// 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 BestHTTP.PlatformSupport.Memory;
using System;
namespace BestHTTP.Decompression.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 = BufferPool.Get(w, true);
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();
BufferPool.Release(window);
window = null;
hufts = null;
}
internal void SetDictionary(byte[] d, int start, int n)
{
Array.Copy(d, start, window, 0, n);
readAt = writeAt = n;
}
// Returns true if inflate is currently at the end of a block generated
// by Z_SYNC_FLUSH or Z_FULL_FLUSH.
internal int SyncPoint()
{
return mode == InflateBlockMode.LENS ? 1 : 0;
}
// copy as much as possible from the sliding window to the output area
internal int Flush(int r)
{
int nBytes;
for (int pass=0; pass < 2; pass++)
{
if (pass==0)
{
// compute number of bytes to copy as far as end of window
nBytes = (int)((readAt <= writeAt ? writeAt : end) - readAt);
}
else
{
// compute bytes to copy
nBytes = writeAt - readAt;
}
// workitem 8870
if (nBytes == 0)
{
if (r == ZlibConstants.Z_BUF_ERROR)
r = ZlibConstants.Z_OK;
return r;
}
if (nBytes > _codec.AvailableBytesOut)
nBytes = _codec.AvailableBytesOut;
if (nBytes != 0 && r == ZlibConstants.Z_BUF_ERROR)
r = ZlibConstants.Z_OK;
// update counters
_codec.AvailableBytesOut -= nBytes;
_codec.TotalBytesOut += nBytes;
// update check information
if (checkfn != null)
_codec._Adler32 = check = Adler.Adler32(check, window, readAt, nBytes);
// copy as far as end of window
Array.Copy(window, readAt, _codec.OutputBuffer, _codec.NextOut, nBytes);
_codec.NextOut += nBytes;
readAt += nBytes;
// see if more to copy at beginning of window
if (readAt == end && pass == 0)
{
// wrap pointers
readAt = 0;
if (writeAt == end)
writeAt = 0;
}
else pass++;
}
// done
return r;
}
}
internal static class InternalInflateConstants
{
// And'ing with mask[n] masks the lower n bits
internal static readonly int[] InflateMask = new int[] {
0x00000000, 0x00000001, 0x00000003, 0x00000007,
0x0000000f, 0x0000001f, 0x0000003f, 0x0000007f,
0x000000ff, 0x000001ff, 0x000003ff, 0x000007ff,
0x00000fff, 0x00001fff, 0x00003fff, 0x00007fff, 0x0000ffff };
}
sealed class InflateCodes
{
// waiting for "i:"=input,
// "o:"=output,
// "x:"=nothing
private const int START = 0; // x: set up for LEN
private const int LEN = 1; // i: get length/literal/eob next
private const int LENEXT = 2; // i: getting length extra (have base)
private const int DIST = 3; // i: get distance next
private const int DISTEXT = 4; // i: getting distance extra
private const int COPY = 5; // o: copying bytes in window, waiting for space
private const int LIT = 6; // o: got literal, waiting for output space
private const int WASH = 7; // o: got eob, possibly still output waiting
private const int END = 8; // x: got eob and all data flushed
private const int BADCODE = 9; // x: got error
internal int mode; // current inflate_codes mode
// mode dependent information
internal int len;
internal int[] tree; // pointer into tree
internal int tree_index = 0;
internal int need; // bits needed
internal int lit;
