/*
 * Copyright (c) 1995, 1997, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */


package sun.misc;
import java.io.PrintStream;
import java.io.OutputStream;
import java.io.IOException;

This class encodes a buffer into the classic: "Hexadecimal Dump" format of
the past. It is useful for analyzing the contents of binary buffers.
The format produced is as follows:
xxxx: 00 11 22 33 44 55 66 77   88 99 aa bb cc dd ee ff ................

Where xxxx is the offset into the buffer in 16 byte chunks, followed
by ascii coded hexadecimal bytes followed by the ASCII representation of
the bytes or '.' if they are not valid bytes.
Author:
     Chuck McManis/**
 * This class encodes a buffer into the classic: "Hexadecimal Dump" format of
 * the past. It is useful for analyzing the contents of binary buffers.
 * The format produced is as follows:
 * <pre>
 * xxxx: 00 11 22 33 44 55 66 77   88 99 aa bb cc dd ee ff ................
 * </pre>
 * Where xxxx is the offset into the buffer in 16 byte chunks, followed
 * by ascii coded hexadecimal bytes followed by the ASCII representation of
 * the bytes or '.' if they are not valid bytes.
 *
 * @author      Chuck McManis
 */

public class HexDumpEncoder extends CharacterEncoder {

    private int offset;
    private int thisLineLength;
    private int currentByte;
    private byte thisLine[] = new byte[16];

    static void hexDigit(PrintStream p, byte x) {
        char c;

        c = (char) ((x >> 4) & 0xf);
        if (c > 9)
            c = (char) ((c-10) + 'A');
        else
            c = (char)(c + '0');
        p.write(c);
        c = (char) (x & 0xf);
        if (c > 9)
            c = (char)((c-10) + 'A');
        else
            c = (char)(c + '0');
        p.write(c);
    }

    protected int bytesPerAtom() {
        return (1);
    }

    protected int bytesPerLine() {
        return (16);
    }

    protected void encodeBufferPrefix(OutputStream o) throws IOException {
        offset = 0;
        super.encodeBufferPrefix(o);
    }

    protected void encodeLinePrefix(OutputStream o, int len) throws IOException {
        hexDigit(pStream, (byte)((offset >>> 8) & 0xff));
        hexDigit(pStream, (byte)(offset & 0xff));
        pStream.print(": ");
        currentByte = 0;
        thisLineLength = len;
    }

    protected void encodeAtom(OutputStream o, byte buf[], int off, int len) throws IOException {
        thisLine[currentByte] = buf[off];
        hexDigit(pStream, buf[off]);
        pStream.print(" ");
        currentByte++;
        if (currentByte == 8)
            pStream.print("  ");
    }

    protected void encodeLineSuffix(OutputStream o) throws IOException {
        if (thisLineLength < 16) {
            for (int i = thisLineLength; i < 16; i++) {
                pStream.print("   ");
                if (i == 7)
                    pStream.print("  ");
            }
        }
        pStream.print(" ");
        for (int i = 0; i < thisLineLength; i++) {
            if ((thisLine[i] < ' ') || (thisLine[i] > 'z')) {
                pStream.print(".");
            } else {
                pStream.write(thisLine[i]);
            }
        }
        pStream.println();
        offset += thisLineLength;
    }

}