Implemented H2 based SubscriptionsRepository

broker/src/main/java/io/moquette/persistence/H2Builder.java

@@ -0,0 +1,51 @@
+package io.moquette.persistence;
+
+import io.moquette.BrokerConstants;
+import io.moquette.broker.ISubscriptionsRepository;
+import io.moquette.broker.config.IConfig;
+import org.h2.mvstore.MVStore;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+
+public class H2Builder {
+
+    private static final Logger LOG = LoggerFactory.getLogger(H2Builder.class);
+
+    private final String storePath;
+    private final int autosaveInterval; // in seconds
+    private final ScheduledExecutorService scheduler;
+    private MVStore mvStore;
+
+    public H2Builder(IConfig props, ScheduledExecutorService scheduler) {
+        this.storePath = props.getProperty(BrokerConstants.PERSISTENT_STORE_PROPERTY_NAME, "");
+        final String autosaveProp = props.getProperty(BrokerConstants.AUTOSAVE_INTERVAL_PROPERTY_NAME, "30");
+        this.autosaveInterval = Integer.parseInt(autosaveProp);
+        this.scheduler = scheduler;
+    }
+
+    @SuppressWarnings("FutureReturnValueIgnored")
+    public H2Builder initStore() {
+        LOG.info("Initializing H2 store");
+        if (storePath == null || storePath.isEmpty()) {
+            throw new IllegalArgumentException("H2 store path can't be null or empty");
+        }
+        mvStore = new MVStore.Builder()
+            .fileName(storePath)
+            .autoCommitDisabled()
+            .open();
+
+        LOG.trace("Scheduling H2 commit task");
+        scheduler.scheduleWithFixedDelay(() -> {
+            LOG.trace("Committing to H2");
+            mvStore.commit();
+        }, autosaveInterval, autosaveInterval, TimeUnit.SECONDS);
+        return this;
+    }
+
+    public ISubscriptionsRepository subscriptionsRepository() {
+        return new H2SubscriptionsRepository(mvStore);
+    }
+}