ONOS-2190 - Move org.onosproject.net.config.* out of the incubator
Change-Id: I57cac27ae370ce1155b4f637646d6c25732844e9
diff --git a/core/api/src/main/java/org/onosproject/net/config/Config.java b/core/api/src/main/java/org/onosproject/net/config/Config.java
new file mode 100644
index 0000000..ee7b584
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/config/Config.java
@@ -0,0 +1,305 @@
+/*
+ * 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.config;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.node.ArrayNode;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import com.google.common.annotations.Beta;
+import com.google.common.collect.Lists;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.function.Function;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Base abstraction of a configuration facade for a specific subject. Derived
+ * classes should keep all state in the specified JSON tree as that is the
+ * only state that will be distributed or persisted; this class is merely
+ * a facade for interacting with a particular facet of configuration on a
+ * given subject.
+ *
+ * @param <S> type of subject
+ */
+@Beta
+public abstract class Config<S> {
+
+ protected S subject;
+ protected String key;
+ protected ObjectNode node;
+ protected ObjectMapper mapper;
+ protected ConfigApplyDelegate delegate;
+
+ /**
+ * Initializes the configuration behaviour with necessary context.
+ *
+ * @param subject configuration subject
+ * @param key configuration key
+ * @param node JSON object node where configuration data is stored
+ * @param mapper JSON object mapper
+ * @param delegate delegate context
+ */
+ public void init(S subject, String key, ObjectNode node, ObjectMapper mapper,
+ ConfigApplyDelegate delegate) {
+ this.subject = checkNotNull(subject);
+ this.key = key;
+ this.node = checkNotNull(node);
+ this.mapper = checkNotNull(mapper);
+ this.delegate = checkNotNull(delegate);
+ }
+
+ /**
+ * Returns the specific subject to which this configuration pertains.
+ *
+ * @return configuration subject
+ */
+ public S subject() {
+ return subject;
+ }
+
+ /**
+ * Returns the configuration key. This is primarily aimed for use in
+ * composite JSON trees in external representations and has no bearing on
+ * the internal behaviours.
+ *
+ * @return configuration key
+ */
+ public String key() {
+ return key;
+ }
+
+ /**
+ * Returns the JSON node that contains the configuration data.
+ *
+ * @return JSON node backing the configuration
+ */
+ public ObjectNode node() {
+ return node;
+ }
+
+ /**
+ * Applies any configuration changes made via this configuration.
+ */
+ public void apply() {
+ delegate.onApply(this);
+ }
+
+
+ // Miscellaneous helpers for interacting with JSON
+
+ /**
+ * Gets the specified property as a string.
+ *
+ * @param name property name
+ * @param defaultValue default value if property not set
+ * @return property value or default value
+ */
+ protected String get(String name, String defaultValue) {
+ return node.path(name).asText(defaultValue);
+ }
+
+ /**
+ * Sets the specified property as a string or clears it if null value given.
+ *
+ * @param name property name
+ * @param value new value or null to clear the property
+ * @return self
+ */
+ protected Config<S> setOrClear(String name, String value) {
+ if (value != null) {
+ node.put(name, value);
+ } else {
+ node.remove(name);
+ }
+ return this;
+ }
+
+ /**
+ * Gets the specified property as a boolean.
+ *
+ * @param name property name
+ * @param defaultValue default value if property not set
+ * @return property value or default value
+ */
+ protected boolean get(String name, boolean defaultValue) {
+ return node.path(name).asBoolean(defaultValue);
+ }
+
+ /**
+ * Sets the specified property as a boolean or clears it if null value given.
+ *
+ * @param name property name
+ * @param value new value or null to clear the property
+ * @return self
+ */
+ protected Config<S> setOrClear(String name, Boolean value) {
+ if (value != null) {
+ node.put(name, value.booleanValue());
+ } else {
+ node.remove(name);
+ }
+ return this;
+ }
+
+ /**
+ * Gets the specified property as an integer.
