org.greencheek.related.indexing.util.ResizableByteBufferNoBoundsChecking Maven / Gradle / Ivy

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 *
 *  * Licensed to Relateit under one or more contributor
 *  * license agreements. See the NOTICE file distributed with
 *  * this work for additional information regarding copyright
 *  * ownership. Relateit 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
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package org.greencheek.related.indexing.util;

import java.nio.BufferOverflowException;
import java.nio.ByteBuffer;

public class ResizableByteBufferNoBoundsChecking implements ResizableByteBuffer {

    protected byte[] buf;
    protected int currentCapacityLeft;
    protected int position;
    private final int maxCapacity;
    private boolean hasSpaceToGrow = true;

    public ResizableByteBufferNoBoundsChecking(int initialCapacity, int maxCapacity) {
        currentCapacityLeft = initialCapacity;
        buf = new byte[initialCapacity];
        this.maxCapacity = maxCapacity;
        if(initialCapacity == maxCapacity) {
            hasSpaceToGrow = false;
        }
    }

    @Override
    public int size() {
        return position;
    }

    @Override
    public void reset() {
        position = 0;
        currentCapacityLeft = buf.length;
    }

    @Override
    public byte[] getBuf() {
        return buf;
    }

    @Override
    public ByteBuffer toByteBuffer() {
        return ByteBuffer.wrap(buf,0,position);
    }

    private void checkSizeAndGrow(int extra) {
        if(extra>currentCapacityLeft) {
           if(hasSpaceToGrow) {
               grow(extra);
           } else {
               throw new BufferOverflowException();
           }
        }
    }

    private void grow(int extra) {
        int currentCapacity = buf.length;
        int requiredCapacity = position+extra;

        int newSize = currentCapacity*2;
        if(newSize>=maxCapacity) {
            // new size is less than the required capacity
            newSize = maxCapacity;
            if(newSize