com.google.uzaygezen.core.Query.java Source code

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Here is the source code for com.google.uzaygezen.core.Query.java

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/*
 * Copyright (C) 2008 Google Inc.
 *
 * 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.uzaygezen.core;

import java.util.List;

import org.apache.commons.lang3.builder.ReflectionToStringBuilder;
import org.apache.commons.lang3.builder.ToStringStyle;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.Iterables;
import com.google.uzaygezen.core.ranges.Range;

/**
 * Represents a computed query which can be applied, perhaps after further
 * transformations, into an external system such as a storage server.
 * 
 * @author Daniel Aioanei
 *
 * @param <T> filter type
 */
public class Query<F, R> {

    private final List<FilteredIndexRange<F, R>> filteredIndexRanges;

    private static final Query<?, ?> EMPTY_QUERY = of(
            ImmutableList.<FilteredIndexRange<Object, Range<Object, Object>>>of());

    private Query(List<FilteredIndexRange<F, R>> filteredIndexRanges) {
        this.filteredIndexRanges = ImmutableList.copyOf(filteredIndexRanges);
    }

    public static <F, R> Query<F, R> of(List<FilteredIndexRange<F, R>> filteredIndexRanges) {
        return new Query<F, R>(filteredIndexRanges);
    }

    public List<FilteredIndexRange<F, R>> getFilteredIndexRanges() {
        return filteredIndexRanges;
    }

    public boolean isPotentialOverSelectivity() {
        boolean potentialOverSelectivity = Iterables.any(filteredIndexRanges,
                FilteredIndexRange.<F, R>potentialOverSelectivityExtractor());
        return potentialOverSelectivity;
    }

    @Override
    public int hashCode() {
        return 31 * filteredIndexRanges.hashCode();
    }

    @Override
    public boolean equals(Object o) {
        if (!(o instanceof Query)) {
            return false;
        }
        Query<?, ?> other = (Query<?, ?>) o;
        return filteredIndexRanges.equals(other.filteredIndexRanges);
    }

    @Override
    public String toString() {
        return ReflectionToStringBuilder.toString(this, ToStringStyle.SHORT_PREFIX_STYLE);
    }

    @SuppressWarnings("unchecked")
    public static <F, R> Query<F, R> emptyQuery() {
        return (Query<F, R>) EMPTY_QUERY;
    }
}