123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706707708709710711712713714715716717718719720721722723724725726727728729730731732733734735736737738739740741742743744745746747748749750751752753754755756757758759760761762763764765766767768769770771772773774775776777778779780781782783784785786787788789790791792793794795796797798799800801802803804805806807808809810811812813814815816817818819820821822823824825826827828829830831832833834835836837838839840841842843844845846847848849850851852853854855856857858859860861862863864865866867868869870871872873874875876877878879880881882883884885886887888889890891892893894895896897898899900901902903904905906907908909910911912913914915916917918919920921922923924925926927928929930931932933934935936937938939940941942943944945946947948949950951952953954955956957958959960961962963964965966967968969970971972973974975976977978979980981982983984985986987988989990991992993994995996997998999100010011002100310041005100610071008100910101011101210131014101510161017101810191020102110221023102410251026102710281029103010311032103310341035103610371038103910401041104210431044104510461047104810491050105110521053105410551056105710581059106010611062106310641065106610671068106910701071107210731074107510761077107810791080108110821083108410851086108710881089109010911092109310941095109610971098109911001101110211031104110511061107110811091110111111121113111411151116111711181119112011211122112311241125112611271128112911301131113211331134113511361137113811391140114111421143114411451146114711481149115011511152115311541155115611571158115911601161116211631164116511661167116811691170117111721173117411751176117711781179118011811182118311841185118611871188118911901191119211931194119511961197119811991200120112021203120412051206120712081209121012111212121312141215121612171218121912201221122212231224122512261227122812291230123112321233123412351236123712381239124012411242124312441245124612471248124912501251125212531254125512561257125812591260126112621263126412651266126712681269127012711272127312741275127612771278127912801281128212831284128512861287128812891290129112921293129412951296129712981299130013011302130313041305130613071308130913101311131213131314131513161317131813191320132113221323132413251326132713281329133013311332133313341335133613371338133913401341134213431344134513461347134813491350135113521353135413551356135713581359136013611362136313641365136613671368136913701371137213731374137513761377137813791380138113821383138413851386138713881389139013911392139313941395139613971398139914001401140214031404140514061407140814091410141114121413141414151416141714181419142014211422142314241425142614271428142914301431143214331434143514361437143814391440144114421443144414451446144714481449145014511452145314541455145614571458145914601461146214631464146514661467146814691470147114721473147414751476147714781479148014811482148314841485148614871488148914901491149214931494149514961497149814991500150115021503150415051506150715081509151015111512151315141515151615171518151915201521152215231524152515261527152815291530153115321533153415351536153715381539154015411542154315441545154615471548154915501551155215531554155515561557155815591560156115621563156415651566156715681569157015711572157315741575157615771578157915801581158215831584158515861587158815891590159115921593159415951596159715981599160016011602160316041605160616071608160916101611161216131614161516161617161816191620162116221623162416251626162716281629163016311632163316341635163616371638163916401641164216431644164516461647164816491650165116521653165416551656165716581659166016611662166316641665166616671668166916701671167216731674167516761677167816791680168116821683168416851686168716881689169016911692169316941695169616971698169917001701170217031704170517061707170817091710171117121713171417151716171717181719172017211722172317241725172617271728172917301731173217331734173517361737173817391740174117421743174417451746174717481749175017511752175317541755175617571758175917601761176217631764176517661767176817691770177117721773177417751776177717781779178017811782178317841785178617871788178917901791179217931794179517961797179817991800180118021803180418051806180718081809181018111812181318141815181618171818181918201821182218231824182518261827182818291830183118321833183418351836183718381839184018411842184318441845184618471848184918501851185218531854185518561857185818591860186118621863186418651866186718681869187018711872187318741875187618771878187918801881188218831884188518861887188818891890189118921893189418951896189718981899190019011902190319041905190619071908190919101911191219131914191519161917191819191920192119221923192419251926192719281929193019311932193319341935193619371938193919401941194219431944194519461947194819491950195119521953195419551956195719581959196019611962196319641965196619671968196919701971197219731974197519761977197819791980198119821983198419851986198719881989 |
- // 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 SharpCompress.Compressors.Deflate
- {
- internal sealed class InflateBlocks
- {
- private const int MANY = 1440;
- // Table for deflate from PKZIP's appnote.txt.
