static HuffmanTree()
{
// construct the static literal tree and distance tree
staticLiteralLengthTree = new HuffmanTree(GetStaticLiteralTreeLength());
staticDistanceTree = new HuffmanTree(GetStaticDistanceTreeLength());
}
static HuffmanTree()
{
// construct the static literal tree and distance tree
StaticLiteralLengthTree = new HuffmanTree(GetStaticLiteralTreeLength());
StaticDistanceTree = new HuffmanTree(GetStaticDistanceTreeLength());
}
//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);
}
// Format of the dynamic block header:
// 5 Bits: HLIT, # of Literal/Length codes - 257 (257 - 286)
// 5 Bits: HDIST, # of Distance codes - 1 (1 - 32)
// 4 Bits: HCLEN, # of Code Length codes - 4 (4 - 19)
//
// (HCLEN + 4) x 3 bits: code lengths for the code length
// alphabet given just above, in the order: 16, 17, 18,
// 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
//
// These code lengths are interpreted as 3-bit integers
// (0-7); as above, a code length of 0 means the
// corresponding symbol (literal/length or distance code
// length) is not used.
//
// HLIT + 257 code lengths for the literal/length alphabet,
// encoded using the code length Huffman code
//
// HDIST + 1 code lengths for the distance alphabet,
// encoded using the code length Huffman code
//
// The code length repeat codes can cross from HLIT + 257 to the
// HDIST + 1 code lengths. In other words, all code lengths form
// a single sequence of HLIT + HDIST + 258 values.
bool DecodeDynamicBlockHeader()
{
switch (state)
{
case InflaterState.ReadingNumLitCodes:
literalLengthCodeCount = input.GetBits(5);
if (literalLengthCodeCount < 0)
{
return(false);
}
literalLengthCodeCount += 257;
state = InflaterState.ReadingNumDistCodes;
goto case InflaterState.ReadingNumDistCodes;
case InflaterState.ReadingNumDistCodes:
distanceCodeCount = input.GetBits(5);
if (distanceCodeCount < 0)
{
return(false);
}
distanceCodeCount += 1;
state = InflaterState.ReadingNumCodeLengthCodes;
goto case InflaterState.ReadingNumCodeLengthCodes;
case InflaterState.ReadingNumCodeLengthCodes:
codeLengthCodeCount = input.GetBits(4);
if (codeLengthCodeCount < 0)
{
return(false);
}
codeLengthCodeCount += 4;
loopCounter = 0;
state = InflaterState.ReadingCodeLengthCodes;
goto case InflaterState.ReadingCodeLengthCodes;
case InflaterState.ReadingCodeLengthCodes:
while (loopCounter < codeLengthCodeCount)
{
int bits = input.GetBits(3);
if (bits < 0)
{
return(false);
}
codeLengthTreeCodeLength[codeOrder[loopCounter]] = (byte)bits;
++loopCounter;
}
for (int i = codeLengthCodeCount; i < codeOrder.Length; i++)
{
codeLengthTreeCodeLength[codeOrder[i]] = 0;
}
// create huffman tree for code length
codeLengthTree = new HuffmanTree(codeLengthTreeCodeLength);
codeArraySize = literalLengthCodeCount + distanceCodeCount;
loopCounter = 0; // reset loop count
state = InflaterState.ReadingTreeCodesBefore;
goto case InflaterState.ReadingTreeCodesBefore;
case InflaterState.ReadingTreeCodesBefore:
case InflaterState.ReadingTreeCodesAfter:
while (loopCounter < codeArraySize)
{
if (state == InflaterState.ReadingTreeCodesBefore)
{
if ((lengthCode = codeLengthTree.GetNextSymbol(input)) < 0)
{
return(false);
}
}
// The alphabet for code lengths is as follows:
// 0 - 15: Represent code lengths of 0 - 15
// 16: Copy the previous code length 3 - 6 times.
