Adding asyncConsistentMultimap interface.

Change-Id: I3cd3632e29ff8c5eaf8328a7fdf77ead0b2d9093
diff --git a/core/api/src/main/java/org/onosproject/store/service/AsyncConsistentMultimap.java b/core/api/src/main/java/org/onosproject/store/service/AsyncConsistentMultimap.java
new file mode 100644
index 0000000..a7db4c0
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/store/service/AsyncConsistentMultimap.java
@@ -0,0 +1,210 @@
+/*
+ * Copyright 2016 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.service;
+
+import com.google.common.collect.Multimap;
+import com.google.common.collect.Multiset;
+
+import java.util.Collection;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.CompletableFuture;
+
+/**
+ * Interface for a distributed multimap.
+ *
+ * NOTE: Editing any returned collection will NOT effect the map itself and
+ * changes in the map will NOT be reflected in the returned collections.
+ * Certain operations may be too expensive when backed by a distributed data
+ * structure and have been labeled as such.
+ */
+public interface AsyncConsistentMultimap<K, V> extends DistributedPrimitive {
+
+    @Override
+    default DistributedPrimitive.Type primitiveType() {
+        return Type.CONSISTENT_MULTIMAP;
+    }
+
+    @Override
+    default CompletableFuture<Void> destroy() {
+        return clear();
+    }
+
+    /**
+     * Returns the number of key-value pairs in this multimap.
+     * @return the number of key-value pairs
+     */
+    CompletableFuture<Integer> size();
+
+    /**
+     * Returns if this multimap contains no key-value pairs.
+     * @return completable future that will be true if no key-value pairs
+     * exist, false otherwise
+     */
+    CompletableFuture<Boolean> isEmpty();
+
+    /**
+     * Returns true if there is at lease one key-value pair with a key equal to
+     * key.
+     * @param key the key to query
+     * @return a future whose value will be true if the map contains a
+     * key-value pair with key false otherwise
+     */
+    CompletableFuture<Boolean> containsKey(K key);
+
+    /**
+     * Returns true if this map contains at lease one key-value pair with a
+     * value equal to value.
+     * @param value the value to query
+     * @return a future whose value will be true if there is a key-value pair
+     * with the specified value, false otherwise.
+     */
+    CompletableFuture<Boolean> containsValue(V value);
+
+    /**
+     * Returns true if this map contains at least one key-value pair with key
+     * and value specified.
+     * @return a future whose value will be true if there is a key-value pair
+     * with the specified key and value,
+     * false otherwise.
+     */
+    CompletableFuture<Boolean> containsEntry(K key, V value);
+
+    /**
+     * If the key-value pair does not already exist adds either the key value
+     * pair or the value to the set of values associated with the key and
+     * returns true, if the key-value pair already exists then behavior is
+     * implementation specific with some implementations allowing duplicates
+     * and others ignoring put requests for existing entries.
+     * @param key the key to add
+     * @param value the value to add
+     * @return a future whose value will betrue if the map has changed because
+     * of this call, false otherwise
+     */
+    CompletableFuture<Boolean> put(K key, V value);
+
+    /**
+     * Removes the key-value pair with the specified values if it exists. In
+     * implementations that allow duplicates which matching entry will be
+     * removed is undefined.
+     * @param key the key of the pair to be removed
+     * @param value the value of the pair to be removed
+     * @return a future whose value will be true if the map changed because of
+     * this call, false otherwise.
+     */
+    CompletableFuture<Boolean> remove(K key, V value);
+
+    /**
+     * Adds the set of key-value pairs of the specified key with each of the
+     * values in the iterable if each key-value pair does not already exist,
+     * if the pair does exist the behavior is implementation specific.
+     * (Same as repeated puts but with efficiency gains.)