// if EXT or COPY, where and how much
internal int bitsToGet; // bits to get for extra
internal int dist; // distance back to copy from
internal byte lbits; // ltree bits decoded per branch
internal byte dbits; // dtree bits decoder per branch
internal int[] ltree; // literal/length/eob tree
internal int ltree_index; // literal/length/eob tree
internal int[] dtree; // distance tree
internal int dtree_index; // distance tree
internal InflateCodes()
{
}
internal void Init(int bl, int bd, int[] tl, int tl_index, int[] td, int td_index)
{
mode = START;
lbits = (byte)bl;
dbits = (byte)bd;
ltree = tl;
ltree_index = tl_index;
dtree = td;
dtree_index = td_index;
tree = null;
}
internal int Process(InflateBlocks blocks, int r)
{
int j; // temporary storage
int tindex; // temporary pointer
int e; // extra bits or operation
int b = 0; // bit buffer
int k = 0; // bits in bit buffer
int p = 0; // input data pointer
int n; // bytes available there
int q; // output window write pointer
int m; // bytes to end of window or read pointer
int f; // pointer to copy strings from
ZlibCodec z = blocks._codec;
// copy input/output information to locals (UPDATE macro restores)
p = z.NextIn;
n = z.AvailableBytesIn;
b = blocks.bitb;
k = blocks.bitk;
q = blocks.writeAt; m = q < blocks.readAt ? blocks.readAt - q - 1 : blocks.end - q;
// process input and output based on current state
while (true)
{
switch (mode)
{
// waiting for "i:"=input, "o:"=output, "x:"=nothing
case START: // x: set up for LEN
if (m >= 258 && n >= 10)
{
blocks.bitb = b; blocks.bitk = k;
z.AvailableBytesIn = n;
z.TotalBytesIn += p - z.NextIn;
z.NextIn = p;
blocks.writeAt = q;
r = InflateFast(lbits, dbits, ltree, ltree_index, dtree, dtree_index, blocks, z);
p = z.NextIn;
n = z.AvailableBytesIn;
b = blocks.bitb;
k = blocks.bitk;
q = blocks.writeAt; m = q < blocks.readAt ? blocks.readAt - q - 1 : blocks.end - q;
if (r != ZlibConstants.Z_OK)
{
mode = (r == ZlibConstants.Z_STREAM_END) ? WASH : BADCODE;
break;
}
}
need = lbits;
tree = ltree;
tree_index = ltree_index;
mode = LEN;
goto case LEN;
case LEN: // i: get length/literal/eob next
j = need;
while (k < j)
{
if (n != 0)
r = ZlibConstants.Z_OK;
else
{
blocks.bitb = b; blocks.bitk = k;
z.AvailableBytesIn = n;
z.TotalBytesIn += p - z.NextIn;
z.NextIn = p;
blocks.writeAt = q;
return blocks.Flush(r);
}
n--;
b |= (z.InputBuffer[p++] & 0xff) << k;
k += 8;
}
tindex = (tree_index + (b & InternalInflateConstants.InflateMask[j])) * 3;
b >>= (tree[tindex + 1]);
k -= (tree[tindex + 1]);
e = tree[tindex];
if (e == 0)
{
// literal
lit = tree[tindex + 2];
mode = LIT;
break;
}
if ((e & 16) != 0)
{
// length
bitsToGet = e & 15;
len = tree[tindex + 2];
mode = LENEXT;
break;
}
if ((e & 64) == 0)
{
// next table
need = e;
tree_index = tindex / 3 + tree[tindex + 2];
break;
}
if ((e & 32) != 0)
{
// end of block
mode = WASH;
break;
}
mode = BADCODE; // invalid code
z.Message = "invalid literal/length code";
r = ZlibConstants.Z_DATA_ERROR;
blocks.bitb = b; blocks.bitk = k;
z.AvailableBytesIn = n;
z.TotalBytesIn += p - z.NextIn;
z.NextIn = p;
blocks.writeAt = q;