// The next 2 bits indicate repeat length
// (0 = 3, ... , 3 = 6)
// Example: Codes 8, 16 (+2 bits 11),
// 16 (+2 bits 10) will expand to
// 12 code lengths of 8 (1 + 6 + 5)
// 17: Repeat a code length of 0 for 3 - 10 times.
// (3 bits of length)
// 18: Repeat a code length of 0 for 11 - 138 times
// (7 bits of length)
if (lengthCode <= 15)
{
codeList[loopCounter++] = (byte)lengthCode;
}
else
{
if (!input.EnsureBitsAvailable(7)) // it doesn't matter if we require more bits here
{
state = InflaterState.ReadingTreeCodesAfter;
return(false);
}
int repeatCount;
if (lengthCode == 16)
{
if (loopCounter == 0) // can't have "prev code" on first code
{
throw new InvalidDataException();
}
byte previousCode = codeList[loopCounter - 1];
repeatCount = input.GetBits(2) + 3;
if (loopCounter + repeatCount > codeArraySize)
{
throw new InvalidDataException();
}
for (int j = 0; j < repeatCount; j++)
{
codeList[loopCounter++] = previousCode;
}
}
else if (lengthCode == 17)
{
repeatCount = input.GetBits(3) + 3;
if (loopCounter + repeatCount > codeArraySize)
{
throw new InvalidDataException();
}
for (int j = 0; j < repeatCount; j++)
{
codeList[loopCounter++] = 0;
}
}
else // code == 18
{
repeatCount = input.GetBits(7) + 11;
if (loopCounter + repeatCount > codeArraySize)
{
throw new InvalidDataException();
}
for (int j = 0; j < repeatCount; j++)
{
codeList[loopCounter++] = 0;
}
}
}
state = InflaterState.ReadingTreeCodesBefore; // we want to read the next code.
}
break;
default:
Debug.Assert(false, "check why we are here!");
throw new InvalidDataException(SR.GetString(SR.UnknownState));
}
byte[] literalTreeCodeLength = new byte[HuffmanTree.MaxLiteralTreeElements];
byte[] distanceTreeCodeLength = new byte[HuffmanTree.MaxDistTreeElements];
// Create literal and distance tables
Array.Copy(codeList, literalTreeCodeLength, literalLengthCodeCount);
Array.Copy(codeList, literalLengthCodeCount, distanceTreeCodeLength, 0, distanceCodeCount);
// Make sure there is an end-of-block code, otherwise how could we ever end?
if (literalTreeCodeLength[HuffmanTree.EndOfBlockCode] == 0)
{
throw new InvalidDataException();
}
literalLengthTree = new HuffmanTree(literalTreeCodeLength);
distanceTree = new HuffmanTree(distanceTreeCodeLength);
state = InflaterState.DecodeTop;
return(true);
}
// Format of the dynamic block header:
// 5 Bits: HLIT, # of Literal/Length codes - 257 (257 - 286)
// 5 Bits: HDIST, # of Distance codes - 1 (1 - 32)
// 4 Bits: HCLEN, # of Code Length codes - 4 (4 - 19)
//
// (HCLEN + 4) x 3 bits: code lengths for the code length
// alphabet given just above, in the order: 16, 17, 18,
// 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
//
// These code lengths are interpreted as 3-bit integers
// (0-7); as above, a code length of 0 means the
// corresponding symbol (literal/length or distance code
// length) is not used.
//
// HLIT + 257 code lengths for the literal/length alphabet,
// encoded using the code length Huffman code
//
// HDIST + 1 code lengths for the distance alphabet,
// encoded using the code length Huffman code
//
// The code length repeat codes can cross from HLIT + 257 to the
// HDIST + 1 code lengths. In other words, all code lengths form
// a single sequence of HLIT + HDIST + 258 values.
