Creating persistence service.
Change-Id: Ib78b4001a24c71b4096e5a2a446dbd5009aa1090
diff --git a/core/store/persistence/src/main/java/org/onosproject/persistence/impl/PersistentMap.java b/core/store/persistence/src/main/java/org/onosproject/persistence/impl/PersistentMap.java
new file mode 100644
index 0000000..4506bbd
--- /dev/null
+++ b/core/store/persistence/src/main/java/org/onosproject/persistence/impl/PersistentMap.java
@@ -0,0 +1,192 @@
+/*
+ * 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.persistence.impl;
+
+import com.google.common.collect.Maps;
+import com.google.common.collect.Sets;
+import org.mapdb.DB;
+import org.mapdb.Hasher;
+import org.onosproject.store.service.Serializer;
+
+import java.util.Collection;
+import java.util.Map;
+import java.util.Set;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+
+/**
+ * A map implementation that stores and receives all data from a serialized internal map.
+ */
+public class PersistentMap<K, V> implements Map<K, V> {
+
+ private final Serializer serializer;
+
+ private final org.mapdb.DB database;
+
+ private final Map<byte[], byte[]> items;
+
+ private final String name;
+
+ public PersistentMap(Serializer serializer, DB database, String name) {
+ this.serializer = checkNotNull(serializer);
+ this.database = checkNotNull(database);
+ this.name = checkNotNull(name);
+
+ items = database
+ .createHashMap(name)
+ .keySerializer(org.mapdb.Serializer.BYTE_ARRAY)
+ .valueSerializer(org.mapdb.Serializer.BYTE_ARRAY)
+ .hasher(Hasher.BYTE_ARRAY)
+ .makeOrGet();
+ }
+
+ /**
+ * Reads this set in deserialized form into the provided map.
+ *
+ * @param items the map to be populated
+ */
+ public void readInto(Map<K, V> items) {
+ this.items.forEach((keyBytes, valueBytes) ->
+ items.put(serializer.decode(keyBytes),
+ serializer.decode(valueBytes)));
+ }
+
+ @Override
+ public V remove(Object key) {
+ checkNotNull(key, "Key can not be null.");
+ V removed = get(key);
+ items.remove(serializer.encode(key));
+ return removed;
+ }
+
+ @Override
+ public int size() {
+ return items.size();
+ }
+
+ @Override
+ public boolean isEmpty() {
+ return items.isEmpty();
+ }
+
+ @Override
+ public boolean containsKey(Object key) {
+ checkNotNull(key, "Key cannot be null.");
+ return items.containsKey(serializer.encode(key));
+ }
+
+ @Override
+ public boolean containsValue(Object value) {
+ checkNotNull(value, "Value cannot be null.");
+ byte[] serialized = serializer.encode(value);
+ for (byte[] compareValue : items.values()) {
+ boolean same = true;
+ if (compareValue == null) {
+ same = false;
+ } else if (compareValue.length != serialized.length) {
+ same = false;
+ } else {
+ for (int i = 0; i < serialized.length; i++) {
+ if (serialized[i] != compareValue[i]) {
+ same = false;
+ break;
+ }
+ }
+ }
+ if (same) {
+ return true;
+ }
+ }
+ return false;
+ }
+
+ @Override
+ public V get(Object key) {
+ checkNotNull(key, "Key cannot be null.");
+ return serializer.decode(items.get(serializer.encode(key)));
+ }
+
+ @Override
+ public V put(K key, V value) {
+ checkNotNull(key, "Key cannot be null.");
+ checkNotNull(value, "Value cannot be null.");
+ byte[] prevVal = items.put(serializer.encode(key), serializer.encode(value));
+ if (prevVal == null) {
+ return null;
+ }
+ return serializer.decode(prevVal);
+ }
+
+ @Override
+ public void putAll(Map<? extends K, ? extends V> m) {
+ checkNotNull(m, "The passed in map cannot be null.");
+ m.forEach((k, v) -> items.put(serializer.encode(k), serializer.encode(v)));
+ }
+
+ @Override
+ public void clear() {
+ items.clear();
+ }
+
+ @Override
+ public Set<K> keySet() {
+ Set<K> keys = Sets.newHashSet();
+ items.keySet().forEach(k -> keys.add(serializer.decode(k)));
+ return keys;
+ }
+
+ @Override
+ public Collection<V> values() {
+ Collection<V> values = Sets.newHashSet();
+ items.values().forEach(v -> values.add(serializer.decode(v)));
+ return values;
+ }
+
+ @Override
+ public Set<Entry<K, V>> entrySet() {
+ Set<Entry<K, V>> entries = Sets.newHashSet();
+ items.entrySet().
+ forEach(e -> entries.add(Maps.immutableEntry(serializer.decode(e.getKey()),
+ serializer.decode(e.getValue()))));
+ return entries;
+ }
+
+ @Override
+ public boolean equals(Object map) {
+ //This is not threadsafe and on larger maps incurs a significant processing cost
+ if (!(map instanceof Map)) {
+ return false;
+ }
+ Map asMap = (Map) map;
+ if (this.size() != asMap.size()) {
+ return false;
+ }
+ for (Entry entry : this.entrySet()) {
+ Object key = entry.getKey();
+ if (!asMap.containsKey(key) || !asMap.get(key).equals(entry.getValue())) {
+ return false;
+ }
+ }
+ return true;
+ }
+
+ @Override
+ public int hashCode() {
+ return super.hashCode();
+ }
+}
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