1 /* 2 * IndexEncoder 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.index; 11 12 import java.io.OutputStream; 13 import java.io.IOException; 14 import java.util.ArrayList; 15 import java.util.Iterator; 16 import java.util.zip.CheckedOutputStream; 17 import org.tukaani.xz.common.EncoderUtil; 18 import org.tukaani.xz.XZIOException; 19 20 public class IndexEncoder extends IndexBase { 21 private final ArrayList records = new ArrayList(); 22 23 public IndexEncoder() { 24 super(new XZIOException("XZ Stream or its Index has grown too big")); 25 } 26 27 public void add(long unpaddedSize, long uncompressedSize) 28 throws XZIOException { 29 super.add(unpaddedSize, uncompressedSize); 30 records.add(new IndexRecord(unpaddedSize, uncompressedSize)); 31 } 32 33 public void encode(OutputStream out) throws IOException { 34 java.util.zip.CRC32 crc32 = new java.util.zip.CRC32(); 35 CheckedOutputStream outChecked = new CheckedOutputStream(out, crc32); 36 37 // Index Indicator 38 outChecked.write(0x00); 39 40 // Number of Records 41 EncoderUtil.encodeVLI(outChecked, recordCount); 42 43 // List of Records 44 for (Iterator i = records.iterator(); i.hasNext(); ) { 45 IndexRecord record = (IndexRecord)i.next(); 46 EncoderUtil.encodeVLI(outChecked, record.unpadded); 47 EncoderUtil.encodeVLI(outChecked, record.uncompressed); 48 } 49 50 // Index Padding 51 for (int i = getIndexPaddingSize(); i > 0; --i) 52 outChecked.write(0x00); 53 54 // CRC32 55 long value = crc32.getValue(); 56 for (int i = 0; i < 4; ++i) 57 out.write((byte)(value >>> (i * 8))); 58 } 59 } 60
