com.spotify.statistics.MergingMuninGraphProvider.java Source code

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Here is the source code for com.spotify.statistics.MergingMuninGraphProvider.java

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/*
 * Copyright (c) 2012-2014 Spotify AB
 *
 * 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.spotify.statistics;

import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Lists;

import java.util.List;
import java.util.Map;

/**
 * Merges graph definitions from multiple graph providers.
 */
class MergingMuninGraphProvider implements MuninGraphProvider {

    private final List<MuninGraphProvider> providers;

    /**
     * Create a new empty provider.
     */
    MergingMuninGraphProvider() {
        this(Lists.<MuninGraphProvider>newArrayList());
    }

    /**
     * Create a new provider using a list of providers.
     *
     * @param providers The providers to merge.
     */
    public MergingMuninGraphProvider(final Iterable<MuninGraphProvider> providers) {
        this.providers = Lists.newCopyOnWriteArrayList(providers);
    }

    @Override
    public Map<String, MuninGraph> getGraphs() {
        final ImmutableMap.Builder<String, MuninGraph> builder = ImmutableMap.builder();
        for (final MuninGraphProvider provider : providers) {
            builder.putAll(provider.getGraphs());
        }
        return builder.build();
    }

    /**
     * Add a graph provider, merging its set of graphs with the graphs of all other added providers.
     *
     * @param provider The provider to add.
     */
    public void addProvider(final MuninGraphProvider provider) {
        providers.add(provider);
    }

    /**
     * Remove a graph provider, removing its set of graphs.
     *
     * @param provider The provider to remove.
     */
    public void removeProvider(final MuninGraphProvider provider) {
        providers.remove(provider);
    }
}