1 /* 2 * BCJDecoder 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 import org.tukaani.xz.simple.*; 14 15 class BCJDecoder extends BCJCoder implements FilterDecoder { 16 private final long filterID; 17 private final int startOffset; 18 19 BCJDecoder(long filterID, byte[] props) 20 throws UnsupportedOptionsException { 21 assert isBCJFilterID(filterID); 22 this.filterID = filterID; 23 24 if (props.length == 0) { 25 startOffset = 0; 26 } else if (props.length == 4) { 27 int n = 0; 28 for (int i = 0; i < 4; ++i) 29 n |= (props[i] & 0xFF) << (i * 8); 30 31 startOffset = n; 32 } else { 33 throw new UnsupportedOptionsException( 34 "Unsupported BCJ filter properties"); 35 } 36 } 37 38 public int getMemoryUsage() { 39 return SimpleInputStream.getMemoryUsage(); 40 } 41 42 public InputStream getInputStream(InputStream in) { 43 SimpleFilter simpleFilter = null; 44 45 if (filterID == X86_FILTER_ID) 46 simpleFilter = new X86(false, startOffset); 47 else if (filterID == POWERPC_FILTER_ID) 48 simpleFilter = new PowerPC(false, startOffset); 49 else if (filterID == IA64_FILTER_ID) 50 simpleFilter = new IA64(false, startOffset); 51 else if (filterID == ARM_FILTER_ID) 52 simpleFilter = new ARM(false, startOffset); 53 else if (filterID == ARMTHUMB_FILTER_ID) 54 simpleFilter = new ARMThumb(false, startOffset); 55 else if (filterID == SPARC_FILTER_ID) 56 simpleFilter = new SPARC(false, startOffset); 57 else 58 assert false; 59 60 return new SimpleInputStream(in, simpleFilter); 61 } 62 } 63
