 
 	if (eventBuffer.size() >= 10) {
-		tryShipEvents()
+		// Clear eventBuffer right away since we've already pulled it off of atomicState to reduce the risk of missing
+		// events.  This assumes the grokerSubdomain, accessKey, and bucketKey are set correctly to avoid the eventBuffer
+		// from growing unbounded.
+		atomicState.eventBuffer = []
+		tryShipEvents(eventBuffer)
 	}
+	log.debug "Event added to buffer: " + eventBuffer
 }
 
 // a helper function for shipping the atomicState.eventBuffer to Initial State
-def tryShipEvents() {
+def tryShipEvents(eventBuffer) {
 
+	def grokerSubdomain = atomicState.grokerSubdomain
 	// can't ship events if there is no grokerSubdomain
-	if (atomicState.grokerSubdomain == null || atomicState.grokerSubdomain == "") {
+	if (grokerSubdomain == null || grokerSubdomain == "") {
 		log.error "streaming url is currently null"
 		return
 	}
+	def accessKey = atomicState.accessKey
+	def bucketKey = atomicState.bucketKey
 	// can't ship if access key and bucket key are null, so finish trying
-	if (atomicState.accessKey == null || atomicState.bucketKey == null) {
+	if (accessKey == null || bucketKey == null) {
 		return
 	}
 
 	def eventPost = [
-		uri: "https://${atomicState.grokerSubdomain}.initialstate.com/api/events",
+		uri: "https://${grokerSubdomain}.initialstate.com/api/events",
 		headers: [
 			"Content-Type": "application/json",
-			"X-IS-BucketKey": "${atomicState.bucketKey}",
-			"X-IS-AccessKey": "${atomicState.accessKey}",
+			"X-IS-BucketKey": "${bucketKey}",
+			"X-IS-AccessKey": "${accessKey}",
 			"Accept-Version": "0.0.2"
 		],
-		body: atomicState.eventBuffer
+		body: eventBuffer
 	]
 
 	try {
@@ -389,13 +386,10 @@ def tryShipEvents() {
 			log.debug "shipped events and got ${resp.status}"
 			if (resp.status >= 400) {
 				log.error "shipping failed... ${resp.data}"
-			} else {
-				// clear the buffer
-				atomicState.eventBuffer = []
 			}
 		}
 	} catch (e) {
 		log.error "shipping events failed: $e"
 	}
-	
+
 }