public bool ReadFooter(InputBuffer input)
{
input.SkipToByteBoundary();
if (gzipFooterSubstate == GzipHeaderState.ReadingCRC)
{
while (loopCounter < 4)
{
var bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
expectedCrc32 |= (uint)bits << (8 * loopCounter);
loopCounter++;
}
gzipFooterSubstate = GzipHeaderState.ReadingFileSize;
loopCounter = 0;
}
if (gzipFooterSubstate == GzipHeaderState.ReadingFileSize)
{
if (loopCounter == 0)
{
expectedOutputStreamSizeModulo = 0;
}
while (loopCounter < 4)
{
var bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
expectedOutputStreamSizeModulo |= (uint)bits << (8 * loopCounter);
loopCounter++;
}
}
return(true);
}
public bool ReadFooter(InputBuffer input)
{
input.SkipToByteBoundary();
if (this.gzipFooterSubstate == GZipDecoder.GzipHeaderState.ReadingCRC)
{
while (this.loopCounter < 4)
{
int bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
this.expectedCrc32 |= (uint)((uint)bits << 8 * this.loopCounter);
this.loopCounter++;
}
this.gzipFooterSubstate = GZipDecoder.GzipHeaderState.ReadingFileSize;
this.loopCounter = 0;
}
if (this.gzipFooterSubstate == GZipDecoder.GzipHeaderState.ReadingFileSize)
{
if (this.loopCounter == 0)
{
this.expectedOutputStreamSizeModulo = 0u;
}
while (this.loopCounter < 4)
{
int bits2 = input.GetBits(8);
if (bits2 < 0)
{
return(false);
}
this.expectedOutputStreamSizeModulo |= (uint)((uint)bits2 << 8 * this.loopCounter);
this.loopCounter++;
}
}
return(true);
}
public bool ReadHeader(InputBuffer input)
{
int bits;
switch (this.gzipHeaderSubstate)
{
case GZipDecoder.GzipHeaderState.ReadingID1:
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
if (bits != 31)
{
throw new InvalidDataException(SR.GetString("Corrupted gzip header"));
}
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.ReadingID2;
break;
case GZipDecoder.GzipHeaderState.ReadingID2:
break;
case GZipDecoder.GzipHeaderState.ReadingCM:
goto IL_A5;
case GZipDecoder.GzipHeaderState.ReadingFLG:
goto IL_CE;
case GZipDecoder.GzipHeaderState.ReadingMMTime:
goto IL_F1;
case GZipDecoder.GzipHeaderState.ReadingXFL:
goto IL_128;
case GZipDecoder.GzipHeaderState.ReadingOS:
goto IL_13D;
case GZipDecoder.GzipHeaderState.ReadingXLen1:
goto IL_152;
case GZipDecoder.GzipHeaderState.ReadingXLen2:
goto IL_17B;
case GZipDecoder.GzipHeaderState.ReadingXLenData:
goto IL_1A8;
case GZipDecoder.GzipHeaderState.ReadingFileName:
goto IL_1E5;
case GZipDecoder.GzipHeaderState.ReadingComment:
goto IL_212;
case GZipDecoder.GzipHeaderState.ReadingCRC16Part1:
goto IL_240;
case GZipDecoder.GzipHeaderState.ReadingCRC16Part2:
goto IL_26A;
case GZipDecoder.GzipHeaderState.Done:
return(true);
default:
throw new InvalidDataException(SR.GetString("Unknown state"));
}
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
if (bits != 139)
{
throw new InvalidDataException(SR.GetString("Corrupted gzip header"));
}
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.ReadingCM;
IL_A5:
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
if (bits != 8)
{
throw new InvalidDataException(SR.GetString("Unknown compression mode"));
}
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.ReadingFLG;
IL_CE:
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
this.gzip_header_flag = bits;
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.ReadingMMTime;
this.loopCounter = 0;
IL_F1:
while (this.loopCounter < 4)
{
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
this.loopCounter++;
}
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.ReadingXFL;
this.loopCounter = 0;
IL_128:
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.ReadingOS;
IL_13D:
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.ReadingXLen1;
IL_152:
if ((this.gzip_header_flag & 4) == 0)
{
goto IL_1E5;
}
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
this.gzip_header_xlen = bits;
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.ReadingXLen2;
IL_17B:
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
this.gzip_header_xlen |= bits << 8;
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.ReadingXLenData;
this.loopCounter = 0;
IL_1A8:
while (this.loopCounter < this.gzip_header_xlen)
{
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
this.loopCounter++;
}
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.ReadingFileName;
this.loopCounter = 0;
IL_1E5:
if ((this.gzip_header_flag & 8) == 0)
{
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.ReadingComment;
}
else
{
while (true)
{
bits = input.GetBits(8);
if (bits < 0)
{
break;
}
if (bits == 0)
{
goto Block_20;
}
}
return(false);
Block_20:
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.ReadingComment;
}
IL_212:
if ((this.gzip_header_flag & 16) == 0)
{
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.ReadingCRC16Part1;
}
else
{
while (true)
{
bits = input.GetBits(8);
if (bits < 0)
{
break;
}
if (bits == 0)
{
goto Block_23;
}
}
return(false);
Block_23:
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.ReadingCRC16Part1;
}
IL_240:
if ((this.gzip_header_flag & 2) == 0)
{
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.Done;
return(true);
}
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.ReadingCRC16Part2;
IL_26A:
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.Done;
return(true);
}
public bool ReadHeader(InputBuffer input)
{
while (true)
{
int bits;
switch (gzipHeaderSubstate)
{
case GzipHeaderState.ReadingID1:
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
if (bits != GZipConstants.ID1)
{
throw new InvalidDataException(SR.GetString(SR.CorruptedGZipHeader));
}
gzipHeaderSubstate = GzipHeaderState.ReadingID2;
goto case GzipHeaderState.ReadingID2;
case GzipHeaderState.ReadingID2:
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
if (bits != GZipConstants.ID2)
{
throw new InvalidDataException(SR.GetString(SR.CorruptedGZipHeader));
}
gzipHeaderSubstate = GzipHeaderState.ReadingCM;
goto case GzipHeaderState.ReadingCM;
case GzipHeaderState.ReadingCM:
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
if (bits != GZipConstants.Deflate)
{
throw new InvalidDataException(SR.GetString(SR.UnknownCompressionMode));
}
gzipHeaderSubstate = GzipHeaderState.ReadingFLG;
;
goto case GzipHeaderState.ReadingFLG;
case GzipHeaderState.ReadingFLG:
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
gzip_header_flag = bits;
gzipHeaderSubstate = GzipHeaderState.ReadingMMTime;
loopCounter = 0; // 4 MMTIME bytes
goto case GzipHeaderState.ReadingMMTime;
case GzipHeaderState.ReadingMMTime:
bits = 0;
while (loopCounter < 4)
{
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
loopCounter++;
}
gzipHeaderSubstate = GzipHeaderState.ReadingXFL;
loopCounter = 0;
goto case GzipHeaderState.ReadingXFL;
case GzipHeaderState.ReadingXFL: // ignore XFL
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
gzipHeaderSubstate = GzipHeaderState.ReadingOS;
goto case GzipHeaderState.ReadingOS;
case GzipHeaderState.ReadingOS: // ignore OS
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
gzipHeaderSubstate = GzipHeaderState.ReadingXLen1;
goto case GzipHeaderState.ReadingXLen1;
case GzipHeaderState.ReadingXLen1:
