static InflaterHuffmanTree()
{
try
{
byte[] codeLengths = new byte[0x120];
int num = 0;
while (num < 0x90)
{
codeLengths[num++] = 8;
}
while (num < 0x100)
{
codeLengths[num++] = 9;
}
while (num < 280)
{
codeLengths[num++] = 7;
}
while (num < 0x120)
{
codeLengths[num++] = 8;
}
defLitLenTree = new InflaterHuffmanTree(codeLengths);
codeLengths = new byte[0x20];
num = 0;
while (num < 0x20)
{
codeLengths[num++] = 5;
}
defDistTree = new InflaterHuffmanTree(codeLengths);
}
catch (Exception)
{
throw new ApplicationException("InflaterHuffmanTree: static tree length illegal");
}
}
private bool DecodeHuffman()
{
int freeSpace = this.outputWindow.GetFreeSpace();
while (freeSpace >= 0x102)
{
int num2;
switch (this.mode)
{
case 7:
goto Label_0059;
case 8:
goto Label_00DB;
case 9:
goto Label_0132;
case 10:
goto Label_017A;
default:
throw new FormatException();
}
Label_0039:
this.outputWindow.Write(num2);
if (--freeSpace < 0x102)
{
return true;
}
Label_0059:
if (((num2 = this.litlenTree.GetSymbol(this.input)) & -256) == 0)
{
goto Label_0039;
}
if (num2 < 0x101)
{
if (num2 < 0)
{
return false;
}
this.distTree = null;
this.litlenTree = null;
this.mode = 2;
return true;
}
try
{
this.repLength = CPLENS[num2 - 0x101];
this.neededBits = CPLEXT[num2 - 0x101];
}
catch (Exception)
{
throw new FormatException("Illegal rep length code");
}
Label_00DB:
if (this.neededBits > 0)
{
this.mode = 8;
int num3 = this.input.PeekBits(this.neededBits);
if (num3 < 0)
{
return false;
}
this.input.DropBits(this.neededBits);
this.repLength += num3;
}
this.mode = 9;
Label_0132:
num2 = this.distTree.GetSymbol(this.input);
if (num2 < 0)
{
return false;
}
try
{
this.repDist = CPDIST[num2];
this.neededBits = CPDEXT[num2];
}
catch (Exception)
{
throw new FormatException("Illegal rep dist code");
}
Label_017A:
if (this.neededBits > 0)
{
this.mode = 10;
int num4 = this.input.PeekBits(this.neededBits);
if (num4 < 0)
{
return false;
}
this.input.DropBits(this.neededBits);
this.repDist += num4;
}
this.outputWindow.Repeat(this.repLength, this.repDist);
freeSpace -= this.repLength;
this.mode = 7;
}
return true;
}
private bool Decode()
{
int num2;
int num3;
switch (this.mode)
{
case 0:
return this.DecodeHeader();
case 1:
return this.DecodeDict();
case 2:
if (!this.isLastBlock)
{
int num = this.input.PeekBits(3);
if (num < 0)
{
return false;
}
this.input.DropBits(3);
if ((num & 1) != 0)
{
this.isLastBlock = true;
}
switch ((num >> 1))
{
case 0:
this.input.SkipToByteBoundary();
this.mode = 3;
break;
case 1:
this.litlenTree = InflaterHuffmanTree.defLitLenTree;
this.distTree = InflaterHuffmanTree.defDistTree;
this.mode = 7;
break;
case 2:
this.dynHeader = new InflaterDynHeader();
this.mode = 6;
break;
}
throw new FormatException("Unknown block type " + num);
}
if (!this.nowrap)
{
this.input.SkipToByteBoundary();
this.neededBits = 0x20;
this.mode = 11;
return true;
}
this.mode = 12;
return false;
case 3:
this.uncomprLen = this.input.PeekBits(0x10);