return blocks.Flush(r);
case LENEXT: // i: getting length extra (have base)
j = bitsToGet;
while (k < j)
{
if (n != 0)
r = ZlibConstants.Z_OK;
else
{
blocks.bitb = b; blocks.bitk = k;
z.AvailableBytesIn = n; z.TotalBytesIn += p - z.NextIn; z.NextIn = p;
blocks.writeAt = q;
return blocks.Flush(r);
}
n--; b |= (z.InputBuffer[p++] & 0xff) << k;
k += 8;
}
len += (b & InternalInflateConstants.InflateMask[j]);
b >>= j;
k -= j;
need = dbits;
tree = dtree;
tree_index = dtree_index;
mode = DIST;
goto case DIST;
case DIST: // i: get distance next
j = need;
while (k < j)
{
if (n != 0)
r = ZlibConstants.Z_OK;
else
{
blocks.bitb = b; blocks.bitk = k;
z.AvailableBytesIn = n; z.TotalBytesIn += p - z.NextIn; z.NextIn = p;
blocks.writeAt = q;
return blocks.Flush(r);
}
n--; b |= (z.InputBuffer[p++] & 0xff) << k;
k += 8;
}
tindex = (tree_index + (b & InternalInflateConstants.InflateMask[j])) * 3;
b >>= tree[tindex + 1];
k -= tree[tindex + 1];
e = (tree[tindex]);
if ((e & 0x10) != 0)
{
// distance
bitsToGet = e & 15;
dist = tree[tindex + 2];
mode = DISTEXT;
break;
}
if ((e & 64) == 0)
{
// next table
need = e;
tree_index = tindex / 3 + tree[tindex + 2];
break;
}
mode = BADCODE; // invalid code
z.Message = "invalid distance code";
r = ZlibConstants.Z_DATA_ERROR;
blocks.bitb = b; blocks.bitk = k;
z.AvailableBytesIn = n; z.TotalBytesIn += p - z.NextIn; z.NextIn = p;
blocks.writeAt = q;
return blocks.Flush(r);
case DISTEXT: // i: getting distance extra
j = bitsToGet;
while (k < j)
{
if (n != 0)
r = ZlibConstants.Z_OK;
else
{
blocks.bitb = b; blocks.bitk = k;
z.AvailableBytesIn = n; z.TotalBytesIn += p - z.NextIn; z.NextIn = p;
blocks.writeAt = q;
return blocks.Flush(r);
}
n--; b |= (z.InputBuffer[p++] & 0xff) << k;
k += 8;
}
dist += (b & InternalInflateConstants.InflateMask[j]);
b >>= j;
k -= j;
mode = COPY;
goto case COPY;
case COPY: // o: copying bytes in window, waiting for space
f = q - dist;
while (f < 0)
{
// modulo window size-"while" instead
f += blocks.end; // of "if" handles invalid distances
}
while (len != 0)
{
if (m == 0)
{
if (q == blocks.end && blocks.readAt != 0)
{
q = 0; m = q < blocks.readAt ? blocks.readAt - q - 1 : blocks.end - q;
}
if (m == 0)
{
blocks.writeAt = q; r = blocks.Flush(r);
q = blocks.writeAt; m = q < blocks.readAt ? blocks.readAt - q - 1 : blocks.end - q;
if (q == blocks.end && blocks.readAt != 0)
{
q = 0; m = q < blocks.readAt ? blocks.readAt - q - 1 : blocks.end - q;
}
if (m == 0)
{
blocks.bitb = b; blocks.bitk = k;
z.AvailableBytesIn = n;
z.TotalBytesIn += p - z.NextIn;
z.NextIn = p;
blocks.writeAt = q;
return blocks.Flush(r);
}
}
}
blocks.window[q++] = blocks.window[f++]; m--;
if (f == blocks.end)
f = 0;
len--;
}
mode = START;
break;
case LIT: // o: got literal, waiting for output space
if (m == 0)
{
if (q == blocks.end && blocks.readAt != 0)
{
q = 0; m = q < blocks.readAt ? blocks.readAt - q - 1 : blocks.end - q;
}
if (m == 0)
{
blocks.writeAt = q; r = blocks.Flush(r);
q = blocks.writeAt; m = q < blocks.readAt ? blocks.readAt - q - 1 : blocks.end - q;
if (q == blocks.end && blocks.readAt != 0)
{
