com.netflix.archaius.config.PrefixedViewConfig 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
There is a newer version: 2.8.2
/**
 * Copyright 2015 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.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.function.BiConsumer;

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.api.StrInterpolator.Lookup;
import com.netflix.archaius.interpolate.ConfigStrLookup;

/**
 * View into another Config for properties starting with a specified prefix.
 * 
 * This class is meant to work with dynamic Config object that may have properties
 * added and removed.
 */
public class PrefixedViewConfig extends AbstractConfig {
    private final Config config;
    private final String prefix;
    private final Lookup nonPrefixedLookup;
    private volatile State state;

    private static class State {
        final Map data;
        
        public State(Config config, String prefix) {
            data = new LinkedHashMap();
            config.forEachProperty((k, v) -> {
                if (k.startsWith(prefix)) {
                    data.put(k.substring(prefix.length()+1), v);
                }
            });
        }
    }
    
    public PrefixedViewConfig(final String prefix, final Config config) {
        this.config = config;
        this.prefix = prefix.endsWith(".") ? prefix : prefix + ".";
        this.nonPrefixedLookup = ConfigStrLookup.from(config);
        this.state = new State(config, prefix);
        
        this.config.addListener(new ConfigListener() {
            @Override
            public void onConfigAdded(Config config) {
                state = new State(config, prefix);
            }

            @Override
            public void onConfigRemoved(Config config) {
                state = new State(config, prefix);
            }

            @Override
            public void onConfigUpdated(Config config) {
                state = new State(config, prefix);
            }

            @Override
            public void onError(Throwable error, Config config) {
            }
        });
    }

    @Override
    public Iterator getKeys() {
        return state.data.keySet().iterator();
    }

    @Override
    public boolean containsKey(String key) {
        return state.data.containsKey(key);
    }

    @Override
    public boolean isEmpty() {
        return state.data.isEmpty();
    }

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

    @Override
    public Object getRawProperty(String key) {
        return state.data.get(key);
    }
    
    @Override
    protected Lookup getLookup() { 
        return nonPrefixedLookup; 
    }

    @Override
    public synchronized void setDecoder(Decoder decoder) {
        super.setDecoder(decoder);
        config.setDecoder(decoder);
    }

    @Override
    public synchronized void setStrInterpolator(StrInterpolator interpolator) {
        super.setStrInterpolator(interpolator);
        config.setStrInterpolator(interpolator);
    }

    @Override
    public synchronized void addListener(ConfigListener listener) {
        super.addListener(listener);
        config.addListener(listener);
    }

    @Override
    public synchronized void removeListener(ConfigListener listener) {
        super.removeListener(listener);
        config.removeListener(listener);
    }

    @Override
    public void forEachProperty(BiConsumer consumer) {
        this.state.data.forEach(consumer);
    }
}