com.vertixtech.antiquity.graph.ElementUtils.java Source code

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Here is the source code for com.vertixtech.antiquity.graph.ElementUtils.java

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/**
 * Copyright (c) 2012-2013 "Vertix Technologies, ltd."
 *
 * This file is part of Antiquity.
 *
 * Antiquity is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
package com.vertixtech.antiquity.graph;

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

import com.google.common.base.Joiner;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableMap.Builder;
import com.google.common.hash.HashCode;
import com.google.common.hash.HashFunction;
import com.google.common.hash.Hasher;
import com.google.common.hash.Hashing;
import com.tinkerpop.blueprints.Element;

/**
 * General {@link Element} utilities.
 */
public class ElementUtils {

    public static Map<String, Object> getPropertiesAsMap(Element element) {
        return getPropertiesAsMap(element, null);
    }

    /**
     * Returns {@link Element}'s properties as an immutable map.
     * 
     * @return An immutable map of the specified {@link Element} properties exlcuding the specified keys
     */
    public static Map<String, Object> getPropertiesAsMap(Element element, Set<String> excludedKeys) {
        Builder<String, Object> props = ImmutableMap.builder();

        for (String key : element.getPropertyKeys()) {
            if ((excludedKeys != null) && excludedKeys.contains(key))
                continue;

            props.put(key, element.getProperty(key));
        }

        return props.build();
    }

    /**
     * <p>
     * Calculate the private hash of an {@link Element}.
     * </p>
     * 
     * <p>
     * The private hash contains only the properties of the {@link Element}, without its associated elements.
     * </p>
     * 
     * <p>
     * The hash is calculated based on SHA1 algorithm
     * </p>
     * 
     * TODO Handle arrays values properly.
     * 
     * @param element
     *            The element to calculate the private hash for.
     * @param excludedKeys
     *            the keys to exclude when hash is calculated.
     * @return A string representation of the hash
     * @see HashCode#toString()
     */
    public static String calculateElementPrivateHash(Element element, Set<String> excludedKeys) {
        Map<String, Object> props = ElementUtils.getPropertiesAsMap(element, excludedKeys);
        Joiner.MapJoiner propsJoiner = Joiner.on('&').withKeyValueSeparator("=");

        HashFunction hf = Hashing.sha1();
        Hasher h = hf.newHasher();

        h.putString("[" + element.getId().toString() + "]");
        h.putString(propsJoiner.join(props));

        return h.hash().toString();
    }

    /**
     * Get the specified {@link Element} properties as a string.
     * 
     * @param withHeader
     *            if true the element's id will be printed in the first line.
     * @param e
     *            The element to get the properties string for
     * @return A formatted string containing the specified element's properties
     */
    public static String getElementPropsAsString(Element e, boolean withHeader) {
        StringBuffer elementPropsStr = new StringBuffer();

        if (withHeader)
            elementPropsStr.append(e);
        for (String key : e.getPropertyKeys())
            elementPropsStr.append("\t").append(key).append("->").append(e.getProperty(key));

        return elementPropsStr.toString();
    }
}