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1798 lines
71 KiB
1798 lines
71 KiB
// Inflate.cs |
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// ------------------------------------------------------------------ |
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// |
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// Copyright (c) 2009 Dino Chiesa and Microsoft Corporation. |
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// All rights reserved. |
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// |
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// This code module is part of DotNetZip, a zipfile class library. |
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// |
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// ------------------------------------------------------------------ |
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// |
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// This code is licensed under the Microsoft Public License. |
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// See the file License.txt for the license details. |
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// More info on: http://dotnetzip.codeplex.com |
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// |
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// ------------------------------------------------------------------ |
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// |
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// last saved (in emacs): |
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// Time-stamp: <2010-January-08 18:32:12> |
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// |
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// ------------------------------------------------------------------ |
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// |
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// This module defines classes for decompression. This code is derived |
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// from the jzlib implementation of zlib, but significantly modified. |
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// The object model is not the same, and many of the behaviors are |
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// different. Nonetheless, in keeping with the license for jzlib, I am |
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// reproducing the copyright to that code here. |
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// |
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// ------------------------------------------------------------------ |
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// |
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// Copyright (c) 2000,2001,2002,2003 ymnk, JCraft,Inc. All rights reserved. |
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// |
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// Redistribution and use in source and binary forms, with or without |
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// modification, are permitted provided that the following conditions are met: |
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// |
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// 1. Redistributions of source code must retain the above copyright notice, |
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// this list of conditions and the following disclaimer. |
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// |
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// 2. Redistributions in binary form must reproduce the above copyright |
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// notice, this list of conditions and the following disclaimer in |
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// the documentation and/or other materials provided with the distribution. |
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// |
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// 3. The names of the authors may not be used to endorse or promote products |
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// derived from this software without specific prior written permission. |
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// |
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// THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, |
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// INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND |
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// FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JCRAFT, |
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// INC. OR ANY CONTRIBUTORS TO THIS SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT, |
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// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, |
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// OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
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// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
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// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, |
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// EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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// |
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// ----------------------------------------------------------------------- |
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// |
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// This program is based on zlib-1.1.3; credit to authors |
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// Jean-loup Gailly(jloup@gzip.org) and Mark Adler(madler@alumni.caltech.edu) |
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// and contributors of zlib. |
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// |
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// ----------------------------------------------------------------------- |
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using BestHTTP.PlatformSupport.Memory; |
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using System; |
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namespace BestHTTP.Decompression.Zlib |
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{ |
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sealed class InflateBlocks |
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{ |
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private const int MANY = 1440; |
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|
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// Table for deflate from PKZIP's appnote.txt. |
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internal static readonly int[] border = new int[] |
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{ 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 }; |
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|
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private enum InflateBlockMode |
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{ |
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TYPE = 0, // get type bits (3, including end bit) |
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LENS = 1, // get lengths for stored |
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STORED = 2, // processing stored block |
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TABLE = 3, // get table lengths |
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BTREE = 4, // get bit lengths tree for a dynamic block |
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DTREE = 5, // get length, distance trees for a dynamic block |
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CODES = 6, // processing fixed or dynamic block |
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DRY = 7, // output remaining window bytes |
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DONE = 8, // finished last block, done |
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BAD = 9, // ot a data error--stuck here |
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} |
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|
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private InflateBlockMode mode; // current inflate_block mode |
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|
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internal int left; // if STORED, bytes left to copy |
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|
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internal int table; // table lengths (14 bits) |
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internal int index; // index into blens (or border) |
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internal int[] blens; // bit lengths of codes |
