public bool Decode(StreamManipulator input)
{
decode_loop:
for (; ; )
{
switch (mode)
{
case LNUM:
lnum = input.PeekBits(5);
if (lnum < 0)
{
return false;
}
lnum += 257;
input.DropBits(5);
// System.err.println("LNUM: "+lnum);
mode = DNUM;
goto case DNUM; // fall through
case DNUM:
dnum = input.PeekBits(5);
if (dnum < 0)
{
return false;
}
dnum++;
input.DropBits(5);
// System.err.println("DNUM: "+dnum);
num = lnum + dnum;
litdistLens = new byte[num];
mode = BLNUM;
goto case BLNUM; // fall through
case BLNUM:
blnum = input.PeekBits(4);
if (blnum < 0)
{
return false;
}
blnum += 4;
input.DropBits(4);
blLens = new byte[19];
ptr = 0;
// System.err.println("BLNUM: "+blnum);
mode = BLLENS;
goto case BLLENS; // fall through
case BLLENS:
while (ptr < blnum)
{
int len = input.PeekBits(3);
if (len < 0)
{
return false;
}
input.DropBits(3);
// System.err.println("blLens["+BL_ORDER[ptr]+"]: "+len);
blLens[BL_ORDER[ptr]] = (byte)len;
ptr++;
}
blTree = new InflaterHuffmanTree(blLens);
blLens = null;
ptr = 0;
mode = LENS;
goto case LENS; // fall through
case LENS:
{
int symbol;
while (((symbol = blTree.GetSymbol(input)) & ~15) == 0)
{
/* Normal case: symbol in [0..15] */
// System.err.println("litdistLens["+ptr+"]: "+symbol);
litdistLens[ptr++] = lastLen = (byte)symbol;
if (ptr == num)
{
/* Finished */
return true;
}
}
/* need more input ? */
if (symbol < 0)
{
return false;
}
/* otherwise repeat code */
if (symbol >= 17)
{
/* repeat zero */
// System.err.println("repeating zero");
lastLen = 0;
}
else
{
if (ptr == 0)
{
throw new SharpZipBaseException();
}
}
repSymbol = symbol - 16;
}
mode = REPS;
goto case REPS; // fall through
case REPS:
{
int bits = repBits[repSymbol];
int count = input.PeekBits(bits);
if (count < 0)
{
return false;
}
input.DropBits(bits);
count += repMin[repSymbol];
// System.err.println("litdistLens repeated: "+count);
if (ptr + count > num)
{
throw new SharpZipBaseException();
}
while (count-- > 0)
{
litdistLens[ptr++] = lastLen;
}
if (ptr == num)
{
/* Finished */
return true;
}
}
mode = LENS;
goto decode_loop;
}
}
}
static InflaterHuffmanTree()
{
try {
byte[] codeLengths = new byte[288];
int i = 0;
while (i < 144) {
codeLengths[i++] = 8;
}
while (i < 256) {
codeLengths[i++] = 9;
}
while (i < 280) {
codeLengths[i++] = 7;
}
while (i < 288) {
codeLengths[i++] = 8;
}
defLitLenTree = new InflaterHuffmanTree(codeLengths);
codeLengths = new byte[32];
i = 0;
while (i < 32) {
codeLengths[i++] = 5;
}
defDistTree = new InflaterHuffmanTree(codeLengths);
} catch (Exception) {
throw new ApplicationException("InflaterHuffmanTree: static tree length illegal");
}
}
public bool Decode(StreamManipulator input)
{
int num2;
int num3;
Label_0000:
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_00B9;
case 3:
goto Label_013B;
case 4:
goto Label_01A8;
case 5:
goto Label_01EE;
default:
goto Label_0000;
}
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_00B9:
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_013B:
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_01A8:
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 SharpZipBaseException();
}
this.repSymbol = num2 - 0x10;
this.mode = 5;
Label_01EE:
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 SharpZipBaseException();
}
while (num4-- > 0)
{
this.litdistLens[this.ptr++] = this.lastLen;
}
if (this.ptr == this.num)
{
return true;
}
this.mode = 4;
goto Label_0000;
}
/// <summary>
/// Decodes the huffman encoded symbols in the input stream.
/// </summary>
/// <returns>
/// false if more input is needed, true if output window is
/// full or the current block ends.
/// </returns>
/// <exception cref="System.FormatException">
/// if deflated stream is invalid.
