/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF 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.apache.shardingsphere.db.protocol.postgresql.packet.handshake;

import lombok.AccessLevel;
import lombok.NoArgsConstructor;

import java.security.SecureRandom;
import java.util.Random;

/**
 * Random generator for PostgreSQL.
 */
@NoArgsConstructor(access = AccessLevel.PRIVATE)
public final class PostgreSQLRandomGenerator {
    
    private static final PostgreSQLRandomGenerator INSTANCE = new PostgreSQLRandomGenerator();
    
    private final Random random = new SecureRandom();
    
    /**
     * Get instance.
     *
     * @return instance
     */
    public static PostgreSQLRandomGenerator getInstance() {
        return INSTANCE;
    }
    
    /**
     * Generate random bytes.
     *
     * @param length length for generated random bytes
     * @return generated random bytes
     */
    public byte[] generateRandomBytes(final int length) {
        byte[] result = new byte[length];
        random.nextBytes(result);
        return result;
    }
}
