com.netflix.archaius.config.PrivateViewConfig Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of archaius2-core Show documentation
archaius2-core
The newest version!
/**
 * Copyright 2022 Netflix, Inc.
 *
 * 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 com.netflix.archaius.config;

import java.util.Collections;
import java.util.Map;
import java.util.Map.Entry;

import com.netflix.archaius.api.Config;
import com.netflix.archaius.api.ConfigListener;
import com.netflix.archaius.api.Decoder;
import com.netflix.archaius.api.StrInterpolator;
import com.netflix.archaius.util.Iterables;
import com.netflix.archaius.util.Maps;

/**
 * View into another Config that allows usage of a private {@link Decoder}, {@link StrInterpolator}, and
 * {@link ConfigListener}s that will NOT be shared with the original config.
 * 
 * This class is meant to work with dynamic Config object that may have properties added and removed.
 */
public class PrivateViewConfig extends AbstractDependentConfig {

    /** Listener to update our own state on upstream changes and then propagate the even to our own listeners. */
    private static class ViewConfigListener extends DependentConfigListener {
        private ViewConfigListener(PrivateViewConfig dependentConfig) {
            super(dependentConfig);
        }

        @Override
        public void onSourceConfigAdded(PrivateViewConfig pvc, Config config) {
            pvc.updateState(config);
            pvc.notifyConfigAdded(pvc);
        }

        @Override
        public void onSourceConfigRemoved(PrivateViewConfig pvc, Config config) {
            pvc.updateState(config);
            pvc.notifyConfigRemoved(pvc);
        }

        @Override
        public void onSourceConfigUpdated(PrivateViewConfig pvc, Config config) {
            pvc.updateState(config);
            pvc.notifyConfigUpdated(pvc);
        }

        @Override
        public void onSourceError(Throwable error, PrivateViewConfig pvc, Config config) {
        }
    }

    private volatile CachedState state;

    private void updateState(Config config) {
        this.state = createState(config);
    }

    private CachedState createState(Config config) {
        boolean instrumented = config.instrumentationEnabled();
        int size = Iterables.size(config.keys());
        final Map data = Maps.newLinkedHashMap(size);
        final Map instrumentedKeys = instrumented ? Maps.newHashMap(size) : Collections.emptyMap();

        config.forEachPropertyUninstrumented((k, v) -> {
            data.put(k, v);
            if (instrumented) {
                instrumentedKeys.put(k, config);
            }
        });
        return new CachedState(data, instrumentedKeys);
    }

    @Override
    public CachedState getState() {
        return state;
    }

    public PrivateViewConfig(final Config wrappedConfig) {
        this.state = createState(wrappedConfig);
        wrappedConfig.addListener(new ViewConfigListener(this));
    }

    @Override
    public  T accept(Visitor visitor) {
        T t = null;
        for (Entry entry : state.getData().entrySet()) {
            t = visitor.visitKey(entry.getKey(), entry.getValue());
        }
        return t;
    }
}