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internal int[] bb = new int[1]; // bit length tree depth |
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internal int[] tb = new int[1]; // bit length decoding tree |
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|
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internal InflateCodes codes = new InflateCodes(); // if CODES, current state |
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|
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internal int last; // true if this block is the last block |
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|
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internal ZlibCodec _codec; // pointer back to this zlib stream |
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|
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// mode independent information |
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internal int bitk; // bits in bit buffer |
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internal int bitb; // bit buffer |
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internal int[] hufts; // single malloc for tree space |
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internal byte[] window; // sliding window |
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internal int end; // one byte after sliding window |
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internal int readAt; // window read pointer |
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internal int writeAt; // window write pointer |
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internal System.Object checkfn; // check function |
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internal uint check; // check on output |
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|
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internal InfTree inftree = new InfTree(); |
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|
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internal InflateBlocks(ZlibCodec codec, System.Object checkfn, int w) |
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{ |
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_codec = codec; |
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hufts = new int[MANY * 3]; |
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window = BufferPool.Get(w, true); |
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end = w; |
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this.checkfn = checkfn; |
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mode = InflateBlockMode.TYPE; |
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Reset(); |
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} |
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|
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internal uint Reset() |
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{ |
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uint oldCheck = check; |
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mode = InflateBlockMode.TYPE; |
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bitk = 0; |
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bitb = 0; |
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readAt = writeAt = 0; |
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|
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if (checkfn != null) |
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_codec._Adler32 = check = Adler.Adler32(0, null, 0, 0); |
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return oldCheck; |
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} |
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internal int Process(int r) |
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{ |
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int t; // temporary storage |
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int b; // bit buffer |
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int k; // bits in bit buffer |
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int p; // input data pointer |
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int n; // bytes available there |
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int q; // output window write pointer |
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int m; // bytes to end of window or read pointer |
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|
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// copy input/output information to locals (UPDATE macro restores) |
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|
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p = _codec.NextIn; |
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n = _codec.AvailableBytesIn; |
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b = bitb; |
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k = bitk; |
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|
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q = writeAt; |
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m = (int)(q < readAt ? readAt - q - 1 : end - q); |
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|
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// process input based on current state |
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while (true) |
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{ |
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switch (mode) |
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{ |
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case InflateBlockMode.TYPE: |
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|
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while (k < (3)) |
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{ |
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if (n != 0) |
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{ |
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r = ZlibConstants.Z_OK; |
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} |
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else |
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{ |
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bitb = b; bitk = k; |
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_codec.AvailableBytesIn = n; |
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_codec.TotalBytesIn += p - _codec.NextIn; |
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_codec.NextIn = p; |
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writeAt = q; |
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return Flush(r); |
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} |
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n--; |
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b |= (_codec.InputBuffer[p++] & 0xff) << k; |
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k += 8; |
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} |
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t = (int)(b & 7); |
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last = t & 1; |
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|
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switch ((uint)t >> 1) |
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{ |
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case 0: // stored |
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b >>= 3; k -= (3); |
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t = k & 7; // go to byte boundary |
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b >>= t; k -= t; |
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mode = InflateBlockMode.LENS; // get length of stored block |
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break; |
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|
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case 1: // fixed |
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int[] bl = new int[1]; |
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int[] bd = new int[1]; |
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int[][] tl = new int[1][]; |
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int[][] td = new int[1][]; |
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InfTree.inflate_trees_fixed(bl, bd, tl, td, _codec); |
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codes.Init(bl[0], bd[0], tl[0], 0, td[0], 0); |
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b >>= 3; k -= 3; |
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mode = InflateBlockMode.CODES; |
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break; |
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|
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case 2: // dynamic |
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b >>= 3; k -= 3; |
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mode = InflateBlockMode.TABLE; |
