Use expiring cache to keep measurements.

verkeersdrukte/src/main/java/nl/bertriksikken/verkeersdrukte/app/VerkeersDrukteApp.java

@@ -31,7 +31,7 @@ public void initialize(Bootstrap<VerkeersDrukteAppConfig> bootstrap) {
 
     @Override
     public void run(VerkeersDrukteAppConfig configuration, Environment environment) {
-        TrafficHandler ndwHandler = new TrafficHandler(configuration.getNdwConfig());
+        TrafficHandler ndwHandler = new TrafficHandler(configuration);
         VerkeersDrukteResource resource = new VerkeersDrukteResource(ndwHandler, configuration.getTrafficConfig());
         environment.healthChecks().register("ndw", new VerkeersDrukteHealthCheck(ndwHandler));
         environment.jersey().register(resource);

verkeersdrukte/src/main/java/nl/bertriksikken/verkeersdrukte/app/VerkeersDrukteAppConfig.java

@@ -7,7 +7,7 @@
 import nl.bertriksikken.verkeersdrukte.traffic.TrafficConfig;
 
 @JsonIgnoreProperties(ignoreUnknown = true)
-final class VerkeersDrukteAppConfig extends Configuration {
+public final class VerkeersDrukteAppConfig extends Configuration {
 
     @JsonProperty("ndw")
     private NdwConfig ndwConfig = new NdwConfig();

verkeersdrukte/src/main/java/nl/bertriksikken/verkeersdrukte/traffic/MeasurementCache.java

@@ -1,24 +1,24 @@
 package nl.bertriksikken.verkeersdrukte.traffic;
 
-import java.time.Instant;
-import java.util.Map;
-import java.util.concurrent.ConcurrentHashMap;
+import com.google.common.cache.Cache;
+import com.google.common.cache.CacheBuilder;
+
+import java.time.Duration;
 
 public final class MeasurementCache {
 
-    private final Instant publishedDateTime;
-    private Map<String, AggregateMeasurement> measurementMap = new ConcurrentHashMap<>();
+    private final Cache<String, AggregateMeasurement> cache;
 
-    MeasurementCache(Instant publishedDateTime) {
-        this.publishedDateTime = publishedDateTime;
+    MeasurementCache(Duration expiryDuration) {
+        cache = CacheBuilder.newBuilder().expireAfterWrite(expiryDuration).build();
     }
 
     public void put(String location, AggregateMeasurement measurement) {
-        measurementMap.put(location, measurement);
+        cache.put(location, measurement);
     }
 
     public AggregateMeasurement get(String location) {
-        return measurementMap.get(location);
+        return cache.getIfPresent(location);
     }
 
 }

verkeersdrukte/src/main/java/nl/bertriksikken/verkeersdrukte/traffic/TrafficConfig.java

@@ -1,11 +1,10 @@
 package nl.bertriksikken.verkeersdrukte.traffic;
 
 import com.fasterxml.jackson.annotation.JsonAutoDetect;
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.annotation.JsonProperty;
 
+import java.time.Duration;
 import java.time.ZoneId;
-import java.util.TimeZone;
 
 @JsonAutoDetect(getterVisibility = JsonAutoDetect.Visibility.NONE)
 public final class TrafficConfig {
@@ -14,6 +13,8 @@ public final class TrafficConfig {
     private String timeZone = "Europe/Amsterdam";
     @JsonProperty("baseUrl")
     private String baseUrl = "http://stofradar.nl:9002";
+    @JsonProperty("expiryDurationMinutes")
+    private int expiryDurationMinutes = 1440;
 
     public ZoneId getTimeZone() {
         return ZoneId.of(timeZone);
@@ -22,4 +23,8 @@ public ZoneId getTimeZone() {
     public String getBaseUrl() {
         return baseUrl;
     }
+
+    public Duration getExpiryDuration() {
+        return Duration.ofMinutes(expiryDurationMinutes);
+    }
 }

verkeersdrukte/src/main/java/nl/bertriksikken/verkeersdrukte/traffic/TrafficHandler.java