if (this.uncomprLen >= 0)
{
this.input.DropBits(0x10);
this.mode = 4;
goto Label_0193;
}
return false;
case 4:
goto Label_0193;
case 5:
goto Label_01DC;
case 6:
if (this.dynHeader.Decode(this.input))
{
this.litlenTree = this.dynHeader.BuildLitLenTree();
this.distTree = this.dynHeader.BuildDistTree();
this.mode = 7;
goto Label_0268;
}
return false;
case 7:
case 8:
case 9:
case 10:
goto Label_0268;
case 11:
return this.DecodeChksum();
case 12:
return false;
default:
throw new FormatException();
}
return true;
Label_0193:
num2 = this.input.PeekBits(0x10);
if (num2 < 0)
{
return false;
}
this.input.DropBits(0x10);
if (num2 != (this.uncomprLen ^ 0xffff))
{
throw new FormatException("broken uncompressed block");
}
this.mode = 5;
Label_01DC:
num3 = this.outputWindow.CopyStored(this.input, this.uncomprLen);
this.uncomprLen -= num3;
if (this.uncomprLen == 0)
{
this.mode = 2;
return true;
}
return !this.input.IsNeedingInput;
Label_0268:
return this.DecodeHuffman();
}
public void Reset()
{
this.mode = this.nowrap ? 2 : 0;
this.totalIn = this.totalOut = 0;
this.input.Reset();
this.outputWindow.Reset();
this.dynHeader = null;
this.litlenTree = null;
this.distTree = null;
this.isLastBlock = false;
this.adler.Reset();
}
public bool Decode(StreamManipulator input)
{
int num2;
int num3;
Label_0005:
switch (this.mode)
{
case 0:
this.lnum = input.PeekBits(5);
if (this.lnum >= 0)
{
this.lnum += 0x101;
input.DropBits(5);
this.mode = 1;
break;
}
return false;
case 1:
break;
case 2:
goto Label_00D1;
case 3:
goto Label_0161;
case 4:
goto Label_01D6;
case 5:
goto Label_0224;
default:
goto Label_0005;
}
this.dnum = input.PeekBits(5);
if (this.dnum < 0)
{
return false;
}
this.dnum++;
input.DropBits(5);
this.num = this.lnum + this.dnum;
this.litdistLens = new byte[this.num];
this.mode = 2;
Label_00D1:
this.blnum = input.PeekBits(4);
if (this.blnum < 0)
{
return false;
}
this.blnum += 4;
input.DropBits(4);
this.blLens = new byte[0x13];
this.ptr = 0;
this.mode = 3;
Label_0161:
while (this.ptr < this.blnum)
{
int num = input.PeekBits(3);
if (num < 0)
{
return false;
}
input.DropBits(3);
this.blLens[BL_ORDER[this.ptr]] = (byte) num;
this.ptr++;
}
this.blTree = new InflaterHuffmanTree(this.blLens);
this.blLens = null;
this.ptr = 0;
this.mode = 4;
Label_01D6:
while (((num2 = this.blTree.GetSymbol(input)) & -16) == 0)
{
this.litdistLens[this.ptr++] = this.lastLen = (byte) num2;
if (this.ptr == this.num)
{
return true;
}
}
if (num2 < 0)
{
return false;
}
if (num2 >= 0x11)
{
this.lastLen = 0;
}
else if (this.ptr == 0)
{
throw new Exception();
}
this.repSymbol = num2 - 0x10;
this.mode = 5;
Label_0224:
num3 = repBits[this.repSymbol];
int num4 = input.PeekBits(num3);
if (num4 < 0)
{
return false;
}
input.DropBits(num3);
num4 += repMin[this.repSymbol];
if ((this.ptr + num4) > this.num)
{
throw new Exception();
}
while (num4-- > 0)
{
this.litdistLens[this.ptr++] = this.lastLen;
}
if (this.ptr == this.num)
{
return true;
}
this.mode = 4;
goto Label_0005;
}