/*
 * Copyright 2017 NAVER Corp.
 *
 * 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 com.navercorp.pinpoint.common.server.bo.codec.stat.header;

import java.util.BitSet;

/**
 * JDK 7 implementation of {@link BitCountingHeaderEncoder}.
 *
 * @author HyunGil Jeong
 */
public class Jdk7BitCountingHeaderEncoder implements AgentStatHeaderEncoder {

    private final BitSet headerBitSet = new BitSet();
    private int position = 0;

    @Override
    public void addCode(int code) {
        if (code < 0) {
            throw new IllegalArgumentException("code must be positive");
        }
        int fromIndex = this.position;
        int toIndex = this.position + code;
        this.headerBitSet.set(fromIndex, toIndex);
        this.position = toIndex + 1;
    }

    @Override
    public byte[] getHeader() {
        return headerBitSet.toByteArray();
    }
}