| // Inflate.cs |
| // ------------------------------------------------------------------ |
| // |
| // Copyright (c) 2009 Dino Chiesa and Microsoft Corporation. |
| // All rights reserved. |
| // |
| // This code module is part of DotNetZip, a zipfile class library. |
| // |
| // ------------------------------------------------------------------ |
| // |
| // This code is licensed under the Microsoft Public License. |
| // See the file License.txt for the license details. |
| // More info on: http://dotnetzip.codeplex.com |
| // |
| // ------------------------------------------------------------------ |
| // |
| // last saved (in emacs): |
| // Time-stamp: <2010-January-08 18:32:12> |
| // |
| // ------------------------------------------------------------------ |
| // |
| // This module defines classes for decompression. This code is derived |
| // from the jzlib implementation of zlib, but significantly modified. |
| // The object model is not the same, and many of the behaviors are |
| // different. Nonetheless, in keeping with the license for jzlib, I am |
| // reproducing the copyright to that code here. |
| // |
| // ------------------------------------------------------------------ |
| // |
| // Copyright (c) 2000,2001,2002,2003 ymnk, JCraft,Inc. All rights reserved. |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are met: |
| // |
| // 1. Redistributions of source code must retain the above copyright notice, |
| // this list of conditions and the following disclaimer. |
| // |
| // 2. Redistributions in binary form must reproduce the above copyright |
| // notice, this list of conditions and the following disclaimer in |
| // the documentation and/or other materials provided with the distribution. |
| // |
| // 3. The names of the authors may not be used to endorse or promote products |
| // derived from this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, |
| // INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND |
| // FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JCRAFT, |
| // INC. OR ANY CONTRIBUTORS TO THIS SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT, |
| // INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, |
| // OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
| // LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
| // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, |
| // EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| // |
| // ----------------------------------------------------------------------- |
| // |
| // This program is based on zlib-1.1.3; credit to authors |
| // Jean-loup Gailly(jloup@gzip.org) and Mark Adler(madler@alumni.caltech.edu) |
| // and contributors of zlib. |
| // |
| // ----------------------------------------------------------------------- |
| |
| |
| using System; |
| namespace OfficeOpenXml.Packaging.Ionic.Zlib |
| { |
| sealed class InflateBlocks |
| { |
| private const int MANY = 1440; |
| |
| // Table for deflate from PKZIP's appnote.txt. |
| internal static readonly int[] border = new int[] |
| { 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 }; |
| |
| private enum InflateBlockMode |
| { |
| TYPE = 0, // get type bits (3, including end bit) |
| LENS = 1, // get lengths for stored |
| STORED = 2, // processing stored block |
| TABLE = 3, // get table lengths |
