DynamicDeviceConfigServiceView

DynamicConfigService interface to provide a viewport under specified Device's tree.

Change-Id: I6134b526ec24d6c5ca1c0329cf2a1b885eafe35e
diff --git a/apps/config/src/main/java/org/onosproject/d/config/DynamicDeviceConfigServiceView.java b/apps/config/src/main/java/org/onosproject/d/config/DynamicDeviceConfigServiceView.java
new file mode 100644
index 0000000..1ec6929
--- /dev/null
+++ b/apps/config/src/main/java/org/onosproject/d/config/DynamicDeviceConfigServiceView.java
@@ -0,0 +1,170 @@
+/*
+ * Copyright 2017-present Open Networking Foundation
+ *
+ * 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.d.config;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+import static org.slf4j.LoggerFactory.getLogger;
+
+import java.util.Collections;
+import java.util.IdentityHashMap;
+import java.util.Map;
+import java.util.concurrent.CompletableFuture;
+
+import org.onosproject.config.DynamicConfigEvent;
+import org.onosproject.config.DynamicConfigListener;
+import org.onosproject.config.DynamicConfigService;
+import org.onosproject.config.Filter;
+import org.onosproject.config.ForwardingDynamicConfigService;
+import org.onosproject.net.DeviceId;
+import org.onosproject.yang.model.DataNode;
+import org.onosproject.yang.model.ResourceId;
+import org.onosproject.yang.model.RpcInput;
+import org.onosproject.yang.model.RpcOutput;
+import org.slf4j.Logger;
+
+import com.google.common.annotations.Beta;
+
+/**
+ * DynamicConfigService interface to provide a viewport
+ * under specified Device's tree.
+ */
+@Beta
+public class DynamicDeviceConfigServiceView
+        extends ForwardingDynamicConfigService
+        implements DynamicConfigService {
+
+    private static final Logger log = getLogger(DynamicDeviceConfigServiceView.class);
+
+    private final DeviceId deviceId;
+
+    private ResourceId deviceRoot;
+
+    /**
+     * original to wrapped listener.
+     */
+    private final Map<DynamicConfigListener, DynamicConfigListener> wrapped =
+            Collections.synchronizedMap(new IdentityHashMap<>());
+
+    protected DynamicDeviceConfigServiceView(DynamicConfigService delegate, DeviceId deviceId) {
+        super(delegate);
+        this.deviceId = checkNotNull(deviceId);
+        this.deviceRoot = DeviceResourceIds.toResourceId(this.deviceId);
+    }
+
+    /**
+     * Create a DynamicDeviceConfigServiceView for specified {@code deviceId}.
+     *
+     * @param service reference to actual DynamicConfigService.
+     * @param deviceId of the Device to provide view port about.
+     * @return DynamicDeviceConfigServiceView
+     */
+    public static DynamicDeviceConfigServiceView deviceView(DynamicConfigService service,
+                                                            DeviceId deviceId) {
+        return new DynamicDeviceConfigServiceView(service, deviceId);
+    }
+
+    @Override
+    public void createNode(ResourceId path, DataNode node) {
+        super.createNode(toAbsoluteId(path), node);
+    }
+
+    @Override
+    public DataNode readNode(ResourceId path, Filter filter) {
+        // FIXME transform filter? is it possible?
+        return super.readNode(toAbsoluteId(path), filter);
+    }
+
+    @Override
+    public Boolean nodeExist(ResourceId path) {
+        return super.nodeExist(toAbsoluteId(path));
+    }
+
+    @Override
+    public void updateNode(ResourceId path, DataNode node) {
+        super.updateNode(toAbsoluteId(path), node);
+    }
+
+    @Override
+    public void replaceNode(ResourceId path, DataNode node) {
+        super.replaceNode(toAbsoluteId(path), node);
+    }
+
+    @Override
+    public void deleteNode(ResourceId path) {
+        super.deleteNode(toAbsoluteId(path));
+    }
+
+    @Override
+    public CompletableFuture<RpcOutput> invokeRpc(ResourceId id,
+                                                  RpcInput input) {
+        return super.invokeRpc(toAbsoluteId(id), input);
+    }
+
+    @Override
+    public void addListener(DynamicConfigListener listener) {
+        super.addListener(wrapped.computeIfAbsent(listener,
+                                                  DynamicDeviceConfigListener::new));
+    }
+
+    @Override
+    public void removeListener(DynamicConfigListener listener) {
+        DynamicConfigListener w = wrapped.remove(listener);
+        if (w != null) {
+            super.removeListener(w);
+        }
+    }
+
+    private ResourceId toAbsoluteId(ResourceId path) {
+        checkArgument(!path.nodeKeys().contains(DeviceResourceIds.ROOT_NODE),
+                      "%s was already absolute path", path);
+
+        return ResourceIds.concat(deviceRoot, path);
+    }
+
+    private ResourceId toDeviceRelativeId(ResourceId path) {
+        checkArgument(path.nodeKeys().contains(DeviceResourceIds.ROOT_NODE),
+                      "%s was not absolute path", path);
+
+        return ResourceIds.relativize(deviceRoot, path);
+    }
+
+    class DynamicDeviceConfigListener implements DynamicConfigListener {
+
+        private final DynamicConfigListener lsnr;
+
+        DynamicDeviceConfigListener(DynamicConfigListener lsnr) {
+            this.lsnr = checkNotNull(lsnr);
+        }
+
+        private DynamicConfigEvent deviceEvent(DynamicConfigEvent event) {
+            return new DynamicConfigEvent(event.type(),
+                                          toDeviceRelativeId(event.subject()));
+        }
+
+        @Override
+        public boolean isRelevant(DynamicConfigEvent event) {
+            // FIXME ignore event irrelevant to current device
+            return lsnr.isRelevant(deviceEvent(event));
+        }
+
+        @Override
+        public void event(DynamicConfigEvent event) {
+            lsnr.event(deviceEvent(event));
+        }
+
+    }
+}