Add a set of discrete resources that can be encoded as interger

This is for ONOS-4281

Change-Id: I83de45368485a3c4f6c052b64ef82e846c0553e3
(cherry picked from commit 8a70393458fbaff16a26859d11dbc62f49f469b3)

core/api/src/main/java/org/onosproject/net/resource/DiscreteResourceSet.java

@@ -125,4 +125,7 @@ public final class DiscreteResourceSet {
                 && Objects.equals(this.codec, other.codec);
     }
 
+    public boolean contains(DiscreteResource resource) {
+        return values.contains(resource);
+    }
 }

core/store/dist/src/main/java/org/onosproject/store/resource/impl/EncodableDiscreteResources.java

@@ -0,0 +1,130 @@
+/*
+ * Copyright 2016-present 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.resource.impl;
+
+import com.google.common.collect.Sets;
+import org.onosproject.net.resource.DiscreteResource;
+import org.onosproject.net.resource.DiscreteResourceCodec;
+import org.onosproject.net.resource.DiscreteResourceId;
+import org.onosproject.net.resource.DiscreteResourceSet;
+import org.onosproject.net.resource.Resources;
+
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+/**
+ * A set of discrete resources that can be encoded as integers.
+ */
+final class EncodableDiscreteResources implements DiscreteResources {
+    private static final Codecs CODECS = Codecs.getInstance();
+    private final DiscreteResource parent;
+    private final Map<Class<?>, DiscreteResourceSet> values;
+
+    private static Class<?> getClass(DiscreteResource resource) {
+        return resource.valueAs(Object.class).map(Object::getClass).get();
+    }
+
+    static DiscreteResources of(Set<DiscreteResource> resources) {
+        DiscreteResource parent = resources.iterator().next().parent().get();
+        return of(parent, resources);
+    }
+
+    static EncodableDiscreteResources of(DiscreteResource parent, Set<DiscreteResource> resources) {
+        Map<Class<?>, Set<DiscreteResource>> grouped = resources.stream()
+                .collect(Collectors.groupingBy(x -> getClass(x), Collectors.toCollection(LinkedHashSet::new)));
+
+        Map<Class<?>, DiscreteResourceSet> values = new LinkedHashMap<>();
+        for (Map.Entry<Class<?>, Set<DiscreteResource>> entry : grouped.entrySet()) {
+            DiscreteResourceCodec<?> codec = CODECS.getCodec(entry.getKey());
+            values.put(entry.getKey(), DiscreteResourceSet.of(entry.getValue(), codec));
+        }
+
+        return new EncodableDiscreteResources(parent, values);
+    }
+
+    private EncodableDiscreteResources(DiscreteResource parent, Map<Class<?>, DiscreteResourceSet> values) {
+        this.parent = parent;
+        this.values = values;
+    }
+
+    // for serializer
+    private EncodableDiscreteResources() {
+        this.parent = null;
+        this.values = null;
+    }
+
+    @Override
+    public Optional<DiscreteResource> lookup(DiscreteResourceId id) {
+        DiscreteResource resource = Resources.discrete(id).resource();
+        Class<?> cls = getClass(resource);
+        return Optional.ofNullable(values.get(cls))
+                .filter(x -> x.contains(resource))
+                .map(x -> resource);
+    }
+
+    @Override
+    public DiscreteResources difference(DiscreteResources other) {
+        Set<DiscreteResource> diff = Sets.difference(values(), other.values());
+
+        return of(parent, diff);
+    }
+
+    @Override
+    public boolean isEmpty() {
+        return !values.values().stream()
+                .flatMap(x -> x.values().stream())
+                .findAny()
+                .isPresent();
+    }
+
+    @Override
+    public boolean containsAny(List<DiscreteResource> other) {
+        return other.stream()
+                .anyMatch(x -> values().contains(x));
+    }
+
+    @Override
+    public DiscreteResources add(DiscreteResources other) {
+        Set<DiscreteResource> union = Sets.union(values(), other.values());
+
+        return of(parent, union);
+    }
+
+    @Override
+    public DiscreteResources remove(List<DiscreteResource> removed) {
+        return of(parent, Sets.difference(values(), new LinkedHashSet<>(removed)));
+    }
+
+    @Override
+    public Set<DiscreteResource> values() {
+        return values.values().stream()
+                .flatMap(x -> x.values().stream())
+                .collect(Collectors.toCollection(LinkedHashSet::new));
+    }
+
+    DiscreteResource parent() {
+        return parent;
+    }
+
+    Map<Class<?>, DiscreteResourceSet> rawValues() {
+        return values;
+    }
+}

core/store/dist/src/main/java/org/onosproject/store/resource/impl/EncodableDiscreteResourcesSerializer.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2016-present 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.resource.impl;
+
+import com.esotericsoftware.kryo.Kryo;
+import com.esotericsoftware.kryo.Serializer;
+import com.esotericsoftware.kryo.io.Input;
+import com.esotericsoftware.kryo.io.Output;
+import org.onosproject.net.resource.DiscreteResource;
+import org.onosproject.net.resource.DiscreteResourceSet;
+
+import java.util.LinkedHashSet;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+/**
+ * Kryo serializer for {@link EncodableDiscreteResources}.
+ */
+class EncodableDiscreteResourcesSerializer extends Serializer<EncodableDiscreteResources> {
+    @Override
+    public void write(Kryo kryo, Output output, EncodableDiscreteResources object) {
+        kryo.writeObject(output, object.parent());
+        kryo.writeObject(output, new LinkedHashSet<>(object.rawValues().values()));
+    }
+
+    @Override
+    public EncodableDiscreteResources read(Kryo kryo, Input input, Class<EncodableDiscreteResources> cls) {
+        DiscreteResource parent = kryo.readObject(input, DiscreteResource.class);
+        @SuppressWarnings("unchecked")
+        Set<DiscreteResourceSet> resources = kryo.readObject(input, LinkedHashSet.class);
+
+        return EncodableDiscreteResources.of(parent,
+                resources.stream()
+                        .flatMap(x -> x.values().stream())
+                        .collect(Collectors.toCollection(LinkedHashSet::new)));
+    }
+}