if ((gzip_header_flag & (int)GZipOptionalHeaderFlags.ExtraFieldsFlag) == 0)
{
goto case GzipHeaderState.ReadingFileName;
}
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
gzip_header_xlen = bits;
gzipHeaderSubstate = GzipHeaderState.ReadingXLen2;
goto case GzipHeaderState.ReadingXLen2;
case GzipHeaderState.ReadingXLen2:
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
gzip_header_xlen |= bits << 8;
gzipHeaderSubstate = GzipHeaderState.ReadingXLenData;
loopCounter = 0; // 0 bytes of XLEN data read so far
goto case GzipHeaderState.ReadingXLenData;
case GzipHeaderState.ReadingXLenData:
bits = 0;
while (loopCounter < gzip_header_xlen)
{
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
loopCounter++;
}
gzipHeaderSubstate = GzipHeaderState.ReadingFileName;
loopCounter = 0;
goto case GzipHeaderState.ReadingFileName;
case GzipHeaderState.ReadingFileName:
if ((gzip_header_flag & (int)GZipOptionalHeaderFlags.FileNameFlag) == 0)
{
gzipHeaderSubstate = GzipHeaderState.ReadingComment;
goto case GzipHeaderState.ReadingComment;
}
do
{
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
if (bits == 0)
{
break;
}
} while (true);
gzipHeaderSubstate = GzipHeaderState.ReadingComment;
goto case GzipHeaderState.ReadingComment;
case GzipHeaderState.ReadingComment:
if ((gzip_header_flag & (int)GZipOptionalHeaderFlags.CommentFlag) == 0)
{
gzipHeaderSubstate = GzipHeaderState.ReadingCRC16Part1;
goto case GzipHeaderState.ReadingCRC16Part1;
}
do
{
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
if (bits == 0)
{
break;
}
} while (true);
gzipHeaderSubstate = GzipHeaderState.ReadingCRC16Part1;
goto case GzipHeaderState.ReadingCRC16Part1;
case GzipHeaderState.ReadingCRC16Part1:
if ((gzip_header_flag & (int)GZipOptionalHeaderFlags.CRCFlag) == 0)
{
gzipHeaderSubstate = GzipHeaderState.Done;
goto case GzipHeaderState.Done;
}
bits = input.GetBits(8); // ignore crc
if (bits < 0)
{
return(false);
}
gzipHeaderSubstate = GzipHeaderState.ReadingCRC16Part2;
goto case GzipHeaderState.ReadingCRC16Part2;
case GzipHeaderState.ReadingCRC16Part2:
bits = input.GetBits(8); // ignore crc
if (bits < 0)
{
return(false);
}
gzipHeaderSubstate = GzipHeaderState.Done;
goto case GzipHeaderState.Done;
case GzipHeaderState.Done:
return(true);
default:
Debug.Assert(false, "We should not reach unknown state!");
throw new InvalidDataException(SR.GetString(SR.UnknownState));
}
}
}
public bool ReadHeader(InputBuffer input) {
while (true) {
int bits;
switch (gzipHeaderSubstate) {
case GzipHeaderState.ReadingID1:
bits = input.GetBits(8);
if (bits < 0) {
return false;
}
if (bits != GZipConstants.ID1) {
throw new InvalidDataException(SR.GetString(SR.CorruptedGZipHeader));
}
gzipHeaderSubstate = GzipHeaderState.ReadingID2;
goto case GzipHeaderState.ReadingID2;
case GzipHeaderState.ReadingID2:
bits = input.GetBits(8);
if (bits < 0) {
return false;
}
if (bits != GZipConstants.ID2) {
throw new InvalidDataException(SR.GetString(SR.CorruptedGZipHeader));
}
gzipHeaderSubstate = GzipHeaderState.ReadingCM;
goto case GzipHeaderState.ReadingCM;
case GzipHeaderState.ReadingCM:
bits = input.GetBits(8);
if (bits < 0) {
return false;
}
if (bits != GZipConstants.Deflate) { // compression mode must be 8 (deflate)
throw new InvalidDataException(SR.GetString(SR.UnknownCompressionMode));
}
gzipHeaderSubstate = GzipHeaderState.ReadingFLG; ;
goto case GzipHeaderState.ReadingFLG;
case GzipHeaderState.ReadingFLG:
bits = input.GetBits(8);
if (bits < 0) {
return false;
}
gzip_header_flag = bits;
gzipHeaderSubstate = GzipHeaderState.ReadingMMTime;
