org.elasticsearch.hadoop.util.unit.ByteSizeUnit Maven / Gradle / Ivy

/*
 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch licenses this file to you 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 org.elasticsearch.hadoop.util.unit;

/*
 * This file is derived from org.elasticsearch.common.unit.ByteSizeUnit.
 * All copyrights apply.
 * License header for that code follows:
 */

/*
 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch licenses this file to you 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.
 */

/**
* A SizeUnit represents size at a given unit of
* granularity and provides utility methods to convert across units.
* A SizeUnit does not maintain size information, but only
* helps organize and use size representations that may be maintained
* separately across various contexts.
*/
public enum ByteSizeUnit {
    BYTES {
        @Override
        public long toBytes(long size) {
            return size;
        }

        @Override
        public long toKB(long size) {
            return size / (C1 / C0);
        }

        @Override
        public long toMB(long size) {
            return size / (C2 / C0);
        }

        @Override
        public long toGB(long size) {
            return size / (C3 / C0);
        }
    },
    KB {
        @Override
        public long toBytes(long size) {
            return x(size, C1 / C0, MAX / (C1 / C0));
        }

        @Override
        public long toKB(long size) {
            return size;
        }

        @Override
        public long toMB(long size) {
            return size / (C2 / C1);
        }

        @Override
        public long toGB(long size) {
            return size / (C3 / C1);
        }
    },
    MB {
        @Override
        public long toBytes(long size) {
            return x(size, C2 / C0, MAX / (C2 / C0));
        }

        @Override
        public long toKB(long size) {
            return x(size, C2 / C1, MAX / (C2 / C1));
        }

        @Override
        public long toMB(long size) {
            return size;
        }

        @Override
        public long toGB(long size) {
            return size / (C3 / C2);
        }
    },
    GB {
        @Override
        public long toBytes(long size) {
            return x(size, C3 / C0, MAX / (C3 / C0));
        }

        @Override
        public long toKB(long size) {
            return x(size, C3 / C1, MAX / (C3 / C1));
        }

        @Override
        public long toMB(long size) {
            return x(size, C3 / C2, MAX / (C3 / C2));
        }

        @Override
        public long toGB(long size) {
            return size;
        }
    };

    static final long C0 = 1L;
    static final long C1 = C0 * 1024L;
    static final long C2 = C1 * 1024L;
    static final long C3 = C2 * 1024L;

    static final long MAX = Long.MAX_VALUE;

    /**
     * Scale d by m, checking for overflow.
     * This has a short name to make above code more readable.
     */
    static long x(long d, long m, long over) {
        if (d > over)
            return Long.MAX_VALUE;
        if (d < -over)
            return Long.MIN_VALUE;
        return d * m;
    }


    public abstract long toBytes(long size);

    public abstract long toKB(long size);

    public abstract long toMB(long size);

    public abstract long toGB(long size);
}