| BTREE = 4, // get bit lengths tree for a dynamic block |
| DTREE = 5, // get length, distance trees for a dynamic block |
| CODES = 6, // processing fixed or dynamic block |
| DRY = 7, // output remaining window bytes |
| DONE = 8, // finished last block, done |
| BAD = 9, // ot a data error--stuck here |
| } |
| |
| private InflateBlockMode mode; // current inflate_block mode |
| |
| internal int left; // if STORED, bytes left to copy |
| |
| internal int table; // table lengths (14 bits) |
| internal int index; // index into blens (or border) |
| internal int[] blens; // bit lengths of codes |
| internal int[] bb = new int[1]; // bit length tree depth |
| internal int[] tb = new int[1]; // bit length decoding tree |
| |
| internal InflateCodes codes = new InflateCodes(); // if CODES, current state |
| |
| internal int last; // true if this block is the last block |
| |
| internal ZlibCodec _codec; // pointer back to this zlib stream |
| |
| // mode independent information |
| internal int bitk; // bits in bit buffer |
| internal int bitb; // bit buffer |
| internal int[] hufts; // single malloc for tree space |
| internal byte[] window; // sliding window |
| internal int end; // one byte after sliding window |
| internal int readAt; // window read pointer |
| internal int writeAt; // window write pointer |
| internal System.Object checkfn; // check function |
| internal uint check; // check on output |
| |
| internal InfTree inftree = new InfTree(); |
| |
| internal InflateBlocks(ZlibCodec codec, System.Object checkfn, int w) |
| { |
| _codec = codec; |
| hufts = new int[MANY * 3]; |
| window = new byte[w]; |
| end = w; |
| this.checkfn = checkfn; |
| mode = InflateBlockMode.TYPE; |
| Reset(); |
| } |
| |
| internal uint Reset() |
| { |
| uint oldCheck = check; |
| mode = InflateBlockMode.TYPE; |
| bitk = 0; |
| bitb = 0; |
| readAt = writeAt = 0; |
| |
| if (checkfn != null) |
| _codec._Adler32 = check = Adler.Adler32(0, null, 0, 0); |
| return oldCheck; |
| } |
| |
| |
| internal int Process(int r) |
| { |
| int t; // temporary storage |
| 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 |
| |
| // copy input/output information to locals (UPDATE macro restores) |
| |
| p = _codec.NextIn; |
| n = _codec.AvailableBytesIn; |
| b = bitb; |
| k = bitk; |
| |
| q = writeAt; |
| m = (int)(q < readAt ? readAt - q - 1 : end - q); |
| |
| |
| // process input based on current state |
| while (true) |
| { |
| switch (mode) |
| { |
| case InflateBlockMode.TYPE: |
| |
| while (k < (3)) |
| { |
| if (n != 0) |
| { |
| r = ZlibConstants.Z_OK; |
| } |
| else |
| { |
| bitb = b; bitk = k; |
| _codec.AvailableBytesIn = n; |
| _codec.TotalBytesIn += p - _codec.NextIn; |
| _codec.NextIn = p; |
| writeAt = q; |
| return Flush(r); |
| } |
| |
| n--; |
| b |= (_codec.InputBuffer[p++] & 0xff) << k; |
| k += 8; |
| } |
| t = (int)(b & 7); |
| last = t & 1; |
| |
| switch ((uint)t >> 1) |
| { |
| case 0: // stored |
| b >>= 3; k -= (3); |
| t = k & 7; // go to byte boundary |
| b >>= t; k -= t; |
| mode = InflateBlockMode.LENS; // get length of stored block |
| break; |
| |
| case 1: // fixed |
| int[] bl = new int[1]; |
| int[] bd = new int[1]; |
| int[][] tl = new int[1][]; |
| int[][] td = new int[1][]; |
| InfTree.inflate_trees_fixed(bl, bd, tl, td, _codec); |
| codes.Init(bl[0], bd[0], tl[0], 0, td[0], 0); |
