org.jpedal.utils.repositories.FastByteArrayOutputStream Maven / Gradle / Ivy

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/*
 * ===========================================
 * Java Pdf Extraction Decoding Access Library
 * ===========================================
 *
 * Project Info:  http://www.idrsolutions.com
 * Help section for developers at http://www.idrsolutions.com/support/
 *
 * (C) Copyright 1997-2017 IDRsolutions and Contributors.
 *
 * This file is part of JPedal/JPDF2HTML5
 *
 @LICENSE@
 *
 * ---------------
 * FastByteArrayOutputStream.java
 * ---------------
 */
package org.jpedal.utils.repositories;

/**
 * Provides a fast version to replace default Java version (which synchronizes everything!)
 */
public class FastByteArrayOutputStream {

    //how much we resize each time - will be doubled up to 160
    int increment_size = 1000;
    protected int current_item;

    //current max size
    int max_size = 250;

    //holds the data
    protected byte[] items;

    //default size
    public FastByteArrayOutputStream() {
        items = new byte[max_size];
    }


    protected static int incrementSize(int increment_size) {

        if (increment_size < 8000) {
            increment_size *= 4;
        } else if (increment_size < 320000) {
            increment_size *= 2;
        } else {
            increment_size += 320000;
        }

        return increment_size;
    }

    public byte[] toByteArray() {
        final byte[] newbuf = new byte[current_item];
        System.arraycopy(items, 0, newbuf, 0, current_item);
        return newbuf;
    }

    //set size
    public FastByteArrayOutputStream(final int number) {
        max_size = number;
        items = new byte[max_size];
    }


    /**
     * set an element
     */
    public final void write(final byte new_name) {
        if (current_item + 1 >= max_size) {
            checkSize(current_item + 1);
        }

        items[current_item] = new_name;

        current_item++;
    }

    /**
     * set an element
     */
    public final void write(final int new_name) {
        if (current_item + 1 >= max_size) {
            checkSize(current_item + 1);
        }

        items[current_item] = (byte) (new_name & 255);

        current_item++;
    }

    /**
     * set an element
     */
    public final void write(final byte[] new_name, final int start, final int len) {
        final int size = len - start;

        if (current_item + size >= max_size) {
            checkSize(current_item + size);
        }

        for (int i = 0; i < size; i++) {
            items[current_item] = new_name[i + start];
            current_item++;
        }
    }

    /**
     * set an element
     */
    public final void write(final byte[] new_name) {
        final int size = new_name.length;

        if (current_item + size >= max_size) {
            checkSize(current_item + size);
        }

        for (final byte aNew_name : new_name) {
            items[current_item] = aNew_name;
            current_item++;
        }
    }

    /**
     * return the size+1 as in last item (so an array of 0 values is 1) if added
     * If using set, use checkCapacity
     */
    public final int size() {
        return current_item;
    }

    /**
     * check the size of the array and increase if needed
     */
    private void checkSize(final int i) {

        if (i >= max_size) {
            final int old_size = max_size;
            max_size += increment_size;

            //allow for it not creating space
            if (max_size <= i) {
                max_size = i + increment_size + 2;
            }
            final byte[] temp = items;
            items = new byte[max_size];


            System.arraycopy(temp, 0, items, 0, old_size);

            increment_size = incrementSize(increment_size);

        }

    }


}