/// </exception>
private bool DecodeHuffman()
{
int free = outputWindow.GetFreeSpace();
while (free >= 258) {
int symbol;
switch (mode) {
case DECODE_HUFFMAN:
/* This is the inner loop so it is optimized a bit */
while (((symbol = litlenTree.GetSymbol(input)) & ~0xff) == 0) {
outputWindow.Write(symbol);
if (--free < 258) {
return true;
}
}
if (symbol < 257) {
if (symbol < 0) {
return false;
} else {
/* symbol == 256: end of block */
distTree = null;
litlenTree = null;
mode = DECODE_BLOCKS;
return true;
}
}
try {
repLength = CPLENS[symbol - 257];
neededBits = CPLEXT[symbol - 257];
} catch (Exception) {
throw new FormatException("Illegal rep length code");
}
goto case DECODE_HUFFMAN_LENBITS;/* fall through */
case DECODE_HUFFMAN_LENBITS:
if (neededBits > 0) {
mode = DECODE_HUFFMAN_LENBITS;
int i = input.PeekBits(neededBits);
if (i < 0) {
return false;
}
input.DropBits(neededBits);
repLength += i;
}
mode = DECODE_HUFFMAN_DIST;
goto case DECODE_HUFFMAN_DIST;/* fall through */
case DECODE_HUFFMAN_DIST:
symbol = distTree.GetSymbol(input);
if (symbol < 0) {
return false;
}
try {
repDist = CPDIST[symbol];
neededBits = CPDEXT[symbol];
} catch (Exception) {
throw new FormatException("Illegal rep dist code");
}
goto case DECODE_HUFFMAN_DISTBITS;/* fall through */
case DECODE_HUFFMAN_DISTBITS:
if (neededBits > 0) {
mode = DECODE_HUFFMAN_DISTBITS;
int i = input.PeekBits(neededBits);
if (i < 0) {
return false;
}
input.DropBits(neededBits);
repDist += i;
}
outputWindow.Repeat(repLength, repDist);
free -= repLength;
mode = DECODE_HUFFMAN;
break;
default:
throw new FormatException();
}
}
return true;
}
public bool Decode(StreamManipulator input)
{
decode_loop:
for (;;) {
switch (mode) {
case LNUM:
lnum = input.PeekBits(5);
if (lnum < 0) {
return false;
}
lnum += 257;
input.DropBits(5);
litlenLens = new byte[lnum];
// System.err.println("LNUM: "+lnum);
mode = DNUM;
goto case DNUM;/* fall through */
case DNUM:
dnum = input.PeekBits(5);
if (dnum < 0) {
return false;
}
dnum++;
input.DropBits(5);
distLens = new byte[dnum];
// System.err.println("DNUM: "+dnum);
mode = BLNUM;
goto case BLNUM;/* fall through */
case BLNUM:
blnum = input.PeekBits(4);
if (blnum < 0) {
return false;
}
blnum += 4;
input.DropBits(4);
blLens = new byte[19];
ptr = 0;
// System.err.println("BLNUM: "+blnum);
mode = BLLENS;
goto case BLLENS;/* fall through */
case BLLENS:
while (ptr < blnum) {
int len = input.PeekBits(3);
if (len < 0) {
return false;
}
input.DropBits(3);
// System.err.println("blLens["+BL_ORDER[ptr]+"]: "+len);
blLens[BL_ORDER[ptr]] = (byte) len;
ptr++;
}
blTree = new InflaterHuffmanTree(blLens);
blLens = null;
ptr = 0;
mode = LLENS;
goto case LLENS;/* fall through */
case LLENS:
while (ptr < lnum) {
int symbol = blTree.GetSymbol(input);
if (symbol < 0) {
return false;
}
switch (symbol) {
default:
// System.err.println("litlenLens["+ptr+"]: "+symbol);
litlenLens[ptr++] = (byte) symbol;