+     * @param key the key to use for all pairs to be added
+     * @param values the set of values to be added in pairs with the key
+     * @return a future whose value will be true if any change in the map
+     * results from this call, false otherwise
+     */
+    CompletableFuture<Boolean> putAll(K key, Iterable<? extends V> values);
+
+    /**
+     * Adds all entries from this multimap that are not already present, and
+     * may or may not add duplicate entries depending on the implementation.
+     * @param multiMap the map whose entries should be added
+     * @return a future whose value will be true if any change results from
+     * this call, false otherwise
+     */
+    CompletableFuture<Boolean> putAll(
+            Multimap<? extends K, ? extends V> multiMap);
+
+    /**
+     * Stores all the values in values associated with the key specified,
+     * removes all preexisting values and returns a collection of the removed
+     * values which may be empty if the entry did not exist.
+     * @param key the key for all entries to be added
+     * @param values the values to be associated with the key
+     * @return a future whose value will be the collection of removed values,
+     * which may be empty
+     */
+    CompletableFuture<Collection<V>> replaceValues(K key, Iterable<V> values);
+
+    /**
+     * Removes all values associated with the specified key as well as the key
+     * itself.
+     * @param key the key whose key-value pairs will be removed
+     * @return a future whose value is the set of values that were removed,
+     * which may be empty
+     */
+    CompletableFuture<Collection<V>> removeAll(K key);
+
+    /**
+     * Removes all key-value pairs, after which it will be empty.
+     * @return a future whose value is irrelevant, simply used to determine if
+     * the call has completed
+     */
+    CompletableFuture<Void> clear();
+
+    /**
+     * Returns a collection of values associated with the specified key, if the
+     * key is not in the map it will return an empty collection.
+     * @param key the key whose associated values will be returned
+     * @return a future whose value will be the collection of the values
+     * associated with the specified key, the collection may be empty
+     */
+    CompletableFuture<Collection<V>> get(K key);
+
+    /**
+     * Returns a set of the keys contained in this multimap with one or more
+     * associated values.
+     * @return a future whose value will be the collection of all keys with one
+     * or more associated values, this may be empty
+     */
+    CompletableFuture<Set<K>> keySet();
+
+    /**
+     * Returns a multiset of the keys present in this multimap with one or more
+     * associated values each. Keys will appear once for each key-value pair
+     * in which they participate.
+     * @return a future whose value will be a multiset of the keys, this may
+     * be empty
+     */
+    CompletableFuture<Multiset<K>> keys();
+
+    /**
+     * Returns a collection of values in the set with duplicates permitted, the
+     * size of this collection will equal the size of the map at the time of
+     * creation.
+     * @return a future whose value will be a collection of values, this may be
+     * empty
+     */
+     CompletableFuture<Collection<V>> values();
+
+    /**
+     * Returns a collection of each key-value pair in this map.
+     * @return a future whose value will be a collection of all entries in the
+     * map, this may be empty
+     */
+    CompletableFuture<Collection<Map.Entry<K, V>>> entries();
+
+    /**
+     * Returns a map of keys to collections of values that reflect the set of
+     * key-value pairs contained in the multimap, where the key value pairs
+     * would be the key paired with each of the values in the collection.
+     * @return a future whose value will be a map of keys to collections of
+     * values, the returned map may be empty.
+     */
+    CompletableFuture<Map<K, Collection<V>>> asMap();
+}
diff --git a/core/api/src/main/java/org/onosproject/store/service/DistributedPrimitive.java b/core/api/src/main/java/org/onosproject/store/service/DistributedPrimitive.java
index e28cd20..e8111d6 100644
--- a/core/api/src/main/java/org/onosproject/store/service/DistributedPrimitive.java
+++ b/core/api/src/main/java/org/onosproject/store/service/DistributedPrimitive.java
@@ -39,6 +39,11 @@
         EVENTUALLY_CONSISTENT_MAP,
 
         /**
+         * Consistent Multimap.
+         */
+        CONSISTENT_MULTIMAP,
+
+        /**
          * distributed set.
          */
         SET,