q = 0; m = q < blocks.readAt ? blocks.readAt - q - 1 : blocks.end - q;
}
if (m == 0)
{
blocks.bitb = b; blocks.bitk = k;
z.AvailableBytesIn = n; z.TotalBytesIn += p - z.NextIn; z.NextIn = p;
blocks.writeAt = q;
return blocks.Flush(r);
}
}
}
r = ZlibConstants.Z_OK;
blocks.window[q++] = (byte)lit; m--;
mode = START;
break;
case WASH: // o: got eob, possibly more output
if (k > 7)
{
// return unused byte, if any
k -= 8;
n++;
p--; // can always return one
}
blocks.writeAt = q; r = blocks.Flush(r);
q = blocks.writeAt; m = q < blocks.readAt ? blocks.readAt - q - 1 : blocks.end - q;
if (blocks.readAt != blocks.writeAt)
{
blocks.bitb = b; blocks.bitk = k;
z.AvailableBytesIn = n; z.TotalBytesIn += p - z.NextIn; z.NextIn = p;
blocks.writeAt = q;
return blocks.Flush(r);
}
mode = END;
goto case END;
case END:
r = ZlibConstants.Z_STREAM_END;
blocks.bitb = b; blocks.bitk = k;
z.AvailableBytesIn = n; z.TotalBytesIn += p - z.NextIn; z.NextIn = p;
blocks.writeAt = q;
return blocks.Flush(r);
case BADCODE: // x: got error
r = ZlibConstants.Z_DATA_ERROR;
blocks.bitb = b; blocks.bitk = k;
z.AvailableBytesIn = n; z.TotalBytesIn += p - z.NextIn; z.NextIn = p;
blocks.writeAt = q;
return blocks.Flush(r);
default:
r = ZlibConstants.Z_STREAM_ERROR;
blocks.bitb = b; blocks.bitk = k;
z.AvailableBytesIn = n; z.TotalBytesIn += p - z.NextIn; z.NextIn = p;
blocks.writeAt = q;
return blocks.Flush(r);
}
}
}
// Called with number of bytes left to write in window at least 258
// (the maximum string length) and number of input bytes available
// at least ten. The ten bytes are six bytes for the longest length/
// distance pair plus four bytes for overloading the bit buffer.
internal int InflateFast(int bl, int bd, int[] tl, int tl_index, int[] td, int td_index, InflateBlocks s, ZlibCodec z)
{
int t; // temporary pointer
int[] tp; // temporary pointer
int tp_index; // temporary pointer
int e; // extra bits or operation
int b; // bit buffer
int k; // bits in bit buffer
int p; // input data pointer
int n; // bytes available there
int q; // output window write pointer
int m; // bytes to end of window or read pointer
int ml; // mask for literal/length tree
int md; // mask for distance tree
int c; // bytes to copy
int d; // distance back to copy from
int r; // copy source pointer
int tp_index_t_3; // (tp_index+t)*3
// load input, output, bit values
p = z.NextIn; n = z.AvailableBytesIn; b = s.bitb; k = s.bitk;
q = s.writeAt; m = q < s.readAt ? s.readAt - q - 1 : s.end - q;
// initialize masks
ml = InternalInflateConstants.InflateMask[bl];
md = InternalInflateConstants.InflateMask[bd];
// do until not enough input or output space for fast loop
do
{
// assume called with m >= 258 && n >= 10
// get literal/length code
while (k < (20))
{
// max bits for literal/length code
n--;
b |= (z.InputBuffer[p++] & 0xff) << k; k += 8;
}
t = b & ml;
tp = tl;
tp_index = tl_index;
tp_index_t_3 = (tp_index + t) * 3;
if ((e = tp[tp_index_t_3]) == 0)
{
b >>= (tp[tp_index_t_3 + 1]); k -= (tp[tp_index_t_3 + 1]);
s.window[q++] = (byte)tp[tp_index_t_3 + 2];
m--;
continue;
}
do
{
