1 /* 2 * DeltaDecoder 3 * 4 * Author: Lasse Collin <lasse.collin (at) tukaani.org> 5 * 6 * This file has been put into the public domain. 7 * You can do whatever you want with this file. 8 */ 9 10 package org.tukaani.xz; 11 12 import java.io.InputStream; 13 14 class DeltaDecoder extends DeltaCoder implements FilterDecoder { 15 private final int distance; 16 17 DeltaDecoder(byte[] props) throws UnsupportedOptionsException { 18 if (props.length != 1) 19 throw new UnsupportedOptionsException( 20 "Unsupported Delta filter properties"); 21 22 distance = (props[0] & 0xFF) + 1; 23 } 24 25 public int getMemoryUsage() { 26 return 1; 27 } 28 29 public InputStream getInputStream(InputStream in) { 30 return new DeltaInputStream(in, distance); 31 } 32 } 33