<html><head><meta name="color-scheme" content="light dark"></head><body><pre style="word-wrap: break-word; white-space: pre-wrap;">/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 2000-2009 Oracle.  All rights reserved.
 *
 * $Id$
 */

package com.sleepycat.bind.tuple;

import com.sleepycat.db.DatabaseEntry;

/**
 * A concrete &lt;code&gt;TupleBinding&lt;/code&gt; for a &lt;code&gt;Double&lt;/code&gt; primitive
 * wrapper or a &lt;code&gt;double&lt;/code&gt; primitive.
 *
 * &lt;p&gt;&lt;em&gt;Note:&lt;/em&gt; This class produces byte array values that by default
 * (without a custom comparator) do &lt;em&gt;not&lt;/em&gt; sort correctly for negative
 * values.  Only non-negative values are sorted correctly by default.  To sort
 * all values correctly by default, use {@link SortedDoubleBinding}.&lt;/p&gt;
 *
 * &lt;p&gt;There are two ways to use this class:&lt;/p&gt;
 * &lt;ol&gt;
 * &lt;li&gt;When using the {@link com.sleepycat.db} package directly, the static
 * methods in this class can be used to convert between primitive values and
 * {@link DatabaseEntry} objects.&lt;/li&gt;
 * &lt;li&gt;When using the {@link com.sleepycat.collections} package, an instance of
 * this class can be used with any stored collection.  The easiest way to
 * obtain a binding instance is with the {@link
 * TupleBinding#getPrimitiveBinding} method.&lt;/li&gt;
 * &lt;/ol&gt;
 */
public class DoubleBinding extends TupleBinding&lt;Double&gt; {

    private static final int DOUBLE_SIZE = 8;

    // javadoc is inherited
    public Double entryToObject(TupleInput input) {

        return input.readDouble();
    }

    // javadoc is inherited
    public void objectToEntry(Double object, TupleOutput output) {

        output.writeDouble(object);
    }

    // javadoc is inherited
    protected TupleOutput getTupleOutput(Double object) {

        return sizedOutput();
    }

    /**
     * Converts an entry buffer into a simple &lt;code&gt;double&lt;/code&gt; value.
     *
     * @param entry is the source entry buffer.
     *
     * @return the resulting value.
     */
    public static double entryToDouble(DatabaseEntry entry) {

        return entryToInput(entry).readDouble();
    }

    /**
     * Converts a simple &lt;code&gt;double&lt;/code&gt; value into an entry buffer.
     *
     * @param val is the source value.
     *
     * @param entry is the destination entry buffer.
     */
    public static void doubleToEntry(double val, DatabaseEntry entry) {

        outputToEntry(sizedOutput().writeDouble(val), entry);
    }

    /**
     * Returns a tuple output object of the exact size needed, to avoid
     * wasting space when a single primitive is output.
     */
    static TupleOutput sizedOutput() {

        return new TupleOutput(new byte[DOUBLE_SIZE]);
    }
}
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