loopCounter = 0; // 4 MMTIME bytes
goto case GzipHeaderState.ReadingMMTime;
case GzipHeaderState.ReadingMMTime:
bits = 0;
while (loopCounter < 4) {
bits = input.GetBits(8);
if (bits < 0) {
return false;
}
loopCounter++;
}
gzipHeaderSubstate = GzipHeaderState.ReadingXFL;
loopCounter = 0;
goto case GzipHeaderState.ReadingXFL;
case GzipHeaderState.ReadingXFL: // ignore XFL
bits = input.GetBits(8);
if (bits < 0) {
return false;
}
gzipHeaderSubstate = GzipHeaderState.ReadingOS;
goto case GzipHeaderState.ReadingOS;
case GzipHeaderState.ReadingOS: // ignore OS
bits = input.GetBits(8);
if (bits < 0) {
return false;
}
gzipHeaderSubstate = GzipHeaderState.ReadingXLen1;
goto case GzipHeaderState.ReadingXLen1;
case GzipHeaderState.ReadingXLen1:
if ((gzip_header_flag & (int)GZipOptionalHeaderFlags.ExtraFieldsFlag) == 0) {
goto case GzipHeaderState.ReadingFileName;
}
bits = input.GetBits(8);
if (bits < 0) {
return false;
}
gzip_header_xlen = bits;
gzipHeaderSubstate = GzipHeaderState.ReadingXLen2;
goto case GzipHeaderState.ReadingXLen2;
case GzipHeaderState.ReadingXLen2:
bits = input.GetBits(8);
if (bits < 0) {
return false;
}
gzip_header_xlen |= (bits << 8);
gzipHeaderSubstate = GzipHeaderState.ReadingXLenData;
loopCounter = 0; // 0 bytes of XLEN data read so far
goto case GzipHeaderState.ReadingXLenData;
case GzipHeaderState.ReadingXLenData:
bits = 0;
while (loopCounter < gzip_header_xlen) {
bits = input.GetBits(8);
if (bits < 0) {
return false;
}
loopCounter++;
}
gzipHeaderSubstate = GzipHeaderState.ReadingFileName;
loopCounter = 0;
goto case GzipHeaderState.ReadingFileName;
case GzipHeaderState.ReadingFileName:
if ((gzip_header_flag & (int)GZipOptionalHeaderFlags.FileNameFlag) == 0) {
gzipHeaderSubstate = GzipHeaderState.ReadingComment;
goto case GzipHeaderState.ReadingComment;
}
do {
bits = input.GetBits(8);
if (bits < 0) {
return false;
}
if (bits == 0) { // see '\0' in the file name string
break;
}
} while (true);
gzipHeaderSubstate = GzipHeaderState.ReadingComment;
goto case GzipHeaderState.ReadingComment;
case GzipHeaderState.ReadingComment:
if ((gzip_header_flag & (int)GZipOptionalHeaderFlags.CommentFlag) == 0) {
gzipHeaderSubstate = GzipHeaderState.ReadingCRC16Part1;
goto case GzipHeaderState.ReadingCRC16Part1;
}
do {
bits = input.GetBits(8);
if (bits < 0) {
return false;
}
if (bits == 0) { // see '\0' in the file name string
break;
}
} while (true);
gzipHeaderSubstate = GzipHeaderState.ReadingCRC16Part1;
goto case GzipHeaderState.ReadingCRC16Part1;
case GzipHeaderState.ReadingCRC16Part1:
if ((gzip_header_flag & (int)GZipOptionalHeaderFlags.CRCFlag) == 0) {
gzipHeaderSubstate = GzipHeaderState.Done;
goto case GzipHeaderState.Done;
}
bits = input.GetBits(8); // ignore crc
if (bits < 0) {
return false;
}
gzipHeaderSubstate = GzipHeaderState.ReadingCRC16Part2;
goto case GzipHeaderState.ReadingCRC16Part2;
case GzipHeaderState.ReadingCRC16Part2:
bits = input.GetBits(8); // ignore crc
if (bits < 0) {
return false;
}
gzipHeaderSubstate = GzipHeaderState.Done;
goto case GzipHeaderState.Done;
case GzipHeaderState.Done:
return true;
default:
Debug.Assert(false, "We should not reach unknown state!");
throw new InvalidDataException(SR.GetString(SR.UnknownState));
}
}
}
public bool ReadFooter(InputBuffer input) {
input.SkipToByteBoundary();
if (gzipFooterSubstate == GzipHeaderState.ReadingCRC) {
while (loopCounter < 4) {
int bits = input.GetBits(8);
if (bits < 0) {
return false;
}
expectedCrc32 |= ((uint)bits << (8 * loopCounter));
loopCounter++;
}
