send CSV file via REST

performanceDb/src/main/java/org/lucares/performance/db/PerformanceDb.java

@@ -8,6 +8,10 @@ import java.util.Arrays;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Optional;
+import java.util.concurrent.ArrayBlockingQueue;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
 import java.util.stream.Stream;
 
 import org.lucares.collections.LongList;
@@ -34,10 +38,36 @@ public class PerformanceDb implements AutoCloseable {
     private final static Logger METRICS_LOGGER = LoggerFactory.getLogger("org.lucares.metrics.ingestion.block");
 
     private final DataStore dataStore;
+    private final ExecutorService serverThreadPool = Executors.newFixedThreadPool(1);
+    private final ArrayBlockingQueue<Entries> queue;
 
     public PerformanceDb(final Path dataDirectory) throws IOException {
 
+        queue = new ArrayBlockingQueue<>(10);
         dataStore = new DataStore(dataDirectory);
+        startThread();
+    }
+
+    public ArrayBlockingQueue<Entries> getQueue() {
+        return queue;
+    }
+
+    private void startThread() {
+        serverThreadPool.submit(() -> {
+            Thread.currentThread().setName("db-ingestion");
+
+            // TODO move error handling to putEntries
+            boolean finished = false;
+            while (!finished) {
+                try {
+                    putEntries(new BlockingQueueIterator<>(queue, Entries.POISON));
+                    finished = true;
+                } catch (final Exception e) {
+                    LOGGER.warn("Write to database failed. Will retry with the next element.", e);
+                }
+            }
+            return null;
+        });
 
     }
 
@@ -56,7 +86,7 @@ public class PerformanceDb implements AutoCloseable {
         putEntries(iterator);
     }
 
-    public void putEntries(final BlockingIterator<Entries> entriesIterator) throws WriteException {
+    void putEntries(final BlockingIterator<Entries> entriesIterator) throws WriteException {
 
         final Duration timeBetweenSyncs = Duration.ofSeconds(1);
         long count = 0;
@@ -162,6 +192,16 @@ public class PerformanceDb implements AutoCloseable {
     @Override
     public void close() {
         try {
+            LOGGER.debug("adding poison");
+            queue.put(Entries.POISON);
+
+            serverThreadPool.shutdown();
+            try {
+                serverThreadPool.awaitTermination(10, TimeUnit.MINUTES);
+            } catch (final InterruptedException e) {
+                Thread.interrupted();
+            }
+
             dataStore.close();
         } catch (final Exception e) {
             LOGGER.error("failed to close PerformanceDB", e);