KeyAvgMerge.java

package com.alipay.bluewhale.core.stats.keyAvg;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

import com.alipay.bluewhale.core.callback.RunnableCallback;
import com.alipay.bluewhale.core.stats.method.Pair;
import com.alipay.bluewhale.core.stats.method.StatFunction;

public class KeyAvgMerge extends RunnableCallback {

	@SuppressWarnings("unchecked")
	@Override
	public <T> Object execute(T... args) {
		List<Map<Object, Pair>> list = (List<Map<Object, Pair>>) args[0];
		Map<Object, Pair> result = new HashMap<Object, Pair>();
		Map<Object, List<Pair>> trans = new HashMap<Object, List<Pair>>();
		for (Map<Object, Pair> each : list) {
			for (Entry<Object, Pair> e : each.entrySet()) {
				Object key = e.getKey();
				List<Pair> val = new ArrayList<Pair>();
				if (trans.containsKey(key)) {
					val = trans.get(key);
				}
				val.add(e.getValue());
				trans.put(key, val);
			}
		}

		for (Entry<Object, List<Pair>> e : trans.entrySet()) {
			result.put(e.getKey(), StatFunction.merge_keyed_avg(e.getValue()));
		}
		return result;
	}
}