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break; |
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|
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case 3: // illegal |
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b >>= 3; k -= 3; |
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mode = InflateBlockMode.BAD; |
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_codec.Message = "invalid block type"; |
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r = ZlibConstants.Z_DATA_ERROR; |
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bitb = b; bitk = k; |
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_codec.AvailableBytesIn = n; |
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_codec.TotalBytesIn += p - _codec.NextIn; |
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_codec.NextIn = p; |
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writeAt = q; |
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return Flush(r); |
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} |
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break; |
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case InflateBlockMode.LENS: |
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|
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while (k < (32)) |
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{ |
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if (n != 0) |
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{ |
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r = ZlibConstants.Z_OK; |
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} |
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else |
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{ |
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bitb = b; bitk = k; |
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_codec.AvailableBytesIn = n; |
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_codec.TotalBytesIn += p - _codec.NextIn; |
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_codec.NextIn = p; |
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writeAt = q; |
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return Flush(r); |
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} |
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; |
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n--; |
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b |= (_codec.InputBuffer[p++] & 0xff) << k; |
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k += 8; |
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} |
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if ( ( ((~b)>>16) & 0xffff) != (b & 0xffff)) |
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{ |
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mode = InflateBlockMode.BAD; |
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_codec.Message = "invalid stored block lengths"; |
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r = ZlibConstants.Z_DATA_ERROR; |
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|
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bitb = b; bitk = k; |
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_codec.AvailableBytesIn = n; |
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_codec.TotalBytesIn += p - _codec.NextIn; |
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_codec.NextIn = p; |
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writeAt = q; |
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return Flush(r); |
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} |
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left = (b & 0xffff); |
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b = k = 0; // dump bits |
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mode = left != 0 ? InflateBlockMode.STORED : (last != 0 ? InflateBlockMode.DRY : InflateBlockMode.TYPE); |
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break; |
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|
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case InflateBlockMode.STORED: |
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if (n == 0) |
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{ |
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bitb = b; bitk = k; |
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_codec.AvailableBytesIn = n; |
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_codec.TotalBytesIn += p - _codec.NextIn; |
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_codec.NextIn = p; |
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writeAt = q; |
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return Flush(r); |
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} |
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|
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if (m == 0) |
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{ |
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if (q == end && readAt != 0) |
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{ |
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q = 0; m = (int)(q < readAt ? readAt - q - 1 : end - q); |
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} |
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if (m == 0) |
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{ |
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writeAt = q; |
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r = Flush(r); |
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q = writeAt; m = (int)(q < readAt ? readAt - q - 1 : end - q); |
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if (q == end && readAt != 0) |
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{ |
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q = 0; m = (int)(q < readAt ? readAt - q - 1 : end - q); |
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} |
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if (m == 0) |
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{ |
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bitb = b; bitk = k; |
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_codec.AvailableBytesIn = n; |
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_codec.TotalBytesIn += p - _codec.NextIn; |
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_codec.NextIn = p; |
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writeAt = q; |
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return Flush(r); |
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} |
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} |
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} |
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r = ZlibConstants.Z_OK; |
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t = left; |
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if (t > n) |
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t = n; |
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if (t > m) |
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t = m; |
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Array.Copy(_codec.InputBuffer, p, window, q, t); |
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p += t; n -= t; |
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q += t; m -= t; |
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if ((left -= t) != 0) |
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break; |
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mode = last != 0 ? InflateBlockMode.DRY : InflateBlockMode.TYPE; |
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break; |
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|
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case InflateBlockMode.TABLE: |
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|
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while (k < (14)) |
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{ |
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if (n != 0) |
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{ |
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r = ZlibConstants.Z_OK; |
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} |
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else |
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{ |
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bitb = b; bitk = k; |
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_codec.AvailableBytesIn = n; |
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_codec.TotalBytesIn += p - _codec.NextIn; |
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_codec.NextIn = p; |
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writeAt = q; |
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return Flush(r); |
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} |
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|