b >>= (tp[tp_index_t_3 + 1]); k -= (tp[tp_index_t_3 + 1]);
if ((e & 16) != 0)
{
e &= 15;
c = tp[tp_index_t_3 + 2] + ((int)b & InternalInflateConstants.InflateMask[e]);
b >>= e; k -= e;
// decode distance base of block to copy
while (k < 15)
{
// max bits for distance code
n--;
b |= (z.InputBuffer[p++] & 0xff) << k; k += 8;
}
t = b & md;
tp = td;
tp_index = td_index;
tp_index_t_3 = (tp_index + t) * 3;
e = tp[tp_index_t_3];
do
{
b >>= (tp[tp_index_t_3 + 1]); k -= (tp[tp_index_t_3 + 1]);
if ((e & 16) != 0)
{
// get extra bits to add to distance base
e &= 15;
while (k < e)
{
// get extra bits (up to 13)
n--;
b |= (z.InputBuffer[p++] & 0xff) << k; k += 8;
}
d = tp[tp_index_t_3 + 2] + (b & InternalInflateConstants.InflateMask[e]);
b >>= e; k -= e;
// do the copy
m -= c;
if (q >= d)
{
// offset before dest
// just copy
r = q - d;
if (q - r > 0 && 2 > (q - r))
{
s.window[q++] = s.window[r++]; // minimum count is three,
s.window[q++] = s.window[r++]; // so unroll loop a little
c -= 2;
}
else
{
Array.Copy(s.window, r, s.window, q, 2);
q += 2; r += 2; c -= 2;
}
}
else
{
// else offset after destination
r = q - d;
do
{
r += s.end; // force pointer in window
}
while (r < 0); // covers invalid distances
e = s.end - r;
if (c > e)
{
// if source crosses,
c -= e; // wrapped copy
if (q - r > 0 && e > (q - r))
{
do
{
s.window[q++] = s.window[r++];
}
while (--e != 0);
}
else
{
Array.Copy(s.window, r, s.window, q, e);
q += e; r += e; e = 0;
}
r = 0; // copy rest from start of window
}
}
// copy all or what's left
if (q - r > 0 && c > (q - r))
{
do
{
s.window[q++] = s.window[r++];
}
while (--c != 0);
}
else
{
Array.Copy(s.window, r, s.window, q, c);
q += c; r += c; c = 0;
}
break;
}
else if ((e & 64) == 0)
{
t += tp[tp_index_t_3 + 2];
t += (b & InternalInflateConstants.InflateMask[e]);
tp_index_t_3 = (tp_index + t) * 3;
e = tp[tp_index_t_3];
}
else
{
z.Message = "invalid distance code";
c = z.AvailableBytesIn - n; c = (k >> 3) < c ? k >> 3 : c; n += c; p -= c; k -= (c << 3);
s.bitb = b; s.bitk = k;
z.AvailableBytesIn = n; z.TotalBytesIn += p - z.NextIn; z.NextIn = p;
s.writeAt = q;
return ZlibConstants.Z_DATA_ERROR;
}
}
while (true);
break;
}
if ((e & 64) == 0)
{
t += tp[tp_index_t_3 + 2];
t += (b & InternalInflateConstants.InflateMask[e]);
tp_index_t_3 = (tp_index + t) * 3;
if ((e = tp[tp_index_t_3]) == 0)
{
b >>= (tp[tp_index_t_3 + 1]); k -= (tp[tp_index_t_3 + 1]);
s.window[q++] = (byte)tp[tp_index_t_3 + 2];
m--;
break;
}
}
else if ((e & 32) != 0)
{
c = z.AvailableBytesIn - n; c = (k >> 3) < c ? k >> 3 : c; n += c; p -= c; k -= (c << 3);
s.bitb = b; s.bitk = k;
z.AvailableBytesIn = n; z.TotalBytesIn += p - z.NextIn; z.NextIn = p;
s.writeAt = q;
return ZlibConstants.Z_STREAM_END;
}
else
{
z.Message = "invalid literal/length code";
c = z.AvailableBytesIn - n; c = (k >> 3) < c ? k >> 3 : c; n += c; p -= c; k -= (c << 3);
s.bitb = b; s.bitk = k;
z.AvailableBytesIn = n; z.TotalBytesIn += p - z.NextIn; z.NextIn = p;
s.writeAt = q;
return ZlibConstants.Z_DATA_ERROR;
}
}
while (true);
}
while (m >= 258 && n >= 10);
// not enough input or output--restore pointers and return
