com.opengamma.language.config.ConfigurationDelta.java Source code

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Here is the source code for com.opengamma.language.config.ConfigurationDelta.java

Source

/**
 * Copyright (C) 2011 - present by OpenGamma Inc. and the OpenGamma group of companies
 *
 * Please see distribution for license.
 */

package com.opengamma.language.config;

import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;

import com.google.common.collect.Sets;

/**
 * Represents a 'delta' between two sets of configuration items.
 */
public final class ConfigurationDelta {

    private final Set<ConfigurationItem> _added;
    private final Set<ConfigurationItem> _removed;

    private ConfigurationDelta(final Set<ConfigurationItem> added, final Set<ConfigurationItem> removed) {
        _added = added;
        _removed = removed;
    }

    public static ConfigurationDelta of(final Collection<ConfigurationItem> first,
            final Collection<ConfigurationItem> second) {
        final Set<ConfigurationItem> firstSet = (first != null) ? new HashSet<ConfigurationItem>(first)
                : Collections.<ConfigurationItem>emptySet();
        final Set<ConfigurationItem> secondSet = (second != null) ? new HashSet<ConfigurationItem>(second)
                : Collections.<ConfigurationItem>emptySet();
        return new ConfigurationDelta(Sets.difference(secondSet, firstSet), Sets.difference(firstSet, secondSet));
    }

    public static ConfigurationDelta empty() {
        return of(null, null);
    }

    public Set<ConfigurationItem> getAdded() {
        return _added;
    }

    public Set<ConfigurationItem> getRemoved() {
        return _removed;
    }

    public boolean hasChanged() {
        return !getAdded().isEmpty() || !getRemoved().isEmpty();
    }

}