| /* java.util.zip.InflaterDynHeader |
| Copyright (C) 2001 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath 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 for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| package java.util.zip; |
| |
| class InflaterDynHeader |
| { |
| private static final int LNUM = 0; |
| private static final int DNUM = 1; |
| private static final int BLNUM = 2; |
| private static final int BLLENS = 3; |
| private static final int LENS = 4; |
| private static final int REPS = 5; |
| |
| private static final int repMin[] = { 3, 3, 11 }; |
| private static final int repBits[] = { 2, 3, 7 }; |
| |
| |
| private byte[] blLens; |
| private byte[] litdistLens; |
| |
| private InflaterHuffmanTree blTree; |
| |
| private int mode; |
| private int lnum, dnum, blnum, num; |
| private int repSymbol; |
| private byte lastLen; |
| private int ptr; |
| |
| private static final int[] BL_ORDER = |
| { 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 }; |
| |
| public InflaterDynHeader() |
| { |
| } |
| |
| public boolean decode(StreamManipulator input) throws DataFormatException |
| { |
| decode_loop: |
| for (;;) |
| { |
| switch (mode) |
| { |
| case LNUM: |
| lnum = input.peekBits(5); |
| if (lnum < 0) |
| return false; |
| lnum += 257; |
| input.dropBits(5); |
| // System.err.println("LNUM: "+lnum); |
| mode = DNUM; |
| /* fall through */ |
| case DNUM: |
| dnum = input.peekBits(5); |
| if (dnum < 0) |
| return false; |
| dnum++; |
| input.dropBits(5); |
| // System.err.println("DNUM: "+dnum); |
| num = lnum+dnum; |
| litdistLens = new byte[num]; |
| mode = BLNUM; |
| /* fall through */ |
| case BLNUM: |
| blnum = input.peekBits(4); |
| if (blnum < 0) |
| return false; |
| blnum += 4; |
| input.dropBits(4); |
| blLens = new byte[19]; |
| ptr = 0; |
| // System.err.println("BLNUM: "+blnum); |
| mode = BLLENS; |
| /* fall through */ |
| case BLLENS: |
| while (ptr < blnum) |
| { |
| int len = input.peekBits(3); |
| if (len < 0) |
| return false; |
| input.dropBits(3); |
| // System.err.println("blLens["+BL_ORDER[ptr]+"]: "+len); |
| blLens[BL_ORDER[ptr]] = (byte) len; |
| ptr++; |
| } |
| blTree = new InflaterHuffmanTree(blLens); |
| blLens = null; |
| ptr = 0; |
| mode = LENS; |
| /* fall through */ |
| case LENS: |
| { |
| int symbol; |
| while (((symbol = blTree.getSymbol(input)) & ~15) == 0) |
| { |
| /* Normal case: symbol in [0..15] */ |
| |
| // System.err.println("litdistLens["+ptr+"]: "+symbol); |
| litdistLens[ptr++] = lastLen = (byte) symbol; |
| |
| if (ptr == num) |
| { |
| /* Finished */ |
| return true; |
| } |
| } |
| |
| /* need more input ? */ |
| if (symbol < 0) |
| return false; |
| |
| /* otherwise repeat code */ |
| if (symbol >= 17) |
| { |
| /* repeat zero */ |
| // System.err.println("repeating zero"); |
| lastLen = 0; |
| } |
| else |
| { |
| if (ptr == 0) |
| throw new DataFormatException(); |
| } |
| repSymbol = symbol-16; |
| mode = REPS; |
| } |
| /* fall through */ |
| |
| case REPS: |
| { |
| int bits = repBits[repSymbol]; |
| int count = input.peekBits(bits); |
| if (count < 0) |
| return false; |
| input.dropBits(bits); |
| count += repMin[repSymbol]; |
| // System.err.println("litdistLens repeated: "+count); |
| |
| if (ptr + count > num) |
| throw new DataFormatException(); |
| while (count-- > 0) |
| litdistLens[ptr++] = lastLen; |
| |
| if (ptr == num) |
| { |
| /* Finished */ |
| return true; |
| } |
| } |
| mode = LENS; |
| continue decode_loop; |
| } |
| } |
| } |
| |
| public InflaterHuffmanTree buildLitLenTree() throws DataFormatException |
| { |
| byte[] litlenLens = new byte[lnum]; |
| System.arraycopy(litdistLens, 0, litlenLens, 0, lnum); |
| return new InflaterHuffmanTree(litlenLens); |
| } |
| |
| public InflaterHuffmanTree buildDistTree() throws DataFormatException |
| { |
| byte[] distLens = new byte[dnum]; |
| System.arraycopy(litdistLens, lnum, distLens, 0, dnum); |
| return new InflaterHuffmanTree(distLens); |
| } |
| } |