c = z.AvailableBytesIn - n; c = (k >> 3) < c ? k >> 3 : c; n += c; p -= c; k -= (c << 3);
s.bitb = b; s.bitk = k;
z.AvailableBytesIn = n; z.TotalBytesIn += p - z.NextIn; z.NextIn = p;
s.writeAt = q;
return ZlibConstants.Z_OK;
}
}
internal sealed class InflateManager
{
// preset dictionary flag in zlib header
private const int PRESET_DICT = 0x20;
private const int Z_DEFLATED = 8;
private enum InflateManagerMode
{
METHOD = 0, // waiting for method byte
FLAG = 1, // waiting for flag byte
DICT4 = 2, // four dictionary check bytes to go
DICT3 = 3, // three dictionary check bytes to go
DICT2 = 4, // two dictionary check bytes to go
DICT1 = 5, // one dictionary check byte to go
DICT0 = 6, // waiting for inflateSetDictionary
BLOCKS = 7, // decompressing blocks
CHECK4 = 8, // four check bytes to go
CHECK3 = 9, // three check bytes to go
CHECK2 = 10, // two check bytes to go
CHECK1 = 11, // one check byte to go
DONE = 12, // finished check, done
BAD = 13, // got an error--stay here
}
private InflateManagerMode mode; // current inflate mode
internal ZlibCodec _codec; // pointer back to this zlib stream
// mode dependent information
internal int method; // if FLAGS, method byte
// if CHECK, check values to compare
internal uint computedCheck; // computed check value
internal uint expectedCheck; // stream check value
// if BAD, inflateSync's marker bytes count
internal int marker;
// mode independent information
//internal int nowrap; // flag for no wrapper
private bool _handleRfc1950HeaderBytes = true;
internal bool HandleRfc1950HeaderBytes
{
get { return _handleRfc1950HeaderBytes; }
set { _handleRfc1950HeaderBytes = value; }
}
internal int wbits; // log2(window size) (8..15, defaults to 15)
internal InflateBlocks blocks; // current inflate_blocks state
public InflateManager() { }
public InflateManager(bool expectRfc1950HeaderBytes)
{
_handleRfc1950HeaderBytes = expectRfc1950HeaderBytes;
}
internal int Reset()
{
_codec.TotalBytesIn = _codec.TotalBytesOut = 0;
_codec.Message = null;
mode = HandleRfc1950HeaderBytes ? InflateManagerMode.METHOD : InflateManagerMode.BLOCKS;
blocks.Reset();
return ZlibConstants.Z_OK;
}
internal int End()
{
if (blocks != null)
blocks.Free();
blocks = null;
return ZlibConstants.Z_OK;
}
internal int Initialize(ZlibCodec codec, int w)
{
_codec = codec;
_codec.Message = null;
blocks = null;
// handle undocumented nowrap option (no zlib header or check)
//nowrap = 0;
//if (w < 0)
//{
// w = - w;
// nowrap = 1;
//}
// set window size
if (w < 8 || w > 15)
{
End();
throw new ZlibException("Bad window size.");
//return ZlibConstants.Z_STREAM_ERROR;
}
wbits = w;
blocks = new InflateBlocks(codec,
HandleRfc1950HeaderBytes ? this : null,
1 << w);
// reset state
Reset();
return ZlibConstants.Z_OK;
}
internal int Inflate(FlushType flush)
{
int b;
if (_codec.InputBuffer == null)
throw new ZlibException("InputBuffer is null. ");
// int f = (flush == FlushType.Finish)
// ? ZlibConstants.Z_BUF_ERROR
// : ZlibConstants.Z_OK;
// workitem 8870
int f = ZlibConstants.Z_OK;
int r = ZlibConstants.Z_BUF_ERROR;
while (true)
{
switch (mode)