gzipFooterSubstate = GzipHeaderState.ReadingFileSize;
loopCounter = 0;
}
if (gzipFooterSubstate == GzipHeaderState.ReadingFileSize) {
if (loopCounter == 0)
expectedOutputStreamSizeModulo = 0;
while (loopCounter < 4) {
int bits = input.GetBits(8);
if (bits < 0) {
return false;
}
expectedOutputStreamSizeModulo |= ((uint) bits << (8 * loopCounter));
loopCounter++;
}
}
return true;
}
//Each block of compressed data begins with 3 header bits
// containing the following data:
// first bit BFINAL
// next 2 bits BTYPE
// Note that the header bits do not necessarily begin on a byte
// boundary, since a block does not necessarily occupy an integral
// number of bytes.
// BFINAL is set if and only if this is the last block of the data
// set.
// BTYPE specifies how the data are compressed, as follows:
// 00 - no compression
// 01 - compressed with fixed Huffman codes
// 10 - compressed with dynamic Huffman codes
// 11 - reserved (error)
// The only difference between the two compressed cases is how the
// Huffman codes for the literal/length and distance alphabets are
// defined.
//
// This function returns true for success (end of block or output window is full,)
// false if we are short of input
//
private bool Decode()
{
bool eob = false;
bool result = false;
if (Finished())
{
return(true);
}
if (hasFormatReader)
{
if (state == InflaterState.ReadingHeader)
{
if (!formatReader.ReadHeader(input))
{
return(false);
}
state = InflaterState.ReadingBFinal;
}
else if (state == InflaterState.StartReadingFooter || state == InflaterState.ReadingFooter)
{
if (!formatReader.ReadFooter(input))
{
return(false);
}
state = InflaterState.VerifyingFooter;
return(true);
}
}
if (state == InflaterState.ReadingBFinal) // reading bfinal bit
// Need 1 bit
{
if (!input.EnsureBitsAvailable(1))
{
return(false);
}
bfinal = input.GetBits(1);
state = InflaterState.ReadingBType;
}
if (state == InflaterState.ReadingBType)
{
// Need 2 bits
if (!input.EnsureBitsAvailable(2))
{
state = InflaterState.ReadingBType;
return(false);
}
blockType = (BlockType)input.GetBits(2);
if (blockType == BlockType.Dynamic)
{
state = InflaterState.ReadingNumLitCodes;
}
else if (blockType == BlockType.Static)
{
literalLengthTree = HuffmanTree.StaticLiteralLengthTree;
distanceTree = HuffmanTree.StaticDistanceTree;
state = InflaterState.DecodeTop;
}
else if (blockType == BlockType.Uncompressed)
{
state = InflaterState.UncompressedAligning;
}
else
{
throw new InvalidDataException(SR.GetString(SR.UnknownBlockType));
}
}
if (blockType == BlockType.Dynamic)
{
if (state < InflaterState.DecodeTop) // we are reading the header
{
result = DecodeDynamicBlockHeader();
}
else
{
result = DecodeBlock(out eob); // this can returns true when output is full
}
}
else if (blockType == BlockType.Static)
{
result = DecodeBlock(out eob);
}
else if (blockType == BlockType.Uncompressed)
{
result = DecodeUncompressedBlock(out eob);
}
else
{
throw new InvalidDataException(SR.GetString(SR.UnknownBlockType));
}
//
// If we reached the end of the block and the block we were decoding had
// bfinal=1 (final block)
//
if (eob && (bfinal != 0))
{
if (hasFormatReader)
{
state = InflaterState.StartReadingFooter;
}
else
{
state = InflaterState.Done;
}
}
return(result);
}
public Boolean ReadHeader(InputBuffer input)
{
Int32 bits;
switch (this.gzipHeaderSubstate)
{
case GZipDecoder.GzipHeaderState.ReadingID1:
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
if (bits != 31)
{
throw new InvalidDataException(SR.GetString("Corrupted gzip header"));
}