bool DecodeDynamicBlockHeader() {
switch (state) {
case InflaterState.ReadingNumLitCodes:
literalLengthCodeCount = input.GetBits(5);
if( literalLengthCodeCount < 0) {
return false;
}
literalLengthCodeCount += 257;
state = InflaterState.ReadingNumDistCodes;
goto case InflaterState.ReadingNumDistCodes;
case InflaterState.ReadingNumDistCodes:
distanceCodeCount = input.GetBits(5);
if( distanceCodeCount < 0) {
return false;
}
distanceCodeCount += 1;
state = InflaterState.ReadingNumCodeLengthCodes;
goto case InflaterState.ReadingNumCodeLengthCodes;
case InflaterState.ReadingNumCodeLengthCodes:
codeLengthCodeCount = input.GetBits(4);
if( codeLengthCodeCount < 0) {
return false;
}
codeLengthCodeCount += 4;
loopCounter = 0;
state = InflaterState.ReadingCodeLengthCodes;
goto case InflaterState.ReadingCodeLengthCodes;
case InflaterState.ReadingCodeLengthCodes:
while(loopCounter < codeLengthCodeCount) {
int bits = input.GetBits(3);
if( bits < 0) {
return false;
}
codeLengthTreeCodeLength[codeOrder[loopCounter]] = (byte)bits;
++loopCounter;
}
for (int i = codeLengthCodeCount; i < codeOrder.Length; i++) {
codeLengthTreeCodeLength[ codeOrder[i] ] = 0;
}
// create huffman tree for code length
codeLengthTree = new HuffmanTree(codeLengthTreeCodeLength);
codeArraySize = literalLengthCodeCount + distanceCodeCount;
loopCounter = 0; // reset loop count
state = InflaterState.ReadingTreeCodesBefore;
goto case InflaterState.ReadingTreeCodesBefore;
case InflaterState.ReadingTreeCodesBefore:
case InflaterState.ReadingTreeCodesAfter:
while (loopCounter < codeArraySize) {
if( state == InflaterState.ReadingTreeCodesBefore) {
if( (lengthCode = codeLengthTree.GetNextSymbol(input)) < 0) {
return false;
}
}
// The alphabet for code lengths is as follows:
// 0 - 15: Represent code lengths of 0 - 15
// 16: Copy the previous code length 3 - 6 times.
// The next 2 bits indicate repeat length
// (0 = 3, ... , 3 = 6)
// Example: Codes 8, 16 (+2 bits 11),
// 16 (+2 bits 10) will expand to
// 12 code lengths of 8 (1 + 6 + 5)
// 17: Repeat a code length of 0 for 3 - 10 times.
// (3 bits of length)
// 18: Repeat a code length of 0 for 11 - 138 times
// (7 bits of length)
if (lengthCode <= 15) {
codeList[loopCounter++] = (byte)lengthCode;
}
else {
if( !input.EnsureBitsAvailable(7)) { // it doesn't matter if we require more bits here
state = InflaterState.ReadingTreeCodesAfter;
return false;
}
int repeatCount;
if (lengthCode == 16) {
if (loopCounter == 0) { // can't have "prev code" on first code
throw new InvalidDataException();
}
byte previousCode = codeList[loopCounter-1];
repeatCount = input.GetBits(2) + 3;
if (loopCounter + repeatCount > codeArraySize) {
throw new InvalidDataException();
}
for (int j = 0; j < repeatCount; j++) {
codeList[loopCounter++] = previousCode;
}
}
else if (lengthCode == 17) {
repeatCount = input.GetBits(3) + 3;
if (loopCounter + repeatCount > codeArraySize) {
throw new InvalidDataException();
}
for (int j = 0; j < repeatCount; j++) {
codeList[loopCounter++] = 0;
}
}
else { // code == 18
repeatCount = input.GetBits(7) + 11;
if (loopCounter + repeatCount > codeArraySize) {
throw new InvalidDataException();
}
for (int j = 0; j < repeatCount; j++) {
codeList[loopCounter++] = 0;
}
}
}
state = InflaterState.ReadingTreeCodesBefore; // we want to read the next code.