{
case InflateManagerMode.METHOD:
if (_codec.AvailableBytesIn == 0) return r;
r = f;
_codec.AvailableBytesIn--;
_codec.TotalBytesIn++;
if (((method = _codec.InputBuffer[_codec.NextIn++]) & 0xf) != Z_DEFLATED)
{
mode = InflateManagerMode.BAD;
_codec.Message = String.Format("unknown compression method (0x{0:X2})", method);
marker = 5; // can't try inflateSync
break;
}
if ((method >> 4) + 8 > wbits)
{
mode = InflateManagerMode.BAD;
_codec.Message = String.Format("invalid window size ({0})", (method >> 4) + 8);
marker = 5; // can't try inflateSync
break;
}
mode = InflateManagerMode.FLAG;
break;
case InflateManagerMode.FLAG:
if (_codec.AvailableBytesIn == 0) return r;
r = f;
_codec.AvailableBytesIn--;
_codec.TotalBytesIn++;
b = (_codec.InputBuffer[_codec.NextIn++]) & 0xff;
if ((((method << 8) + b) % 31) != 0)
{
mode = InflateManagerMode.BAD;
_codec.Message = "incorrect header check";
marker = 5; // can't try inflateSync
break;
}
mode = ((b & PRESET_DICT) == 0)
? InflateManagerMode.BLOCKS
: InflateManagerMode.DICT4;
break;
case InflateManagerMode.DICT4:
if (_codec.AvailableBytesIn == 0) return r;
r = f;
_codec.AvailableBytesIn--;
_codec.TotalBytesIn++;
expectedCheck = (uint)((_codec.InputBuffer[_codec.NextIn++] << 24) & 0xff000000);
mode = InflateManagerMode.DICT3;
break;
case InflateManagerMode.DICT3:
if (_codec.AvailableBytesIn == 0) return r;
r = f;
_codec.AvailableBytesIn--;
_codec.TotalBytesIn++;
expectedCheck += (uint)((_codec.InputBuffer[_codec.NextIn++] << 16) & 0x00ff0000);
mode = InflateManagerMode.DICT2;
break;
case InflateManagerMode.DICT2:
if (_codec.AvailableBytesIn == 0) return r;
r = f;
_codec.AvailableBytesIn--;
_codec.TotalBytesIn++;
expectedCheck += (uint)((_codec.InputBuffer[_codec.NextIn++] << 8) & 0x0000ff00);
mode = InflateManagerMode.DICT1;
break;
case InflateManagerMode.DICT1:
if (_codec.AvailableBytesIn == 0) return r;
r = f;
_codec.AvailableBytesIn--; _codec.TotalBytesIn++;
expectedCheck += (uint)(_codec.InputBuffer[_codec.NextIn++] & 0x000000ff);
_codec._Adler32 = expectedCheck;
mode = InflateManagerMode.DICT0;
return ZlibConstants.Z_NEED_DICT;
case InflateManagerMode.DICT0:
mode = InflateManagerMode.BAD;
_codec.Message = "need dictionary";
marker = 0; // can try inflateSync
return ZlibConstants.Z_STREAM_ERROR;
case InflateManagerMode.BLOCKS:
r = blocks.Process(r);
if (r == ZlibConstants.Z_DATA_ERROR)
{
mode = InflateManagerMode.BAD;
marker = 0; // can try inflateSync
break;
}
if (r == ZlibConstants.Z_OK) r = f;
if (r != ZlibConstants.Z_STREAM_END)
return r;
r = f;
computedCheck = blocks.Reset();
if (!HandleRfc1950HeaderBytes)
{
mode = InflateManagerMode.DONE;
return ZlibConstants.Z_STREAM_END;
}
mode = InflateManagerMode.CHECK4;
break;
case InflateManagerMode.CHECK4:
if (_codec.AvailableBytesIn == 0) return r;
r = f;
_codec.AvailableBytesIn--;
_codec.TotalBytesIn++;
expectedCheck = (uint)((_codec.InputBuffer[_codec.NextIn++] << 24) & 0xff000000);
mode = InflateManagerMode.CHECK3;
break;
case InflateManagerMode.CHECK3:
if (_codec.AvailableBytesIn == 0) return r;
r = f;
_codec.AvailableBytesIn--; _codec.TotalBytesIn++;