break;
case 16: /* repeat last len 3-6 times */
if (ptr == 0) {
throw new Exception("Repeating, but no prev len");
}
// System.err.println("litlenLens["+ptr+"]: repeat");
repeatedLen = litlenLens[ptr-1];
repBits = 2;
for (int i = 3; i-- > 0; ) {
if (ptr >= lnum) {
throw new Exception();
}
litlenLens[ptr++] = repeatedLen;
}
mode = LREPS;
goto decode_loop;
case 17: /* repeat zero 3-10 times */
// System.err.println("litlenLens["+ptr+"]: zero repeat");
repeatedLen = 0;
repBits = 3;
for (int i = 3; i-- > 0; ) {
if (ptr >= lnum) {
throw new Exception();
}
litlenLens[ptr++] = repeatedLen;
}
mode = LREPS;
goto decode_loop;
case 18: /* repeat zero 11-138 times */
// System.err.println("litlenLens["+ptr+"]: zero repeat");
repeatedLen = 0;
repBits = 7;
for (int i = 11; i-- > 0; ) {
if (ptr >= lnum) {
throw new Exception();
}
litlenLens[ptr++] = repeatedLen;
}
mode = LREPS;
goto decode_loop;
}
}
ptr = 0;
mode = DLENS;
goto case DLENS;/* fall through */
case DLENS:
while (ptr < dnum) {
int symbol = blTree.GetSymbol(input);
if (symbol < 0) {
return false;
}
switch (symbol) {
default:
distLens[ptr++] = (byte) symbol;
// System.err.println("distLens["+ptr+"]: "+symbol);
break;
case 16: /* repeat last len 3-6 times */
if (ptr == 0) {
throw new Exception("Repeating, but no prev len");
}
// System.err.println("distLens["+ptr+"]: repeat");
repeatedLen = distLens[ptr-1];
repBits = 2;
for (int i = 3; i-- > 0; ) {
if (ptr >= dnum) {
throw new Exception();
}
distLens[ptr++] = repeatedLen;
}
mode = DREPS;
goto decode_loop;
case 17: /* repeat zero 3-10 times */
// System.err.println("distLens["+ptr+"]: repeat zero");
repeatedLen = 0;
repBits = 3;
for (int i = 3; i-- > 0; ) {
if (ptr >= dnum) {
throw new Exception();
}
distLens[ptr++] = repeatedLen;
}
mode = DREPS;
goto decode_loop;
case 18: /* repeat zero 11-138 times */
// System.err.println("distLens["+ptr+"]: repeat zero");
repeatedLen = 0;
repBits = 7;
for (int i = 11; i-- > 0; ) {
if (ptr >= dnum) {
throw new Exception();
}
distLens[ptr++] = repeatedLen;
}
mode = DREPS;
goto decode_loop;
}
}
mode = FINISH;
return true;
case LREPS:
{
int count = input.PeekBits(repBits);
if (count < 0) {
return false;
}
input.DropBits(repBits);
// System.err.println("litlenLens repeat: "+repBits);
while (count-- > 0) {
if (ptr >= lnum) {
throw new Exception();
}
litlenLens[ptr++] = repeatedLen;
}
}
mode = LLENS;
goto decode_loop;
case DREPS:
{
int count = input.PeekBits(repBits);
if (count < 0) {
return false;
}
input.DropBits(repBits);
while (count-- > 0) {
if (ptr >= dnum) {
throw new Exception();
}
distLens[ptr++] = repeatedLen;
}
}
mode = DLENS;
goto decode_loop;
}
}
}
/// <summary>
/// Decodes the deflated stream.
/// </summary>
/// <returns>
/// false if more input is needed, or if finished.
/// </returns>
/// <exception cref="System.FormatException">
/// DataFormatException, if deflated stream is invalid.