+ *
+ * @param name property name
+ * @param defaultValue default value if property not set
+ * @return property value or default value
+ */
+ protected int get(String name, int defaultValue) {
+ return node.path(name).asInt(defaultValue);
+ }
+
+ /**
+ * Sets the specified property as an integer or clears it if null value given.
+ *
+ * @param name property name
+ * @param value new value or null to clear the property
+ * @return self
+ */
+ protected Config<S> setOrClear(String name, Integer value) {
+ if (value != null) {
+ node.put(name, value.intValue());
+ } else {
+ node.remove(name);
+ }
+ return this;
+ }
+
+ /**
+ * Gets the specified property as a long.
+ *
+ * @param name property name
+ * @param defaultValue default value if property not set
+ * @return property value or default value
+ */
+ protected long get(String name, long defaultValue) {
+ return node.path(name).asLong(defaultValue);
+ }
+
+ /**
+ * Sets the specified property as a long or clears it if null value given.
+ *
+ * @param name property name
+ * @param value new value or null to clear the property
+ * @return self
+ */
+ protected Config<S> setOrClear(String name, Long value) {
+ if (value != null) {
+ node.put(name, value.longValue());
+ } else {
+ node.remove(name);
+ }
+ return this;
+ }
+
+ /**
+ * Gets the specified property as a double.
+ *
+ * @param name property name
+ * @param defaultValue default value if property not set
+ * @return property value or default value
+ */
+ protected double get(String name, double defaultValue) {
+ return node.path(name).asDouble(defaultValue);
+ }
+
+ /**
+ * Sets the specified property as a double or clears it if null value given.
+ *
+ * @param name property name
+ * @param value new value or null to clear the property
+ * @return self
+ */
+ protected Config<S> setOrClear(String name, Double value) {
+ if (value != null) {
+ node.put(name, value.doubleValue());
+ } else {
+ node.remove(name);
+ }
+ return this;
+ }
+
+ /**
+ * Gets the specified property as an enum.
+ *
+ * @param name property name
+ * @param defaultValue default value if property not set
+ * @param enumClass the enum class
+ * @param <E> type of enum
+ * @return property value or default value
+ */
+ protected <E extends Enum<E>> E get(String name, E defaultValue, Class<E> enumClass) {
+ return Enum.valueOf(enumClass, node.path(name).asText(defaultValue.toString()));
+ }
+
+ /**
+ * Sets the specified property as a double or clears it if null value given.
+ *
+ * @param name property name
+ * @param value new value or null to clear the property
+ * @param <E> type of enum
+ * @return self
+ */
+ protected <E extends Enum> Config<S> setOrClear(String name, E value) {
+ if (value != null) {
+ node.put(name, value.toString());
+ } else {
+ node.remove(name);
+ }
+ return this;
+ }
+
+ /**
+ * Gets the specified array property as a list of items.
+ *
+ * @param name property name
+ * @param function mapper from string to item
+ * @param <T> type of item
+ * @return list of items
+ */
+ protected <T> List<T> getList(String name, Function<String, T> function) {
+ List<T> list = Lists.newArrayList();
+ ArrayNode arrayNode = (ArrayNode) node.path(name);
+ arrayNode.forEach(i -> list.add(function.apply(i.asText())));
+ return list;
+ }
+
+ /**
+ * Sets the specified property as an array of items in a given collection or
+ * clears it if null is given.
+ *
+ * @param name propertyName
+ * @param collection collection of items
+ * @param <T> type of items
+ * @return self
+ */
+ protected <T> Config<S> setOrClear(String name, Collection<T> collection) {
+ if (collection == null) {
+ node.remove(name);
+ } else {
+ ArrayNode arrayNode = mapper.createArrayNode();
+ collection.forEach(i -> arrayNode.add(i.toString()));
+ node.set(name, arrayNode);
+ }
+ return this;
+ }
+
+}