com.sleepycat.bind.tuple.PackedLongBinding Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of starrocks-bdb-je Show documentation
starrocks managed bdb je
The newest version!
/*-
 * Copyright (C) 2002, 2018, Oracle and/or its affiliates. All rights reserved.
 *
 * This file was distributed by Oracle as part of a version of Oracle Berkeley
 * DB Java Edition made available at:
 *
 * http://www.oracle.com/technetwork/database/database-technologies/berkeleydb/downloads/index.html
 *
 * Please see the LICENSE file included in the top-level directory of the
 * appropriate version of Oracle Berkeley DB Java Edition for a copy of the
 * license and additional information.
 */

package com.sleepycat.bind.tuple;

import com.sleepycat.je.DatabaseEntry;
import com.sleepycat.util.PackedInteger;

/**
 * A concrete TupleBinding for an unsorted Long
 * primitive wrapper or an unsorted long primitive, that stores
 * the value in the smallest number of bytes possible.
 *
 * There are two ways to use this class:
 * 
 * When using the {@link com.sleepycat.je} package directly, the static
 * methods in this class can be used to convert between primitive values and
 * {@link DatabaseEntry} objects.
 * When using the {@link com.sleepycat.collections} package, an instance of
 * this class can be used with any stored collection.
 * 
 *
 * @see Integer Formats
 */
public class PackedLongBinding extends TupleBinding {
    
    // javadoc is inherited
    public Long entryToObject(TupleInput input) {

        return input.readPackedLong();
    }
    
    // javadoc is inherited
    public void objectToEntry(Long object, TupleOutput output) {

        output.writePackedLong(object);
    }
    
    // javadoc is inherited
    protected TupleOutput getTupleOutput(Long object) {

        return sizedOutput();
    }
    
    /**
     * Converts an entry buffer into a simple Long value.
     *
     * @param entry is the source entry buffer.
     *
     * @return the resulting value.
     */
    public static Long entryToLong(DatabaseEntry entry) {

        return entryToInput(entry).readPackedLong();
    }
    
    /**
     * Converts a simple Long value into an entry buffer, using 
     * PackedLong format.
     *
     * @param val is the source value.
     *
     * @param entry is the destination entry buffer.
     */
    public static void longToEntry(long val, DatabaseEntry entry) {

        outputToEntry(sizedOutput().writePackedLong(val), entry);
    }
    
    /**
     * Returns a tuple output object of the maximum size needed, to avoid
     * wasting space when a single primitive is output.
     */
    private static TupleOutput sizedOutput() {

        return new TupleOutput(new byte[PackedInteger.MAX_LONG_LENGTH]);
    }
}