org.jpedal.io.RandomAccessDataBuffer Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of OpenViewerFX Show documentation
Open Source (LGPL) JavaFX PDF Viewer for NetBeans plugin
There is a newer version: 7.15.25
/*
 * ===========================================
 * 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@
 *
 * ---------------
 * RandomAccessDataBuffer.java
 * ---------------
 */

package org.jpedal.io;

import java.io.IOException;

public class RandomAccessDataBuffer implements RandomAccessBuffer {

    private byte[] data;
    private long pointer;

    public RandomAccessDataBuffer(final byte[] data) {
        this.data = data;
        this.pointer = -1;
    }

    @Override
    public long getFilePointer() throws IOException {
        return pointer;
    }

    @Override
    public void seek(final long pos) throws IOException {
        if (checkPos(pos)) {
            this.pointer = pos;
        } else {
            throw new IOException("Position out of bounds");
        }
    }

    @Override
    public void close() throws IOException {
        this.data = null;
        this.pointer = -1;
    }

    @Override
    public long length() throws IOException {

        if (data != null) {
            return data.length;
        } else {
            throw new IOException("Data buffer not initialized.");
        }
    }

    @Override
    public int read() throws IOException {
        if (checkPos(this.pointer)) {
            return b2i(this.data[(int) pointer++]);
        } else {
            return -1;
        }
    }

    private int peek() throws IOException {
        if (checkPos(this.pointer)) {
            return b2i(this.data[(int) pointer]);
        } else {
            return -1;
        }
    }

    /**
     * return next line (returns null if no line)
     */
    @Override
    public String readLine() throws IOException {

        if (this.pointer >= this.data.length - 1) {
            return null;
        } else {

            final StringBuilder buf = new StringBuilder();
            int c;
            while ((c = read()) >= 0) {
                if ((c == 10) || (c == 13)) {
                    if (((peek() == 10) || (peek() == 13)) && (peek() != c)) {
                        read();
                    }
                    break;
                }
                buf.append((char) c);
            }
            return buf.toString();
        }
    }

    @Override
    public int read(final byte[] b) throws IOException {
        if (data == null) {
            throw new IOException("Data buffer not initialized.");
        }
        if (pointer < 0 || pointer >= data.length) {
            return -1;
        }
        final int length = Math.min(b.length, data.length - (int) pointer);
        for (int i = 0; i < length; i++) {
            b[i] = data[(int) pointer++];
        }
        return length;
    }

    private static int b2i(final byte b) {
        if (b >= 0) {
            return b;
        }
        return 256 + b;
    }

    private boolean checkPos(final long pos) throws IOException {
        return ((pos >= 0) && (pos < length()));
    }

    /* returns the byte data*/
    @Override
    public byte[] getPdfBuffer() {
        return data;
    }
}