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n--; |
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b |= (_codec.InputBuffer[p++] & 0xff) << k; |
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k += 8; |
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} |
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|
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table = t = (b & 0x3fff); |
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if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29) |
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{ |
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mode = InflateBlockMode.BAD; |
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_codec.Message = "too many length or distance symbols"; |
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r = ZlibConstants.Z_DATA_ERROR; |
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|
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bitb = b; bitk = k; |
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_codec.AvailableBytesIn = n; |
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_codec.TotalBytesIn += p - _codec.NextIn; |
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_codec.NextIn = p; |
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writeAt = q; |
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return Flush(r); |
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} |
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t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f); |
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if (blens == null || blens.Length < t) |
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{ |
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blens = new int[t]; |
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} |
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else |
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{ |
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Array.Clear(blens, 0, t); |
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// for (int i = 0; i < t; i++) |
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// { |
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// blens[i] = 0; |
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// } |
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} |
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|
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b >>= 14; |
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k -= 14; |
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|
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|
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index = 0; |
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mode = InflateBlockMode.BTREE; |
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goto case InflateBlockMode.BTREE; |
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|
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case InflateBlockMode.BTREE: |
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while (index < 4 + (table >> 10)) |
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{ |
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while (k < (3)) |
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{ |
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if (n != 0) |
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{ |
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r = ZlibConstants.Z_OK; |
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} |
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else |
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{ |
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bitb = b; bitk = k; |
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_codec.AvailableBytesIn = n; |
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_codec.TotalBytesIn += p - _codec.NextIn; |
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_codec.NextIn = p; |
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writeAt = q; |
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return Flush(r); |
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} |
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|
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n--; |
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b |= (_codec.InputBuffer[p++] & 0xff) << k; |
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k += 8; |
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} |
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|
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blens[border[index++]] = b & 7; |
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|
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b >>= 3; k -= 3; |
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} |
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|
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while (index < 19) |
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{ |
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blens[border[index++]] = 0; |
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} |
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|
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bb[0] = 7; |
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t = inftree.inflate_trees_bits(blens, bb, tb, hufts, _codec); |
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if (t != ZlibConstants.Z_OK) |
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{ |
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r = t; |
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if (r == ZlibConstants.Z_DATA_ERROR) |
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{ |
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blens = null; |
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mode = InflateBlockMode.BAD; |
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} |
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|
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bitb = b; bitk = k; |
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_codec.AvailableBytesIn = n; |
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_codec.TotalBytesIn += p - _codec.NextIn; |
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_codec.NextIn = p; |
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writeAt = q; |
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return Flush(r); |
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} |
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|
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index = 0; |
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mode = InflateBlockMode.DTREE; |
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goto case InflateBlockMode.DTREE; |
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|
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case InflateBlockMode.DTREE: |
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while (true) |
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{ |
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t = table; |
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if (!(index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))) |
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{ |
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break; |
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} |
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|
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int i, j, c; |
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|
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t = bb[0]; |
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|
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while (k < t) |
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{ |
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if (n != 0) |
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{ |
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r = ZlibConstants.Z_OK; |
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} |
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else |
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{ |
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bitb = b; bitk = k; |
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_codec.AvailableBytesIn = n; |
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_codec.TotalBytesIn += p - _codec.NextIn; |
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_codec.NextIn = p; |
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writeAt = q; |
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return Flush(r); |
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} |
|
|
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n--; |
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b |= (_codec.InputBuffer[p++] & 0xff) << k; |
