1 files changed, 146 insertions, 0 deletions
diff --git a/framework/src/onos/core/api/src/main/java/org/onosproject/net/newresource/ResourcePath.java b/framework/src/onos/core/api/src/main/java/org/onosproject/net/newresource/ResourcePath.java
new file mode 100644
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--- /dev/null
+++ b/framework/src/onos/core/api/src/main/java/org/onosproject/net/newresource/ResourcePath.java
@@ -0,0 +1,146 @@
+/*
+ * 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.net.newresource;
+
+import com.google.common.annotations.Beta;
+import com.google.common.base.MoreObjects;
+import com.google.common.collect.ImmutableList;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Objects;
+import java.util.Optional;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * An object that is used to locate a resource in a network.
+ * A ResourcePath represents a path that is hierarchical and composed of a sequence
+ * of elementary resources that are not globally identifiable. A ResourcePath can be a globally
+ * unique resource identifier.
+ *
+ * Users of this class must keep the semantics of resources regarding the hierarchical structure.
+ * For example, resource path, Link:1/VLAN ID:100, is valid, but resource path, VLAN ID:100/Link:1
+ * is not valid because a link is not a sub-component of a VLAN ID.
+ */
+@Beta
+public final class ResourcePath {
+
+    private final List<Object> resources;
+
+    public static final ResourcePath ROOT = new ResourcePath(ImmutableList.of());
+
+    public static ResourcePath child(ResourcePath parent, Object child) {
+        ImmutableList<Object> components = ImmutableList.builder()
+                .addAll(parent.components())
+                .add(child)
+                .build();
+        return new ResourcePath(components);
+    }
+
+    /**
+     * Creates an resource path from the specified components.
+     *
+     * @param components components of the path. The order represents hierarchical structure of the resource.
+     */
+    public ResourcePath(Object... components) {
+        this(Arrays.asList(components));
+    }
+
+    /**
+     * Creates an resource path from the specified components.
+     *
+     * @param components components of the path. The order represents hierarchical structure of the resource.
+     */
+    public ResourcePath(List<Object> components) {
+        checkNotNull(components);
+
+        this.resources = ImmutableList.copyOf(components);
+    }
+
+    // for serialization
+    private ResourcePath() {
+        this.resources = null;
+    }
+
+    /**
+     * Returns the components of this resource path.
+     *
+     * @return the components of this resource path
+     */
+    public List<Object> components() {
+        return resources;
+    }
+
+    /**
+     * Returns the parent resource path of this instance.
+     * E.g. if this path is Link:1/VLAN ID:100, the return value is the resource path for Link:1.
+     *
+     * @return the parent resource path of this instance.
+     * If there is no parent, empty instance will be returned.
+     */
+    public Optional<ResourcePath> parent() {
+        if (!isRoot()) {
+            return Optional.of(new ResourcePath(resources.subList(0, resources.size() - 1)));
+        }
+
+        return Optional.empty();
+    }
+
+    /**
+     * Returns true if the path represents root.
+     *
+     * @return true if the path represents root, false otherwise.
+     */
+    public boolean isRoot() {
+        return resources.size() == 0;
+    }
+
+    /**
+     * Returns the last component of this instance.
+     *
+     * @return the last component of this instance.
+     * The return value is equal to the last object of {@code components()}.
+     */
+    public Object lastComponent() {
+        int last = resources.size() - 1;
+        return resources.get(last);
+    }
+
+    @Override
+    public int hashCode() {
+        return resources.hashCode();
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (!(obj instanceof ResourcePath)) {
+            return false;
+        }
+        final ResourcePath that = (ResourcePath) obj;
+        return Objects.equals(this.resources, that.resources);
+    }
+
+    @Override
+    public String toString() {
+        return MoreObjects.toStringHelper(this)
+                .add("resources", resources)
+                .toString();
+    }
+}