Compressor.java

/*******************************************************************************
 * Copyright 2015 Maximilian Stark | Dakror <mail@dakror.de>
 * 
 * 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 de.dakror.vloxlands.util;

import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.net.URL;
import java.nio.ByteBuffer;
import java.util.Arrays;
import java.util.zip.DataFormatException;
import java.util.zip.Deflater;
import java.util.zip.Inflater;

/**
 * @author Dakror
 */
public class Compressor {
	public static void compressFile(File f, String s) {
		compressFile(f, (s + ((s.length() < 18) ? "                 " : "")).getBytes());
	}
	
	public static void compressFile(File f, byte[] input) {
		setFileContent(f, compress(input));
	}
	
	public static byte[] compress(byte[] b) {
		byte[] length = ByteBuffer.allocate(4).putInt(b.length).array();
		byte[] buffer = new byte[b.length];
		Deflater deflater = new Deflater(Deflater.BEST_COMPRESSION);
		deflater.setInput(b);
		deflater.finish();
		int len = deflater.deflate(buffer);
		byte[] compr = Arrays.copyOf(buffer, len);
		byte[] output = new byte[compr.length + 4];
		System.arraycopy(length, 0, output, 0, length.length);
		System.arraycopy(compr, 0, output, 4, compr.length);
		
		return output;
	}
	
	public static byte[] decompress(byte[] b) {
		try {
			int length = ByteBuffer.wrap(Arrays.copyOf(b, 4)).getInt();
			Inflater inflater = new Inflater();
			inflater.setInput(Arrays.copyOfRange(b, 4, b.length));
			byte[] buf = new byte[length];
			inflater.inflate(buf);
			inflater.end();
			return buf;
		} catch (DataFormatException e) {
			e.printStackTrace();
			return null;
		}
	}
	
	public static String decompressFile(File f) {
		byte[] decompressed = decompress(getFileContentAsByteArray(f));
		String text = new String(decompressed);
		return text;
	}
	
	public static void setFileContent(File f, byte[] b) {
		try {
			f.createNewFile();
			
			FileOutputStream fos = new FileOutputStream(f);
			fos.write(b);
			fos.close();
		} catch (Exception e) {}
	}
	
	public static byte[] getFileContentAsByteArray(File f) {
		try {
			byte[] fileData = new byte[(int) f.length()];
			DataInputStream dis = new DataInputStream(new FileInputStream(f));
			dis.readFully(fileData);
			dis.close();
			return fileData;
		} catch (Exception e) {
			e.printStackTrace();
			return null;
		}
	}
	
	public static byte[] getURLContentAsByteArray(URL url) {
		try {
			byte[] fileData = new byte[url.openConnection().getContentLength()];
			DataInputStream dis = new DataInputStream(url.openStream());
			dis.readFully(fileData);
			dis.close();
			return fileData;
		} catch (Exception e) {
			e.printStackTrace();
			return null;
		}
	}
	
	public static byte[] compressRow(byte[] b) {
		try {
			ByteArrayOutputStream baos = new ByteArrayOutputStream();
			byte active = b[0];
			byte same = (byte) -127;
			for (int i = 1; i < b.length; i++) {
				if (b[i] == active && same < 127) same += 1;
				else {
					baos.write(new byte[] { same, active });
					same = -127;
					active = b[i];
				}
			}
			
			baos.write(new byte[] { same, active });
			
			return baos.toByteArray();
		} catch (Exception e) {
			e.printStackTrace();
			return null;
		}
	}
	
	public static byte[] decompressRow(byte[] b) {
		ByteArrayOutputStream baos = new ByteArrayOutputStream();
		for (int i = 0; i < b.length; i += 2) {
			for (int j = 0; j < b[i] + 128; j++) {
				baos.write(b[i + 1]);
			}
		}
		return baos.toByteArray();
	}
}