@@ -11,9 +11,9 @@
 import nl.bertriksikken.shapefile.EShapeType;
 import nl.bertriksikken.shapefile.ShapeFile;
 import nl.bertriksikken.shapefile.ShapeRecord;
+import nl.bertriksikken.verkeersdrukte.app.VerkeersDrukteAppConfig;
 import nl.bertriksikken.verkeersdrukte.ndw.FileResponse;
 import nl.bertriksikken.verkeersdrukte.ndw.NdwClient;
-import nl.bertriksikken.verkeersdrukte.ndw.NdwConfig;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -37,12 +37,13 @@ public final class TrafficHandler implements ITrafficHandler, Managed {
     private final ScheduledExecutorService executor = Executors.newSingleThreadScheduledExecutor();
     private final ObjectMapper xmlMapper = new XmlMapper();
     private final NdwClient ndwClient;
-    private MeasurementCache measurementCache = new MeasurementCache(Instant.now());
+    private final MeasurementCache measurementCache;
     private FeatureCollection shapeFile;
 
-    public TrafficHandler(NdwConfig config) {
-        ndwClient = NdwClient.create(config);
+    public TrafficHandler(VerkeersDrukteAppConfig config) {
         xmlMapper.findAndRegisterModules();
+        ndwClient = NdwClient.create(config.getNdwConfig());
+        measurementCache = new MeasurementCache(config.getTrafficConfig().getExpiryDuration());
     }
 
     @Override
@@ -89,7 +90,7 @@ private void downloadTrafficSpeed() {
             Duration age = Duration.between(response.getLastModified(), Instant.now());
             next = response.getLastModified().plusSeconds(65);
             LOG.info("Got data, {} bytes, age {}", response.getContents().length, age);
-            measurementCache = decode(new ByteArrayInputStream(response.getContents()));
+            decode(new ByteArrayInputStream(response.getContents()));
         } catch (IOException e) {
             LOG.warn("Download failed", e);
             next = Instant.now().plusSeconds(60);
@@ -106,15 +107,14 @@ private void downloadTrafficSpeed() {
         notifyClients();
     }
 
-    private MeasurementCache decode(ByteArrayInputStream inputStream) throws IOException {
+    private void decode(ByteArrayInputStream inputStream) throws IOException {
         try (GZIPInputStream gzis = new GZIPInputStream(inputStream)) {
             MeasuredDataPublication publication = MeasuredDataPublication.parse(gzis);
-            MeasurementCache snapshot = new MeasurementCache(publication.getPublicationTime());
+            LOG.info("Got data for time {}", publication.getPublicationTime());
             for (SiteMeasurements measurements : publication.getSiteMeasurementsList()) {
                 AggregateMeasurement aggregateMeasurement = aggregateValues(measurements);
-                snapshot.put(measurements.reference.id, aggregateMeasurement);
+                measurementCache.put(measurements.reference.id, aggregateMeasurement);
             }
-            return snapshot;
         }
     }
 

verkeersdrukte/src/test/java/nl/bertriksikken/verkeersdrukte/traffic/TrafficHandlerTest.java

@@ -1,6 +1,6 @@
 package nl.bertriksikken.verkeersdrukte.traffic;
 
-import nl.bertriksikken.verkeersdrukte.ndw.NdwConfig;
+import nl.bertriksikken.verkeersdrukte.app.VerkeersDrukteAppConfig;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -11,7 +11,7 @@ public final class TrafficHandlerTest {
     private static final Logger LOG = LoggerFactory.getLogger(TrafficHandlerTest.class);
 
     public static void main(String[] args) throws IOException {
-        NdwConfig config = new NdwConfig();
+        VerkeersDrukteAppConfig config = new VerkeersDrukteAppConfig();
         TrafficHandler trafficHandler = new TrafficHandler(config);
         trafficHandler.start();
         trafficHandler.subscribe("client", TrafficHandlerTest::notifyData);