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Diffstat (limited to 'libjava/classpath/java/util/zip/InflaterDynHeader.java')
| -rw-r--r-- | libjava/classpath/java/util/zip/InflaterDynHeader.java | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/libjava/classpath/java/util/zip/InflaterDynHeader.java b/libjava/classpath/java/util/zip/InflaterDynHeader.java new file mode 100644 index 00000000000..bff84a894d8 --- /dev/null +++ b/libjava/classpath/java/util/zip/InflaterDynHeader.java @@ -0,0 +1,203 @@ +/* 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); + } +} |