}
break;
default:
Debug.Assert(false, "check why we are here!");
throw new InvalidDataException(SR.GetString(SR.UnknownState));
}
byte[] literalTreeCodeLength = new byte[HuffmanTree.MaxLiteralTreeElements];
byte[] distanceTreeCodeLength = new byte[HuffmanTree.MaxDistTreeElements];
// Create literal and distance tables
Array.Copy(codeList, literalTreeCodeLength, literalLengthCodeCount);
Array.Copy(codeList, literalLengthCodeCount, distanceTreeCodeLength, 0, distanceCodeCount);
// Make sure there is an end-of-block code, otherwise how could we ever end?
if (literalTreeCodeLength[HuffmanTree.EndOfBlockCode] == 0) {
throw new InvalidDataException();
}
literalLengthTree = new HuffmanTree(literalTreeCodeLength);
distanceTree = new HuffmanTree(distanceTreeCodeLength);
state = InflaterState.DecodeTop;
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;
}
static HuffmanTree()
{
HuffmanTree.staticLiteralLengthTree = new HuffmanTree(HuffmanTree.GetStaticLiteralTreeLength());
HuffmanTree.staticDistanceTree = new HuffmanTree(HuffmanTree.GetStaticDistanceTreeLength());
}
private bool DecodeDynamicBlockHeader()
{
switch (this.state)
{
case InflaterState.ReadingNumLitCodes:
this.literalLengthCodeCount = this.input.GetBits(5);
if (this.literalLengthCodeCount < 0)
{
return(false);
}
this.literalLengthCodeCount += 257;
this.state = InflaterState.ReadingNumDistCodes;
goto IL_62;
case InflaterState.ReadingNumDistCodes:
goto IL_62;
case InflaterState.ReadingNumCodeLengthCodes:
goto IL_94;
case InflaterState.ReadingCodeLengthCodes:
break;
case InflaterState.ReadingTreeCodesBefore:
case InflaterState.ReadingTreeCodesAfter:
goto IL_327;
default:
throw new InvalidDataException(SR.GetString("Unknown state"));
}
IL_105:
while (this.loopCounter < this.codeLengthCodeCount)
{
int bits = this.input.GetBits(3);
if (bits < 0)
{
return(false);
}
this.codeLengthTreeCodeLength[(int)Inflater.codeOrder[this.loopCounter]] = (byte)bits;
this.loopCounter++;
}
for (int i = this.codeLengthCodeCount; i < Inflater.codeOrder.Length; i++)
{
this.codeLengthTreeCodeLength[(int)Inflater.codeOrder[i]] = 0;
}
this.codeLengthTree = new HuffmanTree(this.codeLengthTreeCodeLength);
this.codeArraySize = this.literalLengthCodeCount + this.distanceCodeCount;
this.loopCounter = 0;
this.state = InflaterState.ReadingTreeCodesBefore;
IL_327:
while (this.loopCounter < this.codeArraySize)
{
if (this.state == InflaterState.ReadingTreeCodesBefore && (this.lengthCode = this.codeLengthTree.GetNextSymbol(this.input)) < 0)
{
return(false);
}
if (this.lengthCode <= 15)
{
byte[] arg_1CA_0 = this.codeList;
int num = this.loopCounter;
this.loopCounter = num + 1;
arg_1CA_0[num] = (byte)this.lengthCode;
}
else
{
if (!this.input.EnsureBitsAvailable(7))
{
this.state = InflaterState.ReadingTreeCodesAfter;
return(false);
}
if (this.lengthCode == 16)
{
if (this.loopCounter == 0)
{
throw new InvalidDataException();
}
byte b = this.codeList[this.loopCounter - 1];
int num2 = this.input.GetBits(2) + 3;
if (this.loopCounter + num2 > this.codeArraySize)
{
throw new InvalidDataException();
}
for (int j = 0; j < num2; j++)
{
byte[] arg_259_0 = this.codeList;
int num = this.loopCounter;
this.loopCounter = num + 1;
arg_259_0[num] = b;
}
}
else if (this.lengthCode == 17)
{
int num2 = this.input.GetBits(3) + 3;
if (this.loopCounter + num2 > this.codeArraySize)
{