| b >>= 3; k -= 3; |
| mode = InflateBlockMode.CODES; |
| break; |
| |
| case 2: // dynamic |
| b >>= 3; k -= 3; |
| mode = InflateBlockMode.TABLE; |
| break; |
| |
| case 3: // illegal |
| b >>= 3; k -= 3; |
| mode = InflateBlockMode.BAD; |
| _codec.Message = "invalid block type"; |
| 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); |
| } |
| break; |
| |
| case InflateBlockMode.LENS: |
| |
| while (k < (32)) |
| { |
| if (n != 0) |
| { |
| r = ZlibConstants.Z_OK; |
| } |
| else |
| { |
| bitb = b; bitk = k; |
| _codec.AvailableBytesIn = n; |
| _codec.TotalBytesIn += p - _codec.NextIn; |
| _codec.NextIn = p; |
| writeAt = q; |
| return Flush(r); |
| } |
| ; |
| n--; |
| b |= (_codec.InputBuffer[p++] & 0xff) << k; |
| k += 8; |
| } |
| |
| if ( ( ((~b)>>16) & 0xffff) != (b & 0xffff)) |
| { |
| mode = InflateBlockMode.BAD; |
| _codec.Message = "invalid stored block lengths"; |
| 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); |
| } |
| left = (b & 0xffff); |
| b = k = 0; // dump bits |
| mode = left != 0 ? InflateBlockMode.STORED : (last != 0 ? InflateBlockMode.DRY : InflateBlockMode.TYPE); |
| break; |
| |
| case InflateBlockMode.STORED: |
| if (n == 0) |
| { |
| bitb = b; bitk = k; |
| _codec.AvailableBytesIn = n; |
| _codec.TotalBytesIn += p - _codec.NextIn; |
| _codec.NextIn = p; |
| writeAt = q; |
| return Flush(r); |
| } |
| |
| if (m == 0) |
| { |
| if (q == end && readAt != 0) |
| { |
| q = 0; m = (int)(q < readAt ? readAt - q - 1 : end - q); |
| } |
| if (m == 0) |
| { |
| writeAt = q; |
| r = Flush(r); |
| q = writeAt; m = (int)(q < readAt ? readAt - q - 1 : end - q); |
| if (q == end && readAt != 0) |
| { |
| q = 0; m = (int)(q < readAt ? readAt - q - 1 : end - q); |
| } |
| if (m == 0) |
| { |
| bitb = b; bitk = k; |
| _codec.AvailableBytesIn = n; |
| _codec.TotalBytesIn += p - _codec.NextIn; |
| _codec.NextIn = p; |
| writeAt = q; |
| return Flush(r); |
| } |
| } |
| } |
| r = ZlibConstants.Z_OK; |
| |
| t = left; |
| if (t > n) |
| t = n; |
| if (t > m) |
| t = m; |
| Array.Copy(_codec.InputBuffer, p, window, q, t); |
| p += t; n -= t; |
| q += t; m -= t; |
| if ((left -= t) != 0) |
| break; |
| mode = last != 0 ? InflateBlockMode.DRY : InflateBlockMode.TYPE; |
| break; |
| |
| case InflateBlockMode.TABLE: |
| |
| while (k < (14)) |
| { |
| if (n != 0) |
| { |
| r = ZlibConstants.Z_OK; |
| } |
| else |
| { |
| bitb = b; bitk = k; |
| _codec.AvailableBytesIn = n; |
| _codec.TotalBytesIn += p - _codec.NextIn; |
| _codec.NextIn = p; |
| writeAt = q; |
| return Flush(r); |
| } |
| |
| n--; |
| b |= (_codec.InputBuffer[p++] & 0xff) << k; |
| k += 8; |
| } |
| |
| table = t = (b & 0x3fff); |
| if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29) |
| { |
| mode = InflateBlockMode.BAD; |
| _codec.Message = "too many length or distance symbols"; |
| 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); |
| } |
| t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f); |
| if (blens == null || blens.Length < t) |
| { |
| blens = new int[t]; |
| } |
| else |
| { |
| Array.Clear(blens, 0, t); |
| // for (int i = 0; i < t; i++) |
| // { |
| // blens[i] = 0; |
| // } |
| } |
| |
| b >>= 14; |
| k -= 14; |
| |
| |
| index = 0; |
| mode = InflateBlockMode.BTREE; |
| goto case InflateBlockMode.BTREE; |
| |
| case InflateBlockMode.BTREE: |