/// </exception>
private bool Decode()
{
switch (mode) {
case DECODE_HEADER:
return DecodeHeader();
case DECODE_DICT:
return DecodeDict();
case DECODE_CHKSUM:
return DecodeChksum();
case DECODE_BLOCKS:
if (isLastBlock) {
if (nowrap) {
mode = FINISHED;
return false;
} else {
input.SkipToByteBoundary();
neededBits = 32;
mode = DECODE_CHKSUM;
return true;
}
}
int type = input.PeekBits(3);
if (type < 0) {
return false;
}
input.DropBits(3);
if ((type & 1) != 0) {
isLastBlock = true;
}
switch (type >> 1) {
case DeflaterConstants.STORED_BLOCK:
input.SkipToByteBoundary();
mode = DECODE_STORED_LEN1;
break;
case DeflaterConstants.STATIC_TREES:
litlenTree = InflaterHuffmanTree.defLitLenTree;
distTree = InflaterHuffmanTree.defDistTree;
mode = DECODE_HUFFMAN;
break;
case DeflaterConstants.DYN_TREES:
dynHeader = new InflaterDynHeader();
mode = DECODE_DYN_HEADER;
break;
default:
throw new FormatException("Unknown block type "+type);
}
return true;
case DECODE_STORED_LEN1: {
if ((uncomprLen = input.PeekBits(16)) < 0) {
return false;
}
input.DropBits(16);
mode = DECODE_STORED_LEN2;
}
goto case DECODE_STORED_LEN2; /* fall through */
case DECODE_STORED_LEN2: {
int nlen = input.PeekBits(16);
if (nlen < 0) {
return false;
}
input.DropBits(16);
if (nlen != (uncomprLen ^ 0xffff)) {
throw new FormatException("broken uncompressed block");
}
mode = DECODE_STORED;
}
goto case DECODE_STORED;/* fall through */
case DECODE_STORED: {
int more = outputWindow.CopyStored(input, uncomprLen);
uncomprLen -= more;
if (uncomprLen == 0) {
mode = DECODE_BLOCKS;
return true;
}
return !input.IsNeedingInput;
}
case DECODE_DYN_HEADER:
if (!dynHeader.Decode(input)) {
return false;
}
litlenTree = dynHeader.BuildLitLenTree();
distTree = dynHeader.BuildDistTree();
mode = DECODE_HUFFMAN;
goto case DECODE_HUFFMAN; /* fall through */
case DECODE_HUFFMAN:
case DECODE_HUFFMAN_LENBITS:
case DECODE_HUFFMAN_DIST:
case DECODE_HUFFMAN_DISTBITS:
return DecodeHuffman();
case FINISHED:
return false;
default:
throw new FormatException();
}
}
/// <summary>
/// Resets the inflater so that a new stream can be decompressed. All
/// pending input and output will be discarded.
/// </summary>
public void Reset()
{
mode = nowrap ? DECODE_BLOCKS : DECODE_HEADER;
totalIn = totalOut = 0;
input.Reset();
outputWindow.Reset();
dynHeader = null;
litlenTree = null;
distTree = null;
isLastBlock = false;
adler.Reset();
}
private bool DecodeHuffman()
{
int freeSpace = this.outputWindow.GetFreeSpace();
while (freeSpace >= 0x102)
{
int num2;
switch (this.mode)
{
case 7:
goto Label_0051;
case 8:
goto Label_00C5;
case 9:
goto Label_0114;
case 10:
goto Label_0154;
default:
throw new SharpZipBaseException("Inflater unknown mode");
}
Label_0037:
this.outputWindow.Write(num2);
if (--freeSpace < 0x102)
{
return true;
}
Label_0051:
if (((num2 = this.litlenTree.GetSymbol(this.input)) & -256) == 0)
{
goto Label_0037;
}
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 SharpZipBaseException("Illegal rep length code");
}
Label_00C5:
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_0114:
num2 = this.distTree.GetSymbol(this.input);
if (num2 < 0)
{
return false;
}
try
{
this.repDist = CPDIST[num2];
this.neededBits = CPDEXT[num2];
}
catch (Exception)
{
throw new SharpZipBaseException("Illegal rep dist code");
}
Label_0154:
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 SharpZipBaseException("Unknown block type " + num);
}
if (!this.noHeader)
{
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_0163;
}
return false;
case 4:
goto Label_0163;
case 5:
goto Label_01A5;
case 6:
if (this.dynHeader.Decode(this.input))
{
this.litlenTree = this.dynHeader.BuildLitLenTree();
this.distTree = this.dynHeader.BuildDistTree();
this.mode = 7;
goto Label_0229;
}
return false;
case 7:
case 8:
case 9:
case 10:
goto Label_0229;
case 11:
return this.DecodeChksum();
case 12:
return false;
default:
throw new SharpZipBaseException("Inflater.Decode unknown mode");
}
return true;
Label_0163:
num2 = this.input.PeekBits(0x10);
if (num2 < 0)
{
return false;
}
this.input.DropBits(0x10);
if (num2 != (this.uncomprLen ^ 0xffff))
{
throw new SharpZipBaseException("broken uncompressed block");
}
this.mode = 5;
Label_01A5:
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_0229:
return this.DecodeHuffman();
}
public void Reset()
{
this.mode = this.noHeader ? 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();
}
