Define a class representing a set of discrete resources

Change-Id: Iaafc5ca68ae3b1330e6c8b0b2476d835a42731b6

@@ -30,7 +30,6 @@ import org.onosproject.store.service.StorageService;
 import org.onosproject.store.service.TransactionContext;
 import org.onosproject.store.service.Versioned;
 
-import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -42,19 +41,19 @@ import static org.onosproject.store.resource.impl.ConsistentResourceStore.SERIAL
 
 class ConsistentDiscreteResourceSubStore {
     private ConsistentMap<DiscreteResourceId, ResourceConsumerId> consumers;
-    private ConsistentMap<DiscreteResourceId, Set<DiscreteResource>> childMap;
+    private ConsistentMap<DiscreteResourceId, DiscreteResources> childMap;
 
     ConsistentDiscreteResourceSubStore(StorageService service) {
         this.consumers = service.<DiscreteResourceId, ResourceConsumerId>consistentMapBuilder()
                 .withName(MapNames.DISCRETE_CONSUMER_MAP)
                 .withSerializer(SERIALIZER)
                 .build();
-        this.childMap = service.<DiscreteResourceId, Set<DiscreteResource>>consistentMapBuilder()
+        this.childMap = service.<DiscreteResourceId, DiscreteResources>consistentMapBuilder()
                 .withName(MapNames.DISCRETE_CHILD_MAP)
                 .withSerializer(SERIALIZER)
                 .build();
 
-        Tools.retryable(() -> childMap.put(Resource.ROOT.id(), new LinkedHashSet<>()),
+        Tools.retryable(() -> childMap.put(Resource.ROOT.id(), DiscreteResources.empty()),
                 ConsistentMapException.class, MAX_RETRIES, RETRY_DELAY);
     }
 
@@ -73,13 +72,13 @@ class ConsistentDiscreteResourceSubStore {
     }
 
     Set<DiscreteResource> getChildResources(DiscreteResourceId parent) {
-        Versioned<Set<DiscreteResource>> children = childMap.get(parent);
+        Versioned<DiscreteResources> children = childMap.get(parent);
 
         if (children == null) {
             return ImmutableSet.of();
         }
 
-        return children.value();
+        return children.value().values();
     }
 
     boolean isAvailable(DiscreteResource resource) {

@@ -71,6 +71,7 @@ public class ConsistentResourceStore extends AbstractStore<ResourceEvent, Resour
 
     static final Serializer SERIALIZER = Serializer.using(
             Arrays.asList(KryoNamespaces.API),
+            DiscreteResources.class,
             ContinuousResourceAllocation.class);
 
     // TODO: We should provide centralized values for this

+/*
+ * 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.base.MoreObjects;
+import com.google.common.collect.Sets;
+import org.onosproject.net.resource.DiscreteResource;
+import org.onosproject.net.resource.DiscreteResourceId;
+import org.onosproject.net.resource.Resources;
+
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Objects;
+import java.util.Optional;
+import java.util.Set;
+
+final class DiscreteResources {
+    private final Set<DiscreteResource> values;
+
+    static DiscreteResources empty() {
+        return new DiscreteResources();
+    }
+
+    private DiscreteResources() {
+        this.values = new LinkedHashSet<>();
+    }
+
+    DiscreteResources(List<DiscreteResource> values) {
+        this.values = new LinkedHashSet<>(values);
+    }
+
+    private DiscreteResources(Set<DiscreteResource> values) {
+        this.values = values;
+    }
+
+    Optional<DiscreteResource> lookup(DiscreteResourceId id) {
+        DiscreteResource resource = Resources.discrete(id).resource();
+        if (values.contains(resource)) {
+            return Optional.of(resource);
+        } else {
+            return Optional.empty();
+        }
+    }
+
+    DiscreteResources difference(DiscreteResources other) {
+        return new DiscreteResources(Sets.difference(this.values, other.values));
+    }
+
+    boolean isEmpty() {
+        return values.isEmpty();
+    }
+
+    boolean containsAny(List<DiscreteResource> other) {
+        return other.stream().anyMatch(values::contains);
+    }
+
+    // returns a new instance, not mutate the current instance
+    DiscreteResources add(DiscreteResources other) {
+        Set<DiscreteResource> newValues = new LinkedHashSet<>(this.values);
+        newValues.addAll(other.values);
+        return new DiscreteResources(newValues);
+    }
+
+    // returns a new instance, not mutate the current instance
+    DiscreteResources remove(List<DiscreteResource> removed) {
+        Set<DiscreteResource> newValues = new LinkedHashSet<>(this.values);
+        newValues.removeAll(removed);
+        return new DiscreteResources(newValues);
+    }
+
+    Set<DiscreteResource> values() {
+        // breaks immutability, but intentionally returns the field
+        // because this class is transient
+        return values;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(values);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj == null || getClass() != obj.getClass()) {
+            return false;
+        }
+        final DiscreteResources other = (DiscreteResources) obj;
+        return Objects.equals(this.values, other.values);
+    }
+
+    @Override
+    public String toString() {
+        return MoreObjects.toStringHelper(this)
+                .add("values", values)
+                .toString();
+    }
+}

