ONOS-1362: Support async version of ConsistentMap that lets efficient chaining of operations

Change-Id: I672a15ba2a517db3e22f6ce8d739ca48307e6e63
diff --git a/core/api/src/main/java/org/onosproject/store/service/AsyncConsistentMap.java b/core/api/src/main/java/org/onosproject/store/service/AsyncConsistentMap.java
new file mode 100644
index 0000000..c31c1fa
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/store/service/AsyncConsistentMap.java
@@ -0,0 +1,198 @@
+/*
+ * 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.service;
+
+import java.util.Collection;
+import java.util.Set;
+import java.util.Map.Entry;
+import java.util.concurrent.CompletableFuture;
+
+/**
+ * A distributed, strongly consistent map whose methods are all executed asynchronously.
+ * <p>
+ * This map offers strong read-after-update (where update == create/update/delete)
+ * consistency. All operations to the map are serialized and applied in a consistent
+ * manner.
+ * <p>
+ * The stronger consistency comes at the expense of availability in
+ * the event of a network partition. A network partition can be either due to
+ * a temporary disruption in network connectivity between participating nodes
+ * or due to a node being temporarily down.
+ * </p><p>
+ * All values stored in this map are versioned and the API supports optimistic
+ * concurrency by allowing conditional updates that take into consideration
+ * the version or value that was previously read.
+ * </p><p>
+ * This map does not allow null values. All methods can throw a ConsistentMapException
+ * (which extends RuntimeException) to indicate failures.
+ *
+ */
+public interface AsyncConsistentMap<K, V> {
+
+    /**
+     * Returns the number of entries in the map.
+     *
+     * @return a future for map size.
+     */
+    CompletableFuture<Integer> size();
+
+    /**
+     * Returns true if the map is empty.
+     *
+     * @return a future whose value will be true if map has no entries, false otherwise.
+     */
+    CompletableFuture<Boolean> isEmpty();
+
+    /**
+     * Returns true if this map contains a mapping for the specified key.
+     *
+     * @param key key
+     * @return a future whose value will be true if map contains key, false otherwise.
+     */
+    CompletableFuture<Boolean> containsKey(K key);
+
+    /**
+     * Returns true if this map contains the specified value.
+     *
+     * @param value value
+     * @return a future whose value will be true if map contains value, false otherwise.
+     */
+    CompletableFuture<Boolean> containsValue(V value);
+
+    /**
+     * Returns the value (and version) to which the specified key is mapped, or null if this
+     * map contains no mapping for the key.
+     *
+     * @param key the key whose associated value (and version) is to be returned
+     * @return a future value (and version) to which the specified key is mapped, or null if
+     * this map contains no mapping for the key
+     */
+    CompletableFuture<Versioned<V>> get(K key);
+
+    /**
+     * Associates the specified value with the specified key in this map (optional operation).
+     * If the map previously contained a mapping for the key, the old value is replaced by the
+     * specified value.
+     *
+     * @param key key with which the specified value is to be associated
+     * @param value value to be associated with the specified key
+     * @return the previous value (and version) associated with key, or null if there was
+     * no mapping for key.
+     */
+    CompletableFuture<Versioned<V>> put(K key, V value);
+
+    /**
+     * Removes the mapping for a key from this map if it is present (optional operation).
+     *
+     * @param key key whose value is to be removed from the map
+     * @return the value (and version) to which this map previously associated the key,
+     * or null if the map contained no mapping for the key.
+     */
+    CompletableFuture<Versioned<V>> remove(K key);
+
+    /**
+     * Removes all of the mappings from this map (optional operation).
+     * The map will be empty after this call returns.
+     */
+    CompletableFuture<Void> clear();
+
+    /**
+     * Returns a Set view of the keys contained in this map.
+     * This method differs from the behavior of java.util.Map.keySet() in that
+     * what is returned is a unmodifiable snapshot view of the keys in the ConsistentMap.
+     * Attempts to modify the returned set, whether direct or via its iterator,
+     * result in an UnsupportedOperationException.
+     *
+     * @return a set of the keys contained in this map
+     */
+    CompletableFuture<Set<K>> keySet();
+