| while (index < 4 + (table >> 10)) |
| { |
| while (k < (3)) |
| { |
| if (n != 0) |
| { |
| r = ZlibConstants.Z_OK; |
| } |
| else |
| { |
| bitb = b; bitk = k; |
| _codec.AvailableBytesIn = n; |
| _codec.TotalBytesIn += p - _codec.NextIn; |
| _codec.NextIn = p; |
| writeAt = q; |
| return Flush(r); |
| } |
| |
| n--; |
| b |= (_codec.InputBuffer[p++] & 0xff) << k; |
| k += 8; |
| } |
| |
| blens[border[index++]] = b & 7; |
| |
| b >>= 3; k -= 3; |
| } |
| |
| while (index < 19) |
| { |
| blens[border[index++]] = 0; |
| } |
| |
| bb[0] = 7; |
| t = inftree.inflate_trees_bits(blens, bb, tb, hufts, _codec); |
| if (t != ZlibConstants.Z_OK) |
| { |
| r = t; |
| if (r == ZlibConstants.Z_DATA_ERROR) |
| { |
| blens = null; |
| mode = InflateBlockMode.BAD; |
| } |
| |
| bitb = b; bitk = k; |
| _codec.AvailableBytesIn = n; |
| _codec.TotalBytesIn += p - _codec.NextIn; |
| _codec.NextIn = p; |
| writeAt = q; |
| return Flush(r); |
| } |
| |
| index = 0; |
| mode = InflateBlockMode.DTREE; |
| goto case InflateBlockMode.DTREE; |
| |
| case InflateBlockMode.DTREE: |
| while (true) |
| { |
| t = table; |
| if (!(index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))) |
| { |
| break; |
| } |
| |
| int i, j, c; |
| |
| t = bb[0]; |
| |
| while (k < t) |
| { |
| if (n != 0) |
| { |
| r = ZlibConstants.Z_OK; |
| } |
| else |
| { |
| bitb = b; bitk = k; |
| _codec.AvailableBytesIn = n; |
| _codec.TotalBytesIn += p - _codec.NextIn; |
| _codec.NextIn = p; |
| writeAt = q; |
| return Flush(r); |
| } |
| |
| n--; |
| b |= (_codec.InputBuffer[p++] & 0xff) << k; |
| k += 8; |
| } |
| |
| t = hufts[(tb[0] + (b & InternalInflateConstants.InflateMask[t])) * 3 + 1]; |
| c = hufts[(tb[0] + (b & InternalInflateConstants.InflateMask[t])) * 3 + 2]; |
| |
| if (c < 16) |
| { |
| b >>= t; k -= t; |
| blens[index++] = c; |
| } |
| else |
| { |
| // c == 16..18 |
| i = c == 18 ? 7 : c - 14; |
| j = c == 18 ? 11 : 3; |
| |
| while (k < (t + i)) |
| { |
| if (n != 0) |
| { |
| r = ZlibConstants.Z_OK; |
| } |
| else |
| { |
| bitb = b; bitk = k; |
| _codec.AvailableBytesIn = n; |
| _codec.TotalBytesIn += p - _codec.NextIn; |
| _codec.NextIn = p; |
| writeAt = q; |
| return Flush(r); |
| } |
| |
| n--; |
| b |= (_codec.InputBuffer[p++] & 0xff) << k; |
| k += 8; |
| } |
| |
| b >>= t; k -= t; |
| |
| j += (b & InternalInflateConstants.InflateMask[i]); |
| |
| b >>= i; k -= i; |
| |
| i = index; |
| t = table; |
| if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) || (c == 16 && i < 1)) |
| { |
| blens = null; |
| mode = InflateBlockMode.BAD; |
| _codec.Message = "invalid bit length repeat"; |
| 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); |
| } |
| |
| c = (c == 16) ? blens[i-1] : 0; |
| do |
| { |
| blens[i++] = c; |
| } |
| 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]; |
| int[] td = new int[1]; |
| |
| t = table; |
| t = inftree.inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f), blens, bl, bd, tl, td, hufts, _codec); |
| |
| if (t != ZlibConstants.Z_OK) |
| { |
| if (t == ZlibConstants.Z_DATA_ERROR) |
| { |
| blens = null; |
| mode = InflateBlockMode.BAD; |
| } |
| r = t; |
| |
| 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); |
| } |
| |
| 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(); |
| 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(); |
| } |
| } |
| } |