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k += 8; |
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} |
|
|
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t = hufts[(tb[0] + (b & InternalInflateConstants.InflateMask[t])) * 3 + 1]; |
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c = hufts[(tb[0] + (b & InternalInflateConstants.InflateMask[t])) * 3 + 2]; |
|
|
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if (c < 16) |
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{ |
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b >>= t; k -= t; |
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blens[index++] = c; |
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} |
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else |
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{ |
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// c == 16..18 |
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i = c == 18 ? 7 : c - 14; |
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j = c == 18 ? 11 : 3; |
|
|
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while (k < (t + i)) |
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{ |
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if (n != 0) |
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{ |
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r = ZlibConstants.Z_OK; |
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} |
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else |
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{ |
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bitb = b; bitk = k; |
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_codec.AvailableBytesIn = n; |
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_codec.TotalBytesIn += p - _codec.NextIn; |
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_codec.NextIn = p; |
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writeAt = q; |
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return Flush(r); |
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} |
|
|
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n--; |
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b |= (_codec.InputBuffer[p++] & 0xff) << k; |
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k += 8; |
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} |
|
|
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b >>= t; k -= t; |
|
|
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j += (b & InternalInflateConstants.InflateMask[i]); |
|
|
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b >>= i; k -= i; |
|
|
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i = index; |
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t = table; |
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if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) || (c == 16 && i < 1)) |
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{ |
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blens = null; |
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mode = InflateBlockMode.BAD; |
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_codec.Message = "invalid bit length repeat"; |
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r = ZlibConstants.Z_DATA_ERROR; |
|
|
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bitb = b; bitk = k; |
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_codec.AvailableBytesIn = n; |
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_codec.TotalBytesIn += p - _codec.NextIn; |
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_codec.NextIn = p; |
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writeAt = q; |
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return Flush(r); |
|
} |
|
|
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c = (c == 16) ? blens[i-1] : 0; |
|
do |
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{ |
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blens[i++] = c; |
|
} |
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while (--j != 0); |
|
index = i; |
|
} |
|
} |
|
|
|
tb[0] = -1; |
|
{ |
|
int[] bl = new int[] { 9 }; // must be <= 9 for lookahead assumptions |
|
int[] bd = new int[] { 6 }; // must be <= 9 for lookahead assumptions |
|
int[] tl = new int[1]; |
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int[] td = new int[1]; |
|
|
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t = table; |
|
t = inftree.inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f), blens, bl, bd, tl, td, hufts, _codec); |
|
|
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if (t != ZlibConstants.Z_OK) |
|
{ |
|
if (t == ZlibConstants.Z_DATA_ERROR) |
|
{ |
|
blens = null; |
|
mode = InflateBlockMode.BAD; |
|
} |
|
r = t; |
|
|
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bitb = b; bitk = k; |
|
_codec.AvailableBytesIn = n; |
|
_codec.TotalBytesIn += p - _codec.NextIn; |
|
_codec.NextIn = p; |
|
writeAt = q; |
|
return Flush(r); |
|
} |
|
codes.Init(bl[0], bd[0], hufts, tl[0], hufts, td[0]); |
|
} |
|
mode = InflateBlockMode.CODES; |
|
goto case InflateBlockMode.CODES; |
|
|
|
case InflateBlockMode.CODES: |
|
bitb = b; bitk = k; |
|
_codec.AvailableBytesIn = n; |
|
_codec.TotalBytesIn += p - _codec.NextIn; |
|
_codec.NextIn = p; |
|
writeAt = q; |
|
|
|
r = codes.Process(this, r); |
|
if (r != ZlibConstants.Z_STREAM_END) |
|
{ |
|
return Flush(r); |
|
} |
|
|
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r = ZlibConstants.Z_OK; |
|
p = _codec.NextIn; |
|
n = _codec.AvailableBytesIn; |
|
b = bitb; |
|
k = bitk; |
|
q = writeAt; |
|
m = (int)(q < readAt ? readAt - q - 1 : end - q); |
|
|
|
if (last == 0) |
|
{ |
|
mode = InflateBlockMode.TYPE; |
|
break; |
|
} |
|
mode = InflateBlockMode.DRY; |
|
goto case InflateBlockMode.DRY; |
|
|
|
case InflateBlockMode.DRY: |
|
writeAt = q; |
|
r = Flush(r); |
|
q = writeAt; m = (int)(q < readAt ? readAt - q - 1 : end - q); |
|
if (readAt != writeAt) |
|
{ |
|
bitb = b; bitk = k; |
|
_codec.AvailableBytesIn = n; |
|
_codec.TotalBytesIn += p - _codec.NextIn; |
|
_codec.NextIn = p; |
|
writeAt = q; |
|
return Flush(r); |
|
} |
|
mode = InflateBlockMode.DONE; |
|
goto case InflateBlockMode.DONE; |
|
|
|
case InflateBlockMode.DONE: |
|
r = ZlibConstants.Z_STREAM_END; |
|
bitb = b; |
|
bitk = k; |
|
_codec.AvailableBytesIn = n; |
|
_codec.TotalBytesIn += p - _codec.NextIn; |
|
_codec.NextIn = p; |
|
writeAt = q; |
|
return Flush(r); |
|
|
|
case InflateBlockMode.BAD: |
|
r = ZlibConstants.Z_DATA_ERROR; |
|
|
|
bitb = b; bitk = k; |
|
_codec.AvailableBytesIn = n; |
|
_codec.TotalBytesIn += p - _codec.NextIn; |
|
_codec.NextIn = p; |
|
writeAt = q; |
|
return Flush(r); |
|
|
|
|
|
default: |
|
r = ZlibConstants.Z_STREAM_ERROR; |
|
|
|
bitb = b; bitk = k; |
|
_codec.AvailableBytesIn = n; |
|
_codec.TotalBytesIn += p - _codec.NextIn; |
|
_codec.NextIn = p; |
|
writeAt = q; |
|
return Flush(r); |
|
} |
|
} |
|
} |
|
|
|
|
|
internal void Free() |
|
{ |
|
Reset(); |
|
BufferPool.Release(window); |
|
window = null; |
|
hufts = null; |
|
} |
|
|
|
internal void SetDictionary(byte[] d, int start, int n) |
|
{ |
|
Array.Copy(d, start, window, 0, n); |
|
readAt = writeAt = n; |
|
} |
|
|
|
// Returns true if inflate is currently at the end of a block generated |
|
// by Z_SYNC_FLUSH or Z_FULL_FLUSH. |
|
internal int SyncPoint() |
|
{ |
|
return mode == InflateBlockMode.LENS ? 1 : 0; |
|
} |
|
|
|
// copy as much as possible from the sliding window to the output area |
|
internal int Flush(int r) |
|
{ |
|
int nBytes; |
|
|
|
for (int pass=0; pass < 2; pass++) |
|
{ |
|
if (pass==0) |
|
{ |
|
// compute number of bytes to copy as far as end of window |
|
nBytes = (int)((readAt <= writeAt ? writeAt : end) - readAt); |
|
} |
|
else |
|
{ |
|
// compute bytes to copy |
|
nBytes = writeAt - readAt; |
|
} |
|
|
|
// workitem 8870 |
|
if (nBytes == 0) |
|
{ |
|
if (r == ZlibConstants.Z_BUF_ERROR) |
|
r = ZlibConstants.Z_OK; |
|
return r; |
|
} |
|
|
|
if (nBytes > _codec.AvailableBytesOut) |
|
nBytes = _codec.AvailableBytesOut; |
|
|
|
if (nBytes != 0 && r == ZlibConstants.Z_BUF_ERROR) |
|
r = ZlibConstants.Z_OK; |
|
|
|
// update counters |
|
_codec.AvailableBytesOut -= nBytes; |
|
_codec.TotalBytesOut += nBytes; |
|
|
|
// update check information |
|
if (checkfn != null) |
|
_codec._Adler32 = check = Adler.Adler32(check, window, readAt, nBytes); |
|
|
|
// copy as far as end of window |
|
Array.Copy(window, readAt, _codec.OutputBuffer, _codec.NextOut, nBytes); |
|
_codec.NextOut += nBytes; |
|
readAt += nBytes; |
|
|
|
// see if more to copy at beginning of window |
|
if (readAt == end && pass == 0) |
|
{ |
|
// wrap pointers |
|
readAt = 0; |
|
if (writeAt == end) |
|
writeAt = 0; |
|
} |
|
else pass++; |
|
} |
|
|
|
// done |
|
return r; |
|
} |
|
} |
|
|
|
|
|
internal static class InternalInflateConstants |
|
{ |
|
// And'ing with mask[n] masks the lower n bits |
