com.cloudera.science.ml.parallel.summary.InternalStats.java Source code

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Here is the source code for com.cloudera.science.ml.parallel.summary.InternalStats.java

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/**
 * Copyright (c) 2013, Cloudera, Inc. All Rights Reserved.
 *
 * Cloudera, Inc. licenses this file to you 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
 *
 * This software 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.cloudera.science.ml.parallel.summary;

import java.util.Map;
import java.util.Set;

import org.apache.crunch.fn.Aggregators.SimpleAggregator;

import com.cloudera.science.ml.core.summary.Entry;
import com.cloudera.science.ml.core.summary.SummaryStats;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Maps;
import com.google.common.collect.Sets;

class InternalStats {

    public static final class Aggregator extends SimpleAggregator<InternalStats> {
        private InternalStats agg;
        private final int maxLevels;

        public Aggregator(int maxLevels) {
            this.maxLevels = maxLevels;
        }

        @Override
        public void reset() {
            agg = new InternalStats();
        }

        @Override
        public Iterable<InternalStats> results() {
            return ImmutableList.of(agg);
        }

        @Override
        public void update(InternalStats other) {
            agg.merge(other, maxLevels);
        }
    }

    private InternalNumeric internalNumeric;
    private Map<String, Entry> histogram;
    private boolean trimmed;

    public SummaryStats toSummaryStats(String name, long recordCount) {
        if (internalNumeric == null) {
            if (histogram == null) {
                return new SummaryStats(name);
            } else {
                return new SummaryStats(name, histogram, trimmed);
            }
        } else {
            return new SummaryStats(name, internalNumeric.toNumeric(recordCount));
        }
    }

    private InternalNumeric internalNumeric() {
        if (internalNumeric == null) {
            internalNumeric = new InternalNumeric();
        }
        return internalNumeric;
    }

    private Map<String, Entry> histogram() {
        if (histogram == null) {
            histogram = Maps.newHashMap();
        }
        return histogram;
    }

    public void addSymbol(String symbol, int maxLevels) {
        Map<String, Entry> h = histogram();
        Entry entry = h.get(symbol);
        if (entry == null) {
            if (h.size() < maxLevels) {
                entry = new Entry();
                h.put(symbol, entry);
            } else {
                trimmed = true;
                return;
            }
        }
        entry.inc();
    }

    public void addNumeric(double value) {
        internalNumeric().update(value);
    }

    public void merge(InternalStats other, int maxLevels) {
        if (other.internalNumeric != null) {
            internalNumeric().merge(other.internalNumeric);
        } else {
            Map<String, Entry> entries = histogram();
            Map<String, Entry> merged = Maps.newTreeMap();
            Set<String> keys = Sets.newTreeSet(Sets.union(entries.keySet(), other.histogram().keySet()));
            for (String key : keys) {
                Entry e = entries.get(key);
                Entry entry = other.histogram().get(key);
                Entry newEntry = new Entry();
                if (e != null) {
                    newEntry.inc(e.getCount());
                }
                if (entry != null) {
                    newEntry.inc(entry.getCount());
                }
                merged.put(key, newEntry);
                if (merged.size() == maxLevels) {
                    this.trimmed = true;
                    break;
                }
            }
            entries.clear();
            entries.putAll(merged);
            if (other.trimmed) {
                this.trimmed = true;
            }
        }
    }
}