- internal static readonly int[] border = {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
- internal ZlibCodec _codec; // pointer back to this zlib stream
- internal int[] bb = new int[1]; // bit length tree depth
- // mode independent information
- internal int bitb; // bit buffer
- internal int bitk; // bits in bit buffer
- internal int[] blens; // bit lengths of codes
- internal uint check; // check on output
- internal Object checkfn; // check function
- internal InflateCodes codes = new InflateCodes(); // if CODES, current state
- internal int end; // one byte after sliding window
- internal int[] hufts; // single malloc for tree space
- internal int index; // index into blens (or border)
- internal InfTree inftree = new InfTree();
- internal int last; // true if this block is the last block
- internal int left; // if STORED, bytes left to copy
- private InflateBlockMode mode; // current inflate_block mode
- internal int readAt; // window read pointer
- internal int table; // table lengths (14 bits)
- internal int[] tb = new int[1]; // bit length decoding tree
- internal byte[] window; // sliding window
- internal int writeAt; // window write pointer
- internal InflateBlocks(ZlibCodec codec, 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 = (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 = (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
- var bl = new int[1];
- var bd = new int[1];
- var tl = new int[1][];
- var 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 = (q < readAt ? readAt - q - 1 : end - q);
- }
- if (m == 0)
- {
- writeAt = q;
- r = Flush(r);
- q = writeAt;
- m = (q < readAt ? readAt - q - 1 : end - q);
- if (q == end && readAt != 0)
- {
- q = 0;
- m = (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;
- {
- var bl = new[] {9}; // must be <= 9 for lookahead assumptions
- var bd = new[] {6}; // must be <= 9 for lookahead assumptions
- var tl = new int[1];
- var 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 = (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 = (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 = ((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;
- }
- #region Nested type: InflateBlockMode
- 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
- }
- #endregion
- }
- internal static class InternalInflateConstants
- {
- // And'ing with mask[n] masks the lower n bits
- internal static readonly int[] InflateMask =
- {
- 0x00000000, 0x00000001, 0x00000003, 0x00000007,
- 0x0000000f, 0x0000001f, 0x0000003f, 0x0000007f,
- 0x000000ff, 0x000001ff, 0x000003ff, 0x000007ff,
- 0x00000fff, 0x00001fff, 0x00003fff, 0x00007fff, 0x0000ffff
- };
- }
- internal 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
- // if EXT or COPY, where and how much
- internal int bitsToGet; // bits to get for extra
- internal byte dbits; // dtree bits decoder per branch
- internal int dist; // distance back to copy from
- internal int[] dtree; // distance tree
- internal int dtree_index; // distance tree
- internal byte lbits; // ltree bits decoded per branch
- internal int len;
- internal int lit;
- internal int[] ltree; // literal/length/eob tree
- internal int ltree_index; // literal/length/eob tree
- internal int mode; // current inflate_codes mode
- internal int need; // bits needed
- internal int[] tree; // pointer into tree
- internal int tree_index;
- 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
- {
- // Handling missing trailing bit(s)
- var tmp_tindex = (tree_index + (b & InternalInflateConstants.InflateMask[k])) * 3;
- if (k >= tree[tmp_tindex + 1])
- {
- break;
- }
- 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
- {
- // Handling missing trailing bit(s)
- var tmp_tindex = (tree_index + (b & InternalInflateConstants.InflateMask[k])) * 3;
- if (k >= tree[tmp_tindex + 1])
- {
- break;
- }
- 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] + (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;
- }
- 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 static readonly byte[] mark = {0, 0, 0xff, 0xff};
- internal ZlibCodec _codec; // pointer back to this zlib stream
- internal InflateBlocks blocks; // current inflate_blocks state
- // mode dependent information
- // 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;
- internal int method; // if FLAGS, method byte
- private InflateManagerMode mode; // current inflate mode
- // mode independent information
- //internal int nowrap; // flag for no wrapper
- internal int wbits; // log2(window size) (8..15, defaults to 15)
- public InflateManager()
- {
- }
- public InflateManager(bool expectRfc1950HeaderBytes)
- {
- HandleRfc1950HeaderBytes = expectRfc1950HeaderBytes;
- }
- internal bool HandleRfc1950HeaderBytes { get; set; } = true;
- 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;
- }
- 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();
- }
- #region Nested type: InflateManagerMode
- 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
- }
- #endregion
- }
- }
|