@@ -15,27 +15,23 @@
  */
 package org.onosproject.store.resource.impl;
 
-import com.google.common.collect.Sets;
 import org.onosproject.net.resource.DiscreteResource;
 import org.onosproject.net.resource.DiscreteResourceId;
 import org.onosproject.net.resource.Resource;
 import org.onosproject.net.resource.ResourceConsumerId;
-import org.onosproject.net.resource.Resources;
 import org.onosproject.store.service.TransactionContext;
 import org.onosproject.store.service.TransactionalMap;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Optional;
-import java.util.Set;
 
 import static org.onosproject.store.resource.impl.ConsistentResourceStore.SERIALIZER;
 
 class TransactionalDiscreteResourceSubStore {
     private final Logger log = LoggerFactory.getLogger(getClass());
-    private final TransactionalMap<DiscreteResourceId, Set<DiscreteResource>> childMap;
+    private final TransactionalMap<DiscreteResourceId, DiscreteResources> childMap;
     private final TransactionalMap<DiscreteResourceId, ResourceConsumerId> consumers;
 
     TransactionalDiscreteResourceSubStore(TransactionContext tx) {
@@ -49,17 +45,12 @@ class TransactionalDiscreteResourceSubStore {
             return Optional.of(Resource.ROOT);
         }
 
-        Set<DiscreteResource> values = childMap.get(id.parent().get());
+        DiscreteResources values = childMap.get(id.parent().get());
         if (values == null) {
             return Optional.empty();
         }
 
-        DiscreteResource resource = Resources.discrete(id).resource();
-        if (values.contains(resource)) {
-            return Optional.of(resource);
-        } else {
-            return Optional.empty();
-        }
+        return values.lookup(id);
     }
 
     boolean register(DiscreteResourceId key, List<DiscreteResource> values) {
@@ -68,21 +59,20 @@ class TransactionalDiscreteResourceSubStore {
             return true;
         }
 
-        Set<DiscreteResource> requested = new LinkedHashSet<>(values);
-        Set<DiscreteResource> oldValues = childMap.putIfAbsent(key, requested);
+        DiscreteResources requested = new DiscreteResources(values);
+        DiscreteResources oldValues = childMap.putIfAbsent(key, requested);
         if (oldValues == null) {
             return true;
         }
 
-        Set<DiscreteResource> addedValues = Sets.difference(requested, oldValues);
+        DiscreteResources addedValues = requested.difference(oldValues);
         // no new value, then no-op
         if (addedValues.isEmpty()) {
             // don't write to map because all values are already stored
             return true;
         }
 
-        Set<DiscreteResource> newValues = new LinkedHashSet<>(oldValues);
-        newValues.addAll(addedValues);
+        DiscreteResources newValues = oldValues.add(addedValues);
         return childMap.replace(key, oldValues, newValues);
     }
 
@@ -100,20 +90,19 @@ class TransactionalDiscreteResourceSubStore {
             return false;
         }
 
-        Set<DiscreteResource> oldValues = childMap.putIfAbsent(key, new LinkedHashSet<>());
+        DiscreteResources oldValues = childMap.putIfAbsent(key, DiscreteResources.empty());
         if (oldValues == null) {
             log.trace("No-Op removing values. key {} did not exist", key);
             return true;
         }
 
-        if (values.stream().allMatch(x -> !oldValues.contains(x))) {
+        if (!oldValues.containsAny(values)) {
             // don't write map because none of the values are stored
             log.trace("No-Op removing values. key {} did not contain {}", key, values);
             return true;
         }
 
-        LinkedHashSet<DiscreteResource> newValues = new LinkedHashSet<>(oldValues);
-        newValues.removeAll(values);
+        DiscreteResources newValues = oldValues.remove(values);
         return childMap.replace(key, oldValues, newValues);
     }