expectedCheck += (uint)((_codec.InputBuffer[_codec.NextIn++] << 16) & 0x00ff0000);
mode = InflateManagerMode.CHECK2;
break;
case InflateManagerMode.CHECK2:
if (_codec.AvailableBytesIn == 0) return r;
r = f;
_codec.AvailableBytesIn--;
_codec.TotalBytesIn++;
expectedCheck += (uint)((_codec.InputBuffer[_codec.NextIn++] << 8) & 0x0000ff00);
mode = InflateManagerMode.CHECK1;
break;
case InflateManagerMode.CHECK1:
if (_codec.AvailableBytesIn == 0) return r;
r = f;
_codec.AvailableBytesIn--; _codec.TotalBytesIn++;
expectedCheck += (uint)(_codec.InputBuffer[_codec.NextIn++] & 0x000000ff);
if (computedCheck != expectedCheck)
{
mode = InflateManagerMode.BAD;
_codec.Message = "incorrect data check";
marker = 5; // can't try inflateSync
break;
}
mode = InflateManagerMode.DONE;
return ZlibConstants.Z_STREAM_END;
case InflateManagerMode.DONE:
return ZlibConstants.Z_STREAM_END;
case InflateManagerMode.BAD:
throw new ZlibException(String.Format("Bad state ({0})", _codec.Message));
default:
throw new ZlibException("Stream error.");
}
}
}
internal int SetDictionary(byte[] dictionary)
{
int index = 0;
int length = dictionary.Length;
if (mode != InflateManagerMode.DICT0)
throw new ZlibException("Stream error.");
if (Adler.Adler32(1, dictionary, 0, dictionary.Length) != _codec._Adler32)
{
return ZlibConstants.Z_DATA_ERROR;
}
_codec._Adler32 = Adler.Adler32(0, null, 0, 0);
if (length >= (1 << wbits))
{
length = (1 << wbits) - 1;
index = dictionary.Length - length;
}
blocks.SetDictionary(dictionary, index, length);
mode = InflateManagerMode.BLOCKS;
return ZlibConstants.Z_OK;
}
private static readonly byte[] mark = new byte[] { 0, 0, 0xff, 0xff };
internal int Sync()
{
int n; // number of bytes to look at
int p; // pointer to bytes
int m; // number of marker bytes found in a row
long r, w; // temporaries to save total_in and total_out
// set up
if (mode != InflateManagerMode.BAD)
{
mode = InflateManagerMode.BAD;
marker = 0;
}
if ((n = _codec.AvailableBytesIn) == 0)
return ZlibConstants.Z_BUF_ERROR;
p = _codec.NextIn;
m = marker;
// search
while (n != 0 && m < 4)
{
if (_codec.InputBuffer[p] == mark[m])
{
m++;
}
else if (_codec.InputBuffer[p] != 0)
{
m = 0;
}
else
{
m = 4 - m;
}
p++; n--;
}
// restore
_codec.TotalBytesIn += p - _codec.NextIn;
_codec.NextIn = p;
_codec.AvailableBytesIn = n;
marker = m;
// return no joy or set up to restart on a new block
if (m != 4)
{
return ZlibConstants.Z_DATA_ERROR;
}
r = _codec.TotalBytesIn;
w = _codec.TotalBytesOut;
Reset();
_codec.TotalBytesIn = r;
_codec.TotalBytesOut = w;
mode = InflateManagerMode.BLOCKS;
return ZlibConstants.Z_OK;
}
// Returns true if inflate is currently at the end of a block generated
// by Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
// implementation to provide an additional safety check. PPP uses Z_SYNC_FLUSH
// but removes the length bytes of the resulting empty stored block. When
// decompressing, PPP checks that at the end of input packet, inflate is
// waiting for these length bytes.
internal int SyncPoint(ZlibCodec z)
{
return blocks.SyncPoint();
}
}
}