throw new InvalidDataException();
}
for (int k = 0; k < num2; k++)
{
byte[] arg_2BC_0 = this.codeList;
int num = this.loopCounter;
this.loopCounter = num + 1;
arg_2BC_0[num] = 0;
}
}
else
{
int num2 = this.input.GetBits(7) + 11;
if (this.loopCounter + num2 > this.codeArraySize)
{
throw new InvalidDataException();
}
for (int l = 0; l < num2; l++)
{
byte[] arg_313_0 = this.codeList;
int num = this.loopCounter;
this.loopCounter = num + 1;
arg_313_0[num] = 0;
}
}
}
this.state = InflaterState.ReadingTreeCodesBefore;
}
byte[] array = new byte[288];
byte[] array2 = new byte[32];
Array.Copy(this.codeList, array, this.literalLengthCodeCount);
Array.Copy(this.codeList, this.literalLengthCodeCount, array2, 0, this.distanceCodeCount);
if (array[256] == 0)
{
throw new InvalidDataException();
}
this.literalLengthTree = new HuffmanTree(array);
this.distanceTree = new HuffmanTree(array2);
this.state = InflaterState.DecodeTop;
return(true);
IL_62:
this.distanceCodeCount = this.input.GetBits(5);
if (this.distanceCodeCount < 0)
{
return(false);
}
this.distanceCodeCount++;
this.state = InflaterState.ReadingNumCodeLengthCodes;
IL_94:
this.codeLengthCodeCount = this.input.GetBits(4);
if (this.codeLengthCodeCount < 0)
{
return(false);
}
this.codeLengthCodeCount += 4;
this.loopCounter = 0;
this.state = InflaterState.ReadingCodeLengthCodes;
goto IL_105;
}
private bool Decode()
{
bool flag = false;
if (this.Finished())
{
return(true);
}
if (this.hasFormatReader)
{
if (this.state == InflaterState.ReadingHeader)
{
if (!this.formatReader.ReadHeader(this.input))
{
return(false);
}
this.state = InflaterState.ReadingBFinal;
}
else if (this.state == InflaterState.StartReadingFooter || this.state == InflaterState.ReadingFooter)
{
if (!this.formatReader.ReadFooter(this.input))
{
return(false);
}
this.state = InflaterState.VerifyingFooter;
return(true);
}
}
if (this.state == InflaterState.ReadingBFinal)
{
if (!this.input.EnsureBitsAvailable(1))
{
return(false);
}
this.bfinal = this.input.GetBits(1);
this.state = InflaterState.ReadingBType;
}
if (this.state == InflaterState.ReadingBType)
{
if (!this.input.EnsureBitsAvailable(2))
{
this.state = InflaterState.ReadingBType;
return(false);
}
this.blockType = (BlockType)this.input.GetBits(2);
if (this.blockType == BlockType.Dynamic)
{
this.state = InflaterState.ReadingNumLitCodes;
}
else if (this.blockType == BlockType.Static)
{
this.literalLengthTree = HuffmanTree.StaticLiteralLengthTree;
this.distanceTree = HuffmanTree.StaticDistanceTree;
this.state = InflaterState.DecodeTop;
}
else
{
if (this.blockType != BlockType.Uncompressed)
{
throw new InvalidDataException(SR.GetString("Unknown block type"));
}
this.state = InflaterState.UncompressedAligning;
}
}
bool result;
if (this.blockType == BlockType.Dynamic)
{
if (this.state < InflaterState.DecodeTop)
{
result = this.DecodeDynamicBlockHeader();
}
else
{
result = this.DecodeBlock(out flag);
}
}
else if (this.blockType == BlockType.Static)
{
result = this.DecodeBlock(out flag);
}
else
{
if (this.blockType != BlockType.Uncompressed)
{
throw new InvalidDataException(SR.GetString("Unknown block type"));
}
result = this.DecodeUncompressedBlock(out flag);
}
if (flag && this.bfinal != 0)
{
if (this.hasFormatReader)
{
this.state = InflaterState.StartReadingFooter;
}
else
{
this.state = InflaterState.Done;
}
}
return(result);
}