1 files changed, 103 insertions, 0 deletions
diff --git a/framework/src/onos/core/store/dist/src/main/java/org/onosproject/store/ecmap/MapDbPersistentStore.java b/framework/src/onos/core/store/dist/src/main/java/org/onosproject/store/ecmap/MapDbPersistentStore.java
new file mode 100644
index 00000000..e62a2d5c
--- /dev/null
+++ b/framework/src/onos/core/store/dist/src/main/java/org/onosproject/store/ecmap/MapDbPersistentStore.java
@@ -0,0 +1,103 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 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.
+ */
+
+package org.onosproject.store.ecmap;
+
+import org.mapdb.DB;
+import org.mapdb.DBMaker;
+import org.mapdb.Hasher;
+import org.mapdb.Serializer;
+import org.onosproject.store.serializers.KryoSerializer;
+
+import java.io.File;
+import java.util.Map;
+import java.util.concurrent.ExecutorService;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * MapDB based implementation of a persistent store.
+ */
+class MapDbPersistentStore<K, V> implements PersistentStore<K, V> {
+
+    private final ExecutorService executor;
+    private final KryoSerializer serializer;
+
+    private final DB database;
+
+    private final Map<byte[], byte[]> items;
+
+    /**
+     * Creates a new MapDB based persistent store.
+     *
+     * @param filename filename of the database on disk
+     * @param executor executor to use for tasks that write to the disk
+     * @param serializer serializer for keys and values
+     */
+    MapDbPersistentStore(String filename, ExecutorService executor,
+                         KryoSerializer serializer) {
+        this.executor = checkNotNull(executor);
+        this.serializer = checkNotNull(serializer);
+
+        File databaseFile = new File(filename);
+
+        database = DBMaker.newFileDB(databaseFile).make();
+
+        items = database.createHashMap("items")
+                .keySerializer(Serializer.BYTE_ARRAY)
+                .valueSerializer(Serializer.BYTE_ARRAY)
+                .hasher(Hasher.BYTE_ARRAY)
+                .makeOrGet();
+    }
+
+    @Override
+    public void readInto(Map<K, MapValue<V>> items) {
+        this.items.forEach((keyBytes, valueBytes) ->
+                              items.put(serializer.decode(keyBytes),
+                                        serializer.decode(valueBytes)));
+    }
+
+    @Override
+    public void update(K key, MapValue<V> value) {
+        executor.submit(() -> updateInternal(key, value));
+    }
+
+    @Override
+    public void remove(K key) {
+        executor.submit(() -> removeInternal(key));
+    }
+
+    private void updateInternal(K key, MapValue<V> newValue) {
+        byte[] keyBytes = serializer.encode(key);
+
+        items.compute(keyBytes, (k, existingBytes) -> {
+            MapValue<V> existing = existingBytes == null ? null :
+                                      serializer.decode(existingBytes);
+            if (existing == null || newValue.isNewerThan(existing)) {
+                return serializer.encode(newValue);
+            } else {
+                return existingBytes;
+            }
+        });
+        database.commit();
+    }
+
+    private void removeInternal(K key) {
+        byte[] keyBytes = serializer.encode(key);
+        items.remove(keyBytes);
+        database.commit();
+    }
+}