+    /**
+     * Returns the collection of values (and associated versions) contained in this map.
+     * This method differs from the behavior of java.util.Map.values() in that
+     * what is returned is a unmodifiable snapshot view of the values in the ConsistentMap.
+     * Attempts to modify the returned collection, whether direct or via its iterator,
+     * result in an UnsupportedOperationException.
+     *
+     * @return a collection of the values (and associated versions) contained in this map
+     */
+    CompletableFuture<Collection<Versioned<V>>> values();
+
+    /**
+     * Returns the set of entries contained in this map.
+     * This method differs from the behavior of java.util.Map.entrySet() in that
+     * what is returned is a unmodifiable snapshot view of the entries in the ConsistentMap.
+     * Attempts to modify the returned set, whether direct or via its iterator,
+     * result in an UnsupportedOperationException.
+     *
+     * @return set of entries contained in this map.
+     */
+    CompletableFuture<Set<Entry<K, Versioned<V>>>> entrySet();
+
+    /**
+     * If the specified key is not already associated with a value
+     * associates it with the given value and returns null, else returns the current value.
+     *
+     * @param key key with which the specified value is to be associated
+     * @param value value to be associated with the specified key
+     * @return the previous value associated with the specified key or null
+     * if key does not already mapped to a value.
+     */
+    CompletableFuture<Versioned<V>> putIfAbsent(K key, V value);
+
+    /**
+     * Removes the entry for the specified key only if it is currently
+     * mapped to the specified value.
+     *
+     * @param key key with which the specified value is associated
+     * @param value value expected to be associated with the specified key
+     * @return true if the value was removed
+     */
+    CompletableFuture<Boolean> remove(K key, V value);
+
+    /**
+     * Removes the entry for the specified key only if its current
+     * version in the map is equal to the specified version.
+     *
+     * @param key key with which the specified version is associated
+     * @param version version expected to be associated with the specified key
+     * @return true if the value was removed
+     */
+    CompletableFuture<Boolean> remove(K key, long version);
+
+    /**
+     * Replaces the entry for the specified key only if currently mapped
+     * to the specified value.
+     *
+     * @param key key with which the specified value is associated
+     * @param oldValue value expected to be associated with the specified key
+     * @param newValue value to be associated with the specified key
+     * @return true if the value was replaced
+     */
+    CompletableFuture<Boolean> replace(K key, V oldValue, V newValue);
+
+    /**
+     * Replaces the entry for the specified key only if it is currently mapped to the
+     * specified version.
+     *
+     * @param key key key with which the specified value is associated
+     * @param oldVersion version expected to be associated with the specified key
+     * @param newValue value to be associated with the specified key
+     * @return true if the value was replaced
+     */
+    CompletableFuture<Boolean> replace(K key, long oldVersion, V newValue);
+}
diff --git a/core/api/src/main/java/org/onosproject/store/service/StorageService.java b/core/api/src/main/java/org/onosproject/store/service/StorageService.java
index c99b7b8..7e447cc 100644
--- a/core/api/src/main/java/org/onosproject/store/service/StorageService.java
+++ b/core/api/src/main/java/org/onosproject/store/service/StorageService.java
@@ -30,9 +30,8 @@
 
     /**
      * Creates a ConsistentMap.
-     *
      * @param name map name
-     * @param serializer serializer to use for serializing keys and values.
+     * @param serializer serializer to use for serializing keys and values
      * @return consistent map.
      * @param <K> key type
      * @param <V> value type
@@ -40,6 +39,16 @@
     <K, V> ConsistentMap<K , V> createConsistentMap(String name, Serializer serializer);
 
     /**
+     * Creates a AsyncConsistentMap.
+     * @param name map name
+     * @param serializer serializer to use for serializing keys and values
+     * @return async consistent map
+     * @param <K> key type
+     * @param <V> value type
+     */
+    <K, V> AsyncConsistentMap<K , V> createAsyncConsistentMap(String name, Serializer serializer);
+
+    /**
      * Creates a new transaction context.
      * @return transaction context
      */