|
internal static readonly int[] InflateMask = new int[] { |
|
0x00000000, 0x00000001, 0x00000003, 0x00000007, |
|
0x0000000f, 0x0000001f, 0x0000003f, 0x0000007f, |
|
0x000000ff, 0x000001ff, 0x000003ff, 0x000007ff, |
|
0x00000fff, 0x00001fff, 0x00003fff, 0x00007fff, 0x0000ffff }; |
|
} |
|
|
|
|
|
sealed class InflateCodes |
|
{ |
|
// waiting for "i:"=input, |
|
// "o:"=output, |
|
// "x:"=nothing |
|
private const int START = 0; // x: set up for LEN |
|
private const int LEN = 1; // i: get length/literal/eob next |
|
private const int LENEXT = 2; // i: getting length extra (have base) |
|
private const int DIST = 3; // i: get distance next |
|
private const int DISTEXT = 4; // i: getting distance extra |
|
private const int COPY = 5; // o: copying bytes in window, waiting for space |
|
private const int LIT = 6; // o: got literal, waiting for output space |
|
private const int WASH = 7; // o: got eob, possibly still output waiting |
|
private const int END = 8; // x: got eob and all data flushed |
|
private const int BADCODE = 9; // x: got error |
|
|
|
internal int mode; // current inflate_codes mode |
|
|
|
// mode dependent information |
|
internal int len; |
|
|
|
internal int[] tree; // pointer into tree |
|
internal int tree_index = 0; |
|
internal int need; // bits needed |
|
|
|
internal int lit; |
|
|
|
// if EXT or COPY, where and how much |
|
internal int bitsToGet; // bits to get for extra |
|
internal int dist; // distance back to copy from |
|
|
|
internal byte lbits; // ltree bits decoded per branch |
|
internal byte dbits; // dtree bits decoder per branch |
|
internal int[] ltree; // literal/length/eob tree |
|
internal int ltree_index; // literal/length/eob tree |
|
internal int[] dtree; // distance tree |
|
internal int dtree_index; // distance tree |
|
|
|
internal InflateCodes() |
|
{ |
|
} |
|
|
|
internal void Init(int bl, int bd, int[] tl, int tl_index, int[] td, int td_index) |
|
{ |
|
mode = START; |
|
lbits = (byte)bl; |
|
dbits = (byte)bd; |
|
ltree = tl; |
|
ltree_index = tl_index; |
|
dtree = td; |
|
dtree_index = td_index; |
|
tree = null; |
|
} |
|
|
|
internal int Process(InflateBlocks blocks, int r) |
|
{ |
|
int j; // temporary storage |
|
int tindex; // temporary pointer |
|
int e; // extra bits or operation |
|
int b = 0; // bit buffer |
|
int k = 0; // bits in bit buffer |
|
int p = 0; // input data pointer |
|
int n; // bytes available there |
|
int q; // output window write pointer |
|
int m; // bytes to end of window or read pointer |
|
int f; // pointer to copy strings from |
|
|
|
ZlibCodec z = blocks._codec; |
|
|
|
// copy input/output information to locals (UPDATE macro restores) |
|
p = z.NextIn; |
|
n = z.AvailableBytesIn; |
|
b = blocks.bitb; |
|
k = blocks.bitk; |
|
q = blocks.writeAt; m = q < blocks.readAt ? blocks.readAt - q - 1 : blocks.end - q; |
|
|
|
// process input and output based on current state |
|
while (true) |
|
{ |
|
switch (mode) |
|
{ |
|
// waiting for "i:"=input, "o:"=output, "x:"=nothing |
|
case START: // x: set up for LEN |
|
if (m >= 258 && n >= 10) |
|
{ |
|
blocks.bitb = b; blocks.bitk = k; |
|
z.AvailableBytesIn = n; |
|
z.TotalBytesIn += p - z.NextIn; |
|
z.NextIn = p; |
|
blocks.writeAt = q; |
|
r = InflateFast(lbits, dbits, ltree, ltree_index, dtree, dtree_index, blocks, z); |
|
|
|
p = z.NextIn; |
|
n = z.AvailableBytesIn; |
|
b = blocks.bitb; |
|
k = blocks.bitk; |
|
q = blocks.writeAt; m = q < blocks.readAt ? blocks.readAt - q - 1 : blocks.end - q; |
|
|
|
if (r != ZlibConstants.Z_OK) |
|
{ |
|
mode = (r == ZlibConstants.Z_STREAM_END) ? WASH : BADCODE; |
|
break; |
|
} |
|
} |
|
need = lbits; |
|
tree = ltree; |
|
tree_index = ltree_index; |
|
|
|
mode = LEN; |
|
goto case LEN; |
|
|
|
case LEN: // i: get length/literal/eob next |
|
j = need; |
|
|
|
while (k < j) |
|
{ |
|
if (n != 0) |
|
r = ZlibConstants.Z_OK; |
|
else |
|
{ |
|
blocks.bitb = b; blocks.bitk = k; |
|
z.AvailableBytesIn = n; |
|
z.TotalBytesIn += p - z.NextIn; |
|
z.NextIn = p; |
|
blocks.writeAt = q; |
|
return blocks.Flush(r); |
|
} |
|
n--; |
|
b |= (z.InputBuffer[p++] & 0xff) << k; |
|
k += 8; |
|
} |
|
|
|
tindex = (tree_index + (b & InternalInflateConstants.InflateMask[j])) * 3; |
|
|
|
b >>= (tree[tindex + 1]); |
|
k -= (tree[tindex + 1]); |
|
|
|
e = tree[tindex]; |
|
|
|
if (e == 0) |
|
{ |
|
// literal |
|
lit = tree[tindex + 2]; |
|
mode = LIT; |
|
break; |
|
} |
|
if ((e & 16) != 0) |
|
{ |
|
// length |
|
bitsToGet = e & 15; |
|
len = tree[tindex + 2]; |
|
mode = LENEXT; |
|
break; |
|
} |
|
if ((e & 64) == 0) |
|
{ |
|
// next table |
|
need = e; |
|
tree_index = tindex / 3 + tree[tindex + 2]; |
|
break; |
|
} |
|
if ((e & 32) != 0) |
|
{ |
|
// end of block |
|
mode = WASH; |
|
break; |
|
} |
|
mode = BADCODE; // invalid code |
|
z.Message = "invalid literal/length code"; |
|
r = ZlibConstants.Z_DATA_ERROR; |
|
|
|
blocks.bitb = b; blocks.bitk = k; |
|
z.AvailableBytesIn = n; |
|
z.TotalBytesIn += p - z.NextIn; |
|
z.NextIn = p; |
|
blocks.writeAt = q; |
|
return blocks.Flush(r); |
|
|
|
|
|
case LENEXT: // i: getting length extra (have base) |
|
j = bitsToGet; |
|
|
|
while (k < j) |
|
{ |
|
if (n != 0) |
|
r = ZlibConstants.Z_OK; |
|
else |
|
{ |
|
blocks.bitb = b; blocks.bitk = k; |
|
z.AvailableBytesIn = n; z.TotalBytesIn += p - z.NextIn; z.NextIn = p; |
|
blocks.writeAt = q; |
|
return blocks.Flush(r); |
|
} |
|
n--; b |= (z.InputBuffer[p++] & 0xff) << k; |
|
k += 8; |
|
} |
|
|
|
len += (b & InternalInflateConstants.InflateMask[j]); |
|
|
|
b >>= j; |
|
k -= j; |
|
|
|
need = dbits; |
|
tree = dtree; |
|
tree_index = dtree_index; |
|
mode = DIST; |
|
goto case DIST; |
|
|
|
case DIST: // i: get distance next |
|
j = need; |
|
|
|
while (k < j) |
|
{ |
|
if (n != 0) |
|
r = ZlibConstants.Z_OK; |
|
else |
|
{ |
|
blocks.bitb = b; blocks.bitk = k; |
|
z.AvailableBytesIn = n; z.TotalBytesIn += p - z.NextIn; z.NextIn = p; |
|
blocks.writeAt = q; |
|
return blocks.Flush(r); |
|
} |
|
n--; b |= (z.InputBuffer[p++] & 0xff) << k; |
|
k += 8; |
|
} |
|
|
|
tindex = (tree_index + (b & InternalInflateConstants.InflateMask[j])) * 3; |
|
|
|
b >>= tree[tindex + 1]; |
|
k -= tree[tindex + 1]; |
|
|
|
e = (tree[tindex]); |
|
if ((e & 0x10) != 0) |
|
{ |
|
// distance |
|
bitsToGet = e & 15; |
|
dist = tree[tindex + 2]; |
|
mode = DISTEXT; |
|
break; |
|
} |
|
if ((e & 64) == 0) |
|
{ |
|
// next table |
|
need = e; |
|
tree_index = tindex / 3 + tree[tindex + 2]; |
|
break; |
|
} |
|
mode = BADCODE; // invalid code |
|
z.Message = "invalid distance code"; |
|
r = ZlibConstants.Z_DATA_ERROR; |
|
|
|
blocks.bitb = b; blocks.bitk = k; |
|
z.AvailableBytesIn = n; z.TotalBytesIn += p - z.NextIn; z.NextIn = p; |
|
blocks.writeAt = q; |
|
return blocks.Flush(r); |
|
|
|
|
|
case DISTEXT: // i: getting distance extra |
|
j = bitsToGet; |
|
|
|
while (k < j) |
|
{ |
|
if (n != 0) |
|
r = ZlibConstants.Z_OK; |
|
else |
|
{ |
|
blocks.bitb = b; blocks.bitk = k; |
|
z.AvailableBytesIn = n; z.TotalBytesIn += p - z.NextIn; z.NextIn = p; |
|
blocks.writeAt = q; |
|
return blocks.Flush(r); |
|
} |
|
n--; b |= (z.InputBuffer[p++] & 0xff) << k; |
|
k += 8; |
|
} |
|
|
|
dist += (b & InternalInflateConstants.InflateMask[j]); |
|
|
|
b >>= j; |
|
k -= j; |
|
|
|
mode = COPY; |
|
goto case COPY; |
|
|
|
case COPY: // o: copying bytes in window, waiting for space |
|
f = q - dist; |
|
while (f < 0) |
|
{ |
|
// modulo window size-"while" instead |
|
f += blocks.end; // of "if" handles invalid distances |
|
} |
|
while (len != 0) |
|
{ |
|
if (m == 0) |
|
{ |
|
if (q == blocks.end && blocks.readAt != 0) |
|
{ |
|
q = 0; m = q < blocks.readAt ? blocks.readAt - q - 1 : blocks.end - q; |
|
} |
|
if (m == 0) |
|
{ |
|
blocks.writeAt = q; r = blocks.Flush(r); |
|
q = blocks.writeAt; m = q < blocks.readAt ? blocks.readAt - q - 1 : blocks.end - q; |
|
|
|
if (q == blocks.end && blocks.readAt != 0) |
|
{ |
|
q = 0; m = q < blocks.readAt ? blocks.readAt - q - 1 : blocks.end - q; |
|
} |
|
|
|
if (m == 0) |
|
{ |
|
blocks.bitb = b; blocks.bitk = k; |
|
z.AvailableBytesIn = n; |
|
z.TotalBytesIn += p - z.NextIn; |
|
z.NextIn = p; |
|
blocks.writeAt = q; |
|
return blocks.Flush(r); |
|
} |
|
} |
|
} |
|
|
|
blocks.window[q++] = blocks.window[f++]; m--; |
|
|
|
if (f == blocks.end) |
|
f = 0; |
|
len--; |
|
} |
|
mode = START; |
|
break; |
|
|
|
case LIT: // o: got literal, waiting for output space |
|
if (m == 0) |
|
{ |
|
if (q == blocks.end && blocks.readAt != 0) |
|
{ |
|
q = 0; m = q < blocks.readAt ? blocks.readAt - q - 1 : blocks.end - q; |
|
} |
|
if (m == 0) |
|
{ |
|
blocks.writeAt = q; r = blocks.Flush(r); |
|
q = blocks.writeAt; m = q < blocks.readAt ? blocks.readAt - q - 1 : blocks.end - q; |
|
|
|
if (q == blocks.end && blocks.readAt != 0) |
|
{ |
|
q = 0; m = q < blocks.readAt ? blocks.readAt - q - 1 : blocks.end - q; |
|
} |
|
if (m == 0) |
|
{ |
|
blocks.bitb = b; blocks.bitk = k; |
|
z.AvailableBytesIn = n; z.TotalBytesIn += p - z.NextIn; z.NextIn = p; |
|
blocks.writeAt = q; |
