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/*
 * 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 io.trino.parquet.dictionary;

import io.trino.parquet.DictionaryPage;
import io.trino.parquet.reader.SimpleSliceInputStream;
import io.trino.parquet.reader.decoders.ValueDecoder;

import static com.google.common.base.MoreObjects.toStringHelper;
import static io.trino.parquet.reader.decoders.PlainValueDecoders.LongPlainValueDecoder;

public class DoubleDictionary
        implements Dictionary
{
    private final double[] content;

    public DoubleDictionary(DictionaryPage dictionaryPage)
    {
        int length = dictionaryPage.getDictionarySize();
        long[] buffer = new long[length];
        ValueDecoder doubleReader = new LongPlainValueDecoder();
        doubleReader.init(new SimpleSliceInputStream(dictionaryPage.getSlice()));
        doubleReader.read(buffer, 0, length);

        content = new double[length];
        for (int i = 0; i < length; i++) {
            content[i] = Double.longBitsToDouble(buffer[i]);
        }
    }

    @Override
    public double decodeToDouble(int id)
    {
        return content[id];
    }

    @Override
    public String toString()
    {
        return toStringHelper(this)
                .add("content", content)
                .toString();
    }
}