NumericTools.java

/**
 *  Copyright 2012 Universitat Pompeu Fabra.
 *
 *  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 org.onexus.collection.store.sql.adapters;

public final class NumericTools {

    private static int mask = 15;
    private static final char[] digits = {'0', '1', '2', '3', '4', '5', '6',
            '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',
            'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w',
            'x', 'y', 'z'};

    private NumericTools() {
    }

    public static void toHexString(StringBuilder str, int i) {
        char[] buf = new char[10];
        int charPos = 10;
        do {
            buf[--charPos] = digits[i & mask];
            i >>>= 4;
        } while (i != 0);
        buf[--charPos] = 'x';
        buf[--charPos] = '0';

        str.append(buf, charPos, 10 - charPos);
    }

    public static void toHexString(StringBuilder str, long i) {
        char[] buf = new char[18];
        int charPos = 18;
        do {
            buf[--charPos] = digits[(int) (i & mask)];
            i >>>= 4;
        } while (i != 0);
        buf[--charPos] = 'x';
        buf[--charPos] = '0';

        str.append(buf, charPos, 18 - charPos);
    }
}