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.ReadingID2;
break;
case GZipDecoder.GzipHeaderState.ReadingID2:
break;
case GZipDecoder.GzipHeaderState.ReadingCM:
goto IL_BB;
case GZipDecoder.GzipHeaderState.ReadingFLG:
goto IL_EF;
case GZipDecoder.GzipHeaderState.ReadingMMTime:
goto IL_11A;
case GZipDecoder.GzipHeaderState.ReadingXFL:
goto IL_15F;
case GZipDecoder.GzipHeaderState.ReadingOS:
goto IL_17C;
case GZipDecoder.GzipHeaderState.ReadingXLen1:
goto IL_199;
case GZipDecoder.GzipHeaderState.ReadingXLen2:
goto IL_1CF;
case GZipDecoder.GzipHeaderState.ReadingXLenData:
goto IL_204;
case GZipDecoder.GzipHeaderState.ReadingFileName:
goto IL_24F;
case GZipDecoder.GzipHeaderState.ReadingComment:
goto IL_297;
case GZipDecoder.GzipHeaderState.ReadingCRC16Part1:
goto IL_2E0;
case GZipDecoder.GzipHeaderState.ReadingCRC16Part2:
goto IL_318;
case GZipDecoder.GzipHeaderState.Done:
return(true);
default:
throw new InvalidDataException(SR.GetString("Unknown state"));
}
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
if (bits != 139)
{
throw new InvalidDataException(SR.GetString("Corrupted gzip header"));
}
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.ReadingCM;
IL_BB:
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
if (bits != 8)
{
throw new InvalidDataException(SR.GetString("Unknown compression mode"));
}
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.ReadingFLG;
IL_EF:
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
this.gzip_header_flag = bits;
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.ReadingMMTime;
this.loopCounter = 0;
IL_11A:
while (this.loopCounter < 4)
{
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
this.loopCounter++;
}
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.ReadingXFL;
this.loopCounter = 0;
IL_15F:
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.ReadingOS;
IL_17C:
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.ReadingXLen1;
IL_199:
if ((this.gzip_header_flag & 4) == 0)
{
goto IL_24F;
}
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
this.gzip_header_xlen = bits;
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.ReadingXLen2;
IL_1CF:
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
this.gzip_header_xlen |= bits << 8;
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.ReadingXLenData;
this.loopCounter = 0;
IL_204:
while (this.loopCounter < this.gzip_header_xlen)
{
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
this.loopCounter++;
}
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.ReadingFileName;
this.loopCounter = 0;
IL_24F:
if ((this.gzip_header_flag & 8) == 0)
{
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.ReadingComment;
}
else
{
for (;;)
{
bits = input.GetBits(8);
if (bits < 0)
{
break;
}
if (bits == 0)
{
goto Block_20;
}
}
return(false);
Block_20:
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.ReadingComment;
}
IL_297:
if ((this.gzip_header_flag & 16) == 0)
{
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.ReadingCRC16Part1;
}
else
{
for (;;)
{
bits = input.GetBits(8);
if (bits < 0)
{
break;
}
if (bits == 0)
{
goto Block_23;
}
}
return(false);
Block_23:
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.ReadingCRC16Part1;
}
IL_2E0:
if ((this.gzip_header_flag & 2) == 0)
{
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.Done;
return(true);
}
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.ReadingCRC16Part2;
IL_318:
bits = input.GetBits(8);
if (bits < 0)
{
return(false);
}
this.gzipHeaderSubstate = GZipDecoder.GzipHeaderState.Done;
return(true);
}