|
return blocks.Flush(r); |
|
} |
|
} |
|
} |
|
r = ZlibConstants.Z_OK; |
|
|
|
blocks.window[q++] = (byte)lit; m--; |
|
|
|
mode = START; |
|
break; |
|
|
|
case WASH: // o: got eob, possibly more output |
|
if (k > 7) |
|
{ |
|
// return unused byte, if any |
|
k -= 8; |
|
n++; |
|
p--; // can always return one |
|
} |
|
|
|
blocks.writeAt = q; r = blocks.Flush(r); |
|
q = blocks.writeAt; m = q < blocks.readAt ? blocks.readAt - q - 1 : blocks.end - q; |
|
|
|
if (blocks.readAt != blocks.writeAt) |
|
{ |
|
blocks.bitb = b; blocks.bitk = k; |
|
z.AvailableBytesIn = n; z.TotalBytesIn += p - z.NextIn; z.NextIn = p; |
|
blocks.writeAt = q; |
|
return blocks.Flush(r); |
|
} |
|
mode = END; |
|
goto case END; |
|
|
|
case END: |
|
r = ZlibConstants.Z_STREAM_END; |
|
blocks.bitb = b; blocks.bitk = k; |
|
z.AvailableBytesIn = n; z.TotalBytesIn += p - z.NextIn; z.NextIn = p; |
|
blocks.writeAt = q; |
|
return blocks.Flush(r); |
|
|
|
case BADCODE: // x: got error |
|
|
|
r = ZlibConstants.Z_DATA_ERROR; |
|
|
|
blocks.bitb = b; blocks.bitk = k; |
|
z.AvailableBytesIn = n; z.TotalBytesIn += p - z.NextIn; z.NextIn = p; |
|
blocks.writeAt = q; |
|
return blocks.Flush(r); |
|
|
|
default: |
|
r = ZlibConstants.Z_STREAM_ERROR; |
|
|
|
blocks.bitb = b; blocks.bitk = k; |
|
z.AvailableBytesIn = n; z.TotalBytesIn += p - z.NextIn; z.NextIn = p; |
|
blocks.writeAt = q; |
|
return blocks.Flush(r); |
|
} |
|
} |
|
} |
|
|
|
|
|
// Called with number of bytes left to write in window at least 258 |
|
// (the maximum string length) and number of input bytes available |
|
// at least ten. The ten bytes are six bytes for the longest length/ |
|
// distance pair plus four bytes for overloading the bit buffer. |
|
|
|
internal int InflateFast(int bl, int bd, int[] tl, int tl_index, int[] td, int td_index, InflateBlocks s, ZlibCodec z) |
|
{ |
|
int t; // temporary pointer |
|
int[] tp; // temporary pointer |
|
int tp_index; // temporary pointer |
|
int e; // extra bits or operation |
|
int b; // bit buffer |
|
int k; // bits in bit buffer |
|
int p; // input data pointer |
|
int n; // bytes available there |
|
int q; // output window write pointer |
|
int m; // bytes to end of window or read pointer |
|
int ml; // mask for literal/length tree |
|
int md; // mask for distance tree |
|
int c; // bytes to copy |
|
int d; // distance back to copy from |
|
int r; // copy source pointer |
|
|
|
int tp_index_t_3; // (tp_index+t)*3 |
|
|
|
// load input, output, bit values |
|
p = z.NextIn; n = z.AvailableBytesIn; b = s.bitb; k = s.bitk; |
|
q = s.writeAt; m = q < s.readAt ? s.readAt - q - 1 : s.end - q; |
|
|
|
// initialize masks |
|
ml = InternalInflateConstants.InflateMask[bl]; |
|
md = InternalInflateConstants.InflateMask[bd]; |
|
|
|
// do until not enough input or output space for fast loop |
|
do |
|
{ |
|
// assume called with m >= 258 && n >= 10 |
|
// get literal/length code |
|
while (k < (20)) |
|
{ |
|
// max bits for literal/length code |
|
n--; |
|
b |= (z.InputBuffer[p++] & 0xff) << k; k += 8; |
|
} |
|
|
|
t = b & ml; |
|
tp = tl; |
|
tp_index = tl_index; |
|
tp_index_t_3 = (tp_index + t) * 3; |
|
if ((e = tp[tp_index_t_3]) == 0) |
|
{ |
|
b >>= (tp[tp_index_t_3 + 1]); k -= (tp[tp_index_t_3 + 1]); |
|
|
|
s.window[q++] = (byte)tp[tp_index_t_3 + 2]; |
|
m--; |
|
continue; |
|
} |
|
do |
|
{ |
|
|
|
b >>= (tp[tp_index_t_3 + 1]); k -= (tp[tp_index_t_3 + 1]); |
|
|
|
if ((e & 16) != 0) |
|
{ |
|
e &= 15; |
|
c = tp[tp_index_t_3 + 2] + ((int)b & InternalInflateConstants.InflateMask[e]); |
|
|
|
b >>= e; k -= e; |
|
|
|
// decode distance base of block to copy |
|
while (k < 15) |
|
{ |
|
// max bits for distance code |
|
n--; |
|
b |= (z.InputBuffer[p++] & 0xff) << k; k += 8; |
|
} |
|
|
|
t = b & md; |
|
tp = td; |
|
tp_index = td_index; |
|
tp_index_t_3 = (tp_index + t) * 3; |
|
e = tp[tp_index_t_3]; |
|
|
|
do |
|
{ |
|
|
|
b >>= (tp[tp_index_t_3 + 1]); k -= (tp[tp_index_t_3 + 1]); |
|
|
|
if ((e & 16) != 0) |
|
{ |
|
// get extra bits to add to distance base |
|
e &= 15; |
|
while (k < e) |
|
{ |
|
// get extra bits (up to 13) |
|
n--; |
|
b |= (z.InputBuffer[p++] & 0xff) << k; k += 8; |
|
} |
|
|
|
d = tp[tp_index_t_3 + 2] + (b & InternalInflateConstants.InflateMask[e]); |
|
|
|
b >>= e; k -= e; |
|
|
|
// do the copy |
|
m -= c; |
|
if (q >= d) |
|
{ |
|
// offset before dest |
|
// just copy |
|
r = q - d; |
|
if (q - r > 0 && 2 > (q - r)) |
|
{ |
|
s.window[q++] = s.window[r++]; // minimum count is three, |
|
s.window[q++] = s.window[r++]; // so unroll loop a little |
|
c -= 2; |
|
} |
|
else |
|
{ |
|
Array.Copy(s.window, r, s.window, q, 2); |
|
q += 2; r += 2; c -= 2; |
|
} |
|
} |
|
else |
|
{ |
|
// else offset after destination |
|
r = q - d; |
|
do |
|
{ |
|
r += s.end; // force pointer in window |
|
} |
|
while (r < 0); // covers invalid distances |
|
e = s.end - r; |
|
if (c > e) |
|
{ |
|
// if source crosses, |
|
c -= e; // wrapped copy |
|
if (q - r > 0 && e > (q - r)) |
|
{ |
|
do |
|
{ |
|
s.window[q++] = s.window[r++]; |
|
} |
|
while (--e != 0); |
|
} |
|
else |
|
{ |
|
Array.Copy(s.window, r, s.window, q, e); |
|
q += e; r += e; e = 0; |
|
} |
|
r = 0; // copy rest from start of window |
|
} |
|
} |
|
|
|
// copy all or what's left |
|
if (q - r > 0 && c > (q - r)) |
|
{ |
|
do |
|
{ |
|
s.window[q++] = s.window[r++]; |
|
} |
|
while (--c != 0); |
|
} |
|
else |
|
{ |
|
Array.Copy(s.window, r, s.window, q, c); |
|
q += c; r += c; c = 0; |
|
} |
|
break; |
|
} |
|
else if ((e & 64) == 0) |
|
{ |
|
t += tp[tp_index_t_3 + 2]; |
|
t += (b & InternalInflateConstants.InflateMask[e]); |
|
tp_index_t_3 = (tp_index + t) * 3; |
|
e = tp[tp_index_t_3]; |
|
} |
|
else |
|
{ |
|
z.Message = "invalid distance code"; |
|
|
|
c = z.AvailableBytesIn - n; c = (k >> 3) < c ? k >> 3 : c; n += c; p -= c; k -= (c << 3); |
|
|
|
s.bitb = b; s.bitk = k; |
|
z.AvailableBytesIn = n; z.TotalBytesIn += p - z.NextIn; z.NextIn = p; |
|
s.writeAt = q; |
|
|
|
return ZlibConstants.Z_DATA_ERROR; |
|
} |
|
} |
|
while (true); |
|
break; |
|
} |
|
|
|
if ((e & 64) == 0) |
|
{ |
|
t += tp[tp_index_t_3 + 2]; |
|
t += (b & InternalInflateConstants.InflateMask[e]); |
|
tp_index_t_3 = (tp_index + t) * 3; |
|
if ((e = tp[tp_index_t_3]) == 0) |
|
{ |
|
b >>= (tp[tp_index_t_3 + 1]); k -= (tp[tp_index_t_3 + 1]); |
|
s.window[q++] = (byte)tp[tp_index_t_3 + 2]; |
|
m--; |
|
break; |
|
} |
|
} |
|
else if ((e & 32) != 0) |
|
{ |
|
c = z.AvailableBytesIn - n; c = (k >> 3) < c ? k >> 3 : c; n += c; p -= c; k -= (c << 3); |
|
|
|
s.bitb = b; s.bitk = k; |
|
z.AvailableBytesIn = n; z.TotalBytesIn += p - z.NextIn; z.NextIn = p; |
|
s.writeAt = q; |
|
|
|
return ZlibConstants.Z_STREAM_END; |
|
} |
|
else |
|
{ |
|
z.Message = "invalid literal/length code"; |
|
|
|
c = z.AvailableBytesIn - n; c = (k >> 3) < c ? k >> 3 : c; n += c; p -= c; k -= (c << 3); |
|
|
|
s.bitb = b; s.bitk = k; |
|
z.AvailableBytesIn = n; z.TotalBytesIn += p - z.NextIn; z.NextIn = p; |
|
s.writeAt = q; |
|
|
|
return ZlibConstants.Z_DATA_ERROR; |
|
} |
|
} |
|
while (true); |
|
} |
|
while (m >= 258 && n >= 10); |
|
|
|
// not enough input or output--restore pointers and return |
|
c = z.AvailableBytesIn - n; c = (k >> 3) < c ? k >> 3 : c; n += c; p -= c; k -= (c << 3); |
|
|
|
s.bitb = b; s.bitk = k; |
|
z.AvailableBytesIn = n; z.TotalBytesIn += p - z.NextIn; z.NextIn = p; |
|
s.writeAt = q; |
|
|
|
return ZlibConstants.Z_OK; |
|
} |
|
} |
|
|
|
|
|
internal sealed class InflateManager |
|
{ |
|
// preset dictionary flag in zlib header |
|
private const int PRESET_DICT = 0x20; |
|
|
|
private const int Z_DEFLATED = 8; |
|
|
|
private enum InflateManagerMode |
|
{ |
|
METHOD = 0, // waiting for method byte |
|
FLAG = 1, // waiting for flag byte |
|
DICT4 = 2, // four dictionary check bytes to go |
|
DICT3 = 3, // three dictionary check bytes to go |
|
DICT2 = 4, // two dictionary check bytes to go |
|
DICT1 = 5, // one dictionary check byte to go |
|
DICT0 = 6, // waiting for inflateSetDictionary |
|
BLOCKS = 7, // decompressing blocks |
|
CHECK4 = 8, // four check bytes to go |
|
CHECK3 = 9, // three check bytes to go |
|
CHECK2 = 10, // two check bytes to go |
|
CHECK1 = 11, // one check byte to go |
|
DONE = 12, // finished check, done |
|
BAD = 13, // got an error--stay here |
|
} |
|
|
|
private InflateManagerMode mode; // current inflate mode |
|
internal ZlibCodec _codec; // pointer back to this zlib stream |
|
|
|
// mode dependent information |
|
internal int method; // if FLAGS, method byte |
|
|
|
// if CHECK, check values to compare |
|
internal uint computedCheck; // computed check value |
|
internal uint expectedCheck; // stream check value |
|
|
|
// if BAD, inflateSync's marker bytes count |
|
internal int marker; |
|
|
|
// mode independent information |
|
//internal int nowrap; // flag for no wrapper |
|
private bool _handleRfc1950HeaderBytes = true; |
|
internal bool HandleRfc1950HeaderBytes |
|
{ |
|
get { return _handleRfc1950HeaderBytes; } |
|
set { _handleRfc1950HeaderBytes = value; } |
