com.google.mr4c.keys.KeyTransformer.java Source code

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Here is the source code for com.google.mr4c.keys.KeyTransformer.java

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/**
  * Copyright 2014 Google Inc. All rights reserved.
  * 
  * 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.google.mr4c.keys;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import org.apache.commons.collections.CollectionUtils;

public class KeyTransformer {

    Map<DataKeyDimension, ElementTransformer> m_dims = new HashMap<DataKeyDimension, ElementTransformer>();

    public synchronized void addDimension(ElementTransformer eleTrans) {
        DataKeyDimension dim = eleTrans.getDimension();
        if (m_dims.containsKey(dim)) {
            throw new IllegalArgumentException(String.format("Already have a transformer for dimension [%s]", dim));
        }
        m_dims.put(dim, eleTrans);
    }

    public synchronized DataKey transformKey(DataKey key) {
        if (!CollectionUtils.containsAny(key.getDimensions(), m_dims.keySet())) {
            return key; // no dim in this key has a transform
        }
        Set<DataKeyElement> newElements = new HashSet<DataKeyElement>();
        for (DataKeyDimension dim : key.getDimensions()) {
            DataKeyElement element = key.getElement(dim);
            ElementTransformer trans = m_dims.get(dim);
            DataKeyElement newElement = trans == null ? element : trans.transformElement(element);
            newElements.add(newElement);
        }
        return DataKeyFactory.newKey(newElements);
    }

}