|
} |
|
internal int wbits; // log2(window size) (8..15, defaults to 15) |
|
|
|
internal InflateBlocks blocks; // current inflate_blocks state |
|
|
|
public InflateManager() { } |
|
|
|
public InflateManager(bool expectRfc1950HeaderBytes) |
|
{ |
|
_handleRfc1950HeaderBytes = expectRfc1950HeaderBytes; |
|
} |
|
|
|
internal int Reset() |
|
{ |
|
_codec.TotalBytesIn = _codec.TotalBytesOut = 0; |
|
_codec.Message = null; |
|
mode = HandleRfc1950HeaderBytes ? InflateManagerMode.METHOD : InflateManagerMode.BLOCKS; |
|
blocks.Reset(); |
|
return ZlibConstants.Z_OK; |
|
} |
|
|
|
internal int End() |
|
{ |
|
if (blocks != null) |
|
blocks.Free(); |
|
blocks = null; |
|
return ZlibConstants.Z_OK; |
|
} |
|
|
|
internal int Initialize(ZlibCodec codec, int w) |
|
{ |
|
_codec = codec; |
|
_codec.Message = null; |
|
blocks = null; |
|
|
|
// handle undocumented nowrap option (no zlib header or check) |
|
//nowrap = 0; |
|
//if (w < 0) |
|
//{ |
|
// w = - w; |
|
// nowrap = 1; |
|
//} |
|
|
|
// set window size |
|
if (w < 8 || w > 15) |
|
{ |
|
End(); |
|
throw new ZlibException("Bad window size."); |
|
|
|
//return ZlibConstants.Z_STREAM_ERROR; |
|
} |
|
wbits = w; |
|
|
|
blocks = new InflateBlocks(codec, |
|
HandleRfc1950HeaderBytes ? this : null, |
|
1 << w); |
|
|
|
// reset state |
|
Reset(); |
|
return ZlibConstants.Z_OK; |
|
} |
|
|
|
|
|
internal int Inflate(FlushType flush) |
|
{ |
|
int b; |
|
|
|
if (_codec.InputBuffer == null) |
|
throw new ZlibException("InputBuffer is null. "); |
|
|
|
// int f = (flush == FlushType.Finish) |
|
// ? ZlibConstants.Z_BUF_ERROR |
|
// : ZlibConstants.Z_OK; |
|
|
|
// workitem 8870 |
|
int f = ZlibConstants.Z_OK; |
|
int r = ZlibConstants.Z_BUF_ERROR; |
|
|
|
while (true) |
|
{ |
|
switch (mode) |
|
{ |
|
case InflateManagerMode.METHOD: |
|
if (_codec.AvailableBytesIn == 0) return r; |
|
r = f; |
|
_codec.AvailableBytesIn--; |
|
_codec.TotalBytesIn++; |
|
if (((method = _codec.InputBuffer[_codec.NextIn++]) & 0xf) != Z_DEFLATED) |
|
{ |
|
mode = InflateManagerMode.BAD; |
|
_codec.Message = String.Format("unknown compression method (0x{0:X2})", method); |
|
marker = 5; // can't try inflateSync |
|
break; |
|
} |
|
if ((method >> 4) + 8 > wbits) |
|
{ |
|
mode = InflateManagerMode.BAD; |
|
_codec.Message = String.Format("invalid window size ({0})", (method >> 4) + 8); |
|
marker = 5; // can't try inflateSync |
|
break; |
|
} |
|
mode = InflateManagerMode.FLAG; |
|
break; |
|
|
|
|
|
case InflateManagerMode.FLAG: |
|
if (_codec.AvailableBytesIn == 0) return r; |
|
r = f; |
|
_codec.AvailableBytesIn--; |
|
_codec.TotalBytesIn++; |
|
b = (_codec.InputBuffer[_codec.NextIn++]) & 0xff; |
|
|
|
if ((((method << 8) + b) % 31) != 0) |
|
{ |
|
mode = InflateManagerMode.BAD; |
|
_codec.Message = "incorrect header check"; |
|
marker = 5; // can't try inflateSync |
|
break; |
|
} |
|
|
|
mode = ((b & PRESET_DICT) == 0) |
|
? InflateManagerMode.BLOCKS |
|
: InflateManagerMode.DICT4; |
|
break; |
|
|
|
case InflateManagerMode.DICT4: |
|
if (_codec.AvailableBytesIn == 0) return r; |
|
r = f; |
|
_codec.AvailableBytesIn--; |
|
_codec.TotalBytesIn++; |
|
expectedCheck = (uint)((_codec.InputBuffer[_codec.NextIn++] << 24) & 0xff000000); |
|
mode = InflateManagerMode.DICT3; |
|
break; |
|
|
|
case InflateManagerMode.DICT3: |
|
if (_codec.AvailableBytesIn == 0) return r; |
|
r = f; |
|
_codec.AvailableBytesIn--; |
|
_codec.TotalBytesIn++; |
|
expectedCheck += (uint)((_codec.InputBuffer[_codec.NextIn++] << 16) & 0x00ff0000); |
|
mode = InflateManagerMode.DICT2; |
|
break; |
|
|
|
case InflateManagerMode.DICT2: |
|
|
|
if (_codec.AvailableBytesIn == 0) return r; |
|
r = f; |
|
_codec.AvailableBytesIn--; |
|
_codec.TotalBytesIn++; |
|
expectedCheck += (uint)((_codec.InputBuffer[_codec.NextIn++] << 8) & 0x0000ff00); |
|
mode = InflateManagerMode.DICT1; |
|
break; |
|
|
|
|
|
case InflateManagerMode.DICT1: |
|
if (_codec.AvailableBytesIn == 0) return r; |
|
r = f; |
|
_codec.AvailableBytesIn--; _codec.TotalBytesIn++; |
|
expectedCheck += (uint)(_codec.InputBuffer[_codec.NextIn++] & 0x000000ff); |
|
_codec._Adler32 = expectedCheck; |
|
mode = InflateManagerMode.DICT0; |
|
return ZlibConstants.Z_NEED_DICT; |
|
|
|
|
|
case InflateManagerMode.DICT0: |
|
mode = InflateManagerMode.BAD; |
|
_codec.Message = "need dictionary"; |
|
marker = 0; // can try inflateSync |
|
return ZlibConstants.Z_STREAM_ERROR; |
|
|
|
|
|
case InflateManagerMode.BLOCKS: |
|
r = blocks.Process(r); |
|
if (r == ZlibConstants.Z_DATA_ERROR) |
|
{ |
|
mode = InflateManagerMode.BAD; |
|
marker = 0; // can try inflateSync |
|
break; |
|
} |
|
|
|
if (r == ZlibConstants.Z_OK) r = f; |
|
|
|
if (r != ZlibConstants.Z_STREAM_END) |
|
return r; |
|
|
|
r = f; |
|
computedCheck = blocks.Reset(); |
|
if (!HandleRfc1950HeaderBytes) |
|
{ |
|
mode = InflateManagerMode.DONE; |
|
return ZlibConstants.Z_STREAM_END; |
|
} |
|
mode = InflateManagerMode.CHECK4; |
|
break; |
|
|
|
case InflateManagerMode.CHECK4: |
|
if (_codec.AvailableBytesIn == 0) return r; |
|
r = f; |
|
_codec.AvailableBytesIn--; |
|
_codec.TotalBytesIn++; |
|
expectedCheck = (uint)((_codec.InputBuffer[_codec.NextIn++] << 24) & 0xff000000); |
|
mode = InflateManagerMode.CHECK3; |
|
break; |
|
|
|
case InflateManagerMode.CHECK3: |
|
if (_codec.AvailableBytesIn == 0) return r; |
|
r = f; |
|
_codec.AvailableBytesIn--; _codec.TotalBytesIn++; |
|
expectedCheck += (uint)((_codec.InputBuffer[_codec.NextIn++] << 16) & 0x00ff0000); |
|
mode = InflateManagerMode.CHECK2; |
|
break; |
|
|
|
case InflateManagerMode.CHECK2: |
|
if (_codec.AvailableBytesIn == 0) return r; |
|
r = f; |
|
_codec.AvailableBytesIn--; |
|
_codec.TotalBytesIn++; |
|
expectedCheck += (uint)((_codec.InputBuffer[_codec.NextIn++] << 8) & 0x0000ff00); |
|
mode = InflateManagerMode.CHECK1; |
|
break; |
|
|
|
case InflateManagerMode.CHECK1: |
|
if (_codec.AvailableBytesIn == 0) return r; |
|
r = f; |
|
_codec.AvailableBytesIn--; _codec.TotalBytesIn++; |
|
expectedCheck += (uint)(_codec.InputBuffer[_codec.NextIn++] & 0x000000ff); |
|
if (computedCheck != expectedCheck) |
|
{ |
|
mode = InflateManagerMode.BAD; |
|
_codec.Message = "incorrect data check"; |
|
marker = 5; // can't try inflateSync |
|
break; |
|
} |
|
mode = InflateManagerMode.DONE; |
|
return ZlibConstants.Z_STREAM_END; |
|
|
|
case InflateManagerMode.DONE: |
|
return ZlibConstants.Z_STREAM_END; |
|
|
|
case InflateManagerMode.BAD: |
|
throw new ZlibException(String.Format("Bad state ({0})", _codec.Message)); |
|
|
|
default: |
|
throw new ZlibException("Stream error."); |
|
|
|
} |
|
} |
|
} |
|
|
|
|
|
|
|
internal int SetDictionary(byte[] dictionary) |
|
{ |
|
int index = 0; |
|
int length = dictionary.Length; |
|
if (mode != InflateManagerMode.DICT0) |
|
throw new ZlibException("Stream error."); |
|
|
|
if (Adler.Adler32(1, dictionary, 0, dictionary.Length) != _codec._Adler32) |
|
{ |
|
return ZlibConstants.Z_DATA_ERROR; |
|
} |
|
|
|
_codec._Adler32 = Adler.Adler32(0, null, 0, 0); |
|
|
|
if (length >= (1 << wbits)) |
|
{ |
|
length = (1 << wbits) - 1; |
|
index = dictionary.Length - length; |
|
} |
|
blocks.SetDictionary(dictionary, index, length); |
|
mode = InflateManagerMode.BLOCKS; |
|
return ZlibConstants.Z_OK; |
|
} |
|
|
|
|
|
private static readonly byte[] mark = new byte[] { 0, 0, 0xff, 0xff }; |
|
|
|
internal int Sync() |
|
{ |
|
int n; // number of bytes to look at |
|
int p; // pointer to bytes |
|
int m; // number of marker bytes found in a row |
|
long r, w; // temporaries to save total_in and total_out |
|
|
|
// set up |
|
if (mode != InflateManagerMode.BAD) |
|
{ |
|
mode = InflateManagerMode.BAD; |
|
marker = 0; |
|
} |
|
if ((n = _codec.AvailableBytesIn) == 0) |
|
return ZlibConstants.Z_BUF_ERROR; |
|
p = _codec.NextIn; |
|
m = marker; |
|
|
|
// search |
|
while (n != 0 && m < 4) |
|
{ |
|
if (_codec.InputBuffer[p] == mark[m]) |
|
{ |
|
m++; |
|
} |
|
else if (_codec.InputBuffer[p] != 0) |
|
{ |
|
m = 0; |
|
} |
|
else |
|
{ |
|
m = 4 - m; |
|
} |
|
p++; n--; |
|
} |
|
|
|
// restore |
|
_codec.TotalBytesIn += p - _codec.NextIn; |
|
_codec.NextIn = p; |
|
_codec.AvailableBytesIn = n; |
|
marker = m; |
|
|
|
// return no joy or set up to restart on a new block |
|
if (m != 4) |
|
{ |
|
return ZlibConstants.Z_DATA_ERROR; |
|
} |
|
r = _codec.TotalBytesIn; |
|
w = _codec.TotalBytesOut; |
|
Reset(); |
|
_codec.TotalBytesIn = r; |
|
_codec.TotalBytesOut = w; |
|
mode = InflateManagerMode.BLOCKS; |
|
return ZlibConstants.Z_OK; |
|
} |
|
|
|
|
|
// Returns true if inflate is currently at the end of a block generated |
|
// by Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP |
|
// implementation to provide an additional safety check. PPP uses Z_SYNC_FLUSH |
|
// but removes the length bytes of the resulting empty stored block. When |
|
// decompressing, PPP checks that at the end of input packet, inflate is |
|
// waiting for these length bytes. |
|
internal int SyncPoint(ZlibCodec z) |
|
{ |
|
return blocks.SyncPoint(); |
|
} |
|
} |
|
} |